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GNU Emacs Manual

GNU Emacs Manual
Seventeenth Edition, Updated for Emacs Version 24.2.

Richard Stallman et al.

This is the Seventeenth edition of the GNU Emacs Manual,
updated for Emacs version 24.2.
Copyright c 1985-1987, 1993-2012 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation; with
the Invariant Sections being “The GNU Manifesto,” “Distribution” and
“GNU GENERAL PUBLIC LICENSE,” with the Front-Cover texts being
“A GNU Manual,” and with the Back-Cover Texts as in (a) below. A copy
of the license is included in the section entitled “GNU Free Documentation
License.”
(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
modify this GNU manual. Buying copies from the FSF supports it in
developing GNU and promoting software freedom.”

Published by the Free Software Foundation
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Boston, MA 02110-1301 USA
ISBN 978-0-9831592-4-7

Cover art by Etienne Suvasa; cover design by Matt Lee.

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i

Short Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1 The Organization of the Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Characters, Keys and Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3 Entering and Exiting Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4 Basic Editing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 The Minibuffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6 Running Commands by Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7 Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8 The Mark and the Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
9 Killing and Moving Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
10 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
11 Controlling the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
12 Searching and Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
13 Commands for Fixing Typos. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
14 Keyboard Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
15 File Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
16 Using Multiple Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
17 Multiple Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
18 Frames and Graphical Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
19 International Character Set Support . . . . . . . . . . . . . . . . . . . . . . . . 180
20 Major and Minor Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
21 Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
22 Commands for Human Languages . . . . . . . . . . . . . . . . . . . . . . . . . . 214
23 Editing Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
24 Compiling and Testing Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
25 Maintaining Large Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
26 Abbrevs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
27 Dired, the Directory Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
28 The Calendar and the Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

ii
29 Sending Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30 Reading Mail with Rmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31 Miscellaneous Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32 Emacs Lisp Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33 Customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34 Dealing with Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A GNU GENERAL PUBLIC LICENSE . . . . . . . . . . . . . . . . . . . . . . .
B GNU Free Documentation License . . . . . . . . . . . . . . . . . . . . . . . . . .
C Command Line Arguments for Emacs Invocation . . . . . . . . . . . .
D X Options and Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E Emacs 23 Antinews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F Emacs and Mac OS / GNUstep . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
G Emacs and Microsoft Windows/MS-DOS . . . . . . . . . . . . . . . . . . .
The GNU Manifesto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Key (Character) Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command and Function Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variable Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Concept Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

367
376
397
430
434
468
484
496
505
521
529
531
535
546
555
580
590
604
612

iii

Table of Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1

The Organization of the Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1
1.2
1.3
1.4

2

Characters, Keys and Commands . . . . . . . . . . . . . . . . . . . . . . . 11
2.1
2.2
2.3

3

Kinds of User Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Keys and Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Entering and Exiting Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.1
3.2

4

Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The Echo Area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The Mode Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
The Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Entering Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Exiting Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Basic Editing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11

Inserting Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the Location of Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Erasing Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Undoing Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blank Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuation Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cursor Position Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Numeric Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repeating a Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17
18
20
21
22
22
22
23
23
25
26

iv

5

The Minibuffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.1
5.2
5.3

Minibuffers for File Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Editing in the Minibuffer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Completion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.1 Completion Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.2 Completion Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.3 Completion Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.4 How Completion Alternatives Are Chosen . . . . . . . . . . . . . . . . . . . . . . .
5.3.5 Completion Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4 Minibuffer History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.5 Repeating Minibuffer Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.6 Entering passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6
7

Running Commands by Name . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Help. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9

8

27
28
29
29
30
31
32
33
34
35
36

Documentation for a Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help by Command or Variable Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Apropos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help Mode Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keyword Search for Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help for International Language Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Help Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Help on Active Text and Tooltips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40
40
41
43
43
44
44
45
46

The Mark and the Region. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
8.1
8.2
8.3
8.4
8.5
8.6
8.7

Setting the Mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commands to Mark Textual Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating on the Region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Mark Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Global Mark Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shift Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disabling Transient Mark Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

47
49
50
51
51
52
52

v

9

Killing and Moving Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.1

Deletion and Killing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.1.1 Deletion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.1.2 Killing by Lines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.1.3 Other Kill Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.1.4 Options for Killing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 Yanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.1 The Kill Ring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.2 Yanking Earlier Kills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2.3 Appending Kills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.3 “Cut and Paste” Operations on Graphical Displays . . . . . . . . . . . . . . . . . . .
9.3.1 Using the Clipboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.3.2 Cut and Paste with Other Window Applications . . . . . . . . . . . . . . . .
9.3.3 Secondary Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.4 Accumulating Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.5 Rectangles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.6 CUA Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10

Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
10.1
10.2
10.3
10.4
10.5
10.6
10.7

11

54
54
55
56
56
57
57
58
58
59
59
60
61
61
63
64

Saving Positions in Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Saving Text in Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Saving Rectangles in Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Saving Window Configurations in Registers . . . . . . . . . . . . . . . . . . . . . . . . .
Keeping Numbers in Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keeping File Names in Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bookmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

66
66
67
67
68
68
68

Controlling the Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
11.1
11.2
11.3
11.4
11.5
11.6
11.7
11.8
11.9
11.10
11.11
11.12
11.13
11.14
11.15
11.16
11.17

Scrolling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recentering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Scrolling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horizontal Scrolling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Narrowing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
View Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Follow Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Text Faces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Colors for Faces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Faces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Text Scale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Font Lock mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interactive Highlighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Window Fringes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displaying Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Useless Whitespace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selective Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70
71
72
73
74
75
75
75
76
77
79
80
81
83
83
84
85

vi
11.18
11.19
11.20
11.21
11.22
11.23

12

Optional Mode Line Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Text Is Displayed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Displaying the Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Line Truncation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Visual Line Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customization of Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

85
87
88
89
89
90

Searching and Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
12.1 Incremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
12.1.1 Basics of Incremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
12.1.2 Repeating Incremental Search. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
12.1.3 Errors in Incremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
12.1.4 Special Input for Incremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
12.1.5 Isearch Yanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
12.1.6 Scrolling During Incremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
12.1.7 Searching the Minibuffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
12.2 Nonincremental Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
12.3 Word Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
12.4 Regular Expression Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
12.5 Syntax of Regular Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
12.6 Backslash in Regular Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
12.7 Regular Expression Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
12.8 Searching and Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
12.9 Replacement Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
12.9.1 Unconditional Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
12.9.2 Regexp Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
12.9.3 Replace Commands and Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
12.9.4 Query Replace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
12.10 Other Search-and-Loop Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

13

Commands for Fixing Typos . . . . . . . . . . . . . . . . . . . . . . . . . . 110
13.1
13.2
13.3
13.4

14

Undo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transposing Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Case Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking and Correcting Spelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

110
111
112
112

Keyboard Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
14.1
14.2
14.3
14.4
14.5
14.6
14.7

Basic Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Keyboard Macro Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Keyboard Macro Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Executing Macros with Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Naming and Saving Keyboard Macros. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Editing a Keyboard Macro. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stepwise Editing a Keyboard Macro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

116
118
118
120
121
122
122

vii

15

File Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
15.1 File Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.2 Visiting Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3 Saving Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.1 Commands for Saving Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.2 Backup Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.2.1 Single or Numbered Backups . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.2.2 Automatic Deletion of Backups . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.2.3 Copying vs. Renaming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.3 Customizing Saving of Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.4 Protection against Simultaneous Editing . . . . . . . . . . . . . . . . . . . . . .
15.3.5 Shadowing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.3.6 Updating Time Stamps Automatically . . . . . . . . . . . . . . . . . . . . . . . .
15.4 Reverting a Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.5 Auto-Saving: Protection Against Disasters . . . . . . . . . . . . . . . . . . . . . . . . .
15.5.1 Auto-Save Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.5.2 Controlling Auto-Saving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.5.3 Recovering Data from Auto-Saves. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.6 File Name Aliases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.7 File Directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.8 Comparing Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.9 Diff Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.10 Miscellaneous File Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.11 Accessing Compressed Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.12 File Archives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.13 Remote Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.14 Quoted File Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.15 File Name Cache . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.16 Convenience Features for Finding Files. . . . . . . . . . . . . . . . . . . . . . . . . . . .
15.17 Filesets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16

124
125
128
128
130
130
131
132
132
133
134
135
135
136
136
137
137
138
139
140
141
143
144
144
145
146
147
148
148

Using Multiple Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
16.1 Creating and Selecting Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.2 Listing Existing Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.3 Miscellaneous Buffer Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.4 Killing Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.5 Operating on Several Buffers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.6 Indirect Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.7 Convenience Features and Customization of Buffer Handling . . . . . . .
16.7.1 Making Buffer Names Unique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16.7.2 Switching Between Buffers using Substrings . . . . . . . . . . . . . . . . . . .
16.7.3 Customizing Buffer Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

150
152
152
153
154
156
157
157
158
158

viii

17

Multiple Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
17.1 Concepts of Emacs Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.2 Splitting Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.3 Using Other Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.4 Displaying in Another Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.5 Deleting and Rearranging Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.6 Displaying a Buffer in a Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.6.1 How display-buffer works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17.7 Convenience Features for Window Handling . . . . . . . . . . . . . . . . . . . . . . . .

18

Frames and Graphical Displays . . . . . . . . . . . . . . . . . . . . . . . 165
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
18.9
18.10
18.11
18.12
18.13
18.14
18.15
18.16
18.17
18.18
18.19
18.20

19

159
159
160
161
162
163
163
164

Mouse Commands for Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mouse Commands for Words and Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Following References with the Mouse. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mouse Clicks for Menus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mode Line Mouse Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Creating Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speedbar Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Multiple Displays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scroll Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drag and Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Menu Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tool Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Dialog Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tooltips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mouse Avoidance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Non-Window Terminals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using a Mouse in Text Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

165
167
167
168
169
169
170
171
174
175
175
176
176
176
177
177
178
178
179
179

International Character Set Support . . . . . . . . . . . . . . . . . 180
19.1
19.2
19.3
19.4
19.5
19.6
19.7
19.8
19.9
19.10
19.11
19.12

Introduction to International Character Sets . . . . . . . . . . . . . . . . . . . . . . .
Disabling Multibyte Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Language Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selecting an Input Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coding Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recognizing Coding Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifying a File’s Coding System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Choosing Coding Systems for Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifying a Coding System for File Text . . . . . . . . . . . . . . . . . . . . . . . . .
Coding Systems for Interprocess Communication . . . . . . . . . . . . . . . . . .
Coding Systems for File Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

180
182
183
185
186
188
190
192
192
193
194
195

ix
19.13
19.14
19.15
19.16
19.17
19.18
19.19
19.20

20

Major Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Minor Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Choosing File Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
21.1
21.2
21.3
21.4

22

196
197
198
199
200
200
202
202

Major and Minor Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
20.1
20.2
20.3

21

Coding Systems for Terminal I/O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fontsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defining fontsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modifying Fontsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Undisplayable Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unibyte Editing Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bidirectional Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Indentation Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tab Stops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tabs vs. Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Convenience Features for Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

210
211
212
212

Commands for Human Languages . . . . . . . . . . . . . . . . . . . . 214
22.1 Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.2 Sentences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.3 Paragraphs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.4 Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5 Filling Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5.1 Auto Fill Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5.2 Explicit Fill Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5.3 The Fill Prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.5.4 Adaptive Filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.6 Case Conversion Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.7 Text Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.8 Outline Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.8.1 Format of Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.8.2 Outline Motion Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.8.3 Outline Visibility Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.8.4 Viewing One Outline in Multiple Views . . . . . . . . . . . . . . . . . . . . . . .
22.8.5 Folding Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.9 Org Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.9.1 Org as an organizer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.9.2 Org as an authoring system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.10 TEX Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.10.1 TEX Editing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.10.2 LaTEX Editing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.10.3 TEX Printing Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

214
215
216
217
218
218
219
220
222
223
223
224
225
226
226
228
228
229
230
230
231
232
233
233

x
22.10.4 TEX Mode Miscellany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.11 SGML and HTML Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.12 Nroff Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13 Enriched Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.1 Enriched Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.2 Hard and Soft Newlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.3 Editing Format Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.4 Faces in Enriched Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.5 Indentation in Enriched Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.6 Justification in Enriched Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.13.7 Setting Other Text Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14 Editing Text-based Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.1 What is a Text-based Table? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.2 Creating a Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.3 Table Recognition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.4 Commands for Table Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.5 Cell Justification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.6 Table Rows and Columns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.14.7 Converting Between Plain Text and Tables . . . . . . . . . . . . . . . . . .
22.14.8 Table Miscellany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22.15 Two-Column Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

235
236
237
237
238
238
239
239
240
241
241
241
242
243
243
244
244
245
245
246
247

Editing Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
23.1 Major Modes for Programming Languages . . . . . . . . . . . . . . . . . . . . . . . . .
23.2 Top-Level Definitions, or Defuns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2.1 Left Margin Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2.2 Moving by Defuns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2.3 Imenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2.4 Which Function Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3 Indentation for Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3.1 Basic Program Indentation Commands. . . . . . . . . . . . . . . . . . . . . . . .
23.3.2 Indenting Several Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3.3 Customizing Lisp Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3.4 Commands for C Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3.5 Customizing C Indentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.4 Commands for Editing with Parentheses . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.4.1 Expressions with Balanced Parentheses . . . . . . . . . . . . . . . . . . . . . . .
23.4.2 Moving in the Parenthesis Structure . . . . . . . . . . . . . . . . . . . . . . . . . .
23.4.3 Matching Parentheses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5 Manipulating Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.1 Comment Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.2 Multiple Lines of Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.3 Options Controlling Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6 Documentation Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.1 Info Documentation Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.2 Man Page Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

249
250
250
251
251
252
252
252
253
254
254
255
256
256
257
258
258
259
260
261
261
262
262

xi
23.6.3 Emacs Lisp Documentation Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.7 Hideshow minor mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.8 Completion for Symbol Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.9 Glasses minor mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.10 Semantic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.11 Other Features Useful for Editing Programs . . . . . . . . . . . . . . . . . . . . . . .
23.12 C and Related Modes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.12.1 C Mode Motion Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.12.2 Electric C Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.12.3 Hungry Delete Feature in C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.12.4 Other Commands for C Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.13 Asm Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24

263
263
264
264
265
265
266
266
267
267
268
270

Compiling and Testing Programs . . . . . . . . . . . . . . . . . . . . . 271
24.1 Running Compilations under Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.2 Compilation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.3 Subshells for Compilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.4 Searching with Grep under Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.5 Finding Syntax Errors On The Fly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6 Running Debuggers Under Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.1 Starting GUD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.2 Debugger Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.3 Commands of GUD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.4 GUD Customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5 GDB Graphical Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.1 GDB User Interface Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.2 Source Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.3 Breakpoints Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.4 Threads Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.5 Stack Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.6 Other GDB Buffers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.7 Watch Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.6.5.8 Multithreaded Debugging. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.7 Executing Lisp Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.8 Libraries of Lisp Code for Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.9 Evaluating Emacs Lisp Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.10 Lisp Interaction Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24.11 Running an External Lisp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

271
272
274
275
276
276
276
277
278
280
281
281
282
282
283
284
284
285
286
287
287
288
290
290

xii

25

Maintaining Large Programs . . . . . . . . . . . . . . . . . . . . . . . . . . 292
25.1 Version Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.1 Introduction to Version Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.1.1 Understanding the problems it addresses . . . . . . . . . . . . . . . . .
25.1.1.2 Supported Version Control Systems . . . . . . . . . . . . . . . . . . . . . .
25.1.1.3 Concepts of Version Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.1.4 Merge-based vs lock-based Version Control . . . . . . . . . . . . . .
25.1.1.5 Changeset-based vs File-based Version Control . . . . . . . . . . .
25.1.1.6 Decentralized vs Centralized Repositories . . . . . . . . . . . . . . . .
25.1.1.7 Types of Log File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.2 Version Control and the Mode Line . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.3 Basic Editing under Version Control . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.3.1 Basic Version Control with Merging . . . . . . . . . . . . . . . . . . . . .
25.1.3.2 Basic Version Control with Locking . . . . . . . . . . . . . . . . . . . . . .
25.1.3.3 Advanced Control in C-x v v . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.4 Features of the Log Entry Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.5 Registering a File for Version Control . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.6 Examining And Comparing Old Revisions . . . . . . . . . . . . . . . . . . . .
25.1.7 VC Change Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.8 Undoing Version Control Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.9 VC Directory Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.9.1 The VC Directory Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.9.2 VC Directory Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.10 Version Control Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.10.1 Switching between Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.10.2 Pulling Changes into a Branch . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.10.3 Merging Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.1.10.4 Creating New Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.2 Change Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.2.1 Change Log Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.2.2 Format of ChangeLog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3 Tags Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.1 Source File Tag Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.2 Creating Tags Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.3 Etags Regexps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.4 Selecting a Tags Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.5 Finding a Tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.3.6 Searching and Replacing with Tags Tables . . . . . . . . . . . . . . . . . . . .
25.3.7 Tags Table Inquiries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25.4 Emacs Development Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

292
292
292
293
293
294
295
295
295
296
296
297
298
298
299
300
300
302
304
304
305
305
307
307
308
308
309
309
310
310
311
312
314
315
317
317
318
319
320

xiii

26

Abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
26.1
26.2
26.3
26.4
26.5
26.6
26.7

27

322
322
323
324
325
326
327

Dired, the Directory Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
27.1
27.2
27.3
27.4
27.5
27.6
27.7
27.8
27.9
27.10
27.11
27.12
27.13
27.14
27.15
27.16
27.17
27.18

28

Abbrev Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Defining Abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controlling Abbrev Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Examining and Editing Abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Saving Abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dynamic Abbrev Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customizing Dynamic Abbreviation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Entering Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Navigation in the Dired Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Deleting Files with Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flagging Many Files at Once . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Visiting Files in Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dired Marks vs. Flags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating on Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shell Commands in Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transforming File Names in Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
File Comparison with Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subdirectories in Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Moving Over Subdirectories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hiding Subdirectories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Updating the Dired Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dired and find . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Editing the Dired Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Viewing Image Thumbnails in Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other Dired Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

329
330
330
331
332
333
335
337
338
339
339
340
340
341
342
343
343
344

The Calendar and the Diary . . . . . . . . . . . . . . . . . . . . . . . . . . 346
28.1 Movement in the Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.1.1 Motion by Standard Lengths of Time . . . . . . . . . . . . . . . . . . . . . . . . .
28.1.2 Beginning or End of Week, Month or Year . . . . . . . . . . . . . . . . . . . .
28.1.3 Specified Dates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.2 Scrolling in the Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.3 Counting Days . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.4 Miscellaneous Calendar Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.5 Writing Calendar Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.6 Holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.7 Times of Sunrise and Sunset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.8 Phases of the Moon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.9 Conversion To and From Other Calendars . . . . . . . . . . . . . . . . . . . . . . . . . .
28.9.1 Supported Calendar Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.9.2 Converting To Other Calendars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.9.3 Converting From Other Calendars . . . . . . . . . . . . . . . . . . . . . . . . . . . .

346
346
347
347
348
348
349
349
351
352
353
353
354
355
356

xiv
28.9.4 Converting from the Mayan Calendar . . . . . . . . . . . . . . . . . . . . . . . . .
28.10 The Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.10.1 Displaying the Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.10.2 The Diary File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.10.3 Date Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.10.4 Commands to Add to the Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.10.5 Special Diary Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.11 Appointments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.12 Importing and Exporting Diary Entries . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.13 Daylight Saving Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28.14 Summing Time Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

29

Sending Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
29.1 The Format of the Mail Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.2 Mail Header Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.3 Mail Aliases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.4 Mail Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.4.1 Mail Sending . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.4.2 Mail Header Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.4.3 Citing Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.4.4 Mail Miscellany . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.5 Mail Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.6 Mail Amusements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29.7 Mail-Composition Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

30

357
358
359
360
360
361
362
364
364
365
366

367
368
370
370
370
372
373
373
374
374
375

Reading Mail with Rmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
30.1 Basic Concepts of Rmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.2 Scrolling Within a Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.3 Moving Among Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.4 Deleting Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.5 Rmail Files and Inboxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.6 Multiple Rmail Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.7 Copying Messages Out to Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.8 Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.9 Rmail Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.10 Sending Replies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.11 Summaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.11.1 Making Summaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.11.2 Editing in Summaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.12 Sorting the Rmail File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.13 Display of Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.14 Rmail and Coding Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.15 Editing Within a Message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.16 Digest Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30.17 Reading Rot13 Messages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

376
376
377
378
379
380
381
383
384
385
386
387
388
390
391
392
392
393
393

xv
30.18 movemail program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
30.19 Retrieving Mail from Remote Mailboxes . . . . . . . . . . . . . . . . . . . . . . . . . . 395
30.20 Retrieving Mail from Local Mailboxes in Various Formats . . . . . . . . . 396

31

Miscellaneous Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
31.1 Gnus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.1.1 Gnus Buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.1.2 When Gnus Starts Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.1.3 Using the Gnus Group Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.1.4 Using the Gnus Summary Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.2 Document Viewing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.2.1 DocView Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.2.2 DocView Searching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.2.3 DocView Slicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.2.4 DocView Conversion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3 Running Shell Commands from Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.1 Single Shell Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.2 Interactive Subshell. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.3 Shell Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.4 Shell Prompts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.5 Shell Command History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.5.1 Shell History Ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.5.2 Shell History Copying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.5.3 Shell History References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.6 Directory Tracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.7 Shell Mode Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.8 Emacs Terminal Emulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.9 Term Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.10 Remote Host Shell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.3.11 Serial Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.4 Using Emacs as a Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.4.1 Invoking emacsclient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.4.2 emacsclient Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.5 Printing Hard Copies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.5.1 PostScript Hardcopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.5.2 Variables for PostScript Hardcopy . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.5.3 Printing Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.6 Sorting Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.7 Editing Binary Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.8 Saving Emacs Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.9 Recursive Editing Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.10 Emulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.11 Hyperlinking and Navigation Features . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.11.1 Following URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.11.2 Activating URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.11.3 Finding Files and URLs at Point . . . . . . . . . . . . . . . . . . . . . . . . . . . .

397
397
397
398
399
399
400
400
400
401
401
402
403
403
406
407
407
408
408
409
409
410
411
411
412
412
413
414
417
418
419
420
420
422
423
424
425
426
426
426
427

xvi
31.12

32

Emacs Lisp Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
32.1
32.2
32.3

33

Other Amusements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428

The Package Menu Buffer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
Package Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431
Package Files and Directory Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432

Customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
33.1 Easy Customization Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.1 Customization Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.2 Browsing and Searching for Settings . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.3 Changing a Variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.4 Saving Customizations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.5 Customizing Faces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.6 Customizing Specific Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.7 Custom Themes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.1.8 Creating Custom Themes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2 Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.1 Examining and Setting Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.2 Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.3 Local Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.4 Local Variables in Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.4.1 Specifying File Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.4.2 Safety of File Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.2.5 Per-Directory Local Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3 Customizing Key Bindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.1 Keymaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.2 Prefix Keymaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.3 Local Keymaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.4 Minibuffer Keymaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.5 Changing Key Bindings Interactively . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.6 Rebinding Keys in Your Init File . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.7 Modifier Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.8 Rebinding Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.9 Named ASCII Control Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.10 Rebinding Mouse Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.3.11 Disabling Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4 The Emacs Initialization File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4.1 Init File Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4.2 Init File Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4.3 Terminal-specific Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4.4 How Emacs Finds Your Init File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33.4.5 Non-ASCII Characters in Init Files . . . . . . . . . . . . . . . . . . . . . . . . . . . .

434
434
435
436
438
439
440
441
442
443
443
445
446
447
447
449
450
452
452
453
453
454
454
455
456
457
458
459
460
461
462
463
465
466
466

xvii

34

Dealing with Common Problems . . . . . . . . . . . . . . . . . . . . . . 468
34.1 Quitting and Aborting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2 Dealing with Emacs Trouble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.1 If DEL Fails to Delete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.2 Recursive Editing Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.3 Garbage on the Screen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.4 Garbage in the Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.5 Running out of Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.6 Recovery After a Crash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.2.7 Emergency Escape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.3 Reporting Bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.3.1 Reading Existing Bug Reports and Known Problems . . . . . . . . . .
34.3.2 When Is There a Bug. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.3.3 Understanding Bug Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.3.4 Checklist for Bug Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.3.5 Sending Patches for GNU Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.4 Contributing to Emacs Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34.5 How To Get Help with GNU Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

468
469
470
470
470
471
471
471
472
473
473
474
475
475
481
483
483

Appendix A

GNU GENERAL PUBLIC LICENSE . . . . 484

Appendix B

GNU Free Documentation License . . . . . . . . 496

Appendix C Command Line Arguments for Emacs
Invocation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
C.1
C.2
C.3
C.4

Action Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Initial Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Argument Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Environment Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.4.1 General Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.4.2 Miscellaneous Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.4.3 The MS-Windows System Registry . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.5 Specifying the Display Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.6 Font Specification Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.7 Window Color Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.8 Options for Window Size and Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.9 Internal and External Borders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.10 Frame Titles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.11 Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.12 Other Display Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

505
507
509
509
510
513
514
514
515
515
517
518
519
519
519

xviii

Appendix D

X Options and Resources . . . . . . . . . . . . . . . . . . 521

D.1 X Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.2 Table of X Resources for Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3 GTK resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.1 GTK Resource Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.2 GTK widget names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.3 GTK Widget Names in Emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4 GTK styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

521
522
523
524
525
525
526

Appendix E

Emacs 23 Antinews . . . . . . . . . . . . . . . . . . . . . . . . . 529

Appendix F

Emacs and Mac OS / GNUstep . . . . . . . . . . . 531

F.1

Basic Emacs usage under Mac OS and GNUstep . . . . . . . . . . . . . . . . . . . .
F.1.1 Grabbing environment variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.2 Mac / GNUstep Customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.2.1 Font and Color Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.2.2 Customization options specific to Mac OS / GNUstep. . . . . . . . . .
F.3 Windowing System Events under Mac OS / GNUstep . . . . . . . . . . . . . . .
F.4 GNUstep Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

531
531
532
532
532
532
534

Appendix G Emacs and Microsoft Windows/MS-DOS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535
G.1
G.2
G.3
G.4
G.5
G.6
G.7
G.8
G.9
G.10
G.11

How to Start Emacs on MS-Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Text Files and Binary Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
File Names on MS-Windows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emulation of ls on MS-Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HOME and Startup Directories on MS-Windows. . . . . . . . . . . . . . . . . . . .
Keyboard Usage on MS-Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mouse Usage on MS-Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subprocesses on Windows 9X/ME and Windows NT/2K/XP . . . . . . .
Printing and MS-Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifying Fonts on MS-Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous Windows-specific features . . . . . . . . . . . . . . . . . . . . . . . . . . .

535
536
538
538
538
539
540
540
541
543
545

The GNU Manifesto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546
What’s GNU? Gnu’s Not Unix! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Why I Must Write GNU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Why GNU Will Be Compatible with Unix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How GNU Will Be Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Why Many Other Programmers Want to Help . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How You Can Contribute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Why All Computer Users Will Benefit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Some Easily Rebutted Objections to GNU’s Goals . . . . . . . . . . . . . . . . . . . . . . . .

546
547
547
547
547
548
548
549

xix

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555
Key (Character) Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580
Command and Function Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590
Variable Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 604
Concept Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 612

Preface

1

Preface
This manual documents the use and simple customization of the Emacs editor.
Simple Emacs customizations do not require you to be a programmer, but if you
are not interested in customizing, you can ignore the customization hints.
This is primarily a reference manual, but can also be used as a primer. If you
are new to Emacs, we recommend you start with the integrated, learn-by-doing
tutorial, before reading the manual. To run the tutorial, start Emacs and type C-h
t. The tutorial describes commands, tells you when to try them, and explains the
results. The tutorial is available in several languages.
On first reading, just skim chapters 1 and 2, which describe the notational
conventions of the manual and the general appearance of the Emacs display screen.
Note which questions are answered in these chapters, so you can refer back later.
After reading chapter 4, you should practice the commands shown there. The next
few chapters describe fundamental techniques and concepts that are used constantly.
You need to understand them thoroughly, so experiment with them until you are
fluent.
Chapters 14 through 19 describe intermediate-level features that are useful for
many kinds of editing. Chapter 20 and following chapters describe optional but
useful features; read those chapters when you need them.
Read the Common Problems chapter if Emacs does not seem to be working
properly. It explains how to cope with several common problems (see Section 34.2
[Dealing with Emacs Trouble], page 469), as well as when and how to report Emacs
bugs (see Section 34.3 [Bugs], page 473).
To find the documentation of a particular command, look in the index. Keys
(character commands) and command names have separate indexes. There is also a
glossary, with a cross reference for each term.
This manual is available as a printed book and also as an Info file. The Info
file is for reading from Emacs itself, or with the Info program. Info is the principal
format for documentation in the GNU system. The Info file and the printed book
contain substantially the same text and are generated from the same source files,
which are also distributed with GNU Emacs.
GNU Emacs is a member of the Emacs editor family. There are many Emacs
editors, all sharing common principles of organization. For information on the
underlying philosophy of Emacs and the lessons learned from its development, see
Emacs, the Extensible, Customizable Self-Documenting Display Editor, available
from ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-519A.pdf.
This version of the manual is mainly intended for use with GNU Emacs installed
on GNU and Unix systems. GNU Emacs can also be used on MS-DOS, Microsoft
Windows, and Macintosh systems. The Info file version of this manual contains
some more information about using Emacs on those systems. Those systems use
different file name syntax; in addition MS-DOS does not support all GNU Emacs
features. See Appendix G [Microsoft Windows], page 535, for information about
using Emacs on Windows. See Appendix F [Mac OS / GNUstep], page 531, for
information about using Emacs on Macintosh (and GNUstep).

Distribution

2

Distribution
GNU Emacs is free software; this means that everyone is free to use it and free to
redistribute it under certain conditions. GNU Emacs is not in the public domain;
it is copyrighted and there are restrictions on its distribution, but these restrictions
are designed to permit everything that a good cooperating citizen would want to
do. What is not allowed is to try to prevent others from further sharing any version
of GNU Emacs that they might get from you. The precise conditions are found in
the GNU General Public License that comes with Emacs and also appears in this
manual1 . See Appendix A [Copying], page 484.
One way to get a copy of GNU Emacs is from someone else who has it. You need
not ask for our permission to do so, or tell any one else; just copy it. If you have
access to the Internet, you can get the latest distribution version of GNU Emacs
by anonymous FTP; see http://www.gnu.org/software/emacs on our website for
more information.
You may also receive GNU Emacs when you buy a computer. Computer manufacturers are free to distribute copies on the same terms that apply to everyone else.
These terms require them to give you the full sources, including whatever changes
they may have made, and to permit you to redistribute the GNU Emacs received
from them under the usual terms of the General Public License. In other words, the
program must be free for you when you get it, not just free for the manufacturer.
If you find GNU Emacs useful, please send a donation to the Free Software
Foundation to support our work. Donations to the Free Software Foundation are
tax deductible in the US. If you use GNU Emacs at your workplace, please suggest
that the company make a donation. For more information on how you can help,
see http://www.gnu.org/help/help.html.
We also sell hardcopy versions of this manual and An Introduction to Programming in Emacs Lisp, by Robert J. Chassell. You can visit our online store at
http://shop.fsf.org/. The income from sales goes to support the foundation’s
purpose: the development of new free software, and improvements to our existing
programs including GNU Emacs.
To contact the FSF, go to http://www.fsf.org/about/contact/, or write to
Free Software Foundation
51 Franklin Street, Fifth Floor
Boston, MA 02110-1301
USA

Acknowledgments
Contributors to GNU Emacs include Jari Aalto, Per Abrahamsen, Tomas Abrahamsson, Jay K. Adams, Alon Albert, Michael Albinus, Nagy Andras, Benjamin
Andresen, Ralf Angeli, Joe Arceneaux, Emil Åström, Miles Bader, David Bakhash,
1

This manual is itself covered by the GNU Free Documentation License. This license is
similar in spirit to the General Public License, but is more suitable for documentation.
See Appendix B [GNU Free Documentation License], page 496.

Distribution

3

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Berezin, Karl Berry, Anna M. Bigatti, Ray Blaak, Martin Blais, Jim Blandy, Johan Bockgård, Jan Böcker, Joel Boehland, Lennart Borgman, Per Bothner, Terrence Brannon, Frank Bresz, Peter Breton, Emmanuel Briot, Kevin Broadey, Vincent Broman, Michael Brouwer, David M. Brown, Stefan Bruda, Georges BrunCottan, Joe Buehler, Scott Byer, Wlodek Bzyl, Bill Carpenter, Per Cederqvist,
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Kyle Jones, Terry Jones, Simon Josefsson, Alexandre Julliard, Arne Jørgensen, Tomoji Kagatani, Brewster Kahle, Tokuya Kameshima, Lute Kamstra, Ivan Kanis,
David Kastrup, David Kaufman, Henry Kautz, Taichi Kawabata, Taro Kawagishi, Howard Kaye, Michael Kifer, Richard King, Peter Kleiweg, Karel Klı́č, Shuhei
Kobayashi, Pavel Kobyakov, Larry K. Kolodney, David M. Koppelman, Koseki
Yoshinori, Robert Krawitz, Sebastian Kremer, Ryszard Kubiak, Igor Kuzmin, David
Kågedal, Daniel LaLiberte, Karl Landstrom, Mario Lang, Aaron Larson, James R.
Larus, Vinicius Jose Latorre, Werner Lemberg, Frederic Lepied, Peter Liljenberg,
Christian Limpach, Lars Lindberg, Chris Lindblad, Anders Lindgren, Thomas Link,
Juri Linkov, Francis Litterio, Sergey Litvinov, Emilio C. Lopes, Martin Lorentzon, Dave Love, Eric Ludlam, Károly Lőrentey, Sascha Lüdecke, Greg McGary,
Roland McGrath, Michael McNamara, Alan Mackenzie, Christopher J. Madsen,
Neil M. Mager, Ken Manheimer, Bill Mann, Brian Marick, Simon Marshall, Bengt
Martensson, Charlie Martin, Yukihiro Matsumoto, David Maus, Thomas May, Will
Mengarini, David Megginson, Stefan Merten, Ben A. Mesander, Wayne Mesard,

Distribution

4

Brad Miller, Lawrence Mitchell, Richard Mlynarik, Gerd Moellmann, Stefan Monnier, Keith Moore, Jan Moringen, Morioka Tomohiko, Glenn Morris, Don Morrison, Diane Murray, Riccardo Murri, Sen Nagata, Erik Naggum, Gergely Nagy,
Nobuyoshi Nakada, Thomas Neumann, Mike Newton, Thien-Thi Nguyen, Jurgen
Nickelsen, Dan Nicolaescu, Hrvoje Niksic, Jeff Norden, Andrew Norman, Kentaro
Ohkouchi, Christian Ohler, Kenichi Okada, Alexandre Oliva, Bob Olson, Michael
Olson, Takaaki Ota, Pieter E. J. Pareit, Ross Patterson, David Pearson, Juan
Pechiar, Jeff Peck, Damon Anton Permezel, Tom Perrine, William M. Perry, Per
Persson, Jens Petersen, Daniel Pfeiffer, Justus Piater, Richard L. Pieri, Fred Pierresteguy, François Pinard, Daniel Pittman, Christian Plaunt, Alexander Pohoyda,
David Ponce, Francesco A. Potorti, Michael D. Prange, Mukesh Prasad, Ken Raeburn, Marko Rahamaa, Ashwin Ram, Eric S. Raymond, Paul Reilly, Edward M.
Reingold, David Reitter, Alex Rezinsky, Rob Riepel, Lara Rios, Adrian Robert, Nick
Roberts, Roland B. Roberts, John Robinson, Denis B. Roegel, Danny Roozendaal,
Sebastian Rose, William Rosenblatt, Markus Rost, Guillermo J. Rozas, Martin
Rudalics, Ivar Rummelhoff, Jason Rumney, Wolfgang Rupprecht, Benjamin Rutt,
Kevin Ryde, James B. Salem, Masahiko Sato, Timo Savola, Jorgen Schaefer, Holger Schauer, William Schelter, Ralph Schleicher, Gregor Schmid, Michael Schmidt,
Ronald S. Schnell, Philippe Schnoebelen, Jan Schormann, Alex Schroeder, Stefan
Schoef, Rainer Schoepf, Raymond Scholz, Eric Schulte, Andreas Schwab, Randal
Schwartz, Oliver Seidel, Manuel Serrano, Paul Sexton, Hovav Shacham, Stanislav
Shalunov, Marc Shapiro, Richard Sharman, Olin Shivers, Tibor Šimko, Espen
Skoglund, Rick Sladkey, Lynn Slater, Chris Smith, David Smith, Paul D. Smith,
Wilson Snyder, William Sommerfeld, Simon South, Andre Spiegel, Michael Staats,
Thomas Steffen, Ulf Stegemann, Reiner Steib, Sam Steingold, Ake Stenhoff, Peter
Stephenson, Ken Stevens, Andy Stewart, Jonathan Stigelman, Martin Stjernholm,
Kim F. Storm, Steve Strassmann, Christopher Suckling, Olaf Sylvester, Naoto Takahashi, Steven Tamm, Luc Teirlinck, Jean-Philippe Theberge, Jens T. Berger Thielemann, Spencer Thomas, Jim Thompson, Toru Tomabechi, David O’Toole, Markus
Triska, Tom Tromey, Enami Tsugutomo, Eli Tziperman, Daiki Ueno, Masanobu
Umeda, Rajesh Vaidheeswarran, Neil W. Van Dyke, Didier Verna, Joakim Verona,
Ulrik Vieth, Geoffrey Voelker, Johan Vromans, Inge Wallin, John Paul Wallington,
Colin Walters, Barry Warsaw, Christoph Wedler, Ilja Weis, Zhang Weize, Morten
Welinder, Joseph Brian Wells, Rodney Whitby, John Wiegley, Sascha Wilde, Ed
Wilkinson, Mike Williams, Roland Winkler, Bill Wohler, Steven A. Wood, Dale R.
Worley, Francis J. Wright, Felix S. T. Wu, Tom Wurgler, Yamamoto Mitsuharu,
Katsumi Yamaoka, Masatake Yamato, Jonathan Yavner, Ryan Yeske, Ilya Zakharevich, Milan Zamazal, Victor Zandy, Eli Zaretskii, Jamie Zawinski, Andrew Zhilin,
Shenghuo Zhu, Piotr Zielinski, Ian T. Zimmermann, Reto Zimmermann, Neal Ziring, Teodor Zlatanov, and Detlev Zundel.

Introduction

5

Introduction
You are reading about GNU Emacs, the GNU incarnation of the advanced, selfdocumenting, customizable, extensible editor Emacs. (The ‘G’ in ‘GNU’ is not
silent.)
We call Emacs advanced because it can do much more than simple insertion
and deletion of text. It can control subprocesses, indent programs automatically,
show multiple files at once, and more. Emacs editing commands operate in terms
of characters, words, lines, sentences, paragraphs, and pages, as well as expressions
and comments in various programming languages.
Self-documenting means that at any time you can use special commands, known
as help commands, to find out what your options are, or to find out what any
command does, or to find all the commands that pertain to a given topic. See
Chapter 7 [Help], page 38.
Customizable means that you can easily alter the behavior of Emacs commands
in simple ways. For instance, if you use a programming language in which comments
start with ‘<**’ and end with ‘**>’, you can tell the Emacs comment manipulation
commands to use those strings (see Section 23.5 [Comments], page 258). To take
another example, you can rebind the basic cursor motion commands (up, down, left
and right) to any keys on the keyboard that you find comfortable. See Chapter 33
[Customization], page 434.
Extensible means that you can go beyond simple customization and create entirely new commands. New commands are simply programs written in the Lisp
language, which are run by Emacs’s own Lisp interpreter. Existing commands can
even be redefined in the middle of an editing session, without having to restart
Emacs. Most of the editing commands in Emacs are written in Lisp; the few exceptions could have been written in Lisp but use C instead for efficiency. Writing an
extension is programming, but non-programmers can use it afterwards. See Section
“Preface” in An Introduction to Programming in Emacs Lisp, if you want to learn
Emacs Lisp programming.

Chapter 1: The Organization of the Screen

6

1 The Organization of the Screen
On a graphical display, such as on GNU/Linux using the X Window System, Emacs
occupies a “graphical window”. On a text terminal, Emacs occupies the entire
terminal screen. We will use the term frame to mean a graphical window or terminal
screen occupied by Emacs. Emacs behaves very similarly on both kinds of frames.
It normally starts out with just one frame, but you can create additional frames if
you wish (see Chapter 18 [Frames], page 165).
Each frame consists of several distinct regions. At the top of the frame is a menu
bar, which allows you to access commands via a series of menus. On a graphical
display, directly below the menu bar is a tool bar, a row of icons that perform
editing commands if you click on them. At the very bottom of the frame is an echo
area, where informative messages are displayed and where you enter information
when Emacs asks for it.
The main area of the frame, below the tool bar (if one exists) and above the
echo area, is called the window. Henceforth in this manual, we will use the word
“window” in this sense. Graphical display systems commonly use the word “window” with a different meaning; but, as stated above, we refer to those “graphical
windows” as “frames”.
An Emacs window is where the buffer—the text you are editing—is displayed.
On a graphical display, the window possesses a scroll bar on one side, which can
be used to scroll through the buffer. The last line of the window is a mode line.
This displays various information about what is going on in the buffer, such as
whether there are unsaved changes, the editing modes that are in use, the current
line number, and so forth.
When you start Emacs, there is normally only one window in the frame. However, you can subdivide this window horizontally or vertically to create multiple
windows, each of which can independently display a buffer (see Chapter 17 [Windows], page 159).
At any time, one window is the selected window. On a graphical display, the
selected window shows a more prominent cursor (usually solid and blinking); other
windows show a less prominent cursor (usually a hollow box). On a text terminal,
there is only one cursor, which is shown in the selected window. The buffer displayed
in the selected window is called the current buffer, and it is where editing happens.
Most Emacs commands implicitly apply to the current buffer; the text displayed in
unselected windows is mostly visible for reference. If you use multiple frames on a
graphical display, selecting a particular frame selects a window in that frame.

1.1 Point
The cursor in the selected window shows the location where most editing commands
take effect, which is called point1 . Many Emacs commands move point to different
1

The term “point” comes from the character ‘.’, which was the command in TECO (the
language in which the original Emacs was written) for accessing the editing position.

Chapter 1: The Organization of the Screen

7

places in the buffer; for example, you can place point by clicking mouse button 1
(normally the left button) at the desired location.
By default, the cursor in the selected window is drawn as a solid block and appears to be on a character, but you should think of point as between two characters;
it is situated before the character under the cursor. For example, if your text looks
like ‘frob’ with the cursor over the ‘b’, then point is between the ‘o’ and the ‘b’.
If you insert the character ‘!’ at that position, the result is ‘fro!b’, with point
between the ‘!’ and the ‘b’. Thus, the cursor remains over the ‘b’, as before.
If you are editing several files in Emacs, each in its own buffer, each buffer has
its own value of point. A buffer that is not currently displayed remembers its value
of point if you later display it again. Furthermore, if a buffer is displayed in multiple
windows, each of those windows has its own value of point.
See Section 11.20 [Cursor Display], page 88, for options that control how Emacs
displays the cursor.

1.2 The Echo Area
The line at the very bottom of the frame is the echo area. It is used to display small
amounts of text for various purposes.
The echo area is so-named because one of the things it is used for is echoing, which means displaying the characters of a multi-character command as you
type. Single-character commands are not echoed. Multi-character commands (see
Section 2.2 [Keys], page 11) are echoed if you pause for more than a second in the
middle of a command. Emacs then echoes all the characters of the command so
far, to prompt you for the rest. Once echoing has started, the rest of the command
echoes immediately as you type it. This behavior is designed to give confident users
fast response, while giving hesitant users maximum feedback.
The echo area is also used to display an error message when a command cannot
do its job. Error messages may be accompanied by beeping or by flashing the screen.
Some commands display informative messages in the echo area to tell you what
the command has done, or to provide you with some specific information. These
informative messages, unlike error messages, are not accompanied with a beep or
flash. For example, C-x = (hold down CTRL and type x, then let go of CTRL
and type =) displays a message describing the character at point, its position in
the buffer, and its current column in the window. Commands that take a long
time often display messages ending in ‘...’ while they are working (sometimes also
indicating how much progress has been made, as a percentage), and add ‘done’
when they are finished.
Informative echo area messages are saved in a special buffer named ‘*Messages*’.
(We have not explained buffers yet; see Chapter 16 [Buffers], page 150, for more
information about them.) If you miss a message that appeared briefly on the screen,
you can switch to the ‘*Messages*’ buffer to see it again. The ‘*Messages*’ buffer
is limited to a certain number of lines, specified by the variable message-log-max.
(We have not explained variables either; see Section 33.2 [Variables], page 443, for

Chapter 1: The Organization of the Screen

8

more information about them.) Beyond this limit, one line is deleted from the
beginning whenever a new message line is added at the end.
See Section 11.23 [Display Custom], page 90, for options that control how Emacs
uses the echo area.
The echo area is also used to display the minibuffer, a special window where you
can input arguments to commands, such as the name of a file to be edited. When
the minibuffer is in use, the text displayed in the echo area begins with a prompt
string, and the active cursor appears within the minibuffer, which is temporarily
considered the selected window. You can always get out of the minibuffer by typing
C-g. See Chapter 5 [Minibuffer], page 27.

1.3 The Mode Line
At the bottom of each window is a mode line, which describes what is going on in
the current buffer. When there is only one window, the mode line appears right
above the echo area; it is the next-to-last line in the frame. On a graphical display,
the mode line is drawn with a 3D box appearance. Emacs also usually draws the
mode line of the selected window with a different color than that of unselected
windows, in order to make it stand out.
The text displayed in the mode line has the following format:
cs :ch-fr buf
pos line
(major minor )
On a text terminal, this text is followed by a series of dashes extending to the right
edge of the window. These dashes are omitted on a graphical display.
The cs string and the colon character after it describe the character set and
newline convention used for the current buffer. Normally, Emacs automatically
handles these settings for you, but it is sometimes useful to have this information.
cs describes the character set of the text in the buffer (see Section 19.6 [Coding
Systems], page 188). If it is a dash (‘-’), that indicates no special character set
handling (with the possible exception of end-of-line conventions, described in the
next paragraph). ‘=’ means no conversion whatsoever, and is usually used for files
containing non-textual data. Other characters represent various coding systems—
for example, ‘1’ represents ISO Latin-1.
On a text terminal, cs is preceded by two additional characters that describe the
coding systems for keyboard input and terminal output. Furthermore, if you are
using an input method, cs is preceded by a string that identifies the input method
(see Section 19.4 [Input Methods], page 185).
The character after cs is usually a colon. If a different string is displayed, that
indicates a nontrivial end-of-line convention for encoding a file. Usually, lines of text
are separated by newline characters in a file, but two other conventions are sometimes used. The MS-DOS convention uses a “carriage-return” character followed
by a “linefeed” character; when editing such files, the colon changes to either a
backslash (‘\’) or ‘(DOS)’, depending on the operating system. Another convention,
employed by older Macintosh systems, uses a “carriage-return” character instead of
a newline; when editing such files, the colon changes to either a forward slash (‘/’)

Chapter 1: The Organization of the Screen

9

or ‘(Mac)’. On some systems, Emacs displays ‘(Unix)’ instead of the colon for files
that use newline as the line separator.
The next element on the mode line is the string indicated by ch. This shows
two dashes (‘--’) if the buffer displayed in the window has the same contents as
the corresponding file on the disk; i.e., if the buffer is “unmodified”. If the buffer
is modified, it shows two stars (‘**’). For a read-only buffer, it shows ‘%*’ if the
buffer is modified, and ‘%%’ otherwise.
The character after ch is normally a dash (‘-’). However, if the defaultdirectory for the current buffer is on a remote machine, ‘@’ is displayed instead
(see Section 15.1 [File Names], page 124).
fr gives the selected frame name (see Chapter 18 [Frames], page 165). It appears
only on text terminals. The initial frame’s name is ‘F1’.
buf is the name of the buffer displayed in the window. Usually, this is the same
as the name of a file you are editing. See Chapter 16 [Buffers], page 150.
pos tells you whether there is additional text above the top of the window, or
below the bottom. If your buffer is small and all of it is visible in the window, pos is
‘All’. Otherwise, it is ‘Top’ if you are looking at the beginning of the buffer, ‘Bot’ if
you are looking at the end of the buffer, or ‘nn %’, where nn is the percentage of the
buffer above the top of the window. With Size Indication mode, you can display
the size of the buffer as well. See Section 11.18 [Optional Mode Line], page 85.
line is the character ‘L’ followed by the line number at point. (You can display the current column number too, by turning on Column Number mode. See
Section 11.18 [Optional Mode Line], page 85.)
major is the name of the major mode used in the buffer. A major mode is a
principal editing mode for the buffer, such as Text mode, Lisp mode, C mode, and
so forth. See Section 20.1 [Major Modes], page 204. Some major modes display
additional information after the major mode name. For example, Compilation
buffers and Shell buffers display the status of the subprocess.
minor is a list of some of the enabled minor modes, which are optional editing
modes that provide additional features on top of the major mode. See Section 20.2
[Minor Modes], page 205.
Some features are listed together with the minor modes whenever they are turned
on, even though they are not really minor modes. ‘Narrow’ means that the buffer
being displayed has editing restricted to only a portion of its text (see Section 11.5
[Narrowing], page 74). ‘Def’ means that a keyboard macro is currently being defined
(see Chapter 14 [Keyboard Macros], page 116).
In addition, if Emacs is inside a recursive editing level, square brackets (‘[...]’)
appear around the parentheses that surround the modes. If Emacs is in one recursive editing level within another, double square brackets appear, and so on. Since
recursive editing levels affect Emacs globally, such square brackets appear in the
mode line of every window. See Section 31.9 [Recursive Edit], page 424.
You can change the appearance of the mode line as well as the format of its
contents. See Section 11.18 [Optional Mode Line], page 85. In addition, the mode
line is mouse-sensitive; clicking on different parts of the mode line performs various
commands. See Section 18.5 [Mode Line Mouse], page 169.

Chapter 1: The Organization of the Screen

10

1.4 The Menu Bar
Each Emacs frame normally has a menu bar at the top which you can use to perform
common operations. There’s no need to list them here, as you can more easily see
them yourself.
On a graphical display, you can use the mouse to choose a command from the
menu bar. An arrow on the right edge of a menu item means it leads to a subsidiary
menu, or submenu. A ‘...’ at the end of a menu item means that the command
will prompt you for further input before it actually does anything.
Some of the commands in the menu bar have ordinary key bindings as well; if
so, a key binding is shown in parentheses after the item itself. To view the full
command name and documentation for a menu item, type C-h k, and then select
the menu bar with the mouse in the usual way (see Section 7.1 [Key Help], page 40).
Instead of using the mouse, you can also invoke the first menu bar item by
pressing F10 (to run the command menu-bar-open). You can then navigate the
menus with the arrow keys. To activate a selected menu item, press RET; to cancel
menu navigation, press ESC.
On a text terminal, you can use the menu bar by typing M-‘ or F10 (these run
the command tmm-menubar). This lets you select a menu item with the keyboard.
A provisional choice appears in the echo area. You can use the up and down arrow
keys to move through the menu to different items, and then you can type RET to
select the item. Each menu item is also designated by a letter or digit (usually the
initial of some word in the item’s name). This letter or digit is separated from the
item name by ‘=>’. You can type the item’s letter or digit to select the item.

Chapter 2: Characters, Keys and Commands

11

2 Characters, Keys and Commands
This chapter explains the character sets used by Emacs for input commands, and
the fundamental concepts of keys and commands, whereby Emacs interprets your
keyboard and mouse input.

2.1 Kinds of User Input
GNU Emacs is primarily designed for use with the keyboard. While it is possible to
use the mouse to issue editing commands through the menu bar and tool bar, that
is not as efficient as using the keyboard. Therefore, this manual mainly documents
how to edit with the keyboard.
Keyboard input into Emacs is based on a heavily-extended version of ASCII.
Simple characters, like ‘a’, ‘B’, ‘3’, ‘=’, and the space character (denoted as SPC),
are entered by typing the corresponding key. Control characters, such as RET,
TAB, DEL, ESC, F1, HOME, and LEFT, are also entered this way, as are certain characters found on non-English keyboards (see Chapter 19 [International],
page 180).
Emacs also recognizes control characters that are entered using modifier keys.
Two commonly-used modifier keys are CONTROL (usually labeled CTRL), and
META (usually labeled ALT)1 . For example, Control-a is entered by holding
down the CTRL key while pressing a; we will refer to this as C-a for short. Similarly
Meta-a, or M-a for short, is entered by holding down the ALT key and pressing a.
Modifier keys can also be applied to non-alphanumerical characters, e.g. C-F1 or
M-LEFT.
You can also type Meta characters using two-character sequences starting with
ESC. Thus, you can enter M-a by typing ESC a. You can enter C-M-a by typing
ESC C-a. Unlike META, ESC is entered as a separate character. You don’t hold
down ESC while typing the next character; instead, press ESC and release it, then
enter the next character. This feature is useful on certain text terminals where the
META key does not function reliably.
On graphical displays, the window manager might block some keyboard inputs,
including M-TAB, M-SPC, C-M-d and C-M-l. If you have this problem, you can either
customize your window manager to not block those keys, or “rebind” the affected
Emacs commands (see Chapter 33 [Customization], page 434).
Simple characters and control characters, as well as certain non-keyboard inputs
such as mouse clicks, are collectively referred to as input events. For details about
how Emacs internally handles input events, see Section “Input Events” in The
Emacs Lisp Reference Manual.

2.2 Keys
Some Emacs commands are invoked by just one input event; for example, C-f moves
forward one character in the buffer. Other commands take two or more input events
to invoke, such as C-x C-f and C-x 4 C-f.
1

We refer to ALT as META for historical reasons.

Chapter 2: Characters, Keys and Commands

12

A key sequence, or key for short, is a sequence of one or more input events
that is meaningful as a unit. If a key sequence invokes a command, we call it a
complete key; for example, C-f, C-x C-f and C-x 4 C-f are all complete keys. If
a key sequence isn’t long enough to invoke a command, we call it a prefix key;
from the preceding example, we see that C-x and C-x 4 are prefix keys. Every key
sequence is either a complete key or a prefix key.
A prefix key combines with the following input event to make a longer key
sequence. For example, C-x is a prefix key, so typing C-x alone does not invoke a
command; instead, Emacs waits for further input (if you pause for longer than a
second, it echoes the C-x key to prompt for that input; see Section 1.2 [Echo Area],
page 7). C-x combines with the next input event to make a two-event key sequence,
which could itself be a prefix key (such as C-x 4), or a complete key (such as C-x
C-f). There is no limit to the length of key sequences, but in practice they are
seldom longer than three or four input events.
You can’t add input events onto a complete key. For example, because C-f is a
complete key, the two-event sequence C-f C-k is two key sequences, not one.
By default, the prefix keys in Emacs are C-c, C-h, C-x, C-x RET, C-x @, C-x
a, C-x n, C-x r, C-x v, C-x 4, C-x 5, C-x 6, ESC, M-g, and M-o. (F1 and F2 are
aliases for C-h and C-x 6.) This list is not cast in stone; if you customize Emacs,
you can make new prefix keys. You could even eliminate some of the standard
ones, though this is not recommended for most users; for example, if you remove
the prefix definition of C-x 4, then C-x 4 C-f becomes an invalid key sequence. See
Section 33.3 [Key Bindings], page 452.
Typing the help character (C-h or F1) after a prefix key displays a list of the
commands starting with that prefix. The sole exception to this rule is ESC: ESC
C-h is equivalent to C-M-h, which does something else entirely. You can, however,
use F1 to display a list of commands starting with ESC.

2.3 Keys and Commands
This manual is full of passages that tell you what particular keys do. But Emacs does
not assign meanings to keys directly. Instead, Emacs assigns meanings to named
commands, and then gives keys their meanings by binding them to commands.
Every command has a name chosen by a programmer. The name is usually made
of a few English words separated by dashes; for example, next-line or forwardword. Internally, each command is a special type of Lisp function, and the actions
associated with the command are performed by running the function. See Section
“What Is a Function” in The Emacs Lisp Reference Manual.
The bindings between keys and commands are recorded in tables called keymaps.
See Section 33.3.1 [Keymaps], page 452.
When we say that “C-n moves down vertically one line” we are glossing over a
subtle distinction that is irrelevant in ordinary use, but vital for Emacs customization. The command next-line does a vertical move downward. C-n has this effect
because it is bound to next-line. If you rebind C-n to the command forward-word,
C-n will move forward one word instead.

Chapter 2: Characters, Keys and Commands

13

In this manual, we will often speak of keys like C-n as commands, even though
strictly speaking the key is bound to a command. Usually we state the name of
the command which really does the work in parentheses after mentioning the key
that runs it. For example, we will say that “The command C-n (next-line) moves
point vertically down”, meaning that the command next-line moves vertically
down, and the key C-n is normally bound to it.
Since we are discussing customization, we should tell you about variables. Often
the description of a command will say, “To change this, set the variable mumblefoo.” A variable is a name used to store a value. Most of the variables documented
in this manual are meant for customization: some command or other part of Emacs
examines the variable and behaves differently according to the value that you set.
You can ignore the information about variables until you are interested in customizing them. Then read the basic information on variables (see Section 33.2 [Variables],
page 443) and the information about specific variables will make sense.

Chapter 3: Entering and Exiting Emacs

14

3 Entering and Exiting Emacs
This chapter explains how to enter Emacs, and how to exit it.

3.1 Entering Emacs
The usual way to invoke Emacs is with the shell command emacs. From a terminal
window running in the X Window System, you can run Emacs in the background
with emacs &; this way, Emacs won’t tie up the terminal window, so you can use it
to run other shell commands.
When Emacs starts up, the initial frame displays a special buffer named ‘*GNU
Emacs*’. This startup screen contains information about Emacs and links to common tasks that are useful for beginning users. For instance, activating the ‘Emacs
Tutorial’ link opens the Emacs tutorial; this does the same thing as the command
C-h t (help-with-tutorial). To activate a link, either move point onto it and
type RET, or click on it with mouse-1 (the left mouse button).
Using a command line argument, you can tell Emacs to visit one or more files
as soon as it starts up. For example, emacs foo.txt starts Emacs with a buffer
displaying the contents of the file ‘foo.txt’. This feature exists mainly for compatibility with other editors, which are designed to be launched from the shell for
short editing sessions. If you call Emacs this way, the initial frame is split into two
windows—one showing the specified file, and the other showing the startup screen.
See Chapter 17 [Windows], page 159.
Generally, it is unnecessary and wasteful to start Emacs afresh each time you
want to edit a file. The recommended way to use Emacs is to start it just once, just
after you log in, and do all your editing in the same Emacs session. See Chapter 15
[Files], page 124, for information on visiting more than one file. If you use Emacs
this way, the Emacs session accumulates valuable context, such as the kill ring,
registers, undo history, and mark ring data, which together make editing more
convenient. These features are described later in the manual.
To edit a file from another program while Emacs is running, you can use the
emacsclient helper program to open a file in the existing Emacs session. See
Section 31.4 [Emacs Server], page 412.
Emacs accepts other command line arguments that tell it to load certain Lisp
files, where to put the initial frame, and so forth. See Appendix C [Emacs Invocation], page 505.
If the variable inhibit-startup-screen is non-nil, Emacs does not display
the startup screen. In that case, if one or more files were specified on the command line, Emacs simply displays those files; otherwise, it displays a buffer named
‘*scratch*’, which can be used to evaluate Emacs Lisp expressions interactively.
See Section 24.10 [Lisp Interaction], page 290. You can set the variable inhibitstartup-screen using the Customize facility (see Section 33.1 [Easy Customiza-

Chapter 3: Entering and Exiting Emacs

15

tion], page 434), or by editing your initialization file (see Section 33.4 [Init File],
page 461).1
You can also force Emacs to display a file or directory at startup by setting the
variable initial-buffer-choice to a non-nil value. (In that case, even if you
specify one or more files on the command line, Emacs opens but does not display
them.) The value of initial-buffer-choice should be the name of the desired
file or directory.

3.2 Exiting Emacs
C-x C-c

Kill Emacs (save-buffers-kill-terminal).

C-z

On a text terminal, suspend Emacs; on a graphical display, “minimize”
the selected frame (suspend-emacs).

Killing Emacs means terminating the Emacs program. To do this, type C-x C-c
(save-buffers-kill-terminal). A two-character key sequence is used to make it
harder to type by accident. If there are any modified file-visiting buffers when you
type C-x C-c, Emacs first offers to save these buffers. If you do not save them all,
it asks for confirmation again, since the unsaved changes will be lost. Emacs also
asks for confirmation if any subprocesses are still running, since killing Emacs will
also kill the subprocesses (see Section 31.3 [Shell], page 401).
C-x C-c behaves specially if you are using Emacs as a server. If you type it from
a “client frame”, it closes the client connection. See Section 31.4 [Emacs Server],
page 412.
Emacs can, optionally, record certain session information when you kill it, such
as the files you were visiting at the time. This information is then available the
next time you start Emacs. See Section 31.8 [Saving Emacs Sessions], page 423.
If the value of the variable confirm-kill-emacs is non-nil, C-x C-c assumes
that its value is a predicate function, and calls that function. If the result of the
function call is non-nil, the session is killed, otherwise Emacs continues to run.
One convenient function to use as the value of confirm-kill-emacs is the function
yes-or-no-p. The default value of confirm-kill-emacs is nil.
To kill Emacs without being prompted about saving, type M-x kill-emacs.
C-z runs the command suspend-frame. On a graphical display, this command
minimizes (or iconifies) the selected Emacs frame, hiding it in a way that lets you
bring it back later (exactly how this hiding occurs depends on the window system).
On a text terminal, the C-z command suspends Emacs, stopping the program
temporarily and returning control to the parent process (usually a shell); in most
shells, you can resume Emacs after suspending it with the shell command %emacs.
Text terminals usually listen for certain special characters whose meaning is to
kill or suspend the program you are running. This terminal feature is turned off
while you are in Emacs. The meanings of C-z and C-x C-c as keys in Emacs were
1

Setting inhibit-startup-screen in ‘site-start.el’ doesn’t work, because the
startup screen is set up before reading ‘site-start.el’. See Section 33.4 [Init File],
page 461, for information about ‘site-start.el’.

Chapter 3: Entering and Exiting Emacs

16

inspired by the use of C-z and C-c on several operating systems as the characters for
stopping or killing a program, but that is their only relationship with the operating
system. You can customize these keys to run any commands of your choice (see
Section 33.3.1 [Keymaps], page 452).

Chapter 4: Basic Editing Commands

17

4 Basic Editing Commands
Here we explain the basics of how to enter text, make corrections, and save the
text in a file. If this material is new to you, we suggest you first run the Emacs
learn-by-doing tutorial, by typing C-h t (help-with-tutorial).

4.1 Inserting Text
You can insert an ordinary graphic character (e.g., ‘a’, ‘B’, ‘3’, and ‘=’) by typing
the associated key. This adds the character to the buffer at point. Insertion moves
point forward, so that point remains just after the inserted text. See Section 1.1
[Point], page 6.
To end a line and start a new one, type RET (newline). (The RET key may be
labeled RETURN or ENTER on your keyboard, but we refer to it as RET in this
manual.) This command inserts a newline character into the buffer. If point is at
the end of the line, the effect is to create a new blank line after it; if point is in the
middle of a line, the line is split at that position.
As we explain later in this manual, you can change the way Emacs handles text
insertion by turning on minor modes. For instance, the minor mode called Auto Fill
mode splits lines automatically when they get too long (see Section 22.5 [Filling],
page 218). The minor mode called Overwrite mode causes inserted characters to
replace (overwrite) existing text, instead of shoving it to the right. See Section 20.2
[Minor Modes], page 205.
Only graphic characters can be inserted by typing the associated key; other keys
act as editing commands and do not insert themselves. For instance, DEL runs the
command delete-backward-char by default (some modes bind it to a different
command); it does not insert a literal ‘DEL’ character (ASCII character code 127).
To insert a non-graphic character, or a character that your keyboard does not
support, first quote it by typing C-q (quoted-insert). There are two ways to use
C-q:
• C-q followed by any non-graphic character (even C-g) inserts that character.
For instance, C-q DEL inserts a literal ‘DEL’ character.
• C-q followed by a sequence of octal digits inserts the character with the specified octal character code. You can use any number of octal digits; any non-digit
terminates the sequence. If the terminating character is RET, that RET serves
only to terminate the sequence. Any other non-digit terminates the sequence
and then acts as normal input—thus, C-q 1 0 1 B inserts ‘AB’.
The use of octal sequences is disabled in ordinary non-binary Overwrite mode,
to give you a convenient way to insert a digit instead of overwriting with it.
To use decimal or hexadecimal instead of octal, set the variable read-quoted-charradix to 10 or 16. If the radix is 16, the letters a to f serve as part of a character
code, just like digits. Case is ignored.
Instead of C-q, you can use the command C-x 8 RET (ucs-insert). This
prompts for the Unicode name or code-point of a character, using the minibuffer. If
you enter a name, the command provides completion (see Section 5.3 [Completion],

Chapter 4: Basic Editing Commands

18

page 29). If you enter a code-point, it should be a hexadecimal number (which is the
convention for Unicode). The command then inserts the corresponding character
into the buffer. For example, both of the following insert the infinity sign (Unicode
code-point U+221E):
C-x 8 RET infinity RET
C-x 8 RET 221e RET
A numeric argument to either C-q or C-x 8 RET specifies how many copies of
the character to insert (see Section 4.10 [Arguments], page 25).

4.2 Changing the Location of Point
To do more than insert characters, you have to know how to move point (see
Section 1.1 [Point], page 6). The keyboard commands C-f, C-b, C-n, and C-p
move point to the right, left, down, and up, respectively. You can also move point
using the arrow keys present on most keyboards: RIGHT, LEFT, DOWN, and UP;
however, many Emacs users find that it is slower to use the arrow keys than the
control keys, because you need to move your hand to the area of the keyboard where
those keys are located.
You can also click the left mouse button to move point to the position clicked.
Emacs also provides a variety of additional keyboard commands that move point in
more sophisticated ways.
C-f

Move forward one character (forward-char).

RIGHT

This command (right-char) behaves like C-f, with one exception:
when editing right-to-left scripts such as Arabic, it instead moves
backward if the current paragraph is a right-to-left paragraph. See
Section 19.20 [Bidirectional Editing], page 202.

C-b

Move backward one character (backward-char).

LEFT

This command (left-char) behaves like C-b, except it moves forward
if the current paragraph is right-to-left. See Section 19.20 [Bidirectional Editing], page 202.

C-n
DOWN

C-p
UP

Move down one screen line (next-line). This command attempts to
keep the horizontal position unchanged, so if you start in the middle
of one line, you move to the middle of the next.
Move up one screen line (previous-line). This command preserves
position within the line, like C-n.

C-a
HOME

Move to the beginning of the line (move-beginning-of-line).

C-e
END

Move to the end of the line (move-end-of-line).

M-f

Move forward one word (forward-word).

Chapter 4: Basic Editing Commands
C-RIGHT
M-RIGHT

M-b
C-LEFT
M-LEFT

M-r

19

This command (right-word) behaves like M-f, except it moves backward by one word if the current paragraph is right-to-left. See
Section 19.20 [Bidirectional Editing], page 202.
Move backward one word (backward-word).
This command (left-word) behaves like M-f, except it moves forward
by one word if the current paragraph is right-to-left. See Section 19.20
[Bidirectional Editing], page 202.
Without moving the text on the screen, reposition point on the left
margin of the center-most text line of the window; on subsequent
consecutive invocations, move point to the left margin of the top-most
line, the bottom-most line, and so forth, in cyclic order (move-towindow-line-top-bottom).
A numeric argument says which screen line to place point on, counting
downward from the top of the window (zero means the top line). A
negative argument counts lines up from the bottom (−1 means the
bottom line). See Section 4.10 [Arguments], page 25, for more information on numeric arguments.

M-<

Move to the top of the buffer (beginning-of-buffer). With numeric
argument n, move to n/10 of the way from the top.

M->

Move to the end of the buffer (end-of-buffer).

C-v
PAGEDOWN
NEXT
Scroll the display one screen forward, and move point onscreen if necessary (scroll-up-command). See Section 11.1 [Scrolling], page 70.
M-v
PAGEUP
PRIOR

Scroll one screen backward, and move point onscreen if necessary
(scroll-down-command). See Section 11.1 [Scrolling], page 70.

M-x goto-char
Read a number n and move point to buffer position n. Position 1 is
the beginning of the buffer.
M-g M-g
M-g g

Read a number n and move point to the beginning of line number n
(goto-line). Line 1 is the beginning of the buffer. If point is on or
just after a number in the buffer, that is the default for n. Just type
RET in the minibuffer to use it. You can also specify n by giving
M-g M-g a numeric prefix argument. See Section 16.1 [Select Buffer],
page 150, for the behavior of M-g M-g when you give it a plain prefix
argument.

Chapter 4: Basic Editing Commands
C-x C-n

20

Use the current column of point as the semipermanent goal column
for C-n and C-p (set-goal-column). When a semipermanent goal
column is in effect, those commands always try to move to this column,
or as close as possible to it, after moving vertically. The goal column
remains in effect until canceled.

C-u C-x C-n
Cancel the goal column. Henceforth, C-n and C-p try to preserve the
horizontal position, as usual.
When a line of text in the buffer is longer than the width of the window, Emacs
usually displays it on two or more screen lines. For convenience, C-n and C-p move
point by screen lines, as do the equivalent keys DOWN and UP. You can force these
commands to move according to logical lines (i.e., according to the text lines in the
buffer) by setting the variable line-move-visual to nil; if a logical line occupies
multiple screen lines, the cursor then skips over the additional screen lines. For
details, see Section 4.8 [Continuation Lines], page 23. See Section 33.2 [Variables],
page 443, for how to set variables such as line-move-visual.
Unlike C-n and C-p, most of the Emacs commands that work on lines work on
logical lines. For instance, C-a (move-beginning-of-line) and C-e (move-endof-line) respectively move to the beginning and end of the logical line. Whenever
we encounter commands that work on screen lines, such as C-n and C-p, we will
point these out.
When line-move-visual is nil, you can also set the variable track-eol to a
non-nil value. Then C-n and C-p, when starting at the end of the logical line, move
to the end of the next logical line. Normally, track-eol is nil.
C-n normally stops at the end of the buffer when you use it on the last line in
the buffer. However, if you set the variable next-line-add-newlines to a non-nil
value, C-n on the last line of a buffer creates an additional line at the end and moves
down into it.

4.3 Erasing Text
DEL
BACKSPACE
Delete the character before point, or the region if it is active (deletebackward-char).
DELETE

Delete the character after point, or the region if it is active (deleteforward-char).

C-d

Delete the character after point (delete-char).

C-k

Kill to the end of the line (kill-line).

M-d

Kill forward to the end of the next word (kill-word).

M-DEL

Kill back to the beginning of the previous word (backward-killword).

Chapter 4: Basic Editing Commands

21

The DEL (delete-backward-char) command removes the character before
point, moving the cursor and the characters after it backwards. If point was at
the beginning of a line, this deletes the preceding newline, joining this line to the
previous one.
If, however, the region is active, DEL instead deletes the text in the region. See
Chapter 8 [Mark], page 47, for a description of the region.
On most keyboards, DEL is labeled BACKSPACE, but we refer to it as DEL
in this manual. (Do not confuse DEL with the DELETE key; we will discuss
DELETE momentarily.) On some text terminals, Emacs may not recognize the
DEL key properly. See Section 34.2.1 [DEL Does Not Delete], page 470, if you
encounter this problem.
The DELETE (delete-forward-char) command deletes in the “opposite direction”: it deletes the character after point, i.e. the character under the cursor.
If point was at the end of a line, this joins the following line onto this one. Like
DEL, it deletes the text in the region if the region is active (see Chapter 8 [Mark],
page 47).
C-d (delete-char) deletes the character after point, similar to DELETE, but
regardless of whether the region is active.
See Section 9.1.1 [Deletion], page 54, for more detailed information about the
above deletion commands.
C-k (kill-line) erases (kills) a line at a time. If you type C-k at the beginning
or middle of a line, it kills all the text up to the end of the line. If you type C-k at
the end of a line, it joins that line with the following line.
See Chapter 9 [Killing], page 54, for more information about C-k and related
commands.

4.4 Undoing Changes
C-/
C-x u
C-_

Undo one entry of the undo records—usually, one command worth
(undo).
The same.

Emacs records a list of changes made in the buffer text, so you can undo recent
changes. This is done using the undo command, which is bound to C-/ (as well
as C-x u and C-_). Normally, this command undoes the last change, moving point
back to where it was before the change. The undo command applies only to changes
in the buffer; you can’t use it to undo cursor motion.
Although each editing command usually makes a separate entry in the undo
records, very simple commands may be grouped together. Sometimes, an entry
may cover just part of a complex command.
If you repeat C-/ (or its aliases), each repetition undoes another, earlier change,
back to the limit of the undo information available. If all recorded changes have
already been undone, the undo command displays an error message and does nothing.

Chapter 4: Basic Editing Commands

22

To learn more about the undo command, see Section 13.1 [Undo], page 110.

4.5 Files
Text that you insert in an Emacs buffer lasts only as long as the Emacs session. To
keep any text permanently, you must put it in a file.
Suppose there is a file named ‘test.emacs’ in your home directory. To begin
editing this file in Emacs, type
C-x C-f test.emacs RET
Here the file name is given as an argument to the command C-x C-f (find-file).
That command uses the minibuffer to read the argument, and you type RET to
terminate the argument (see Chapter 5 [Minibuffer], page 27).
Emacs obeys this command by visiting the file: it creates a buffer, copies the
contents of the file into the buffer, and then displays the buffer for editing. If you
alter the text, you can save the new text in the file by typing C-x C-s (savebuffer). This copies the altered buffer contents back into the file ‘test.emacs’,
making them permanent. Until you save, the changed text exists only inside Emacs,
and the file ‘test.emacs’ is unaltered.
To create a file, just visit it with C-x C-f as if it already existed. This creates
an empty buffer, in which you can insert the text you want to put in the file. Emacs
actually creates the file the first time you save this buffer with C-x C-s.
To learn more about using files in Emacs, see Chapter 15 [Files], page 124.

4.6 Help
If you forget what a key does, you can find out by typing C-h k (describe-key),
followed by the key of interest; for example, C-h k C-n tells you what C-n does.
The prefix key C-h stands for “help”. The key F1 serves as an alias for C-h.
Apart from C-h k, there are many other help commands providing different kinds
of help.
See Chapter 7 [Help], page 38, for details.

4.7 Blank Lines
Here are special commands and techniques for inserting and deleting blank lines.
C-o

Insert a blank line after the cursor (open-line).

C-x C-o

Delete all but one of many consecutive blank lines (delete-blanklines).

We have seen how RET (newline) starts a new line of text. However, it may be
easier to see what you are doing if you first make a blank line and then insert the
desired text into it. This is easy to do using the key C-o (open-line), which inserts
a newline after point but leaves point in front of the newline. After C-o, type the
text for the new line.
You can make several blank lines by typing C-o several times, or by giving it
a numeric argument specifying how many blank lines to make. See Section 4.10

Chapter 4: Basic Editing Commands

23

[Arguments], page 25, for how. If you have a fill prefix, the C-o command inserts
the fill prefix on the new line, if typed at the beginning of a line. See Section 22.5.3
[Fill Prefix], page 220.
The easy way to get rid of extra blank lines is with the command C-x C-o
(delete-blank-lines). If point lies within a run of several blank lines, C-x C-o
deletes all but one of them. If point is on a single blank line, C-x C-o deletes it. If
point is on a nonblank line, C-x C-o deletes all following blank lines, if any exists.

4.8 Continuation Lines
Sometimes, a line of text in the buffer—a logical line—is too long to fit in the
window, and Emacs displays it as two or more screen lines. This is called line
wrapping or continuation, and the long logical line is called a continued line. On a
graphical display, Emacs indicates line wrapping with small bent arrows in the left
and right window fringes. On a text terminal, Emacs indicates line wrapping by
displaying a ‘\’ character at the right margin.
Most commands that act on lines act on logical lines, not screen lines. For
instance, C-k kills a logical line. As described earlier, C-n (next-line) and C-p
(previous-line) are special exceptions: they move point down and up, respectively, by one screen line (see Section 4.2 [Moving Point], page 18).
Emacs can optionally truncate long logical lines instead of continuing them.
This means that every logical line occupies a single screen line; if it is longer than
the width of the window, the rest of the line is not displayed. On a graphical display,
a truncated line is indicated by a small straight arrow in the right fringe; on a text
terminal, it is indicated by a ‘$’ character in the right margin. See Section 11.21
[Line Truncation], page 89.
By default, continued lines are wrapped at the right window edge. Since the
wrapping may occur in the middle of a word, continued lines can be difficult to
read. The usual solution is to break your lines before they get too long, by inserting
newlines. If you prefer, you can make Emacs insert a newline automatically when
a line gets too long, by using Auto Fill mode. See Section 22.5 [Filling], page 218.
Sometimes, you may need to edit files containing many long logical lines, and it
may not be practical to break them all up by adding newlines. In that case, you
can use Visual Line mode, which enables word wrapping: instead of wrapping long
lines exactly at the right window edge, Emacs wraps them at the word boundaries
(i.e., space or tab characters) nearest to the right window edge. Visual Line mode
also redefines editing commands such as C-a, C-n, and C-k to operate on screen
lines rather than logical lines. See Section 11.22 [Visual Line Mode], page 89.

4.9 Cursor Position Information
Here are commands to get information about the size and position of parts of the
buffer, and to count words and lines.
M-x what-line
Display the line number of point.

Chapter 4: Basic Editing Commands

24

M-x line-number-mode
M-x column-number-mode
Toggle automatic display of the current line number or column number. See Section 11.18 [Optional Mode Line], page 85.
Display the number of lines, words, and characters that are present
in the region (count-words-region). See Chapter 8 [Mark], page 47,
for information about the region.

M-=

M-x count-words
Display the number of lines, words, and characters that are present
in the buffer. If the region is active (see Chapter 8 [Mark], page 47),
display the numbers for the region instead.
C-x =

Display the character code of character after point, character position
of point, and column of point (what-cursor-position).

M-x hl-line-mode
Enable or disable highlighting of the current line. See Section 11.20
[Cursor Display], page 88.
M-x size-indication-mode
Toggle automatic display of the size of the buffer. See Section 11.18
[Optional Mode Line], page 85.
M-x what-line displays the current line number in the echo area. This command
is usually redundant, because the current line number is shown in the mode line
(see Section 1.3 [Mode Line], page 8). However, if you narrow the buffer, the mode
line shows the line number relative to the accessible portion (see Section 11.5 [Narrowing], page 74). By contrast, what-line displays both the line number relative
to the narrowed region and the line number relative to the whole buffer.
M-= (count-words-region) displays a message reporting the number of lines,
words, and characters in the region. M-x count-words displays a similar message
for the entire buffer, or for the region if the region is active. See Chapter 8 [Mark],
page 47, for an explanation of the region.
The command C-x = (what-cursor-position) shows information about the
current cursor position and the buffer contents at that position. It displays a line
in the echo area that looks like this:
Char: c (99, #o143, #x63) point=28062 of 36168 (78%) column=53

After ‘Char:’, this shows the character in the buffer at point. The text inside
the parenthesis shows the corresponding decimal, octal and hex character codes; for
more information about how C-x = displays character information, see Section 19.1
[International Chars], page 180. After ‘point=’ is the position of point as a character
count (the first character in the buffer is position 1, the second character is position
2, and so on). The number after that is the total number of characters in the buffer,
and the number in parenthesis expresses the position as a percentage of the total.
After ‘column=’ is the horizontal position of point, in columns counting from the
left edge of the window.

Chapter 4: Basic Editing Commands

25

If the buffer has been narrowed, making some of the text at the beginning
and the end temporarily inaccessible, C-x = displays additional text describing the
currently accessible range. For example, it might display this:
Char: C (67, #o103, #x43) point=252 of 889 (28%) <231-599> column=0

where the two extra numbers give the smallest and largest character position that
point is allowed to assume. The characters between those two positions are the
accessible ones. See Section 11.5 [Narrowing], page 74.

4.10 Numeric Arguments
In the terminology of mathematics and computing, argument means “data provided
to a function or operation”. You can give any Emacs command a numeric argument
(also called a prefix argument). Some commands interpret the argument as a repetition count. For example, giving C-f an argument of ten causes it to move point
forward by ten characters instead of one. With these commands, no argument is
equivalent to an argument of one, and negative arguments cause them to move or
act in the opposite direction.
The easiest way to specify a numeric argument is to type a digit and/or a minus
sign while holding down the META key. For example,
M-5 C-n
moves down five lines. The keys M-1, M-2, and so on, as well as M--, are bound
to commands (digit-argument and negative-argument) that set up an argument
for the next command. Meta-- without digits normally means −1.
If you enter more than one digit, you need not hold down the META key for the
second and subsequent digits. Thus, to move down fifty lines, type
M-5 0 C-n
Note that this does not insert five copies of ‘0’ and move down one line, as you
might expect—the ‘0’ is treated as part of the prefix argument.
(What if you do want to insert five copies of ‘0’? Type M-5 C-u 0. Here, C-u
“terminates” the prefix argument, so that the next keystroke begins the command
that you want to execute. Note that this meaning of C-u applies only to this case.
For the usual role of C-u, see below.)
Instead of typing M-1, M-2, and so on, another way to specify a numeric argument
is to type C-u (universal-argument) followed by some digits, or (for a negative
argument) a minus sign followed by digits. A minus sign without digits normally
means −1.
C-u alone has the special meaning of “four times”: it multiplies the argument
for the next command by four. C-u C-u multiplies it by sixteen. Thus, C-u C-u C-f
moves forward sixteen characters. Other useful combinations are C-u C-n, C-u C-u
C-n (move down a good fraction of a screen), C-u C-u C-o (make “a lot” of blank
lines), and C-u C-k (kill four lines).
You can use a numeric argument before a self-inserting character to insert multiple copies of it. This is straightforward when the character is not a digit; for
example, C-u 6 4 a inserts 64 copies of the character ‘a’. But this does not work
for inserting digits; C-u 6 4 1 specifies an argument of 641. You can separate the

Chapter 4: Basic Editing Commands

26

argument from the digit to insert with another C-u; for example, C-u 6 4 C-u 1
does insert 64 copies of the character ‘1’.
Some commands care whether there is an argument, but ignore its value. For
example, the command M-q (fill-paragraph) fills text; with an argument, it justifies the text as well. (See Section 22.5 [Filling], page 218, for more information on
M-q.) For these commands, it is enough to the argument with a single C-u.
Some commands use the value of the argument as a repeat count, but do something special when there is no argument. For example, the command C-k (killline) with argument n kills n lines, including their terminating newlines. But C-k
with no argument is special: it kills the text up to the next newline, or, if point
is right at the end of the line, it kills the newline itself. Thus, two C-k commands
with no arguments can kill a nonblank line, just like C-k with an argument of one.
(See Chapter 9 [Killing], page 54, for more information on C-k.)
A few commands treat a plain C-u differently from an ordinary argument. A few
others may treat an argument of just a minus sign differently from an argument of
−1. These unusual cases are described when they come up; they exist to make an
individual command more convenient, and they are documented in that command’s
documentation string.
We use the term “prefix argument” as well as “numeric argument”, to emphasize
that you type these argument before the command, and to distinguish them from
minibuffer arguments that come after the command.

4.11 Repeating a Command
Many simple commands, such as those invoked with a single key or with M-x
command-name RET, can be repeated by invoking them with a numeric argument
that serves as a repeat count (see Section 4.10 [Arguments], page 25). However, if
the command you want to repeat prompts for input, or uses a numeric argument
in another way, that method won’t work.
The command C-x z (repeat) provides another way to repeat an Emacs command many times. This command repeats the previous Emacs command, whatever
that was. Repeating a command uses the same arguments that were used before;
it does not read new arguments each time.
To repeat the command more than once, type additional z’s: each z repeats the
command one more time. Repetition ends when you type a character other than z,
or press a mouse button.
For example, suppose you type C-u 2 0 C-d to delete 20 characters. You can
repeat that command (including its argument) three additional times, to delete a
total of 80 characters, by typing C-x z z z. The first C-x z repeats the command
once, and each subsequent z repeats it once again.

Chapter 5: The Minibuffer

27

5 The Minibuffer
The minibuffer is where Emacs commands read complicated arguments, such as file
names, buffer names, Emacs command names, or Lisp expressions. We call it the
“minibuffer” because it’s a special-purpose buffer with a small amount of screen
space. You can use the usual Emacs editing commands in the minibuffer to edit
the argument text.
When the minibuffer is in use, it appears in the echo area, with a cursor. The
minibuffer starts with a prompt in a distinct color, usually ending with a colon.
The prompt states what kind of input is expected, and how it will be used.
The simplest way to enter a minibuffer argument is to type the text, then RET
to submit the argument and exit the minibuffer. You can cancel the minibuffer,
and the command that wants the argument, by typing C-g.
Sometimes, a default argument appears in the prompt, inside parentheses before
the colon. This default will be used as the argument if you just type RET. For
example, commands that read buffer names usually show a buffer name as the
default; you can type RET to operate on that default buffer.
Since the minibuffer appears in the echo area, it can conflict with other uses of
the echo area. If an error message or an informative message is emitted while the
minibuffer is active, the message hides the minibuffer for a few seconds, or until you
type something; then the minibuffer comes back. While the minibuffer is in use,
keystrokes do not echo.

5.1 Minibuffers for File Names
Commands such as C-x C-f (find-file) use the minibuffer to read a file name
argument (see Section 4.5 [Basic Files], page 22). When the minibuffer is used to
read a file name, it typically starts out with some initial text ending in a slash. This
is the default directory. For example, it may start out like this:
Find file: /u2/emacs/src/
Here, ‘Find file: ’ is the prompt and ‘/u2/emacs/src/’ is the default directory. If
you now type buffer.c as input, that specifies the file ‘/u2/emacs/src/buffer.c’.
See Section 15.1 [File Names], page 124, for information about the default directory.
You can specify the parent directory with ‘..’: ‘/a/b/../foo.el’ is equivalent
to ‘/a/foo.el’. Alternatively, you can use M-DEL to kill directory names backwards
(see Section 22.1 [Words], page 214).
To specify a file in a completely different directory, you can kill the entire default
with C-a C-k (see Section 5.2 [Minibuffer Edit], page 28). Alternatively, you can
ignore the default, and enter an absolute file name starting with a slash or a tilde
after the default directory. For example, you can specify ‘/etc/termcap’ as follows:
Find file: /u2/emacs/src//etc/termcap
Emacs interprets a double slash as “ignore everything before the second slash in
the pair”. In the example above, ‘/u2/emacs/src/’ is ignored, so the argument
you supplied is ‘/etc/termcap’. The ignored part of the file name is dimmed if the

Chapter 5: The Minibuffer

28

terminal allows it. (To disable this dimming, turn off File Name Shadow mode with
the command M-x file-name-shadow-mode.)
Emacs interprets ‘~/’ as your home directory. Thus, ‘~/foo/bar.txt’ specifies
a file named ‘bar.txt’, inside a directory named ‘foo’, which is in turn located
in your home directory. In addition, ‘~user-id /’ means the home directory of a
user whose login name is user-id. Any leading directory name in front of the ‘~’ is
ignored: thus, ‘/u2/emacs/~/foo/bar.txt’ is equivalent to ‘~/foo/bar.txt’.
On MS-Windows and MS-DOS systems, where a user doesn’t always have a
home directory, Emacs uses several alternatives. For MS-Windows, see Section G.5
[Windows HOME], page 538; for MS-DOS, see Section “MS-DOS File Names” in the
digital version of the Emacs Manual. On these systems, the ‘~user-id /’ construct
is supported only for the current user, i.e., only if user-id is the current user’s login
name.
To prevent Emacs from inserting the default directory when reading file names,
change the variable insert-default-directory to nil. In that case, the minibuffer starts out empty. Nonetheless, relative file name arguments are still interpreted
based on the same default directory.
You can also enter remote file names in the minibuffer. See Section 15.13 [Remote Files], page 145.

5.2 Editing in the Minibuffer
The minibuffer is an Emacs buffer, albeit a peculiar one, and the usual Emacs
commands are available for editing the argument text. (The prompt, however, is
read-only, and cannot be changed.)
Since RET in the minibuffer submits the argument, you can’t use it to insert
a newline. You can do that with C-q C-j, which inserts a C-j control character,
which is formally equivalent to a newline character (see Section 4.1 [Inserting Text],
page 17). Alternatively, you can use the C-o (open-line) command (see Section 4.7
[Blank Lines], page 22).
Inside a minibuffer, the keys TAB, SPC, and ? are often bound to completion
commands, which allow you to easily fill in the desired text without typing all of
it. See Section 5.3 [Completion], page 29. As with RET, you can use C-q to insert
a TAB, SPC, or ‘?’ character.
For convenience, C-a (move-beginning-of-line) in a minibuffer moves point to
the beginning of the argument text, not the beginning of the prompt. For example,
this allows you to erase the entire argument with C-a C-k.
When the minibuffer is active, the echo area is treated much like an ordinary
Emacs window. For instance, you can switch to another window (with C-x o), edit
text there, then return to the minibuffer window to finish the argument. You can
even kill text in another window, return to the minibuffer window, and yank the
text into the argument. There are some restrictions on the minibuffer window,
however: for instance, you cannot split it. See Chapter 17 [Windows], page 159.
Normally, the minibuffer window occupies a single screen line. However, if you
add two or more lines’ worth of text into the minibuffer, it expands automatically

Chapter 5: The Minibuffer

29

to accommodate the text. The variable resize-mini-windows controls the resizing of the minibuffer. The default value is grow-only, which means the behavior
we have just described. If the value is t, the minibuffer window will also shrink
automatically if you remove some lines of text from the minibuffer, down to a minimum of one screen line. If the value is nil, the minibuffer window never changes
size automatically, but you can use the usual window-resizing commands on it (see
Chapter 17 [Windows], page 159).
The variable max-mini-window-height controls the maximum height for resizing the minibuffer window. A floating-point number specifies a fraction of the
frame’s height; an integer specifies the maximum number of lines; nil means do
not resize the minibuffer window automatically. The default value is 0.25.
The C-M-v command in the minibuffer scrolls the help text from commands that
display help text of any sort in another window. You can also scroll the help text
with M-PRIOR and M-NEXT (or, equivalently, M-PAGEUP and M-PAGEDOWN). This is
especially useful with long lists of possible completions. See Section 17.3 [Other
Window], page 160.
Emacs normally disallows most commands that use the minibuffer while the
minibuffer is active. To allow such commands in the minibuffer, set the variable
enable-recursive-minibuffers to t.
When not active, the minibuffer is in minibuffer-inactive-mode, and clicking
Mouse-1 there shows the ‘*Messages*’ buffer. If you use a dedicated frame for
minibuffers, Emacs also recognizes certain keys there, for example n to make a new
frame.

5.3 Completion
You can often use a feature called completion to help enter arguments. This means
that after you type part of the argument, Emacs can fill in the rest, or some of it,
based on what was typed so far.
When completion is available, certain keys (usually TAB, RET, and SPC) are
rebound in the minibuffer to special completion commands (see Section 5.3.2 [Completion Commands], page 30). These commands attempt to complete the text in
the minibuffer, based on a set of completion alternatives provided by the command
that requested the argument. You can usually type ? to see a list of completion
alternatives.
Although completion is usually done in the minibuffer, the feature is sometimes
available in ordinary buffers too. See Section 23.8 [Symbol Completion], page 264.
5.3.1 Completion Example
A simple example may help here. M-x uses the minibuffer to read the name of a
command, so completion works by matching the minibuffer text against the names
of existing Emacs commands. Suppose you wish to run the command auto-fillmode. You can do that by typing M-x auto-fill-mode RET, but it is easier to use
completion.

Chapter 5: The Minibuffer

30

If you type M-x a u TAB, the TAB looks for completion alternatives (in this
case, command names) that start with ‘au’. There are several, including autofill-mode and autoconf-mode, but they all begin with auto, so the ‘au’ in the
minibuffer completes to ‘auto’. (More commands may be defined in your Emacs
session. For example, if a command called authorize-me was defined, Emacs could
only complete as far as ‘aut’.)
If you type TAB again immediately, it cannot determine the next character; it
could be ‘-’, ‘a’, or ‘c’. So it does not add any characters; instead, TAB displays a
list of all possible completions in another window.
Next, type -f. The minibuffer now contains ‘auto-f’, and the only command
name that starts with this is auto-fill-mode. If you now type TAB, completion
fills in the rest of the argument ‘auto-fill-mode’ into the minibuffer.
Hence, typing just a u TAB - f TAB allows you to enter ‘auto-fill-mode’.
5.3.2 Completion Commands
Here is a list of the completion commands defined in the minibuffer when completion
is allowed.
TAB

Complete the text in the minibuffer as much as possible; if unable to complete, display a list of possible completions (minibuffercomplete).

SPC

Complete up to one word from the minibuffer text before point
(minibuffer-complete-word). This command is not available for
arguments that often include spaces, such as file names.

RET

Submit the text in the minibuffer as the argument, possibly completing
first (minibuffer-complete-and-exit). See Section 5.3.3 [Completion Exit], page 31.

?

Display a list of completions (minibuffer-completion-help).

TAB (minibuffer-complete) is the most fundamental completion command.
It searches for all possible completions that match the existing minibuffer text, and
attempts to complete as much as it can. See Section 5.3.4 [Completion Styles],
page 32, for how completion alternatives are chosen.
SPC (minibuffer-complete-word) completes like TAB, but only up to the next
hyphen or space. If you have ‘auto-f’ in the minibuffer and type SPC, it finds that
the completion is ‘auto-fill-mode’, but it only inserts ‘ill-’, giving ‘auto-fill-’.
Another SPC at this point completes all the way to ‘auto-fill-mode’.
If TAB or SPC is unable to complete, it displays a list of matching completion
alternatives (if there are any) in another window. You can display the same list with
? (minibuffer-completion-help). The following commands can be used with the
completion list:
Mouse-1
Mouse-2

Clicking mouse button 1 or 2 on a completion alternative chooses it
(mouse-choose-completion).

Chapter 5: The Minibuffer
M-v
PAGEUP
PRIOR

31

Typing M-v, while in the minibuffer, selects the window showing the
completion list (switch-to-completions). This paves the way for
using the commands below. PAGEUP or PRIOR does the same. You
can also select the window in other ways (see Chapter 17 [Windows],
page 159).

RET

While in the completion list buffer, this chooses the completion at
point (choose-completion).

RIGHT

While in the completion list buffer, this moves point to the following
completion alternative (next-completion).

LEFT

While in the completion list buffer, this moves point to the previous
completion alternative (previous-completion).

5.3.3 Completion Exit
When a command reads an argument using the minibuffer with completion, it also
controls what happens when you type RET (minibuffer-complete-and-exit) to
submit the argument. There are four types of behavior:
• Strict completion accepts only exact completion matches. Typing RET exits
the minibuffer only if the minibuffer text is an exact match, or completes to one.
Otherwise, Emacs refuses to exit the minibuffer; instead it tries to complete,
and if no completion can be done it momentarily displays ‘[No match]’ after
the minibuffer text. (You can still leave the minibuffer by typing C-g to cancel
the command.)
An example of a command that uses this behavior is M-x, since it is meaningless
for it to accept a non-existent command name.
• Cautious completion is like strict completion, except RET exits only if the
text is already an exact match. If the text completes to an exact match, RET
performs that completion but does not exit yet; you must type a second RET
to exit.
Cautious completion is used for reading file names for files that must already
exist, for example.
• Permissive completion allows any input; the completion candidates are just
suggestions. Typing RET does not complete, it just submits the argument as
you have entered it.
• Permissive completion with confirmation is like permissive completion, with
an exception: if you typed TAB and this completed the text up to some intermediate state (i.e., one that is not yet an exact completion match), typing
RET right afterward does not submit the argument. Instead, Emacs asks for
confirmation by momentarily displaying ‘[Confirm]’ after the text; type RET
again to confirm and submit the text. This catches a common mistake, in
which one types RET before realizing that TAB did not complete as far as
desired.

Chapter 5: The Minibuffer

32

You can tweak the confirmation behavior by customizing the variable confirmnonexistent-file-or-buffer. The default value, after-completion, gives
the behavior we have just described. If you change it to nil, Emacs does not
ask for confirmation, falling back on permissive completion. If you change it
to any other non-nil value, Emacs asks for confirmation whether or not the
preceding command was TAB.
This behavior is used by most commands that read file names, like C-x C-f,
and commands that read buffer names, like C-x b.
5.3.4 How Completion Alternatives Are Chosen
Completion commands work by narrowing a large list of possible completion alternatives to a smaller subset that “matches” what you have typed in the minibuffer.
In Section 5.3.1 [Completion Example], page 29, we gave a simple example of such
matching. The procedure of determining what constitutes a “match” is quite intricate. Emacs attempts to offer plausible completions under most circumstances.
Emacs performs completion using one or more completion styles—sets of criteria
for matching minibuffer text to completion alternatives. During completion, Emacs
tries each completion style in turn. If a style yields one or more matches, that is
used as the list of completion alternatives. If a style produces no matches, Emacs
falls back on the next style.
The list variable completion-styles specifies the completion styles to use. Each
list element is the name of a completion style (a Lisp symbol). The default completion styles are (in order):
basic

A matching completion alternative must have the same beginning as
the text in the minibuffer before point. Furthermore, if there is any
text in the minibuffer after point, the rest of the completion alternative
must contain that text as a substring.

partial-completion
This aggressive completion style divides the minibuffer text into words
separated by hyphens or spaces, and completes each word separately.
(For example, when completing command names, ‘em-l-m’ completes
to ‘emacs-lisp-mode’.)
Furthermore, a ‘*’ in the minibuffer text is treated as a wildcard—it
matches any character at the corresponding position in the completion
alternative.
emacs22

This completion style is similar to basic, except that it ignores the text
in the minibuffer after point. It is so-named because it corresponds to
the completion behavior in Emacs 22.

The following additional completion styles are also defined, and you can add them
to completion-styles if you wish (see Chapter 33 [Customization], page 434):
substring

A matching completion alternative must contain the text in the minibuffer before point, and the text in the minibuffer after point, as substrings (in that same order).

Chapter 5: The Minibuffer

33

Thus, if the text in the minibuffer is ‘foobar’, with point between
‘foo’ and ‘bar’, that matches ‘a foob barc ’, where a, b, and c can be
any string including the empty string.
initials

This very aggressive completion style attempts to complete acronyms
and initialisms. For example, when completing command names, it
matches ‘lch’ to ‘list-command-history’.

There is also a very simple completion style called emacs21. In this style, if the text
in the minibuffer is ‘foobar’, only matches starting with ‘foobar’ are considered.
You can use different completion styles in different situations, by setting the
variable completion-category-overrides. For example, the default setting says
to use only basic and substring completion for buffer names.
5.3.5 Completion Options
Case is significant when completing case-sensitive arguments, such as command
names. For example, when completing command names, ‘AU’ does not complete
to ‘auto-fill-mode’. Case differences are ignored when completing arguments in
which case does not matter.
When completing file names, case differences are ignored if the variable readfile-name-completion-ignore-case is non-nil. The default value is nil on systems that have case-sensitive file-names, such as GNU/Linux; it is non-nil on
systems that have case-insensitive file-names, such as Microsoft Windows. When
completing buffer names, case differences are ignored if the variable read-buffercompletion-ignore-case is non-nil; the default is nil.
When completing file names, Emacs usually omits certain alternatives that are
considered unlikely to be chosen, as determined by the list variable completionignored-extensions. Each element in the list should be a string; any file name
ending in such a string is ignored as a completion alternative. Any element ending
in a slash (‘/’) represents a subdirectory name. The standard value of completionignored-extensions has several elements including ".o", ".elc", and "~". For
example, if a directory contains ‘foo.c’ and ‘foo.elc’, ‘foo’ completes to ‘foo.c’.
However, if all possible completions end in “ignored” strings, they are not ignored: in the previous example, ‘foo.e’ completes to ‘foo.elc’. Emacs disregards completion-ignored-extensions when showing completion alternatives in
the completion list.
If completion-auto-help is set to nil, the completion commands never display
the completion list buffer; you must type ? to display the list. If the value is lazy,
Emacs only shows the completion list buffer on the second attempt to complete. In
other words, if there is nothing to complete, the first TAB echoes ‘Next char not
unique’; the second TAB shows the completion list buffer.
If completion-cycle-threshold is non-nil, completion commands can “cycle”
through completion alternatives. Normally, if there is more than one completion
alternative for the text in the minibuffer, a completion command completes up
to the longest common substring. If you change completion-cycle-threshold
to t, the completion command instead completes to the first of those completion

Chapter 5: The Minibuffer

34

alternatives; each subsequent invocation of the completion command replaces that
with the next completion alternative, in a cyclic manner. If you give completioncycle-threshold a numeric value n, completion commands switch to this cycling
behavior only when there are fewer than n alternatives.
Icomplete mode presents a constantly-updated display that tells you what completions are available for the text you’ve entered so far. The command to enable or
disable this minor mode is M-x icomplete-mode.

5.4 Minibuffer History
Every argument that you enter with the minibuffer is saved in a minibuffer history
list so you can easily use it again later. You can use the following arguments to
quickly fetch an earlier argument into the minibuffer:
M-p
UP
M-n
DOWN

Move to the previous item in the minibuffer history, an earlier argument (previous-history-element).
Move to the next item in the minibuffer history (next-historyelement).

M-r regexp RET
Move to an earlier item in the minibuffer history that matches regexp
(previous-matching-history-element).
M-s regexp RET
Move to a later item in the minibuffer history that matches regexp
(next-matching-history-element).
While in the minibuffer, M-p or UP (previous-history-element) moves
through the minibuffer history list, one item at a time. Each M-p fetches an earlier
item from the history list into the minibuffer, replacing its existing contents. Typing M-n or DOWN (next-history-element) moves through the minibuffer history
list in the opposite direction, fetching later entries into the minibuffer.
If you type M-n in the minibuffer when there are no later entries in the minibuffer
history (e.g., if you haven’t previously typed M-p), Emacs tries fetching from a list
of default arguments: values that you are likely to enter. You can think of this as
moving through the “future history” list.
If you edit the text inserted by the M-p or M-N minibuffer history commands,
this does not change its entry in the history list. However, the edited argument
does go at the end of the history list when you submit it.
You can use M-r (previous-matching-history-element) to search through
older elements in the history list, and M-s (next-matching-history-element) to
search through newer entries. Each of these commands asks for a regular expression as an argument, and fetches the first matching entry into the minibuffer. See
Section 12.5 [Regexps], page 97, for an explanation of regular expressions. A numeric prefix argument n means to fetch the nth matching entry. These commands

Chapter 5: The Minibuffer

35

are unusual, in that they use the minibuffer to read the regular expression argument, even though they are invoked from the minibuffer. An upper-case letter in the
regular expression makes the search case-sensitive (see Section 12.8 [Search Case],
page 103).
You can also search through the history using an incremental search. See
Section 12.1.7 [Isearch Minibuffer], page 95.
Emacs keeps separate history lists for several different kinds of arguments. For
example, there is a list for file names, used by all the commands that read file
names. Other history lists include buffer names, command names (used by M-x),
and command arguments (used by commands like query-replace).
The variable history-length specifies the maximum length of a minibuffer
history list; adding a new element deletes the oldest element if the list gets too
long. If the value is t, there is no maximum length.
The variable history-delete-duplicates specifies whether to delete duplicates in history. If it is non-nil, adding a new element deletes from the list all
other elements that are equal to it. The default is nil.

5.5 Repeating Minibuffer Commands
Every command that uses the minibuffer once is recorded on a special history list,
the command history, together with the values of its arguments, so that you can
repeat the entire command. In particular, every use of M-x is recorded there, since
M-x uses the minibuffer to read the command name.
C-x ESC ESC
Re-execute a recent minibuffer command from the command history
(repeat-complex-command).
M-x list-command-history
Display the entire command history, showing all the commands C-x
ESC ESC can repeat, most recent first.
C-x ESC ESC re-executes a recent command that used the minibuffer. With no
argument, it repeats the last such command. A numeric argument specifies which
command to repeat; 1 means the last one, 2 the previous, and so on.
C-x ESC ESC works by turning the previous command into a Lisp expression
and then entering a minibuffer initialized with the text for that expression. Even
if you don’t know Lisp, it will probably be obvious which command is displayed
for repetition. If you type just RET, that repeats the command unchanged. You
can also change the command by editing the Lisp expression before you execute it.
The repeated command is added to the front of the command history unless it is
identical to the most recent item.
Once inside the minibuffer for C-x ESC ESC, you can use the usual minibuffer
history commands (see Section 5.4 [Minibuffer History], page 34) to move through
the history list. After finding the desired previous command, you can edit its
expression as usual and then repeat it by typing RET.
Incremental search does not, strictly speaking, use the minibuffer. Therefore,
although it behaves like a complex command, it normally does not appear in the

Chapter 5: The Minibuffer

36

history list for C-x ESC ESC. You can make incremental search commands appear in
the history by setting isearch-resume-in-command-history to a non-nil value.
See Section 12.1 [Incremental Search], page 91.
The list of previous minibuffer-using commands is stored as a Lisp list in the
variable command-history. Each element is a Lisp expression that describes one
command and its arguments. Lisp programs can re-execute a command by calling
eval with the command-history element.

5.6 Entering passwords
Sometimes, you may need to enter a password into Emacs. For instance, when you
tell Emacs to visit a file on another machine via a network protocol such as FTP,
you often need to supply a password to gain access to the machine (see Section 15.13
[Remote Files], page 145).
Entering a password is similar to using a minibuffer. Emacs displays a prompt
in the echo area (such as ‘Password: ’); after you type the required password, press
RET to submit it. To prevent others from seeing your password, every character
you type is displayed as a dot (‘.’) instead of its usual form.
Most of the features and commands associated with the minibuffer can not be
used when entering a password. There is no history or completion, and you cannot
change windows or perform any other action with Emacs until you have submitted
the password.
While you are typing the password, you may press DEL to delete backwards,
removing the last character entered. C-U deletes everything you have typed so far.
C-g quits the password prompt (see Section 34.1 [Quitting], page 468). C-y inserts
the current kill into the password (see Chapter 9 [Killing], page 54). You may type
either RET or ESC to submit the password. Any other self-inserting character key
inserts the associated character into the password, and all other input is ignored.

Chapter 6: Running Commands by Name

37

6 Running Commands by Name
Every Emacs command has a name that you can use to run it. For convenience,
many commands also have key bindings. You can run those commands by typing
the keys, or run them by name. Most Emacs commands have no key bindings, so
the only way to run them is by name. (See Section 33.3 [Key Bindings], page 452,
for how to set up key bindings.)
By convention, a command name consists of one or more words, separated by
hyphens; for example, auto-fill-mode or manual-entry. Command names mostly
use complete English words to make them easier to remember.
To run a command by name, start with M-x, type the command name, then
terminate it with RET. M-x uses the minibuffer to read the command name. The
string ‘M-x’ appears at the beginning of the minibuffer as a prompt to remind you to
enter a command name to be run. RET exits the minibuffer and runs the command.
See Chapter 5 [Minibuffer], page 27, for more information on the minibuffer.
You can use completion to enter the command name. For example, to invoke
the command forward-char, you can type
M-x forward-char RET
or
M-x forw TAB c RET
Note that forward-char is the same command that you invoke with the key C-f.
The existence of a key binding does not stop you from running the command by
name.
To cancel the M-x and not run a command, type C-g instead of entering the
command name. This takes you back to command level.
To pass a numeric argument to the command you are invoking with M-x, specify
the numeric argument before M-x. The argument value appears in the prompt
while the command name is being read, and finally M-x passes the argument to
that command.
When the command you run with M-x has a key binding, Emacs mentions
this in the echo area after running the command. For example, if you type M-x
forward-word, the message says that you can run the same command by typing
M-f. You can turn off these messages by setting the variable suggest-key-bindings
to nil.
In this manual, when we speak of running a command by name, we often omit
the RET that terminates the name. Thus we might say M-x auto-fill-mode rather
than M-x auto-fill-mode RET. We mention the RET only for emphasis, such as
when the command is followed by arguments.
M-x works by running the command execute-extended-command, which is responsible for reading the name of another command and invoking it.

Chapter 7: Help

38

7 Help
Emacs provides a wide variety of help commands, all accessible through the prefix
key C-h (or, equivalently, the function key F1). These help commands are described
in the following sections. You can also type C-h C-h to view a list of help commands
(help-for-help). You can scroll the list with SPC and DEL, then type the help
command you want. To cancel, type C-g.
Many help commands display their information in a special help buffer. In this
buffer, you can type SPC and DEL to scroll and type RET to follow hyperlinks.
See Section 7.4 [Help Mode], page 43.
If you are looking for a certain feature, but don’t know what it is called or where
to look, we recommend three methods. First, try an apropos command, then try
searching the manual index, then look in the FAQ and the package keywords.
C-h a topics RET
This searches for commands whose names match the argument topics.
The argument can be a keyword, a list of keywords, or a regular expression (see Section 12.5 [Regexps], page 97). See Section 7.3 [Apropos],
page 41.
C-h i d m emacs RET i topic RET
This searches for topic in the indices of the Emacs Info manual, displaying the first match found. Press , to see subsequent matches. You
can use a regular expression as topic.
C-h i d m emacs RET s topic RET
Similar, but searches the text of the manual rather than the indices.
C-h C-f

This displays the Emacs FAQ, using Info.

C-h p

This displays the available Emacs packages based on keywords. See
Section 7.5 [Package Keywords], page 43.

C-h or F1 means “help” in various other contexts as well. For instance, you can
type them after a prefix key to view a list of the keys that can follow the prefix
key. (A few prefix keys don’t support C-h in this way, because they define other
meanings for it, but they all support F1 for help.)
Here is a summary of help commands for accessing the built-in documentation.
Most of these are described in more detail in the following sections.
C-h a topics RET
Display a list of commands whose names match topics (aproposcommand).
C-h b

Display all active key bindings; minor mode bindings first, then those
of the major mode, then global bindings (describe-bindings).

C-h c key

Show the name of the command that the key sequence key is bound to
(describe-key-briefly). Here c stands for “character”. For more
extensive information on key, use C-h k.

Chapter 7: Help

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C-h d topics RET
Display the commands and variables whose documentation matches
topics (apropos-documentation).
C-h e

Display the ‘*Messages*’ buffer (view-echo-area-messages).

C-h f function RET
Display documentation on the Lisp function named function
(describe-function). Since commands are Lisp functions, this
works for commands too.
C-h h

Display the ‘HELLO’ file, which shows examples of various character
sets.

C-h i

Run Info, the GNU documentation browser (info). The Emacs manual is available in Info.

C-h k key

Display the name and documentation of the command that key runs
(describe-key).

C-h l

Display a description of your last 300 keystrokes (view-lossage).

C-h m

Display documentation of the current major mode (describe-mode).

C-h n

Display news of recent Emacs changes (view-emacs-news).

C-h p

Find packages by topic keyword (finder-by-keyword). This lists
packages using a package menu buffer. See Chapter 32 [Packages],
page 430.

C-h P package RET
Display documentation about the package named package (describepackage).
C-h r

Display the Emacs manual in Info (info-emacs-manual).

C-h s

Display the contents of the current syntax table (describe-syntax).
The syntax table says which characters are opening delimiters, which
are parts of words, and so on. See Section “Syntax Tables” in The
Emacs Lisp Reference Manual, for details.

C-h t

Enter the Emacs interactive tutorial (help-with-tutorial).

C-h v var RET
Display the documentation of the Lisp variable var (describevariable).
C-h w command RET
Show which keys run the command named command (where-is).
C-h C coding RET
Describe the coding system coding (describe-coding-system).
C-h C RET

Describe the coding systems currently in use.

Chapter 7: Help

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C-h F command RET
Enter Info and go to the node that documents the Emacs command
command (Info-goto-emacs-command-node).
C-h I method RET
Describe the input method method (describe-input-method).
C-h K key

Enter Info and go to the node that documents the key sequence key
(Info-goto-emacs-key-command-node).

C-h L language-env RET
Display information on the character sets, coding systems, and input methods used in language environment language-env (describelanguage-environment).
C-h S symbol RET
Display the Info documentation on symbol symbol according to the
programming language you are editing (info-lookup-symbol).
C-h .

Display the help message for a special text area, if point is in one
(display-local-help). (These include, for example, links in ‘*Help*’
buffers.)

7.1 Documentation for a Key
The help commands to get information about a key sequence are C-h c (describekey-briefly) and C-h k (describe-key).
C-h c key displays in the echo area the name of the command that key is bound
to. For example, C-h c C-f displays ‘forward-char’.
C-h k key is similar but gives more information: it displays a help buffer containing the command’s documentation string, which describes exactly what the
command does.
C-h K key displays the section of the Emacs manual that describes the command
corresponding to key.
C-h c, C-h k and C-h K work for any sort of key sequences, including function
keys, menus, and mouse events. For instance, after C-h k you can select a menu
item from the menu bar, to view the documentation string of the command it runs.
C-h w command RET lists the keys that are bound to command. It displays the
list in the echo area. If it says the command is not on any key, that means you
must use M-x to run it. C-h w runs the command where-is.

7.2 Help by Command or Variable Name
C-h f function RET (describe-function) displays the documentation of Lisp
function function, in a window. Since commands are Lisp functions, you can use
this method to view the documentation of any command whose name you know.
For example,
C-h f auto-fill-mode RET

Chapter 7: Help

41

displays the documentation of auto-fill-mode. This is the only way to get the
documentation of a command that is not bound to any key (one which you would
normally run using M-x).
C-h f is also useful for Lisp functions that you use in a Lisp program. For
example, if you have just written the expression (make-vector len) and want
to check that you are using make-vector properly, type C-h f make-vector RET.
Because C-h f allows all function names, not just command names, you may find
that some of your favorite completion abbreviations that work in M-x don’t work in
C-h f. An abbreviation that is unique among command names may not be unique
among all function names.
If you type C-h f RET, it describes the function called by the innermost Lisp
expression in the buffer around point, provided that function name is a valid, defined
Lisp function. (That name appears as the default while you enter the argument.)
For example, if point is located following the text ‘(make-vector (car x)’, the
innermost list containing point is the one that starts with ‘(make-vector’, so C-h
f RET will describe the function make-vector.
C-h f is also useful just to verify that you spelled a function name correctly. If
the minibuffer prompt for C-h f shows the function name from the buffer as the
default, it means that name is defined as a Lisp function. Type C-g to cancel the
C-h f command if you don’t really want to view the documentation.
C-h v (describe-variable) is like C-h f but describes Lisp variables instead of
Lisp functions. Its default is the Lisp symbol around or before point, if that is the
name of a defined Lisp variable. See Section 33.2 [Variables], page 443.
Help buffers that describe Emacs variables and functions normally have hyperlinks to the corresponding source code, if you have the source files installed (see
Section 31.11 [Hyperlinking], page 426).
To find a command’s documentation in a manual, use C-h F (Info-goto-emacscommand-node). This knows about various manuals, not just the Emacs manual,
and finds the right one.

7.3 Apropos
The apropos commands answer questions like, “What are the commands for working
with files?” More precisely, you specify an apropos pattern, which means either a
word, a list of words, or a regular expression.
Each of the following apropos commands reads an apropos pattern in the minibuffer, searches for items that match the pattern, and displays the results in a
different window.
C-h a

Search for commands (apropos-command). With a prefix argument,
search for noninteractive functions too.

M-x apropos
Search for functions and variables. Both interactive functions (commands) and noninteractive functions can be found by this.

Chapter 7: Help

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M-x apropos-variable
Search for user-customizable variables. With a prefix argument, search
for non-customizable variables too.
M-x apropos-value
Search for variables whose values match the specified pattern. With
a prefix argument, search also for functions with definitions matching
the pattern, and Lisp symbols with properties matching the pattern.
C-h d

Search for functions and variables whose documentation strings match
the specified pattern (apropos-documentation).

The simplest kind of apropos pattern is one word. Anything containing that
word matches the pattern. Thus, to find commands that work on files, type C-h a
file RET. This displays a list of all command names that contain ‘file’, including copy-file, find-file, and so on. Each command name comes with a brief
description and a list of keys you can currently invoke it with. In our example, it
would say that you can invoke find-file by typing C-x C-f.
For more information about a function definition, variable or symbol property
listed in an apropos buffer, you can click on it with Mouse-1 or Mouse-2, or move
there and type RET.
When you specify more than one word in the apropos pattern, a name must
contain at least two of the words in order to match. Thus, if you are looking
for commands to kill a chunk of text before point, you could try C-h a kill back
backward behind before RET. The real command name kill-backward will match
that; if there were a command kill-text-before, it would also match, since it
contains two of the specified words.
For even greater flexibility, you can specify a regular expression (see Section 12.5
[Regexps], page 97). An apropos pattern is interpreted as a regular expression if it
contains any of the regular expression special characters, ‘^$*+?.\[’.
Following the conventions for naming Emacs commands, here are some words
that you’ll find useful in apropos patterns. By using them in C-h a, you will also
get a feel for the naming conventions.
char, line, word, sentence, paragraph, region, page, sexp, list, defun, rect,
buffer, frame, window, face, file, dir, register, mode, beginning, end, forward, backward, next, previous, up, down, search, goto, kill, delete, mark,
insert, yank, fill, indent, case, change, set, what, list, find, view, describe,
default.
If the variable apropos-do-all is non-nil, the apropos commands always behave as if they had been given a prefix argument.
By default, all apropos commands except apropos-documentation list their
results in alphabetical order. If the variable apropos-sort-by-scores is non-nil,
these commands instead try to guess the relevance of each result, and display the
most relevant ones first. The apropos-documentation command lists its results in
order of relevance by default; to list them in alphabetical order, change the variable
apropos-documentation-sort-by-scores to nil.

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7.4 Help Mode Commands
Help buffers provide the same commands as View mode (see Section 11.6 [View
Mode], page 75); for instance, SPC scrolls forward, and DEL scrolls backward. A
few special commands are also provided:
RET

Follow a cross reference at point (help-follow).

TAB

Move point forward to the next hyperlink (forward-button).

S-TAB

Move point back to the previous hyperlink (backward-button).

Mouse-1
Mouse-2

Follow a hyperlink that you click on.

C-c C-c

Show all documentation about the symbol at point (help-followsymbol).

C-c C-b

Go back to the previous help topic (help-go-back).

When a function name, variable name, or face name (see Section 11.8 [Faces],
page 75) appears in the documentation in the help buffer, it is normally an underlined hyperlink. To view the associated documentation, move point there and
type RET (help-follow), or click on the hyperlink with Mouse-1 or Mouse-2. Doing so replaces the contents of the help buffer; to retrace your steps, type C-c C-b
(help-go-back).
A help buffer can also contain hyperlinks to Info manuals, source code definitions, and URLs (web pages). The first two are opened in Emacs, and the third
using a web browser via the browse-url command (see Section 31.11.1 [BrowseURL], page 426).
In a help buffer, TAB (forward-button) moves point forward to the next hyperlink, while S-TAB (backward-button) point back to the previous hyperlink. These
commands act cyclically; for instance, typing TAB at the last hyperlink moves back
to the first hyperlink.
To view all documentation about any symbol in the text, move point to there
and type C-c C-c (help-follow-symbol). This shows all available documentation
about the symbol—as a variable, function and/or face.

7.5 Keyword Search for Packages
Most optional features in Emacs are grouped into packages. Emacs contains several hundred built-in packages, and more can be installed over the network (see
Chapter 32 [Packages], page 430).
To make it easier to find packages related to a topic, most packages are associated
with one or more keywords based on what they do. Type C-h p (finder-bykeyword) to bring up a list of package keywords, together with a description of
what the keywords mean. To view a list of packages for a given keyword, type
RET on that line; this displays the list of packages in a Package Menu buffer (see
Section 32.1 [Package Menu], page 430).

Chapter 7: Help

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C-h P (describe-package) prompts for the name of a package, and displays a
help buffer describing the attributes of the package and the features that it implements.

7.6 Help for International Language Support
For information on a specific language environment (see Section 19.3 [Language
Environments], page 183), type C-h L (describe-language-environment). This
displays a help buffer describing the languages supported by the language environment, and listing the associated character sets, coding systems, and input methods,
as well as some sample text for that language environment.
The command C-h h (view-hello-file) displays the file ‘etc/HELLO’, which
demonstrates various character sets by showing how to say “hello” in many languages.
The command C-h I (describe-input-method) describes an input method—
either a specified input method, or by default the input method currently in use.
See Section 19.4 [Input Methods], page 185.
The command C-h C (describe-coding-system) describes coding systems—
either a specified coding system, or the ones currently in use. See Section 19.6
[Coding Systems], page 188.

7.7 Other Help Commands
C-h i (info) runs the Info program, which browses structured documentation files.
The entire Emacs manual is available within Info, along with many other manuals
for the GNU system. Type h after entering Info to run a tutorial on using Info.
With a numeric argument n, C-h i selects the Info buffer ‘*info*’. This is
useful if you want to browse multiple Info manuals simultaneously. If you specify
just C-u as the prefix argument, C-h i prompts for the name of a documentation
file, so you can browse a file which doesn’t have an entry in the top-level Info menu.
The help commands C-h F function RET and C-h K key , described above, enter
Info and go straight to the documentation of function or key.
When editing a program, if you have an Info version of the manual for the
programming language, you can use C-h S (info-lookup-symbol) to find an entry
for a symbol (keyword, function or variable) in the proper manual. The details of
how this command works depend on the major mode.
If something surprising happens, and you are not sure what you typed, use
C-h l (view-lossage). C-h l displays your last 300 input keystrokes. If you see
commands that you don’t know, you can use C-h c to find out what they do.
To review recent echo area messages, use C-h e (view-echo-area-messages).
This displays the buffer ‘*Messages*’, where those messages are kept.
Each Emacs major mode typically redefines a few keys and makes other changes
in how editing works. C-h m (describe-mode) displays documentation on the current major mode, which normally describes the commands and features that are
changed in this mode.

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C-h b (describe-bindings) and C-h s (describe-syntax) show other information about the current environment within Emacs. C-h b displays a list of all
the key bindings now in effect: first the local bindings of the current minor modes,
then the local bindings defined by the current major mode, and finally the global
bindings (see Section 33.3 [Key Bindings], page 452). C-h s displays the contents of
the syntax table, with explanations of each character’s syntax (see Section “Syntax
Tables” in The Emacs Lisp Reference Manual).
You can get a list of subcommands for a particular prefix key by typing C-h
(describe-prefix-bindings) after the prefix key. (There are a few prefix keys for
which this does not work—those that provide their own bindings for C-h. One of
these is ESC, because ESC C-h is actually C-M-h, which marks a defun.)

7.8 Help Files
Apart from the built-in documentation and manuals, Emacs contains several other
files describing topics like copying conditions, release notes, instructions for debugging and reporting bugs, and so forth. You can use the following commands to view
these files. Apart from C-h g, they all have the form C-h C-char .
C-h C-c

Display the rules under which you can copy and redistribute Emacs
(describe-copying).

C-h C-d

Display help for debugging Emacs (view-emacs-debugging).

C-h C-e

Display information about where to get external packages (viewexternal-packages).

C-h C-f

Display the Emacs frequently-answered-questions list (view-emacsFAQ).

C-h g

Display information about the GNU Project (describe-gnuproject).

C-h C-m

Display information about ordering printed copies of Emacs manuals
(view-order-manuals).

C-h C-n

Display the “news” file, which lists the new features in this version of
Emacs (view-emacs-news).

C-h C-o

Display how to order or download the latest version of Emacs and
other GNU software (describe-distribution).

C-h C-p

Display the list of known Emacs problems, sometimes with suggested
workarounds (view-emacs-problems).

C-h C-t

Display the Emacs to-do list (view-emacs-todo).

C-h C-w

Display the full details on the complete absence of warranty for GNU
Emacs (describe-no-warranty).

Chapter 7: Help

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7.9 Help on Active Text and Tooltips
In Emacs, stretches of “active text” (text that does something special in response
to mouse clicks or RET) often have associated help text. This includes hyperlinks
in Emacs buffers, as well as parts of the mode line. On graphical displays, as well
as some text terminals which support mouse tracking, moving the mouse over the
active text displays the help text as a tooltip. See Section 18.17 [Tooltips], page 178.
On terminals that don’t support mouse-tracking, you can display the help text
for active buffer text at point by typing C-h . (display-local-help). This shows
the help text in the echo area. To display help text automatically whenever it is
available at point, set the variable help-at-pt-display-when-idle to t.

Chapter 8: The Mark and the Region

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8 The Mark and the Region
Many Emacs commands operate on an arbitrary contiguous part of the current
buffer. To specify the text for such a command to operate on, you set the mark at
one end of it, and move point to the other end. The text between point and the
mark is called the region. The region always extends between point and the mark,
no matter which one comes earlier in the text; each time you move point, the region
changes.
Setting the mark at a position in the text also activates it. When the mark is active, we say also that the region is active; Emacs indicates its extent by highlighting
the text within it, using the region face (see Section 33.1.5 [Face Customization],
page 439).
After certain non-motion commands, including any command that changes the
text in the buffer, Emacs automatically deactivates the mark; this turns off the
highlighting. You can also explicitly deactivate the mark at any time, by typing
C-g (see Section 34.1 [Quitting], page 468).
The above default behavior is known as Transient Mark mode. Disabling Transient Mark mode switches Emacs to an alternative behavior, in which the region is
usually not highlighted. See Section 8.7 [Disabled Transient Mark], page 52.
Setting the mark in one buffer has no effect on the marks in other buffers. When
you return to a buffer with an active mark, the mark is at the same place as before.
When multiple windows show the same buffer, they can have different values of
point, and thus different regions, but they all share one common mark position. See
Chapter 17 [Windows], page 159. Ordinarily, only the selected window highlights
its region; however, if the variable highlight-nonselected-windows is non-nil,
each window highlights its own region.

8.1 Setting the Mark
Here are some commands for setting the mark:
C-SPC

Set the mark at point, and activate it (set-mark-command).

C-@

The same.

C-x C-x

Set the mark at point, and activate it; then move point where the
mark used to be (exchange-point-and-mark).

Drag-Mouse-1
Set point and the mark around the text you drag across.
Mouse-3

Set the mark at point, then move point to where you click (mousesave-then-kill).

‘Shifted cursor motion keys’
Set the mark at point if the mark is inactive, then move point. See
Section 8.6 [Shift Selection], page 52.

Chapter 8: The Mark and the Region

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The most common way to set the mark is with C-SPC (set-mark-command)1 .
This sets the mark where point is, and activates it. You can then move point away,
leaving the mark behind.
For example, suppose you wish to convert part of the buffer to upper case. To
accomplish this, go to one end of the desired text, type C-SPC, and move point until
the desired portion of text is highlighted. Now type C-x C-u (upcase-region).
This converts the text in the region to upper case, and then deactivates the mark.
Whenever the mark is active, you can deactivate it by typing C-g (see
Section 34.1 [Quitting], page 468). Most commands that operate on the region
also automatically deactivate the mark, like C-x C-u in the above example.
Instead of setting the mark in order to operate on a region, you can also use it
to “remember” a position in the buffer (by typing C-SPC C-SPC), and later jump
back there (by typing C-u C-SPC). See Section 8.4 [Mark Ring], page 51, for details.
The command C-x C-x (exchange-point-and-mark) exchanges the positions of
point and the mark. C-x C-x is useful when you are satisfied with the position of
point but want to move the other end of the region (where the mark is). Using
C-x C-x a second time, if necessary, puts the mark at the new position with point
back at its original position. Normally, if the mark is inactive, this command first
reactivates the mark wherever it was last set, to ensure that the region is left
highlighted. However, if you call it with a prefix argument, it leaves the mark
inactive and the region unhighlighted; you can use this to jump to the mark in a
manner similar to C-u C-SPC.
You can also set the mark with the mouse. If you press the left mouse button
(down-mouse-1) and drag the mouse across a range of text, this sets the mark
where you first pressed the mouse button and puts point where you release it.
Alternatively, clicking the right mouse button (mouse-3) sets the mark at point
and then moves point to where you clicked. See Section 18.1 [Mouse Commands],
page 165, for a more detailed description of these mouse commands.
Finally, you can set the mark by holding down the shift key while typing certain
cursor motion commands (such as S-RIGHT, S-C-f, S-C-n, etc.) This is called
shift-selection. It sets the mark at point before moving point, but only if there is no
active mark set via shift-selection. The mark set by mouse commands and by shiftselection behaves slightly differently from the usual mark: any subsequent unshifted
cursor motion command deactivates it automatically. For details, See Section 8.6
[Shift Selection], page 52.
Many commands that insert text, such as C-y (yank), set the mark at the other
end of the inserted text, without activating it. This lets you easily return to that
position (see Section 8.4 [Mark Ring], page 51). You can tell that a command does
this when it shows ‘Mark set’ in the echo area.
1

There is no C-SPC character in ASCII; usually, typing C-SPC on a text terminal gives
the character C-@. This key is also bound to set-mark-command, so unless you are
unlucky enough to have a text terminal that behaves differently, you might as well
think of C-@ as C-SPC.

Chapter 8: The Mark and the Region

49

Under X, every time the active region changes, Emacs saves the text in the region
to the primary selection. This lets you insert that text into other X applications
with mouse-2 clicks. See Section 9.3.2 [Primary Selection], page 60.

8.2 Commands to Mark Textual Objects
Here are commands for placing point and the mark around a textual object such as
a word, list, paragraph or page:
M-@

Set mark after end of next word (mark-word). This does not move
point.

C-M-@

Set mark after end of following balanced expression (mark-sexp). This
does not move point.

M-h

Move point to the beginning of the current paragraph, and set mark
at the end (mark-paragraph).

C-M-h

Move point to the beginning of the current defun, and set mark at the
end (mark-defun).

C-x C-p

Move point to the beginning of the current page, and set mark at the
end (mark-page).

C-x h

Move point to the beginning of the buffer, and set mark at the end
(mark-whole-buffer).

M-@ (mark-word) sets the mark at the end of the next word (see Section 22.1
[Words], page 214, for information about words). Repeated invocations of this
command extend the region by advancing the mark one word at a time. As an
exception, if the mark is active and located before point, M-@ moves the mark
backwards from its current position one word at a time.
This command also accepts a numeric argument n, which tells it to advance the
mark by n words. A negative argument moves the mark back by n words.
Similarly, C-M-@ (mark-sexp) puts the mark at the end of the next balanced
expression (see Section 23.4.1 [Expressions], page 256). Repeated invocations extend
the region to subsequent expressions, while positive or negative numeric arguments
move the mark forward or backward by the specified number of expressions.
The other commands in the above list set both point and mark, so as to
delimit an object in the buffer. M-h (mark-paragraph) marks paragraphs (see
Section 22.3 [Paragraphs], page 216), C-M-h (mark-defun) marks top-level definitions (see Section 23.2.2 [Moving by Defuns], page 251), and C-x C-p (mark-page)
marks pages (see Section 22.4 [Pages], page 217). Repeated invocations again play
the same role, extending the region to consecutive objects; similarly, numeric arguments specify how many objects to move the mark by.
C-x h (mark-whole-buffer) sets up the entire buffer as the region, by putting
point at the beginning and the mark at the end.

Chapter 8: The Mark and the Region

50

8.3 Operating on the Region
Once you have a region, here are some of the ways you can operate on it:
• Kill it with C-w (see Chapter 9 [Killing], page 54).
• Copy it to the kill ring with M-w (see Section 9.2 [Yanking], page 57).
• Convert case with C-x C-l or C-x C-u (see Section 22.6 [Case], page 223).
• Undo changes within it using C-u C-/ (see Section 13.1 [Undo], page 110).
• Replace text within it using M-% (see Section 12.9.4 [Query Replace], page 106).
• Indent it with C-x TAB or C-M-\ (see Chapter 21 [Indentation], page 210).
• Fill it as text with M-x fill-region (see Section 22.5 [Filling], page 218).
• Check the spelling of words within it with M-$ (see Section 13.4 [Spelling],
page 112).
• Evaluate it as Lisp code with M-x eval-region (see Section 24.9 [Lisp Eval],
page 288).
• Save it in a register with C-x r s (see Chapter 10 [Registers], page 66).
• Save it in a buffer or a file (see Section 9.4 [Accumulating Text], page 61).
Some commands have a default behavior when the mark is inactive, but operate
on the region if the mark is active. For example, M-$ (ispell-word) normally
checks the spelling of the word at point, but it checks the text in the region if the
mark is active (see Section 13.4 [Spelling], page 112). Normally, such commands use
their default behavior if the region is empty (i.e., if mark and point are at the same
position). If you want them to operate on the empty region, change the variable
use-empty-active-region to t.
As described in Section 4.3 [Erasing], page 20, the DEL (backward-deletechar) and DELETE (delete-forward-char) commands also act this way. If the
mark is active, they delete the text in the region. (As an exception, if you supply
a numeric argument n, where n is not one, these commands delete n characters
regardless of whether the mark is active). If you change the variable deleteactive-region to nil, then these commands don’t act differently when the mark
is active. If you change the value to kill, these commands kill the region instead
of deleting it (see Chapter 9 [Killing], page 54).
Other commands always operate on the region, and have no default behavior.
Such commands usually have the word region in their names, like C-w (killregion) and C-x C-u (upcase-region). If the mark is inactive, they operate on the
“inactive region”—that is, on the text between point and the position at which the
mark was last set (see Section 8.4 [Mark Ring], page 51). To disable this behavior,
change the variable mark-even-if-inactive to nil. Then these commands will
instead signal an error if the mark is inactive.
By default, text insertion occurs normally even if the mark is active—for example, typing a inserts the character ‘a’, then deactivates the mark. If you enable
Delete Selection mode, a minor mode, then inserting text while the mark is active
causes the text in the region to be deleted first. To toggle Delete Selection mode
on or off, type M-x delete-selection-mode.

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8.4 The Mark Ring
Each buffer remembers previous locations of the mark, in the mark ring. Commands
that set the mark also push the old mark onto this ring. One of the uses of the
mark ring is to remember spots that you may want to go back to.
C-SPC C-SPC
Set the mark, pushing it onto the mark ring, without activating it.
C-u C-SPC

Move point to where the mark was, and restore the mark from the
ring of former marks.

The command C-SPC C-SPC is handy when you want to use the mark to remember a position to which you may wish to return. It pushes the current point onto the
mark ring, without activating the mark (which would cause Emacs to highlight the
region). This is actually two consecutive invocations of C-SPC (set-mark-command);
the first C-SPC sets the mark, and the second C-SPC deactivates it. (When Transient
Mark mode is off, C-SPC C-SPC instead activates Transient Mark mode temporarily;
see Section 8.7 [Disabled Transient Mark], page 52.)
To return to a marked position, use set-mark-command with a prefix argument:
C-u C-SPC. This moves point to where the mark was, and deactivates the mark if
it was active. Each subsequent C-u C-SPC jumps to a prior position stored in the
mark ring. The positions you move through in this way are not lost; they go to the
end of the ring.
If you set set-mark-command-repeat-pop to non-nil, then immediately after
you type C-u C-SPC, you can type C-SPC instead of C-u C-SPC to cycle through the
mark ring. By default, set-mark-command-repeat-pop is nil.
Each buffer has its own mark ring. All editing commands use the current buffer’s
mark ring. In particular, C-u C-SPC always stays in the same buffer.
The variable mark-ring-max specifies the maximum number of entries to keep
in the mark ring. This defaults to 16 entries. If that many entries exist and another
one is pushed, the earliest one in the list is discarded. Repeating C-u C-SPC cycles
through the positions currently in the ring.
If you want to move back to the same place over and over, the mark ring may
not be convenient enough. If so, you can record the position in a register for later
retrieval (see Section 10.1 [Saving Positions in Registers], page 66).

8.5 The Global Mark Ring
In addition to the ordinary mark ring that belongs to each buffer, Emacs has a single
global mark ring. Each time you set a mark, this is recorded in the global mark
ring in addition to the current buffer’s own mark ring, if you have switched buffers
since the previous mark setting. Hence, the global mark ring records a sequence of
buffers that you have been in, and, for each buffer, a place where you set the mark.
The length of the global mark ring is controlled by global-mark-ring-max, and is
16 by default.

Chapter 8: The Mark and the Region

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The command C-x C-SPC (pop-global-mark) jumps to the buffer and position
of the latest entry in the global ring. It also rotates the ring, so that successive uses
of C-x C-SPC take you to earlier buffers and mark positions.

8.6 Shift Selection
If you hold down the shift key while typing a cursor motion command, this sets the
mark before moving point, so that the region extends from the original position of
point to its new position. This feature is referred to as shift-selection. It is similar
to the way text is selected in other editors.
The mark set via shift-selection behaves a little differently from what we have
described above. Firstly, in addition to the usual ways of deactivating the mark
(such as changing the buffer text or typing C-g), the mark is deactivated by any
unshifted cursor motion command. Secondly, any subsequent shifted cursor motion
command avoids setting the mark anew. Therefore, a series of shifted cursor motion
commands will continuously adjust the region.
Shift-selection only works if the shifted cursor motion key is not already bound
to a separate command (see Chapter 33 [Customization], page 434). For example,
if you bind S-C-f to another command, typing S-C-f runs that command instead
of performing a shift-selected version of C-f (forward-char).
A mark set via mouse commands behaves the same as a mark set via shiftselection (see Section 8.1 [Setting Mark], page 47). For example, if you specify a
region by dragging the mouse, you can continue to extend the region using shifted
cursor motion commands. In either case, any unshifted cursor motion command
deactivates the mark.
To turn off shift-selection, set shift-select-mode to nil. Doing so does not
disable setting the mark via mouse commands.

8.7 Disabling Transient Mark Mode
The default behavior of the mark and region, in which setting the mark activates it
and highlights the region, is called Transient Mark mode. This is a minor mode that
is enabled by default. It can be toggled with M-x transient-mark-mode, or with
the ‘Active Region Highlighting’ menu item in the ‘Options’ menu. Turning it
off switches Emacs to an alternative mode of operation:
• Setting the mark, with commands like C-SPC or C-x C-x, does not highlight
the region. Therefore, you can’t tell by looking where the mark is located; you
have to remember.
The usual solution to this problem is to set the mark and then use it soon,
before you forget where it is. You can also check where the mark is by using C-x
C-x, which exchanges the positions of the point and the mark (see Section 8.1
[Setting Mark], page 47).
• Many commands that move point long distances, like M-< and C-s, first set
the mark where point was.

Chapter 8: The Mark and the Region

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• Some commands, which ordinarily act on the region when the mark is active,
no longer do so. For example, normally M-% (query-replace) performs replacements within the region, if the mark is active. When Transient Mark
mode is off, it always operates from point to the end of the buffer. Commands
that act this way are identified in their own documentation.
While Transient Mark mode is off, you can activate it temporarily using C-SPC
C-SPC or C-u C-x C-x.
C-SPC C-SPC
Set the mark at point (like plain C-SPC) and enable Transient Mark
mode just once, until the mark is deactivated. (This is not really a
separate command; you are using the C-SPC command twice.)
C-u C-x C-x
Activate the mark and enable Transient Mark mode temporarily, until the mark is next deactivated. (This is the C-x C-x command,
exchange-point-and-mark, with a prefix argument.)
These commands set or activate the mark, and enable Transient Mark mode
only until the mark is deactivated. One reason you may want to use them is that
some commands operate on the entire buffer instead of the region when Transient
Mark mode is off. Enabling Transient Mark mode momentarily gives you a way to
use these commands on the region.
When you specify a region with the mouse (see Section 8.1 [Setting Mark],
page 47), or with shift-selection (see Section 8.6 [Shift Selection], page 52), this
likewise activates Transient Mark mode temporarily and highlights the region.

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9 Killing and Moving Text
In Emacs, killing means erasing text and copying it into the kill ring. Yanking
means bringing text from the kill ring back into the buffer. (Some applications use
the terms “cutting” and “pasting” for similar operations.) The kill ring is so-named
because it can be visualized as a set of blocks of text arranged in a ring, which you
can access in cyclic order. See Section 9.2.1 [Kill Ring], page 57.
Killing and yanking are the most common way to move or copy text within
Emacs. It is very versatile, because there are commands for killing many different
types of syntactic units.

9.1 Deletion and Killing
Most commands which erase text from the buffer save it in the kill ring. These are
known as kill commands, and their names normally contain the word ‘kill’ (e.g.
kill-line). The kill ring stores several recent kills, not just the last one, so killing
is a very safe operation: you don’t have to worry much about losing text that you
previously killed. The kill ring is shared by all buffers, so text that is killed in one
buffer can be yanked into another buffer.
When you use C-/ (undo) to undo a kill command (see Section 13.1 [Undo],
page 110), that brings the killed text back into the buffer, but does not remove it
from the kill ring.
On graphical displays, killing text also copies it to the system clipboard. See
Section 9.3 [Cut and Paste], page 59.
Commands that erase text but do not save it in the kill ring are known as delete
commands; their names usually contain the word ‘delete’. These include C-d
(delete-char) and DEL (delete-backward-char), which delete only one character
at a time, and those commands that delete only spaces or newlines. Commands
that can erase significant amounts of nontrivial data generally do a kill operation
instead.
You can also use the mouse to kill and yank. See Section 9.3 [Cut and Paste],
page 59.
9.1.1 Deletion
Deletion means erasing text and not saving it in the kill ring. For the most part,
the Emacs commands that delete text are those that erase just one character or
only whitespace.
DEL
BACKSPACE
Delete the previous character, or the text in the region if it is active
(delete-backward-char).
DELETE

Delete the next character, or the text in the region if it is active
(delete-forward-char).

C-d

Delete the next character (delete-char).

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M-\

Delete spaces and tabs around point (delete-horizontal-space).

M-SPC

Delete spaces and tabs around point, leaving one space (just-onespace).

C-x C-o

Delete blank lines around the current line (delete-blank-lines).

M-^

Join two lines by deleting the intervening newline, along with any
indentation following it (delete-indentation).

We have already described the basic deletion commands DEL (deletebackward-char), DELETE (delete-forward-char), and C-d (delete-char). See
Section 4.3 [Erasing], page 20. With a numeric argument, they delete the specified
number of characters. If the numeric argument is omitted or one, they delete all
the text in the region if it is active (see Section 8.3 [Using Region], page 50).
The other delete commands are those that delete only whitespace characters:
spaces, tabs and newlines. M-\ (delete-horizontal-space) deletes all the spaces
and tab characters before and after point. With a prefix argument, this only deletes
spaces and tab characters before point. M-SPC (just-one-space) does likewise but
leaves a single space before point, regardless of the number of spaces that existed
previously (even if there were none before). With a numeric argument n, it leaves
n spaces before point if n is positive; if n is negative, it deletes newlines in addition
to spaces and tabs, leaving a single space before point.
C-x C-o (delete-blank-lines) deletes all blank lines after the current line. If
the current line is blank, it deletes all blank lines preceding the current line as well
(leaving one blank line, the current line). On a solitary blank line, it deletes that
line.
M-^ (delete-indentation) joins the current line and the previous line, by
deleting a newline and all surrounding spaces, usually leaving a single space. See
Chapter 21 [Indentation], page 210.
9.1.2 Killing by Lines
C-k

Kill rest of line or one or more lines (kill-line).

C-S-backspace
Kill an entire line at once (kill-whole-line)
The simplest kill command is C-k (kill-line). If used at the end of a line, it
kills the line-ending newline character, merging the next line into the current one
(thus, a blank line is entirely removed). Otherwise, C-k kills all the text from point
up to the end of the line; if point was originally at the beginning of the line, this
leaves the line blank.
Spaces and tabs at the end of the line are ignored when deciding which case
applies. As long as point is after the last visible character in the line, you can
be sure that C-k will kill the newline. To kill an entire non-blank line, go to the
beginning and type C-k twice.
In this context, “line” means a logical text line, not a screen line (see Section 4.8
[Continuation Lines], page 23).

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When C-k is given a positive argument n, it kills n lines and the newlines that
follow them (text on the current line before point is not killed). With a negative
argument −n, it kills n lines preceding the current line, together with the text on
the current line before point. C-k with an argument of zero kills the text before
point on the current line.
If the variable kill-whole-line is non-nil, C-k at the very beginning of a line
kills the entire line including the following newline. This variable is normally nil.
C-S-backspace (kill-whole-line) kills a whole line including its newline, regardless of the position of point within the line. Note that many text terminals will
prevent you from typing the key sequence C-S-backspace.
9.1.3 Other Kill Commands
C-w

Kill the region (kill-region).

M-w

Copy the region into the kill ring (kill-ring-save).

M-d

Kill the next word (kill-word). See Section 22.1 [Words], page 214.

M-DEL

Kill one word backwards (backward-kill-word).

C-x DEL

Kill back to beginning of sentence (backward-kill-sentence). See
Section 22.2 [Sentences], page 215.

M-k

Kill to the end of the sentence (kill-sentence).

C-M-k

Kill the following balanced expression (kill-sexp). See Section 23.4.1
[Expressions], page 256.

M-z char

Kill through the next occurrence of char (zap-to-char).

One of the commonly-used kill commands is C-w (kill-region), which kills the
text in the region (see Chapter 8 [Mark], page 47). Similarly, M-w (kill-ringsave) copies the text in the region into the kill ring without removing it from the
buffer. If the mark is inactive when you type C-w or M-w, the command acts on the
text between point and where you last set the mark (see Section 8.3 [Using Region],
page 50).
Emacs also provides commands to kill specific syntactic units: words, with M-DEL
and M-d (see Section 22.1 [Words], page 214); balanced expressions, with C-M-k (see
Section 23.4.1 [Expressions], page 256); and sentences, with C-x DEL and M-k (see
Section 22.2 [Sentences], page 215).
The command M-z (zap-to-char) combines killing with searching: it reads a
character and kills from point up to (and including) the next occurrence of that
character in the buffer. A numeric argument acts as a repeat count; a negative
argument means to search backward and kill text before point.
9.1.4 Options for Killing
Some specialized buffers contain read-only text, which cannot be modified and therefore cannot be killed. The kill commands work specially in a read-only buffer: they
move over text and copy it to the kill ring, without actually deleting it from the

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buffer. Normally, they also beep and display an error message when this happens.
But if you set the variable kill-read-only-ok to a non-nil value, they just print
a message in the echo area to explain why the text has not been erased.
If you change the variable kill-do-not-save-duplicates to a non-nil value,
identical subsequent kills yield a single kill-ring entry, without duplication.

9.2 Yanking
Yanking means reinserting text previously killed. The usual way to move or copy
text is to kill it and then yank it elsewhere.
C-y

Yank the last kill into the buffer, at point (yank).

M-y

Replace the text just yanked with an earlier batch of killed text (yankpop). See Section 9.2.2 [Earlier Kills], page 58.

C-M-w

Cause the following command, if it is a kill command, to append to
the previous kill (append-next-kill). See Section 9.2.3 [Appending
Kills], page 58.

The basic yanking command is C-y (yank). It inserts the most recent kill, leaving
the cursor at the end of the inserted text. It also sets the mark at the beginning
of the inserted text, without activating the mark; this lets you jump easily to that
position, if you wish, with C-u C-SPC (see Section 8.4 [Mark Ring], page 51).
With a plain prefix argument (C-u C-y), the command instead leaves the cursor
in front of the inserted text, and sets the mark at the end. Using any other prefix
argument specifies an earlier kill; e.g. C-u 4 C-y reinserts the fourth most recent
kill. See Section 9.2.2 [Earlier Kills], page 58.
On graphical displays, C-y first checks if another application has placed any
text in the system clipboard more recently than the last Emacs kill. If so, it inserts
the text in the clipboard instead. Thus, Emacs effectively treats “cut” or “copy”
clipboard operations performed in other applications like Emacs kills, except that
they are not recorded in the kill ring. See Section 9.3 [Cut and Paste], page 59, for
details.
9.2.1 The Kill Ring
The kill ring is a list of blocks of text that were previously killed. There is only
one kill ring, shared by all buffers, so you can kill text in one buffer and yank it
in another buffer. This is the usual way to move text from one buffer to another.
(There are several other methods: for instance, you could store the text in a register;
see Chapter 10 [Registers], page 66. See Section 9.4 [Accumulating Text], page 61,
for some other ways to move text around.)
The maximum number of entries in the kill ring is controlled by the variable
kill-ring-max. The default is 60. If you make a new kill when this limit has been
reached, Emacs makes room by deleting the oldest entry in the kill ring.
The actual contents of the kill ring are stored in a variable named kill-ring;
you can view the entire contents of the kill ring with C-h v kill-ring.

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9.2.2 Yanking Earlier Kills
As explained in Section 9.2 [Yanking], page 57, you can use a numeric argument
to C-y to yank text that is no longer the most recent kill. This is useful if you
remember which kill ring entry you want. If you don’t, you can use the M-y (yankpop) command to cycle through the possibilities.
If the previous command was a yank command, M-y takes the text that was
yanked and replaces it with the text from an earlier kill. So, to recover the text
of the next-to-the-last kill, first use C-y to yank the last kill, and then use M-y to
replace it with the previous kill. M-y is allowed only after a C-y or another M-y.
You can understand M-y in terms of a “last yank” pointer which points at an
entry in the kill ring. Each time you kill, the “last yank” pointer moves to the
newly made entry at the front of the ring. C-y yanks the entry which the “last
yank” pointer points to. M-y moves the “last yank” pointer to a different entry,
and the text in the buffer changes to match. Enough M-y commands can move the
pointer to any entry in the ring, so you can get any entry into the buffer. Eventually
the pointer reaches the end of the ring; the next M-y loops back around to the first
entry again.
M-y moves the “last yank” pointer around the ring, but it does not change the
order of the entries in the ring, which always runs from the most recent kill at the
front to the oldest one still remembered.
M-y can take a numeric argument, which tells it how many entries to advance
the “last yank” pointer by. A negative argument moves the pointer toward the
front of the ring; from the front of the ring, it moves “around” to the last entry and
continues forward from there.
Once the text you are looking for is brought into the buffer, you can stop doing
M-y commands and it will stay there. It’s just a copy of the kill ring entry, so editing
it in the buffer does not change what’s in the ring. As long as no new killing is done,
the “last yank” pointer remains at the same place in the kill ring, so repeating C-y
will yank another copy of the same previous kill.
When you call C-y with a numeric argument, that also sets the “last yank”
pointer to the entry that it yanks.
9.2.3 Appending Kills
Normally, each kill command pushes a new entry onto the kill ring. However, two
or more kill commands in a row combine their text into a single entry, so that a
single C-y yanks all the text as a unit, just as it was before it was killed.
Thus, if you want to yank text as a unit, you need not kill all of it with one
command; you can keep killing line after line, or word after word, until you have
killed it all, and you can still get it all back at once.
Commands that kill forward from point add onto the end of the previous killed
text. Commands that kill backward from point add text onto the beginning. This
way, any sequence of mixed forward and backward kill commands puts all the killed
text into one entry without rearrangement. Numeric arguments do not break the
sequence of appending kills. For example, suppose the buffer contains this text:

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59

This is a line ?of sample text.
with point shown by ?. If you type M-d M-DEL M-d M-DEL, killing alternately forward
and backward, you end up with ‘a line of sample’ as one entry in the kill ring, and
‘This is text.’ in the buffer. (Note the double space between ‘is’ and ‘text’,
which you can clean up with M-SPC or M-q.)
Another way to kill the same text is to move back two words with M-b M-b, then
kill all four words forward with C-u M-d. This produces exactly the same results
in the buffer and in the kill ring. M-f M-f C-u M-DEL kills the same text, all going
backward; once again, the result is the same. The text in the kill ring entry always
has the same order that it had in the buffer before you killed it.
If a kill command is separated from the last kill command by other commands
(not just numeric arguments), it starts a new entry on the kill ring. But you can
force it to append by first typing the command C-M-w (append-next-kill) right
before it. The C-M-w tells the following command, if it is a kill command, to append
the text it kills to the last killed text, instead of starting a new entry. With C-M-w,
you can kill several separated pieces of text and accumulate them to be yanked back
in one place.
A kill command following M-w (kill-ring-save) does not append to the text
that M-w copied into the kill ring.

9.3 “Cut and Paste” Operations on Graphical Displays
In most graphical desktop environments, you can transfer data (usually text) between different applications using a system facility called the clipboard. On X,
two other similar facilities are available: the primary selection and the secondary
selection. When Emacs is run on a graphical display, its kill and yank commands
integrate with these facilities, so that you can easily transfer text between Emacs
and other graphical applications.
By default, Emacs uses UTF-8 as the coding system for inter-program text
transfers. If you find that the pasted text is not what you expected, you can specify
another coding system by typing C-x RET x or C-x RET X. You can also request
a different data type by customizing x-select-request-type. See Section 19.11
[Communication Coding], page 194.
9.3.1 Using the Clipboard
The clipboard is the facility that most graphical applications use for “cutting and
pasting”. When the clipboard exists, the kill and yank commands in Emacs make
use of it.
When you kill some text with a command such as C-w (kill-region), or copy
it to the kill ring with a command such as M-w (kill-ring-save), that text is also
put in the clipboard.
When an Emacs kill command puts text in the clipboard, the existing clipboard
contents are normally lost. Optionally, you can change save-interprogram-pastebefore-kill to t. Then Emacs will first save the clipboard to its kill ring, prevent-

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ing you from losing the old clipboard data—at the risk of high memory consumption
if that data turns out to be large.
Yank commands, such as C-y (yank), also use the clipboard. If another application “owns” the clipboard—i.e., if you cut or copied text there more recently than
your last kill command in Emacs—then Emacs yanks from the clipboard instead of
the kill ring.
Normally, rotating the kill ring with M-y (yank-pop) does not alter the clipboard.
However, if you change yank-pop-change-selection to t, then M-y saves the new
yank to the clipboard.
To prevent kill and yank commands from accessing the clipboard, change the
variable x-select-enable-clipboard to nil.
Many X desktop environments support a feature called the clipboard manager.
If you exit Emacs while it is the current “owner” of the clipboard data, and there is
a clipboard manager running, Emacs transfers the clipboard data to the clipboard
manager so that it is not lost. In some circumstances, this may cause a delay when
exiting Emacs; if you wish to prevent Emacs from transferring data to the clipboard
manager, change the variable x-select-enable-clipboard-manager to nil.
Prior to Emacs 24, the kill and yank commands used the primary selection (see
Section 9.3.2 [Primary Selection], page 60), not the clipboard. If you prefer this
behavior, change x-select-enable-clipboard to nil, x-select-enable-primary
to t, and mouse-drag-copy-region to t. In this case, you can use the following
commands to act explicitly on the clipboard: clipboard-kill-region kills the
region and saves it to the clipboard; clipboard-kill-ring-save copies the region
to the kill ring and saves it to the clipboard; and clipboard-yank yanks the contents
of the clipboard at point.
9.3.2 Cut and Paste with Other Window Applications
Under the X Window System, there exists a primary selection containing the last
stretch of text selected in an X application (usually by dragging the mouse). Typically, this text can be inserted into other X applications by mouse-2 clicks. The
primary selection is separate from the clipboard. Its contents are more “fragile”;
they are overwritten each time you select text with the mouse, whereas the clipboard
is only overwritten by explicit “cut” or “copy” commands.
Under X, whenever the region is active (see Chapter 8 [Mark], page 47), the
text in the region is saved in the primary selection. This applies regardless of
whether the region was made by dragging or clicking the mouse (see Section 18.1
[Mouse Commands], page 165), or by keyboard commands (e.g. by typing C-SPC
and moving point; see Section 8.1 [Setting Mark], page 47).
If you change the variable select-active-regions to only, Emacs saves only
temporarily active regions to the primary selection, i.e. those made with the mouse
or with shift selection (see Section 8.6 [Shift Selection], page 52). If you change
select-active-regions to nil, Emacs avoids saving active regions to the primary
selection entirely.

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To insert the primary selection into an Emacs buffer, click mouse-2 (mouseyank-primary) where you want to insert it. See Section 18.1 [Mouse Commands],
page 165.
MS-Windows provides no primary selection, but Emacs emulates it within a
single Emacs session by storing the selected text internally. Therefore, all the
features and commands related to the primary selection work on Windows as they
do on X, for cutting and pasting within the same session, but not across Emacs
sessions or with other applications.
9.3.3 Secondary Selection
In addition to the primary selection, the X Window System provides a second similar
facility known as the secondary selection. Nowadays, few X applications make use of
the secondary selection, but you can access it using the following Emacs commands:
M-Drag-Mouse-1
Set the secondary selection, with one end at the place where you press
down the button, and the other end at the place where you release
it (mouse-set-secondary). The selected text is highlighted, using
the secondary-selection face, as you drag. The window scrolls
automatically if you drag the mouse off the top or bottom of the
window, just like mouse-set-region (see Section 18.1 [Mouse Commands], page 165).
This command does not alter the kill ring.
M-Mouse-1

Set one endpoint for the secondary selection (mouse-startsecondary).

M-Mouse-3

Set the secondary selection, with one end at the position clicked
and the other at the position specified with M-Mouse-1 (mousesecondary-save-then-kill). This also puts the selected text in the
kill ring. A second M-Mouse-3 at the same place kills the secondary
selection just made.

M-Mouse-2

Insert the secondary selection where you click, placing point at the
end of the yanked text (mouse-yank-secondary).

Double or triple clicking of M-Mouse-1 operates on words and lines, much like
Mouse-1.
If mouse-yank-at-point is non-nil, M-Mouse-2 yanks at point. Then it does
not matter precisely where you click, or even which of the frame’s windows you click
on. See Section 18.1 [Mouse Commands], page 165.

9.4 Accumulating Text
Usually we copy or move text by killing it and yanking it, but there are other
convenient methods for copying one block of text in many places, or for copying
many scattered blocks of text into one place. Here we describe the commands to
accumulate scattered pieces of text into a buffer or into a file.

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M-x append-to-buffer
Append region to the contents of a specified buffer.
M-x prepend-to-buffer
Prepend region to the contents of a specified buffer.
M-x copy-to-buffer
Copy region into a specified buffer, deleting that buffer’s old contents.
M-x insert-buffer
Insert the contents of a specified buffer into current buffer at point.
M-x append-to-file
Append region to the contents of a specified file, at the end.
To accumulate text into a buffer, use M-x append-to-buffer. This reads a
buffer name, then inserts a copy of the region into the buffer specified. If you
specify a nonexistent buffer, append-to-buffer creates the buffer. The text is
inserted wherever point is in that buffer. If you have been using the buffer for
editing, the copied text goes into the middle of the text of the buffer, starting from
wherever point happens to be at that moment.
Point in that buffer is left at the end of the copied text, so successive uses of
append-to-buffer accumulate the text in the specified buffer in the same order as
they were copied. Strictly speaking, append-to-buffer does not always append to
the text already in the buffer—it appends only if point in that buffer is at the end.
However, if append-to-buffer is the only command you use to alter a buffer, then
point is always at the end.
M-x prepend-to-buffer is just like append-to-buffer except that point in
the other buffer is left before the copied text, so successive prependings add text in
reverse order. M-x copy-to-buffer is similar, except that any existing text in the
other buffer is deleted, so the buffer is left containing just the text newly copied
into it.
The command M-x insert-buffer can be used to retrieve the accumulated text
from another buffer. This prompts for the name of a buffer, and inserts a copy of all
the text in that buffer into the current buffer at point, leaving point at the beginning
of the inserted text. It also adds the position of the end of the inserted text to the
mark ring, without activating the mark. See Chapter 16 [Buffers], page 150, for
background information on buffers.
Instead of accumulating text in a buffer, you can append text directly into a file
with M-x append-to-file. This prompts for a filename, and adds the text of the
region to the end of the specified file. The file is changed immediately on disk.
You should use append-to-file only with files that are not being visited in
Emacs. Using it on a file that you are editing in Emacs would change the file
behind Emacs’s back, which can lead to losing some of your editing.
Another way to move text around is to store it in a register. See Chapter 10
[Registers], page 66.

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9.5 Rectangles
Rectangle commands operate on rectangular areas of the text: all the characters
between a certain pair of columns, in a certain range of lines. Emacs has commands
to kill rectangles, yank killed rectangles, clear them out, fill them with blanks or
text, or delete them. Rectangle commands are useful with text in multicolumn
formats, and for changing text into or out of such formats.
To specify a rectangle for a command to work on, set the mark at one corner
and point at the opposite corner. The rectangle thus specified is called the regionrectangle. If point and the mark are in the same column, the region-rectangle is
empty. If they are in the same line, the region-rectangle is one line high.
The region-rectangle is controlled in much the same way as the region is controlled. But remember that a given combination of point and mark values can be
interpreted either as a region or as a rectangle, depending on the command that
uses them.
C-x r k

Kill the text of the region-rectangle, saving its contents as the “last
killed rectangle” (kill-rectangle).

C-x r d

Delete the text of the region-rectangle (delete-rectangle).

C-x r y

Yank the last killed rectangle with its upper left corner at point (yankrectangle).

C-x r o

Insert blank space to fill the space of the region-rectangle (openrectangle). This pushes the previous contents of the region-rectangle
to the right.

C-x r N

Insert line numbers along the left edge of the region-rectangle
(rectangle-number-lines). This pushes the previous contents of
the region-rectangle to the right.

C-x r c

Clear the region-rectangle by replacing all of its contents with spaces
(clear-rectangle).

M-x delete-whitespace-rectangle
Delete whitespace in each of the lines on the specified rectangle, starting from the left edge column of the rectangle.
C-x r t string RET
Replace rectangle contents with string on each line (stringrectangle).
M-x string-insert-rectangle RET string RET
Insert string on each line of the rectangle.
The rectangle operations fall into two classes: commands to erase or insert
rectangles, and commands to make blank rectangles.
There are two ways to erase the text in a rectangle: C-x r d (delete-rectangle)
to delete the text outright, or C-x r k (kill-rectangle) to remove the text and
save it as the last killed rectangle. In both cases, erasing the region-rectangle is like

Chapter 9: Killing and Moving Text

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erasing the specified text on each line of the rectangle; if there is any following text
on the line, it moves backwards to fill the gap.
“Killing” a rectangle is not killing in the usual sense; the rectangle is not stored
in the kill ring, but in a special place that only records the most recent rectangle
killed. This is because yanking a rectangle is so different from yanking linear text
that different yank commands have to be used. Yank-popping is not defined for
rectangles.
To yank the last killed rectangle, type C-x r y (yank-rectangle). The rectangle’s first line is inserted at point, the rectangle’s second line is inserted at the
same horizontal position one line vertically below, and so on. The number of lines
affected is determined by the height of the saved rectangle.
For example, you can convert two single-column lists into a double-column list
by killing one of the single-column lists as a rectangle, and then yanking it beside
the other list.
You can also copy rectangles into and out of registers with C-x r r r and C-x
r i r . See Section 10.3 [Rectangle Registers], page 67.
There are two commands you can use for making blank rectangles: C-x r c
(clear-rectangle) blanks out existing text in the region-rectangle, and C-x r o
(open-rectangle) inserts a blank rectangle.
M-x delete-whitespace-rectangle deletes horizontal whitespace starting
from a particular column. This applies to each of the lines in the rectangle, and
the column is specified by the left edge of the rectangle. The right edge of the
rectangle does not make any difference to this command.
The command C-x r N (rectangle-number-lines) inserts line numbers along
the left edge of the region-rectangle. Normally, the numbering begins from 1 (for
the first line of the rectangle). With a prefix argument, the command prompts for
a number to begin from, and for a format string with which to print the numbers
(see Section “Formatting Strings” in The Emacs Lisp Reference Manual).
The command C-x r t (string-rectangle) replaces the contents of a regionrectangle with a string on each line. The string’s width need not be the same as
the width of the rectangle. If the string’s width is less, the text after the rectangle
shifts left; if the string is wider than the rectangle, the text after the rectangle shifts
right.
The command M-x string-insert-rectangle is similar to string-rectangle,
but inserts the string on each line, shifting the original text to the right.

9.6 CUA Bindings
The command M-x cua-mode sets up key bindings that are compatible with the
Common User Access (CUA) system used in many other applications.
When CUA mode is enabled, the keys C-x, C-c, C-v, and C-z invoke commands
that cut (kill), copy, paste (yank), and undo respectively. The C-x and C-c keys
perform cut and copy only if the region is active. Otherwise, they still act as prefix
keys, so that standard Emacs commands like C-x C-c still work. Note that this

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means the variable mark-even-if-inactive has no effect for C-x and C-c (see
Section 8.3 [Using Region], page 50).
To enter an Emacs command like C-x C-f while the mark is active, use one of
the following methods: either hold Shift together with the prefix key, e.g. S-C-x
C-f, or quickly type the prefix key twice, e.g. C-x C-x C-f.
To disable the overriding of standard Emacs binding by CUA mode, while retaining the other features of CUA mode described below, set the variable cuaenable-cua-keys to nil.
In CUA mode, typed text replaces the active region as in Delete-Selection mode
(see Section 18.1 [Mouse Commands], page 165).
CUA mode provides enhanced rectangle support with visible rectangle highlighting. Use C-RET to start a rectangle, extend it using the movement commands,
and cut or copy it using C-x or C-c. RET moves the cursor to the next (clockwise)
corner of the rectangle, so you can easily expand it in any direction. Normal text
you type is inserted to the left or right of each line in the rectangle (on the same
side as the cursor).
With CUA you can easily copy text and rectangles into and out of registers by
providing a one-digit numeric prefix to the kill, copy, and yank commands, e.g. C-1
C-c copies the region into register 1, and C-2 C-v yanks the contents of register 2.
CUA mode also has a global mark feature which allows easy moving and copying
of text between buffers. Use C-S-SPC to toggle the global mark on and off. When
the global mark is on, all text that you kill or copy is automatically inserted at the
global mark, and text you type is inserted at the global mark rather than at the
current position.
For example, to copy words from various buffers into a word list in a given
buffer, set the global mark in the target buffer, then navigate to each of the words
you want in the list, mark it (e.g. with S-M-f), copy it to the list with C-c or M-w,
and insert a newline after the word in the target list by pressing RET.

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10 Registers
Emacs registers are compartments where you can save text, rectangles, positions,
and other things for later use. Once you save text or a rectangle in a register,
you can copy it into the buffer once, or many times; once you save a position in a
register, you can jump back to that position once, or many times.
Each register has a name that consists of a single character, which we will denote
by r; r can be a letter (such as ‘a’) or a number (such as ‘1’); case matters, so register
‘a’ is not the same as register ‘A’.
A register can store a position, a piece of text, a rectangle, a number, a window
configuration, or a file name, but only one thing at any given time. Whatever you
store in a register remains there until you store something else in that register. To
see what register r contains, use M-x view-register:
M-x view-register RET r
Display a description of what register r contains.
Bookmarks record files and positions in them, so you can return to those positions when you look at the file again. Bookmarks are similar in spirit to registers,
so they are also documented in this chapter.

10.1 Saving Positions in Registers
C-x r SPC r
Record the position of point and the current buffer in register r
(point-to-register).
C-x r j r

Jump to the position and buffer saved in register r (jump-toregister).

Typing C-x r SPC (point-to-register), followed by a character r , saves both
the position of point and the current buffer in register r. The register retains this
information until you store something else in it.
The command C-x r j r switches to the buffer recorded in register r, and moves
point to the recorded position. The contents of the register are not changed, so you
can jump to the saved position any number of times.
If you use C-x r j to go to a saved position, but the buffer it was saved from
has been killed, C-x r j tries to create the buffer again by visiting the same file. Of
course, this works only for buffers that were visiting files.

10.2 Saving Text in Registers
When you want to insert a copy of the same piece of text several times, it may
be inconvenient to yank it from the kill ring, since each subsequent kill moves that
entry further down the ring. An alternative is to store the text in a register and
later retrieve it.
C-x r s r

Copy region into register r (copy-to-register).

Chapter 10: Registers
C-x r i r

67

Insert text from register r (insert-register).

M-x append-to-register RET r
Append region to text in register r.
M-x prepend-to-register RET r
Prepend region to text in register r.
C-x r s r stores a copy of the text of the region into the register named r. If the
mark is inactive, Emacs first reactivates the mark where it was last set. The mark
is deactivated at the end of this command. See Chapter 8 [Mark], page 47. C-u
C-x r s r , the same command with a prefix argument, copies the text into register
r and deletes the text from the buffer as well; you can think of this as “moving”
the region text into the register.
M-x append-to-register RET r appends the copy of the text in the region to
the text already stored in the register named r. If invoked with a prefix argument,
it deletes the region after appending it to the register. The command prependto-register is similar, except that it prepends the region text to the text in the
register instead of appending it.
C-x r i r inserts in the buffer the text from register r. Normally it leaves point
before the text and sets the mark after, without activating it. With a numeric
argument, it instead puts point after the text and the mark before.

10.3 Saving Rectangles in Registers
A register can contain a rectangle instead of linear text. See Section 9.5 [Rectangles],
page 63, for basic information on how to specify a rectangle in the buffer.
C-x r r r

Copy the region-rectangle into register r (copy-rectangle-toregister). With numeric argument, delete it as well.

C-x r i r

Insert the rectangle stored in register r (if it contains a rectangle)
(insert-register).

The C-x r i r (insert-register) command, previously documented in
Section 10.2 [Text Registers], page 66, inserts a rectangle rather than a text string,
if the register contains a rectangle.

10.4 Saving Window Configurations in Registers
You can save the window configuration of the selected frame in a register, or even
the configuration of all windows in all frames, and restore the configuration later.
See Chapter 17 [Windows], page 159, for information about window configurations.
C-x r w r

Save the state of the selected frame’s windows in register r (windowconfiguration-to-register).

C-x r f r

Save the state of all frames, including all their windows, in register r
(frame-configuration-to-register).

Use C-x r j r to restore a window or frame configuration. This is the same
command used to restore a cursor position. When you restore a frame configuration,

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any existing frames not included in the configuration become invisible. If you wish
to delete these frames instead, use C-u C-x r j r .

10.5 Keeping Numbers in Registers
There are commands to store a number in a register, to insert the number in the
buffer in decimal, and to increment it. These commands can be useful in keyboard
macros (see Chapter 14 [Keyboard Macros], page 116).
C-u number C-x r n r
Store number into register r (number-to-register).
C-u number C-x r + r
Increment the number in register r by number (increment-register).
C-x r i r

Insert the number from register r into the buffer.

C-x r i is the same command used to insert any other sort of register contents
into the buffer. C-x r + with no numeric argument increments the register value by
1; C-x r n with no numeric argument stores zero in the register.

10.6 Keeping File Names in Registers
If you visit certain file names frequently, you can visit them more conveniently if
you put their names in registers. Here’s the Lisp code used to put a file name in a
register:
(set-register ?r ’(file . name ))

For example,
(set-register ?z ’(file . "/gd/gnu/emacs/19.0/src/ChangeLog"))

puts the file name shown in register ‘z’.
To visit the file whose name is in register r, type C-x r j r . (This is the same
command used to jump to a position or restore a frame configuration.)

10.7 Bookmarks
Bookmarks are somewhat like registers in that they record positions you can jump
to. Unlike registers, they have long names, and they persist automatically from one
Emacs session to the next. The prototypical use of bookmarks is to record “where
you were reading” in various files.
C-x r m RET
Set the bookmark for the visited file, at point.
C-x r m bookmark RET
Set the bookmark named bookmark at point (bookmark-set).
C-x r b bookmark RET
Jump to the bookmark named bookmark (bookmark-jump).
C-x r l

List all bookmarks (list-bookmarks).

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M-x bookmark-save
Save all the current bookmark values in the default bookmark file.
The prototypical use for bookmarks is to record one current position in each of
several files. So the command C-x r m, which sets a bookmark, uses the visited file
name as the default for the bookmark name. If you name each bookmark after the
file it points to, then you can conveniently revisit any of those files with C-x r b,
and move to the position of the bookmark at the same time.
To display a list of all your bookmarks in a separate buffer, type C-x r l (listbookmarks). If you switch to that buffer, you can use it to edit your bookmark
definitions or annotate the bookmarks. Type C-h m in the bookmark buffer for
more information about its special editing commands.
When you kill Emacs, Emacs saves your bookmarks, if you have changed
any bookmark values.
You can also save the bookmarks at any time
with the M-x bookmark-save command.
Bookmarks are saved to the file
‘~/.emacs.d/bookmarks’ (for compatibility with older versions of Emacs, if you
have a file named ‘~/.emacs.bmk’, that is used instead). The bookmark commands
load your default bookmark file automatically. This saving and loading is how
bookmarks persist from one Emacs session to the next.
If you set the variable bookmark-save-flag to 1, each command that sets a
bookmark will also save your bookmarks; this way, you don’t lose any bookmark
values even if Emacs crashes. The value, if a number, says how many bookmark
modifications should go by between saving. If you set this variable to nil, Emacs
only saves bookmarks if you explicitly use M-x bookmark-save.
Bookmark position values are saved with surrounding context, so that
bookmark-jump can find the proper position even if the file is modified slightly.
The variable bookmark-search-size says how many characters of context to
record on each side of the bookmark’s position.
Here are some additional commands for working with bookmarks:
M-x bookmark-load RET filename RET
Load a file named filename that contains a list of bookmark values.
You can use this command, as well as bookmark-write, to work with
other files of bookmark values in addition to your default bookmark
file.
M-x bookmark-write RET filename RET
Save all the current bookmark values in the file filename.
M-x bookmark-delete RET bookmark RET
Delete the bookmark named bookmark.
M-x bookmark-insert-location RET bookmark RET
Insert in the buffer the name of the file that bookmark bookmark
points to.
M-x bookmark-insert RET bookmark RET
Insert in the buffer the contents of the file that bookmark bookmark
points to.

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11 Controlling the Display
Since only part of a large buffer fits in the window, Emacs has to show only a part
of it. This chapter describes commands and variables that let you specify which
part of the text you want to see, and how the text is displayed.

11.1 Scrolling
If a window is too small to display all the text in its buffer, it displays only a portion
of it. Scrolling commands change which portion of the buffer is displayed.
Scrolling “forward” or “up” advances the portion of the buffer displayed in
the window; equivalently, it moves the buffer text upwards relative to the window.
Scrolling “backward” or “down” displays an earlier portion of the buffer, and moves
the text downwards relative to the window.
In Emacs, scrolling “up” or “down” refers to the direction that the text moves
in the window, not the direction that the window moves relative to the text. This
terminology was adopted by Emacs before the modern meaning of “scrolling up” and
“scrolling down” became widespread. Hence, the strange result that PAGEDOWN
scrolls “up” in the Emacs sense.
The portion of a buffer displayed in a window always contains point. If you
move point past the bottom or top of the window, scrolling occurs automatically
to bring it back onscreen (see Section 11.3 [Auto Scrolling], page 72). You can also
scroll explicitly with these commands:
C-v
NEXT
PAGEDOWN
Scroll forward by nearly a full window (scroll-up-command).
M-v
PRIOR
PAGEUP

Scroll backward (scroll-down-command).

C-v (scroll-up-command) scrolls forward by nearly the whole window height.
The effect is to take the two lines at the bottom of the window and put them at
the top, followed by lines that were not previously visible. If point was in the text
that scrolled off the top, it ends up on the window’s new topmost line. The NEXT
(or PAGEDOWN) key is equivalent to C-v.
M-v (scroll-down-command) scrolls backward in a similar way. The PRIOR (or
PAGEUP) key is equivalent to M-v.
The number of lines of overlap left by these scroll commands is controlled by the
variable next-screen-context-lines, whose default value is 2. You can supply the
commands with a numeric prefix argument, n, to scroll by n lines; Emacs attempts
to leave point unchanged, so that the text and point move up or down together.
C-v with a negative argument is like M-v and vice versa.
By default, these commands signal an error (by beeping or flashing the screen)
if no more scrolling is possible, because the window has reached the beginning or

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end of the buffer. If you change the variable scroll-error-top-bottom to t, the
command moves point to the farthest possible position. If point is already there,
the command signals an error.
Some users like scroll commands to keep point at the same screen position, so
that scrolling back to the same screen conveniently returns point to its original
position. You can enable this behavior via the variable scroll-preserve-screenposition. If the value is t, Emacs adjusts point to keep the cursor at the same
screen position whenever a scroll command moves it off-window, rather than moving
it to the topmost or bottommost line. With any other non-nil value, Emacs adjusts
point this way even if the scroll command leaves point in the window. This variable
affects all the scroll commands documented in this section, as well as scrolling with
the mouse wheel (see Section 18.1 [Mouse Commands], page 165); in general, it
affects any command that has a non-nil scroll-command property. See Section
“Property Lists” in The Emacs Lisp Reference Manual.
The commands M-x scroll-up and M-x scroll-down behave similarly
to scroll-up-command and scroll-down-command, except they do not obey
scroll-error-top-bottom. Prior to Emacs 24, these were the default commands
for scrolling up and down.
The commands M-x scroll-up-line and M-x
scroll-down-line scroll the current window by one line at a time. If you intend
to use any of these commands, you might want to give them key bindings (see
Section 33.3.6 [Init Rebinding], page 455).

11.2 Recentering
C-l

Scroll the selected window so the current line is the center-most text
line; on subsequent consecutive invocations, make the current line the
top line, the bottom line, and so on in cyclic order. Possibly redisplay
the screen too (recenter-top-bottom).

M-x recenter
Scroll the selected window so the current line is the center-most text
line. Possibly redisplay the screen too.
C-M-l

Scroll heuristically to bring useful information onto the screen
(reposition-window).

The C-l (recenter-top-bottom) command recenters the selected window,
scrolling it so that the current screen line is exactly in the center of the window, or
as close to the center as possible.
Typing C-l twice in a row (C-l C-l) scrolls the window so that point is on the
topmost screen line. Typing a third C-l scrolls the window so that point is on the
bottom-most screen line. Each successive C-l cycles through these three positions.
You can change the cycling order by customizing the list variable recenterpositions. Each list element should be the symbol top, middle, or bottom, or
a number; an integer means to move the line to the specified screen line, while a
floating-point number between 0.0 and 1.0 specifies a percentage of the screen space
from the top of the window. The default, (middle top bottom), is the cycling order

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described above. Furthermore, if you change the variable scroll-margin to a nonzero value n, C-l always leaves at least n screen lines between point and the top or
bottom of the window (see Section 11.3 [Auto Scrolling], page 72).
You can also give C-l a prefix argument. A plain prefix argument, C-u C-l,
simply recenters point. A positive argument n puts point n lines down from the top
of the window. An argument of zero puts point on the topmost line. A negative
argument -n puts point n lines from the bottom of the window. When given an
argument, C-l does not clear the screen or cycle through different screen positions.
If the variable recenter-redisplay has a non-nil value, each invocation of C-l
also clears and redisplays the screen; the special value tty (the default) says to do
this on text-terminal frames only. Redisplaying is useful in case the screen becomes
garbled for any reason (see Section 34.2.3 [Screen Garbled], page 470).
The more primitive command M-x recenter behaves like recenter-topbottom, but does not cycle among screen positions.
C-M-l (reposition-window) scrolls the current window heuristically in a way
designed to get useful information onto the screen. For example, in a Lisp file, this
command tries to get the entire current defun onto the screen if possible.

11.3 Automatic Scrolling
Emacs performs automatic scrolling when point moves out of the visible portion of
the text.
Normally, this centers point vertically within the window. However, if you set
scroll-conservatively to a small number n, then if you move point just a little
off the screen (less than n lines), Emacs scrolls the text just far enough to bring
point back on screen. By default, scroll-conservatively is 0. If you set scrollconservatively to a large number (larger than 100), Emacs will never center point
as result of scrolling, even if point moves far away from the text previously displayed
in the window. With such a large value, Emacs will always scroll text just enough
for bringing point into view, so point will end up at the top or bottom of the window,
depending on the scroll direction.
The variable scroll-step determines how many lines to scroll the window when
point moves off the screen. If moving by that number of lines fails to bring point
back into view, point is centered instead. The default value is zero, which causes
point to always be centered after scrolling.
When the window does scroll by a distance longer than scroll-step, you can
control how aggressively it scrolls by setting the variables scroll-up-aggressively
and scroll-down-aggressively. The value of scroll-up-aggressively should
be either nil, or a fraction f between 0 and 1. A fraction specifies where on the
screen to put point when scrolling upward, i.e. forward. When point goes off the
window end, the new start position is chosen to put point f parts of the window
height from the bottom margin. Thus, larger f means more aggressive scrolling:
more new text is brought into view. The default value, nil, is equivalent to 0.5.

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Likewise, scroll-down-aggressively is used for scrolling down, i.e. backward.
The value specifies how far point should be placed from the top margin of the
window; thus, as with scroll-up-aggressively, a larger value is more aggressive.
These two variables are ignored if either scroll-step or scrollconservatively are set to a non-zero value.
The variable scroll-margin restricts how close point can come to the top or
bottom of a window (even if aggressive scrolling specifies a fraction f that is larger
than the window portion between the top and the bottom margins). Its value is a
number of screen lines; if point comes within that many lines of the top or bottom
of the window, Emacs performs automatic scrolling. By default, scroll-margin is
0.

11.4 Horizontal Scrolling
Horizontal scrolling means shifting all the lines sideways within a window, so that
some of the text near the left margin is not displayed. When the text in a window is scrolled horizontally, text lines are truncated rather than continued (see
Section 11.21 [Line Truncation], page 89). If a window shows truncated lines, Emacs
performs automatic horizontal scrolling whenever point moves off the left or right
edge of the screen. To disable automatic horizontal scrolling, set the variable autohscroll-mode to nil. Note that when the automatic horizontal scrolling is turned
off, if point moves off the edge of the screen, the cursor disappears to indicate that.
(On text terminals, the cursor is left at the edge instead.)
The variable hscroll-margin controls how close point can get to the window’s
edges before automatic scrolling occurs. It is measured in columns. For example,
if the value is 5, then moving point within 5 columns of an edge causes horizontal
scrolling away from that edge.
The variable hscroll-step determines how many columns to scroll the window
when point gets too close to the edge. Zero, the default value, means to center point
horizontally within the window. A positive integer value specifies the number of
columns to scroll by. A floating-point number specifies the fraction of the window’s
width to scroll by.
You can also perform explicit horizontal scrolling with the following commands:
C-x <

Scroll text in current window to the left (scroll-left).

C-x >

Scroll to the right (scroll-right).

C-x < (scroll-left) scrolls text in the selected window to the left by the full
width of the window, less two columns. (In other words, the text in the window
moves left relative to the window.) With a numeric argument n, it scrolls by n
columns.
If the text is scrolled to the left, and point moves off the left edge of the window,
the cursor will freeze at the left edge of the window, until point moves back to the
displayed portion of the text. This is independent of the current setting of autohscroll-mode, which, for text scrolled to the left, only affects the behavior at the
right edge of the window.

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C-x > (scroll-right) scrolls similarly to the right. The window cannot be
scrolled any farther to the right once it is displayed normally, with each line starting
at the window’s left margin; attempting to do so has no effect. This means that
you don’t have to calculate the argument precisely for C-x >; any sufficiently large
argument will restore the normal display.
If you use those commands to scroll a window horizontally, that sets a lower
bound for automatic horizontal scrolling. Automatic scrolling will continue to scroll
the window, but never farther to the right than the amount you previously set by
scroll-left.

11.5 Narrowing
Narrowing means focusing in on some portion of the buffer, making the rest temporarily inaccessible. The portion which you can still get to is called the accessible
portion. Canceling the narrowing, which makes the entire buffer once again accessible, is called widening. The bounds of narrowing in effect in a buffer are called
the buffer’s restriction.
Narrowing can make it easier to concentrate on a single subroutine or paragraph
by eliminating clutter. It can also be used to limit the range of operation of a replace
command or repeating keyboard macro.
C-x n n

Narrow down to between point and mark (narrow-to-region).

C-x n w

Widen to make the entire buffer accessible again (widen).

C-x n p

Narrow down to the current page (narrow-to-page).

C-x n d

Narrow down to the current defun (narrow-to-defun).

When you have narrowed down to a part of the buffer, that part appears to
be all there is. You can’t see the rest, you can’t move into it (motion commands
won’t go outside the accessible part), you can’t change it in any way. However, it
is not gone, and if you save the file all the inaccessible text will be saved. The word
‘Narrow’ appears in the mode line whenever narrowing is in effect.
The primary narrowing command is C-x n n (narrow-to-region). It sets the
current buffer’s restrictions so that the text in the current region remains accessible,
but all text before the region or after the region is inaccessible. Point and mark do
not change.
Alternatively, use C-x n p (narrow-to-page) to narrow down to the current
page. See Section 22.4 [Pages], page 217, for the definition of a page. C-x n d
(narrow-to-defun) narrows down to the defun containing point (see Section 23.2
[Defuns], page 250).
The way to cancel narrowing is to widen with C-x n w (widen). This makes all
text in the buffer accessible again.
You can get information on what part of the buffer you are narrowed down to
using the C-x = command. See Section 4.9 [Position Info], page 23.
Because narrowing can easily confuse users who do not understand it, narrowto-region is normally a disabled command. Attempting to use this command

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asks for confirmation and gives you the option of enabling it; if you enable the command, confirmation will no longer be required for it. See Section 33.3.11 [Disabling],
page 460.

11.6 View Mode
View mode is a minor mode that lets you scan a buffer by sequential screenfuls.
It provides commands for scrolling through the buffer conveniently but not for
changing it. Apart from the usual Emacs cursor motion commands, you can type
SPC to scroll forward one windowful, DEL to scroll backward, and s to start an
incremental search.
Typing q (View-quit) disables View mode, and switches back to the buffer and
position before View mode was enabled. Typing e (View-exit) disables View mode,
keeping the current buffer and position.
M-x view-buffer prompts for an existing Emacs buffer, switches to it, and
enables View mode. M-x view-file prompts for a file and visits it with View mode
enabled.

11.7 Follow Mode
Follow mode is a minor mode that makes two windows, both showing the same
buffer, scroll as a single tall “virtual window”. To use Follow mode, go to a frame
with just one window, split it into two side-by-side windows using C-x 3, and then
type M-x follow-mode. From then on, you can edit the buffer in either of the two
windows, or scroll either one; the other window follows it.
In Follow mode, if you move point outside the portion visible in one window and
into the portion visible in the other window, that selects the other window—again,
treating the two as if they were parts of one large window.
To turn off Follow mode, type M-x follow-mode a second time.

11.8 Text Faces
Emacs can display text in several different styles, called faces. Each face can specify various face attributes, such as the font, height, weight, slant, foreground and
background color, and underlining or overlining. Most major modes assign faces to
the text automatically, via Font Lock mode. See Section 11.12 [Font Lock], page 80,
for more information about how these faces are assigned.
To see what faces are currently defined, and what they look like, type M-x
list-faces-display. With a prefix argument, this prompts for a regular expression, and displays only faces with names matching that regular expression (see
Section 12.5 [Regexps], page 97).
It’s possible for a given face to look different in different frames. For instance,
some text terminals do not support all face attributes, particularly font, height, and
width, and some support a limited range of colors.
You can customize a face to alter its appearance, and save those changes for
future Emacs sessions. See Section 33.1.5 [Face Customization], page 439. A face

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does not have to specify every single attribute; often it inherits most attributes from
another face. Any ultimately unspecified attribute is taken from the face named
default.
The default face is the default for displaying text, and all of its attributes are
specified. Its background color is also used as the frame’s background color. See
Section 11.9 [Colors], page 76.
Another special face is the cursor face. On graphical displays, the background
color of this face is used to draw the text cursor. None of the other attributes of this
face have any effect; the foreground color for text under the cursor is taken from
the background color of the underlying text. On text terminals, the appearance of
the text cursor is determined by the terminal, not by the cursor face.
You can also use X resources to specify attributes of any particular face. See
Section D.1 [Resources], page 521.
Emacs can display variable-width fonts, but some Emacs commands, particularly indentation commands, do not account for variable character display widths.
Therefore, we recommend not using variable-width fonts for most faces, particularly
those assigned by Font Lock mode.

11.9 Colors for Faces
Faces can have various foreground and background colors. When you specify a
color for a face—for instance, when customizing the face (see Section 33.1.5 [Face
Customization], page 439)—you can use either a color name or an RGB triplet.
A color name is a pre-defined name, such as ‘dark orange’ or ‘medium sea
green’. To view a list of color names, type M-x list-colors-display. To control
the order in which colors are shown, customize list-colors-sort. If you run this
command on a graphical display, it shows the full range of color names known to
Emacs (these are the standard X11 color names, defined in X’s ‘rgb.txt’ file). If
you run the command on a text terminal, it shows only a small subset of colors that
can be safely displayed on such terminals. However, Emacs understands X11 color
names even on text terminals; if a face is given a color specified by an X11 color
name, it is displayed using the closest-matching terminal color.
An RGB triplet is a string of the form ‘#RRGGBB’. Each of the R, G, and B
components is a hexadecimal number specifying the component’s relative intensity,
one to four digits long (usually two digits are used). The components must have
the same number of digits. For hexadecimal values A to F, either upper or lower
case are acceptable.
The M-x list-colors-display command also shows the equivalent RGB triplet
for each named color. For instance, ‘medium sea green’ is equivalent to ‘#3CB371’.
You can change the foreground and background colors of a face with M-x
set-face-foreground and M-x set-face-background. These commands prompt
in the minibuffer for a face name and a color, with completion, and then set that face
to use the specified color. They affect the face colors on all frames, but their effects
do not persist for future Emacs sessions, unlike using the customization buffer or

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X resources. You can also use frame parameters to set foreground and background
colors for a specific frame; See Section 18.11 [Frame Parameters], page 175.

11.10 Standard Faces
Here are the standard faces for specifying text appearance. You can apply them to
specific text when you want the effects they produce.
default

This face is used for ordinary text that doesn’t specify any face. Its
background color is used as the frame’s background color.

bold

This face uses a bold variant of the default font.

italic

This face uses an italic variant of the default font.

bold-italic
This face uses a bold italic variant of the default font.
underline

This face underlines text.

fixed-pitch
This face forces use of a fixed-width font. It’s reasonable to customize
this face to use a different fixed-width font, if you like, but you should
not make it a variable-width font.
variable-pitch
This face forces use of a variable-width font.
shadow

This face is used for making the text less noticeable than the surrounding ordinary text. Usually this can be achieved by using shades of gray
in contrast with either black or white default foreground color.

Here’s an incomplete list of faces used to highlight parts of the text temporarily
for specific purposes. (Many other modes define their own faces for this purpose.)
highlight

This face is used for text highlighting in various contexts, such as when
the mouse cursor is moved over a hyperlink.

isearch

This face is used to highlight the current Isearch match (see
Section 12.1 [Incremental Search], page 91).

query-replace
This face is used to highlight the current Query Replace match (see
Section 12.9 [Replace], page 103).
lazy-highlight
This face is used to highlight “lazy matches” for Isearch and Query
Replace (matches other than the current one).
region

This face is used for displaying an active region (see Chapter 8 [Mark],
page 47). When Emacs is built with GTK support, its colors are taken
from the current GTK theme.

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secondary-selection
This face is used for displaying a secondary X selection (see
Section 9.3.3 [Secondary Selection], page 61).
trailing-whitespace
The face for highlighting excess spaces and tabs at the end of a line
when show-trailing-whitespace is non-nil (see Section 11.16 [Useless Whitespace], page 84).
escape-glyph
The face for displaying control characters and escape sequences (see
Section 11.19 [Text Display], page 87).
nobreak-space
The face for displaying “no-break” space characters (see Section 11.19
[Text Display], page 87).
The following faces control the appearance of parts of the Emacs frame:
mode-line

This face is used for the mode line of the currently selected window,
and for menu bars when toolkit menus are not used. By default, it’s
drawn with shadows for a “raised” effect on graphical displays, and
drawn as the inverse of the default face on non-windowed terminals.

mode-line-inactive
Like mode-line, but used for mode lines of the windows other than the
selected one (if mode-line-in-non-selected-windows is non-nil).
This face inherits from mode-line, so changes in that face affect mode
lines in all windows.
mode-line-highlight
Like highlight, but used for portions of text on mode lines.
mode-line-buffer-id
This face is used for buffer identification parts in the mode line.
header-line
Similar to mode-line for a window’s header line, which appears at the
top of a window just as the mode line appears at the bottom. Most
windows do not have a header line—only some special modes, such
Info mode, create one.
vertical-border
This face is used for the vertical divider between windows on text
terminals.
minibuffer-prompt
This face is used for the prompt strings displayed in the minibuffer. By default, Emacs automatically adds this face to the value of
minibuffer-prompt-properties, which is a list of text properties
used to display the prompt text. (This variable takes effect when you
enter the minibuffer.)

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fringe

The face for the fringes to the left and right of windows on graphic
displays. (The fringes are the narrow portions of the Emacs frame
between the text area and the window’s right and left borders.) See
Section 11.14 [Fringes], page 83.

cursor

The :background attribute of this face specifies the color of the text
cursor. See Section 11.20 [Cursor Display], page 88.

tooltip

This face is used for tooltip text. By default, if Emacs is built with
GTK support, tooltips are drawn via GTK and this face has no effect.
See Section 18.17 [Tooltips], page 178.

mouse

This face determines the color of the mouse pointer.

The following faces likewise control the appearance of parts of the Emacs frame,
but only on text terminals, or when Emacs is built on X with no toolkit support.
(For all other cases, the appearance of the respective frame elements is determined
by system-wide settings.)
scroll-bar
This face determines the visual appearance of the scroll bar. See
Section 18.12 [Scroll Bars], page 176.
tool-bar

This face determines the color of tool bar icons. See Section 18.15
[Tool Bars], page 177.

menu

This face determines the colors and font of Emacs’s menus.
Section 18.14 [Menu Bars], page 176.

See

11.11 Text Scale
To increase the height of the default face in the current buffer, type C-x C-+ or C-x
C-=. To decrease it, type C-x C--. To restore the default (global) face height, type
C-x C-0. These keys are all bound to the same command, text-scale-adjust,
which looks at the last key typed to determine which action to take.
The final key of these commands may be repeated without the leading C-x. For
instance, C-x C-= C-= C-= increases the face height by three steps. Each step scales
the text height by a factor of 1.2; to change this factor, customize the variable
text-scale-mode-step. As an exception, a numeric argument of 0 to the textscale-adjust command restores the default height, similar to typing C-x C-0.
The commands text-scale-increase and text-scale-decrease increase or
decrease the height of the default face, just like C-x C-+ and C-x C-- respectively.
You may find it convenient to bind to these commands, rather than text-scaleadjust.
The command text-scale-set scales the height of the default face in the current buffer to an absolute level specified by its prefix argument.
The above commands automatically enable the minor mode text-scale-mode
if the current font scaling is other than 1, and disable it otherwise.

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11.12 Font Lock mode
Font Lock mode is a minor mode, always local to a particular buffer, which assigns
faces to (or fontifies) the text in the buffer. Each buffer’s major mode tells Font
Lock mode which text to fontify; for instance, programming language modes fontify
syntactically relevant constructs like comments, strings, and function names.
Font Lock mode is enabled by default. To toggle it in the current buffer, type
M-x font-lock-mode. A positive numeric argument unconditionally enables Font
Lock mode, and a negative or zero argument disables it.
Type M-x global-font-lock-mode to toggle Font Lock mode in all buffers. To
impose this setting for future Emacs sessions, customize the variable global-fontlock-mode (see Section 33.1 [Easy Customization], page 434), or add the following
line to your init file:
(global-font-lock-mode 0)
If you have disabled Global Font Lock mode, you can still enable Font Lock for
specific major modes by adding the function font-lock-mode to the mode hooks
(see Section 33.2.2 [Hooks], page 445). For example, to enable Font Lock mode for
editing C files, you can do this:
(add-hook ’c-mode-hook ’font-lock-mode)
Font Lock mode uses several specifically named faces to do its job, including
font-lock-string-face, font-lock-comment-face, and others. The easiest way
to find them all is to use M-x customize-group RET font-lock-faces RET. You
can then use that customization buffer to customize the appearance of these faces.
See Section 33.1.5 [Face Customization], page 439.
You can customize the variable font-lock-maximum-decoration to alter the
amount of fontification applied by Font Lock mode, for major modes that support
this feature. The value should be a number (with 1 representing a minimal amount
of fontification; some modes support levels as high as 3); or t, meaning “as high as
possible” (the default). You can also specify different numbers for particular major
modes; for example, to use level 1 for C/C++ modes, and the default level otherwise,
use the value
’((c-mode . 1) (c++-mode . 1)))
Comment and string fontification (or “syntactic” fontification) relies on analysis
of the syntactic structure of the buffer text. For the sake of speed, some modes,
including Lisp mode, rely on a special convention: an open-parenthesis or openbrace in the leftmost column always defines the beginning of a defun, and is thus
always outside any string or comment. Therefore, you should avoid placing an
open-parenthesis or open-brace in the leftmost column, if it is inside a string or
comment. See Section 23.2.1 [Left Margin Paren], page 250, for details.
The variable font-lock-beginning-of-syntax-function, which is always
buffer-local, specifies how Font Lock mode can find a position guaranteed to be
outside any comment or string. In modes which use the leftmost column parenthesis convention, the default value of the variable is beginning-of-defun—that tells
Font Lock mode to use the convention. If you set this variable to nil, Font Lock
no longer relies on the convention. This avoids incorrect results, but the price is

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that, in some cases, fontification for a changed text must rescan buffer text from the
beginning of the buffer. This can considerably slow down redisplay while scrolling,
particularly if you are close to the end of a large buffer.
Font Lock highlighting patterns already exist for most modes, but you may want
to fontify additional patterns. You can use the function font-lock-add-keywords,
to add your own highlighting patterns for a particular mode. For example, to
highlight ‘FIXME:’ words in C comments, use this:
(add-hook ’c-mode-hook
(lambda ()
(font-lock-add-keywords nil
’(("\\<\\(FIXME\\):" 1
font-lock-warning-face t)))))
To remove keywords from the font-lock highlighting patterns, use the function fontlock-remove-keywords. See Section “Search-based Fontification” in The Emacs
Lisp Reference Manual.
Fontifying large buffers can take a long time. To avoid large delays when a file
is visited, Emacs initially fontifies only the visible portion of a buffer. As you scroll
through the buffer, each portion that becomes visible is fontified as soon as it is
displayed; this type of Font Lock is called Just-In-Time (or JIT) Lock. You can
control how JIT Lock behaves, including telling it to perform fontification while idle,
by customizing variables in the customization group ‘jit-lock’. See Section 33.1.6
[Specific Customization], page 440.

11.13 Interactive Highlighting
Highlight Changes mode is a minor mode that highlights the parts of the buffer
that were changed most recently, by giving that text a different face. To enable or
disable Highlight Changes mode, use M-x highlight-changes-mode.
Hi Lock mode is a minor mode that highlights text that matches regular expressions you specify. For example, you can use it to highlight all the references to
a certain variable in a program source file, highlight certain parts in a voluminous
output of some program, or highlight certain names in an article. To enable or disable Hi Lock mode, use the command M-x hi-lock-mode. To enable Hi Lock mode
for all buffers, use M-x global-hi-lock-mode or place (global-hi-lock-mode 1)
in your ‘.emacs’ file.
Hi Lock mode works like Font Lock mode (see Section 11.12 [Font Lock],
page 80), except that you specify explicitly the regular expressions to highlight.
You control them with these commands:
C-x w h regexp RET face RET
Highlight text that matches regexp using face face (highlightregexp). The highlighting will remain as long as the buffer is loaded.
For example, to highlight all occurrences of the word “whim” using
the default face (a yellow background) C-x w h whim RET RET. Any
face can be used for highlighting, Hi Lock provides several of its own

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and these are pre-loaded into a list of default values. While being
prompted for a face use M-n and M-p to cycle through them.
You can use this command multiple times, specifying various regular
expressions to highlight in different ways.
C-x w r regexp RET
Unhighlight regexp (unhighlight-regexp).
If you invoke this from the menu, you select the expression to unhighlight from a list. If you invoke this from the keyboard, you use the
minibuffer. It will show the most recently added regular expression;
use M-p to show the next older expression and M-n to select the next
newer expression. (You can also type the expression by hand, with
completion.) When the expression you want to unhighlight appears in
the minibuffer, press RET to exit the minibuffer and unhighlight it.
C-x w l regexp RET face RET
Highlight entire lines containing a match for regexp, using face face
(highlight-lines-matching-regexp).
C-x w b

Insert all the current highlighting regexp/face pairs into the buffer at
point, with comment delimiters to prevent them from changing your
program. (This key binding runs the hi-lock-write-interactivepatterns command.)
These patterns are extracted from the comments, if appropriate, if you
invoke M-x hi-lock-find-patterns, or if you visit the file while Hi
Lock mode is enabled (since that runs hi-lock-find-patterns).

C-x w i

Extract regexp/face pairs from comments in the current buffer (hilock-find-patterns). Thus, you can enter patterns interactively
with highlight-regexp, store them into the file with hi-lockwrite-interactive-patterns, edit them (perhaps including different faces for different parenthesized parts of the match), and finally
use this command (hi-lock-find-patterns) to have Hi Lock highlight the edited patterns.
The variable hi-lock-file-patterns-policy controls whether Hi
Lock mode should automatically extract and highlight patterns found
in a file when it is visited. Its value can be nil (never highlight),
ask (query the user), or a function. If it is a function, hi-lockfind-patterns calls it with the patterns as argument; if the function
returns non-nil, the patterns are used. The default is ask. Note that
patterns are always highlighted if you call hi-lock-find-patterns
directly, regardless of the value of this variable.
Also, hi-lock-find-patterns does nothing if the current major
mode’s symbol is a member of the list hi-lock-exclude-modes.

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11.14 Window Fringes
On graphical displays, each Emacs window normally has narrow fringes on the left
and right edges. The fringes are used to display symbols that provide information
about the text in the window. You can type M-x fringe-mode to disable the fringes,
or modify their width. This command affects fringes in all frames; to modify fringes
on the selected frame only, use M-x set-fringe-style.
The most common use of the fringes is to indicate a continuation line (see
Section 4.8 [Continuation Lines], page 23). When one line of text is split into
multiple screen lines, the left fringe shows a curving arrow for each screen line
except the first, indicating that “this is not the real beginning”. The right fringe
shows a curving arrow for each screen line except the last, indicating that “this is not
the real end”. If the line’s direction is right-to-left (see Section 19.20 [Bidirectional
Editing], page 202), the meanings of the curving arrows in the fringes are swapped.
The fringes indicate line truncation with short horizontal arrows meaning
“there’s more text on this line which is scrolled horizontally out of view”. Clicking
the mouse on one of the arrows scrolls the display horizontally in the direction of
the arrow.
The fringes can also indicate other things, such as buffer boundaries (see
Section 11.15 [Displaying Boundaries], page 83), and where a program you are
debugging is executing (see Section 24.6 [Debuggers], page 276).
The fringe is also used for drawing the cursor, if the current line is exactly as
wide as the window and point is at the end of the line. To disable this, change the
variable overflow-newline-into-fringe to nil; this causes Emacs to continue or
truncate lines that are exactly as wide as the window.

11.15 Displaying Boundaries
On graphical displays, Emacs can indicate the buffer boundaries in the fringes. If
you enable this feature, the first line and the last line are marked with angle images
in the fringes. This can be combined with up and down arrow images which say
whether it is possible to scroll the window.
The buffer-local variable indicate-buffer-boundaries controls how the buffer
boundaries and window scrolling is indicated in the fringes. If the value is left
or right, both angle and arrow bitmaps are displayed in the left or right fringe,
respectively.
If value is an alist, each element (indicator . position ) specifies the position
of one of the indicators. The indicator must be one of top, bottom, up, down, or t
which specifies the default position for the indicators not present in the alist. The
position is one of left, right, or nil which specifies not to show this indicator.
For example, ((top . left) (t . right)) places the top angle bitmap in left
fringe, the bottom angle bitmap in right fringe, and both arrow bitmaps in right
fringe. To show just the angle bitmaps in the left fringe, but no arrow bitmaps, use
((top . left) (bottom . left)).

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11.16 Useless Whitespace
It is easy to leave unnecessary spaces at the end of a line, or empty lines at the end
of a file, without realizing it. In most cases, this trailing whitespace has no effect,
but there are special circumstances where it matters, and it can be a nuisance.
You can make trailing whitespace at the end of a line visible by setting the
buffer-local variable show-trailing-whitespace to t. Then Emacs displays trailing whitespace, using the face trailing-whitespace.
This feature does not apply when point is at the end of the line containing
the whitespace. Strictly speaking, that is “trailing whitespace” nonetheless, but
displaying it specially in that case looks ugly while you are typing in new text. In
this special case, the location of point is enough to show you that the spaces are
present.
Type M-x delete-trailing-whitespace to delete all trailing whitespace within
the buffer. If the region is active, it deletes all trailing whitespace in the region
instead.
On graphical displays, Emacs can indicate unused lines at the end of the window
with a small image in the left fringe (see Section 11.14 [Fringes], page 83). The image
appears for screen lines that do not correspond to any buffer text, so blank lines at
the end of the buffer stand out because they lack this image. To enable this feature,
set the buffer-local variable indicate-empty-lines to a non-nil value. You can
enable or disable this feature for all new buffers by setting the default value of this
variable, e.g. (setq-default indicate-empty-lines t).
Whitespace mode is a buffer-local minor mode that lets you “visualize” many
kinds of whitespace in the buffer, by either drawing the whitespace characters with
a special face or displaying them as special glyphs. To toggle this mode, type M-x
whitespace-mode. The kinds of whitespace visualized are determined by the list
variable whitespace-style. Here is a partial list of possible elements (see the
variable’s documentation for the full list):
face

Enable all visualizations which use special faces. This element has
a special meaning: if it is absent from the list, none of the other
visualizations take effect except space-mark, tab-mark, and newlinemark.

trailing

Highlight trailing whitespace.

tabs

Highlight tab characters.

spaces

Highlight space and non-breaking space characters.

lines

Highlight lines longer than 80 lines. To change the column limit,
customize the variable whitespace-line-column.

newline

Highlight newlines.

empty

Highlight empty lines.

space-mark
Draw space and non-breaking characters with a special glyph.

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Draw tab characters with a special glyph.

newline-mark
Draw newline characters with a special glyph.

11.17 Selective Display
Emacs has the ability to hide lines indented more than a given number of columns.
You can use this to get an overview of a part of a program.
To hide lines in the current buffer, type C-x $ (set-selective-display) with
a numeric argument n. Then lines with at least n columns of indentation disappear
from the screen. The only indication of their presence is that three dots (‘...’)
appear at the end of each visible line that is followed by one or more hidden ones.
The commands C-n and C-p move across the hidden lines as if they were not
there.
The hidden lines are still present in the buffer, and most editing commands see
them as usual, so you may find point in the middle of the hidden text. When this
happens, the cursor appears at the end of the previous line, after the three dots.
If point is at the end of the visible line, before the newline that ends it, the cursor
appears before the three dots.
To make all lines visible again, type C-x $ with no argument.
If you set the variable selective-display-ellipses to nil, the three dots do
not appear at the end of a line that precedes hidden lines. Then there is no visible
indication of the hidden lines. This variable becomes local automatically when set.
See also Section 22.8 [Outline Mode], page 224 for another way to hide part of
the text in a buffer.

11.18 Optional Mode Line Features
The buffer percentage pos indicates the percentage of the buffer above the top
of the window. You can additionally display the size of the buffer by typing M-x
size-indication-mode to turn on Size Indication mode. The size will be displayed
immediately following the buffer percentage like this:
POS of SIZE
Here SIZE is the human readable representation of the number of characters in the
buffer, which means that ‘k’ for 10^3, ‘M’ for 10^6, ‘G’ for 10^9, etc., are used to
abbreviate.
The current line number of point appears in the mode line when Line Number
mode is enabled. Use the command M-x line-number-mode to turn this mode on
and off; normally it is on. The line number appears after the buffer percentage pos,
with the letter ‘L’ to indicate what it is.
Similarly, you can display the current column number by turning on Column
number mode with M-x column-number-mode. The column number is indicated by
the letter ‘C’. However, when both of these modes are enabled, the line and column
numbers are displayed in parentheses, the line number first, rather than with ‘L’

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and ‘C’. For example: ‘(561,2)’. See Section 20.2 [Minor Modes], page 205, for
more information about minor modes and about how to use these commands.
If you have narrowed the buffer (see Section 11.5 [Narrowing], page 74), the
displayed line number is relative to the accessible portion of the buffer. Thus, it
isn’t suitable as an argument to goto-line. (Use what-line command to see the
line number relative to the whole file.)
If the buffer is very large (larger than the value of line-number-displaylimit), Emacs won’t compute the line number, because that would be too slow;
therefore, the line number won’t appear on the mode-line. To remove this limit, set
line-number-display-limit to nil.
Line-number computation can also be slow if the lines in the buffer are too
long. For this reason, Emacs doesn’t display line numbers if the average width, in
characters, of lines near point is larger than the value of line-number-displaylimit-width. The default value is 200 characters.
Emacs can optionally display the time and system load in all mode lines. To
enable this feature, type M-x display-time or customize the option display-timemode. The information added to the mode line looks like this:
hh :mm pm l.ll
Here hh and mm are the hour and minute, followed always by ‘am’ or ‘pm’. l.ll is
the average number, collected for the last few minutes, of processes in the whole
system that were either running or ready to run (i.e. were waiting for an available
processor). (Some fields may be missing if your operating system cannot support
them.) If you prefer time display in 24-hour format, set the variable display-time24hr-format to t.
The word ‘Mail’ appears after the load level if there is mail for you that you
have not read yet. On graphical displays, you can use an icon instead of ‘Mail’
by customizing display-time-use-mail-icon; this may save some space on the
mode line. You can customize display-time-mail-face to make the mail indicator
prominent. Use display-time-mail-file to specify the mail file to check, or set
display-time-mail-directory to specify the directory to check for incoming mail
(any nonempty regular file in the directory is considered as “newly arrived mail”).
When running Emacs on a laptop computer, you can display the battery charge
on the mode-line, by using the command display-battery-mode or customizing
the variable display-battery-mode. The variable battery-mode-line-format
determines the way the battery charge is displayed; the exact mode-line message
depends on the operating system, and it usually shows the current battery charge
as a percentage of the total charge.
On graphical displays, the mode line is drawn as a 3D box. If you don’t like
this effect, you can disable it by customizing the mode-line face and setting its box
attribute to nil. See Section 33.1.5 [Face Customization], page 439.
By default, the mode line of nonselected windows is displayed in a different
face, called mode-line-inactive. Only the selected window is displayed in the
mode-line face. This helps show which window is selected. When the minibuffer
is selected, since it has no mode line, the window from which you activated the

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minibuffer has its mode line displayed using mode-line; as a result, ordinary entry
to the minibuffer does not change any mode lines.
You can disable use of mode-line-inactive by setting variable mode-line-innon-selected-windows to nil; then all mode lines are displayed in the mode-line
face.
You can customize the mode line display for each of the end-of-line formats
by setting each of the variables eol-mnemonic-unix, eol-mnemonic-dos, eolmnemonic-mac, and eol-mnemonic-undecided to the strings you prefer.

11.19 How Text Is Displayed
Most characters are printing characters: when they appear in a buffer, they are
displayed literally on the screen. Printing characters include ASCII numbers, letters,
and punctuation characters, as well as many non-ASCII characters.
The ASCII character set contains non-printing control characters. Two of these
are displayed specially: the newline character (Unicode code point U+000A) is displayed by starting a new line, while the tab character (U+0009) is displayed as a
space that extends to the next tab stop column (normally every 8 columns). The
number of spaces per tab is controlled by the buffer-local variable tab-width, which
must have an integer value between 1 and 1000, inclusive. Note that how the tab
character in the buffer is displayed has nothing to do with the definition of TAB as
a command.
Other ASCII control characters, whose codes are below U+0020 (octal 40, decimal
32), are displayed as a caret (‘^’) followed by the non-control version of the character,
with the escape-glyph face. For instance, the ‘control-A’ character, U+0001, is
displayed as ‘^A’.
The raw bytes with codes U+0080 (octal 200) through U+009F (octal 237) are
displayed as octal escape sequences, with the escape-glyph face. For instance,
character code U+0098 (octal 230) is displayed as ‘\230’. If you change the bufferlocal variable ctl-arrow to nil, the ASCII control characters are also displayed as
octal escape sequences instead of caret escape sequences.
Some non-ASCII characters have the same appearance as an ASCII space or
hyphen (minus) character. Such characters can cause problems if they are entered
into a buffer without your realization, e.g. by yanking; for instance, source code
compilers typically do not treat non-ASCII spaces as whitespace characters. To deal
with this problem, Emacs displays such characters specially: it displays U+00A0 (nobreak space) with the nobreak-space face, and it displays U+00AD (soft hyphen),
U+2010 (hyphen), and U+2011 (non-breaking hyphen) with the escape-glyph face.
To disable this, change the variable nobreak-char-display to nil. If you give this
variable a non-nil and non-t value, Emacs instead displays such characters as a
highlighted backslash followed by a space or hyphen.
You can customize the way any particular character code is displayed by means
of a display table. See Section “Display Tables” in The Emacs Lisp Reference
Manual.

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On graphical displays, some characters may have no glyphs in any of the fonts
available to Emacs. These glyphless characters are normally displayed as boxes
containing the hexadecimal character code. Similarly, on text terminals, characters
that cannot be displayed using the terminal encoding (see Section 19.13 [Terminal
Coding], page 196) are normally displayed as question signs. You can control the
display method by customizing the variable glyphless-char-display-control.
See Section “Glyphless Character Display” in The Emacs Lisp Reference Manual,
for details.

11.20 Displaying the Cursor
On a text terminal, the cursor’s appearance is controlled by the terminal, largely
out of the control of Emacs. Some terminals offer two different cursors: a “visible”
static cursor, and a “very visible” blinking cursor. By default, Emacs uses the very
visible cursor, and switches to it when you start or resume Emacs. If the variable
visible-cursor is nil when Emacs starts or resumes, it uses the normal cursor.
On a graphical display, many more properties of the text cursor can be altered.
To customize its color, change the :background attribute of the face named cursor
(see Section 33.1.5 [Face Customization], page 439). (The other attributes of this
face have no effect; the text shown under the cursor is drawn using the frame’s
background color.) To change its shape, customize the buffer-local variable cursortype; possible values are box (the default), hollow (a hollow box), bar (a vertical
bar), (bar . n ) (a vertical bar n pixels wide), hbar (a horizontal bar), (hbar . n )
(a horizontal bar n pixels tall), or nil (no cursor at all).
To disable cursor blinking, change the variable blink-cursor-mode to nil (see
Section 33.1 [Easy Customization], page 434), or add the line (blink-cursor-mode
0) to your init file. Alternatively, you can change how the cursor looks when it
“blinks off” by customizing the list variable blink-cursor-alist. Each element in
the list should have the form (on-type . off-type ); this means that if the cursor
is displayed as on-type when it blinks on (where on-type is one of the cursor types
described above), then it is displayed as off-type when it blinks off.
Some characters, such as tab characters, are “extra wide”. When the cursor is
positioned over such a character, it is normally drawn with the default character
width. You can make the cursor stretch to cover wide characters, by changing the
variable x-stretch-cursor to a non-nil value.
The cursor normally appears in non-selected windows as a non-blinking hollow
box. (For a bar cursor, it instead appears as a thinner bar.) To turn off cursors in
non-selected windows, change the variable cursor-in-non-selected-windows to
nil.
To make the cursor even more visible, you can use HL Line mode, a minor
mode that highlights the line containing point. Use M-x hl-line-mode to enable or
disable it in the current buffer. M-x global-hl-line-mode enables or disables the
same mode globally.

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11.21 Line Truncation
As an alternative to continuation (see Section 4.8 [Continuation Lines], page 23),
Emacs can display long lines by truncation. This means that all the characters that
do not fit in the width of the screen or window do not appear at all. On graphical
displays, a small straight arrow in the fringe indicates truncation at either end of
the line. On text terminals, this is indicated with ‘$’ signs in the leftmost and/or
rightmost columns.
Horizontal scrolling automatically causes line truncation (see Section 11.4 [Horizontal Scrolling], page 73). You can explicitly enable line truncation for a particular buffer with the command M-x toggle-truncate-lines. This works by locally
changing the variable truncate-lines. If that variable is non-nil, long lines are
truncated; if it is nil, they are continued onto multiple screen lines. Setting the
variable truncate-lines in any way makes it local to the current buffer; until that
time, the default value, which is normally nil, is in effect.
If a split window becomes too narrow, Emacs may automatically enable line
truncation. See Section 17.2 [Split Window], page 159, for the variable truncatepartial-width-windows which controls this.

11.22 Visual Line Mode
Another alternative to ordinary line continuation is to use word wrap. Here, each
long logical line is divided into two or more screen lines, like in ordinary line continuation. However, Emacs attempts to wrap the line at word boundaries near the
right window edge. This makes the text easier to read, as wrapping does not occur
in the middle of words.
Word wrap is enabled by Visual Line mode, an optional minor mode. To turn
on Visual Line mode in the current buffer, type M-x visual-line-mode; repeating
this command turns it off. You can also turn on Visual Line mode using the menu
bar: in the Options menu, select the ‘Line Wrapping in this Buffer’ submenu,
followed by the ‘Word Wrap (Visual Line Mode)’ menu item. While Visual Line
mode is enabled, the mode-line shows the string ‘wrap’ in the mode display. The
command M-x global-visual-line-mode toggles Visual Line mode in all buffers.
In Visual Line mode, some editing commands work on screen lines instead of logical lines: C-a (beginning-of-visual-line) moves to the beginning of the screen
line, C-e (end-of-visual-line) moves to the end of the screen line, and C-k (killvisual-line) kills text to the end of the screen line.
To move by logical lines, use the commands M-x next-logical-line and M-x
previous-logical-line. These move point to the next logical line and the previous logical line respectively, regardless of whether Visual Line mode is enabled. If
you use these commands frequently, it may be convenient to assign key bindings to
them. See Section 33.3.6 [Init Rebinding], page 455.
By default, word-wrapped lines do not display fringe indicators. Visual Line
mode is often used to edit files that contain many long logical lines, so having a
fringe indicator for each wrapped line would be visually distracting. You can change
this by customizing the variable visual-line-fringe-indicators.

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11.23 Customization of Display
This section describes variables that control miscellaneous aspects of the appearance
of the Emacs screen. Beginning users can skip it.
If the variable visible-bell is non-nil, Emacs attempts to make the whole
screen blink when it would normally make an audible bell sound. This variable has
no effect if your terminal does not have a way to make the screen blink.
The variable echo-keystrokes controls the echoing of multi-character keys; its
value is the number of seconds of pause required to cause echoing to start, or zero,
meaning don’t echo at all. The value takes effect when there is something to echo.
See Section 1.2 [Echo Area], page 7.
On graphical displays, Emacs displays the mouse pointer as an hourglass if
Emacs is busy. To disable this feature, set the variable display-hourglass to nil.
The variable hourglass-delay determines the number of seconds of “busy time”
before the hourglass is shown; the default is 1.
If the mouse pointer lies inside an Emacs frame, Emacs makes it invisible each
time you type a character to insert text, to prevent it from obscuring the text.
(To be precise, the hiding occurs when you type a “self-inserting” character. See
Section 4.1 [Inserting Text], page 17.) Moving the mouse pointer makes it visible
again. To disable this feature, set the variable make-pointer-invisible to nil.
On graphical displays, the variable underline-minimum-offset determines the
minimum distance between the baseline and underline, in pixels, for underlined text.
By default, the value is 1; increasing it may improve the legibility of underlined text
for certain fonts. (However, Emacs will never draw the underline below the current
line area.) The variable x-underline-at-descent-line determines how to draw
underlined text. The default is nil, which means to draw it at the baseline level of
the font; if you change it to nil, Emacs draws the underline at the same height as
the font’s descent line.
The variable overline-margin specifies the vertical position of an overline above
the text, including the height of the overline itself, in pixels; the default is 2.
On some text terminals, bold face and inverse video together result in text that
is hard to read. Call the function tty-suppress-bold-inverse-default-colors
with a non-nil argument to suppress the effect of bold-face in this case.

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12 Searching and Replacement
Like other editors, Emacs has commands to search for occurrences of a string.
Emacs also has commands to replace occurrences of a string with a different string.
There are also commands that do the same thing, but search for patterns instead
of fixed strings.
You can also search multiple files under the control of a tags table (see
Section 25.3.6 [Tags Search], page 318) or through the Dired A command (see
Section 27.7 [Operating on Files], page 335), or ask the grep program to do it
(see Section 24.4 [Grep Searching], page 275).

12.1 Incremental Search
The principal search command in Emacs is incremental: it begins searching as soon
as you type the first character of the search string. As you type in the search
string, Emacs shows you where the string (as you have typed it so far) would be
found. When you have typed enough characters to identify the place you want, you
can stop. Depending on what you plan to do next, you may or may not need to
terminate the search explicitly with RET.
C-s

Incremental search forward (isearch-forward).

C-r

Incremental search backward (isearch-backward).

12.1.1 Basics of Incremental Search
C-s

Begin incremental search (isearch-forward).

C-r

Begin reverse incremental search (isearch-backward).

C-s (isearch-forward) starts a forward incremental search. It reads characters
from the keyboard, and moves point just past the end of the next occurrence of those
characters in the buffer.
For instance, if you type C-s and then F, that puts the cursor after the first
‘F’ that occurs in the buffer after the starting point. Then if you then type O, the
cursor moves to just after the first ‘FO’; the ‘F’ in that ‘FO’ might not be the first
‘F’ previously found. After another O, the cursor moves to just after the first ‘FOO’.
At each step, Emacs highlights the current match—the buffer text that matches
the search string—using the isearch face (see Section 11.8 [Faces], page 75). The
current search string is also displayed in the echo area.
If you make a mistake typing the search string, type DEL. Each DEL cancels
the last character of the search string.
When you are satisfied with the place you have reached, type RET. This stops
searching, leaving the cursor where the search brought it. Also, any command not
specially meaningful in searches stops the searching and is then executed. Thus,
typing C-a exits the search and then moves to the beginning of the line. RET is
necessary only if the next command you want to type is a printing character, DEL,
RET, or another character that is special within searches (C-q, C-w, C-r, C-s, C-y,
M-y, M-r, M-c, M-e, and some others described below).

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As a special exception, entering RET when the search string is empty launches
nonincremental search (see Section 12.2 [Nonincremental Search], page 95).
When you exit the incremental search, it adds the original value of point to the
mark ring, without activating the mark; you can thus use C-u C-SPC to return to
where you were before beginning the search. See Section 8.4 [Mark Ring], page 51.
It only does this if the mark was not already active.
To search backwards, use C-r (isearch-backward) instead of C-s to start the
search. A backward search finds matches that end before the starting point, just as
a forward search finds matches that begin after it.
12.1.2 Repeating Incremental Search
Suppose you search forward for ‘FOO’ and find a match, but not the one you expected
to find: the ‘FOO’ you were aiming for occurs later in the buffer. In this event, type
another C-s to move to the next occurrence of the search string. You can repeat this
any number of times. If you overshoot, you can cancel some C-s characters with
DEL. Similarly, each C-r in a backward incremental search repeats the backward
search.
If you pause for a little while during incremental search, Emacs highlights all
the other possible matches for the search string that are present on the screen.
This helps you anticipate where you can get to by typing C-s or C-r to repeat the
search. The other matches are highlighted differently from the current match, using
the customizable face lazy-highlight (see Section 11.8 [Faces], page 75). If you
don’t like this feature, you can disable it by setting isearch-lazy-highlight to
nil.
After exiting a search, you can search for the same string again by typing just
C-s C-s. The first C-s is the key that invokes incremental search, and the second
C-s means “search again”. Similarly, C-r C-r searches backward for the last search
string. In determining the last search string, it doesn’t matter whether the string
was searched for with C-s or C-r.
If you are searching forward but you realize you were looking for something
before the starting point, type C-r to switch to a backward search, leaving the
search string unchanged. Similarly, C-s in a backward search switches to a forward
search.
If a search is failing and you ask to repeat it by typing another C-s, it starts
again from the beginning of the buffer. Repeating a failing reverse search with C-r
starts again from the end. This is called wrapping around, and ‘Wrapped’ appears
in the search prompt once this has happened. If you keep on going past the original
starting point of the search, it changes to ‘Overwrapped’, which means that you are
revisiting matches that you have already seen.
To reuse earlier search strings, use the search ring. The commands M-p and M-n
move through the ring to pick a search string to reuse. These commands leave the
selected search ring element in the minibuffer, where you can edit it.
To edit the current search string in the minibuffer without replacing it with
items from the search ring, type M-e. Type C-s or C-r to finish editing the string
and search for it.

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12.1.3 Errors in Incremental Search
If your string is not found at all, the echo area says ‘Failing I-Search’, and the
cursor moves past the place where Emacs found as much of your string as it could.
Thus, if you search for ‘FOOT’, and there is no ‘FOOT’, you might see the cursor after
the ‘FOO’ in ‘FOOL’. In the echo area, the part of the search string that failed to
match is highlighted using the face isearch-fail.
At this point, there are several things you can do. If your string was mistyped,
you can use DEL to erase some of it and correct it. If you like the place you have
found, you can type RET to remain there. Or you can type C-g, which removes
from the search string the characters that could not be found (the ‘T’ in ‘FOOT’),
leaving those that were found (the ‘FOO’ in ‘FOOT’). A second C-g at that point
cancels the search entirely, returning point to where it was when the search started.
The quit command, C-g, does special things during searches; just what it does
depends on the status of the search. If the search has found what you specified and
is waiting for input, C-g cancels the entire search, moving the cursor back to where
you started the search. If C-g is typed when there are characters in the search string
that have not been found—because Emacs is still searching for them, or because
it has failed to find them—then the search string characters which have not been
found are discarded from the search string. With them gone, the search is now
successful and waiting for more input, so a second C-g will cancel the entire search.
12.1.4 Special Input for Incremental Search
Some of the characters you type during incremental search have special effects.
If the search string you entered contains only lower-case letters, the search is
case-insensitive; as long as an upper-case letter exists in the search string, the search
becomes case-sensitive. If you delete the upper-case character from the search string,
it ceases to have this effect. See Section 12.8 [Search Case], page 103.
To search for a newline character, type C-j.
To search for other control characters, such as CONTROL-S, quote it by typing C-q first (see Section 4.1 [Inserting Text], page 17). To search for non-ASCII
characters, you can either use C-q and enter its octal code, or use an input method
(see Section 19.4 [Input Methods], page 185). If an input method is enabled in the
current buffer when you start the search, you can use it in the search string also.
While typing the search string, you can toggle the input method with the command
C-\ (isearch-toggle-input-method). You can also turn on a non-default input
method with C-^ (isearch-toggle-specified-input-method), which prompts for
the name of the input method. When an input method is active during incremental
search, the search prompt includes the input method mnemonic, like this:
I-search [im ]:
where im is the mnemonic of the active input method. Any input method you
enable during incremental search remains enabled in the current buffer afterwards.
Typing M-% in incremental search invokes query-replace or query-replaceregexp (depending on search mode) with the current search string used as the string
to replace. See Section 12.9.4 [Query Replace], page 106.

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Typing M-TAB in incremental search invokes isearch-complete, which attempts
to complete the search string using the search ring as a list of completion alternatives. See Section 5.3 [Completion], page 29. In many operating systems, the
M-TAB key sequence is captured by the window manager; you then need to rebind
isearch-complete to another key sequence if you want to use it (see Section 33.3.5
[Rebinding], page 454).
When incremental search is active, you can type C-h C-h to access interactive
help options, including a list of special key bindings. These key bindings are part
of the keymap isearch-mode-map (see Section 33.3.1 [Keymaps], page 452).
12.1.5 Isearch Yanking
Within incremental search, C-y (isearch-yank-kill) appends the current kill to
the search string. M-y (isearch-yank-pop), if called after C-y, replaces that appended text with an earlier kill, similar to the usual M-y (yank-pop) command
(see Section 9.2 [Yanking], page 57). Mouse-2 appends the current X selection (see
Section 9.3.2 [Primary Selection], page 60).
C-w (isearch-yank-word-or-char) appends the next character or word at point
to the search string. This is an easy way to search for another occurrence of the
text at point. (The decision of whether to copy a character or a word is heuristic.)
Similarly, M-s C-e (isearch-yank-line) appends the rest of the current line to
the search string. If point is already at the end of a line, it appends the next line.
If the search is currently case-insensitive, both C-w and M-s C-e convert the text
they copy to lower case, so that the search remains case-insensitive.
C-M-w (isearch-del-char) deletes the last character from the search string, and
C-M-y (isearch-yank-char) appends the character after point to the search string.
An alternative method to add the character after point is to enter the minibuffer
with M-e (see Section 12.1.2 [Repeat Isearch], page 92) and type C-f at the end of
the search string in the minibuffer.
12.1.6 Scrolling During Incremental Search
Normally, scrolling commands exit incremental search. If you change the variable
isearch-allow-scroll to a non-nil value, that enables the use of the scroll-bar,
as well as keyboard scrolling commands like C-v, M-v, and C-l (see Section 11.1
[Scrolling], page 70). This applies only to calling these commands via their bound
key sequences—typing M-x will still exit the search. You can give prefix arguments
to these commands in the usual way. This feature won’t let you scroll the current
match out of visibility, however.
The isearch-allow-scroll feature also affects some other commands, such as
C-x 2 (split-window-below) and C-x ^ (enlarge-window), which don’t exactly
scroll but do affect where the text appears on the screen. It applies to any command
whose name has a non-nil isearch-scroll property. So you can control which
commands are affected by changing these properties.
For example, to make C-h l usable within an incremental search in all future
Emacs sessions, use C-h c to find what command it runs (see Section 7.1 [Key Help],

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page 40), which is view-lossage. Then you can put the following line in your init
file (see Section 33.4 [Init File], page 461):
(put ’view-lossage ’isearch-scroll t)
This feature can be applied to any command that doesn’t permanently change point,
the buffer contents, the match data, the current buffer, or the selected window and
frame. The command must not itself attempt an incremental search.
12.1.7 Searching the Minibuffer
If you start an incremental search while the minibuffer is active, Emacs searches the
contents of the minibuffer. Unlike searching an ordinary buffer, the search string is
not shown in the echo area, because that is used to display the minibuffer.
If an incremental search fails in the minibuffer, it tries searching the minibuffer
history. See Section 5.4 [Minibuffer History], page 34. You can visualize the minibuffer and its history as a series of “pages”, with the earliest history element on
the first page and the current minibuffer on the last page. A forward search, C-s,
searches forward to later pages; a reverse search, C-r, searches backwards to earlier
pages. Like in ordinary buffer search, a failing search can wrap around, going from
the last page to the first page or vice versa.
When the current match is on a history element, that history element is pulled
into the minibuffer. If you exit the incremental search normally (e.g. by typing
RET), it remains in the minibuffer afterwards. Canceling the search, with C-g,
restores the contents of the minibuffer when you began the search.

12.2 Nonincremental Search
Emacs also has conventional nonincremental search commands, which require you
to type the entire search string before searching begins.
C-s RET string RET
Search for string.
C-r RET string RET
Search backward for string.
To start a nonincremental search, first type C-s RET. This enters the minibuffer
to read the search string; terminate the string with RET, and then the search takes
place. If the string is not found, the search command signals an error.
When you type C-s RET, the C-s invokes incremental search as usual. That command is specially programmed to invoke the command for nonincremental search,
search-forward, if the string you specify is empty. (Such an empty argument
would otherwise be useless.) C-r RET does likewise, invoking the command searchbackward.

12.3 Word Search
A word search finds a sequence of words without regard to the type of punctuation
between them. For instance, if you enter a search string that consists of two words

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separated by a single space, the search matches any sequence of those two words
separated by one or more spaces, newlines, or other punctuation characters. This is
particularly useful for searching text documents, because you don’t have to worry
whether the words you are looking for are separated by newlines or spaces.
M-s w

If incremental search is active, toggle word search mode (isearchtoggle-word); otherwise, begin an incremental forward word search
(isearch-forward-word).

M-s w RET words RET
Search for words, using a forward nonincremental word search.
M-s w C-r RET words RET
Search backward for words, using a nonincremental word search.
To begin a forward incremental word search, type M-s w. If incremental search is
not already active, this runs the command isearch-forward-word. If incremental
search is already active (whether a forward or backward search), M-s w switches to
a word search while keeping the direction of the search and the current search string
unchanged. You can toggle word search back off by typing M-s w again.
To begin a nonincremental word search, type M-s w RET for a forward search,
or M-s w C-r RET for a backward search. These run the commands word-searchforward and word-search-backward respectively.
Incremental and nonincremental word searches differ slightly in the way they
find a match. In a nonincremental word search, the last word in the search string
must exactly match a whole word. In an incremental word search, the matching is
more lax: the last word in the search string can match part of a word, so that the
matching proceeds incrementally as you type. This additional laxity does not apply
to the lazy highlight, which always matches whole words.

12.4 Regular Expression Search
A regular expression (or regexp for short) is a pattern that denotes a class of alternative strings to match. Emacs provides both incremental and nonincremental ways
to search for a match for a regexp. The syntax of regular expressions is explained
in the next section.
C-M-s

Begin incremental regexp search (isearch-forward-regexp).

C-M-r

Begin reverse incremental regexp search (isearch-backwardregexp).

Incremental search for a regexp is done by typing C-M-s (isearch-forwardregexp), by invoking C-s with a prefix argument (whose value does not matter), or
by typing M-r within a forward incremental search. This command reads a search
string incrementally just like C-s, but it treats the search string as a regexp rather
than looking for an exact match against the text in the buffer. Each time you add
text to the search string, you make the regexp longer, and the new regexp is searched
for. To search backward for a regexp, use C-M-r (isearch-backward-regexp), C-r
with a prefix argument, or M-r within a backward incremental search.

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All of the special key sequences in an ordinary incremental search do similar
things in an incremental regexp search. For instance, typing C-s immediately after
starting the search retrieves the last incremental search regexp used and searches
forward for it. Incremental regexp and non-regexp searches have independent defaults. They also have separate search rings, which you can access with M-p and
M-n.
If you type SPC in incremental regexp search, it matches any sequence of whitespace characters, including newlines. If you want to match just a space, type C-q
SPC. You can control what a bare space matches by setting the variable searchwhitespace-regexp to the desired regexp.
In some cases, adding characters to the regexp in an incremental regexp search
can make the cursor move back and start again. For example, if you have searched
for ‘foo’ and you add ‘\|bar’, the cursor backs up in case the first ‘bar’ precedes
the first ‘foo’. See Section 12.5 [Regexps], page 97.
Forward and backward regexp search are not symmetrical, because regexp
matching in Emacs always operates forward, starting with the beginning of the
regexp. Thus, forward regexp search scans forward, trying a forward match at each
possible starting position. Backward regexp search scans backward, trying a forward match at each possible starting position. These search methods are not mirror
images.
Nonincremental search for a regexp is done with the commands re-searchforward and re-search-backward. You can invoke these with M-x, or by way of
incremental regexp search with C-M-s RET and C-M-r RET.
If you use the incremental regexp search commands with a prefix argument, they
perform ordinary string search, like isearch-forward and isearch-backward. See
Section 12.1 [Incremental Search], page 91.

12.5 Syntax of Regular Expressions
This manual describes regular expression features that users typically use. See
Section “Regular Expressions” in The Emacs Lisp Reference Manual, for additional
features used mainly in Lisp programs.
Regular expressions have a syntax in which a few characters are special constructs and the rest are ordinary. An ordinary character matches that same character and nothing else. The special characters are ‘$^.*+?[\’. The character ‘]’ is
special if it ends a character alternative (see later). The character ‘-’ is special inside a character alternative. Any other character appearing in a regular expression
is ordinary, unless a ‘\’ precedes it. (When you use regular expressions in a Lisp
program, each ‘\’ must be doubled, see the example near the end of this section.)
For example, ‘f’ is not a special character, so it is ordinary, and therefore ‘f’ is
a regular expression that matches the string ‘f’ and no other string. (It does not
match the string ‘ff’.) Likewise, ‘o’ is a regular expression that matches only ‘o’.
(When case distinctions are being ignored, these regexps also match ‘F’ and ‘O’, but
we consider this a generalization of “the same string”, rather than an exception.)

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Any two regular expressions a and b can be concatenated. The result is a regular
expression which matches a string if a matches some amount of the beginning of
that string and b matches the rest of the string. For example, concatenating the
regular expressions ‘f’ and ‘o’ gives the regular expression ‘fo’, which matches only
the string ‘fo’. Still trivial. To do something nontrivial, you need to use one of the
special characters. Here is a list of them.
. (Period)

is a special character that matches any single character except a newline. For example, the regular expressions ‘a.b’ matches any threecharacter string that begins with ‘a’ and ends with ‘b’.

*

is not a construct by itself; it is a postfix operator that means to
match the preceding regular expression repetitively any number of
times, as many times as possible. Thus, ‘o*’ matches any number of
‘o’s, including no ‘o’s.
‘*’ always applies to the smallest possible preceding expression. Thus,
‘fo*’ has a repeating ‘o’, not a repeating ‘fo’. It matches ‘f’, ‘fo’,
‘foo’, and so on.
The matcher processes a ‘*’ construct by matching, immediately, as
many repetitions as can be found. Then it continues with the rest of
the pattern. If that fails, backtracking occurs, discarding some of the
matches of the ‘*’-modified construct in case that makes it possible
to match the rest of the pattern. For example, in matching ‘ca*ar’
against the string ‘caaar’, the ‘a*’ first tries to match all three ‘a’s;
but the rest of the pattern is ‘ar’ and there is only ‘r’ left to match, so
this try fails. The next alternative is for ‘a*’ to match only two ‘a’s.
With this choice, the rest of the regexp matches successfully.

+

is a postfix operator, similar to ‘*’ except that it must match the
preceding expression at least once. Thus, ‘ca+r’ matches the strings
‘car’ and ‘caaaar’ but not the string ‘cr’, whereas ‘ca*r’ matches all
three strings.

?

is a postfix operator, similar to ‘*’ except that it can match the preceding expression either once or not at all. Thus, ‘ca?r’ matches ‘car’
or ‘cr’, and nothing else.

*?, +?, ??

are non-greedy variants of the operators above. The normal operators
‘*’, ‘+’, ‘?’ match as much as they can, as long as the overall regexp can
still match. With a following ‘?’, they will match as little as possible.
Thus, both ‘ab*’ and ‘ab*?’ can match the string ‘a’ and the string
‘abbbb’; but if you try to match them both against the text ‘abbb’,
‘ab*’ will match it all (the longest valid match), while ‘ab*?’ will match
just ‘a’ (the shortest valid match).
Non-greedy operators match the shortest possible string starting at a
given starting point; in a forward search, though, the earliest possible
starting point for match is always the one chosen. Thus, if you search

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for ‘a.*?$’ against the text ‘abbab’ followed by a newline, it matches
the whole string. Since it can match starting at the first ‘a’, it does.
\{n \}

is a postfix operator specifying n repetitions—that is, the preceding
regular expression must match exactly n times in a row. For example,
‘x\{4\}’ matches the string ‘xxxx’ and nothing else.

\{n,m \}

is a postfix operator specifying between n and m repetitions—that is,
the preceding regular expression must match at least n times, but no
more than m times. If m is omitted, then there is no upper limit, but
the preceding regular expression must match at least n times.
‘\{0,1\}’ is equivalent to ‘?’.
‘\{0,\}’ is equivalent to ‘*’.
‘\{1,\}’ is equivalent to ‘+’.

[ ... ]

is a character set, beginning with ‘[’ and terminated by ‘]’.
In the simplest case, the characters between the two brackets are what
this set can match. Thus, ‘[ad]’ matches either one ‘a’ or one ‘d’, and
‘[ad]*’ matches any string composed of just ‘a’s and ‘d’s (including
the empty string). It follows that ‘c[ad]*r’ matches ‘cr’, ‘car’, ‘cdr’,
‘caddaar’, etc.
You can also include character ranges in a character set, by writing the
starting and ending characters with a ‘-’ between them. Thus, ‘[a-z]’
matches any lower-case ASCII letter. Ranges may be intermixed freely
with individual characters, as in ‘[a-z$%.]’, which matches any lowercase ASCII letter or ‘$’, ‘%’ or period.
You can also include certain special character classes in a character set.
A ‘[:’ and balancing ‘:]’ enclose a character class inside a character
alternative. For instance, ‘[[:alnum:]]’ matches any letter or digit.
See Section “Char Classes” in The Emacs Lisp Reference Manual, for
a list of character classes.
To include a ‘]’ in a character set, you must make it the first character.
For example, ‘[]a]’ matches ‘]’ or ‘a’. To include a ‘-’, write ‘-’ as
the first or last character of the set, or put it after a range. Thus,
‘[]-]’ matches both ‘]’ and ‘-’.
To include ‘^’ in a set, put it anywhere but at the beginning of the
set. (At the beginning, it complements the set—see below.)
When you use a range in case-insensitive search, you should write both
ends of the range in upper case, or both in lower case, or both should
be non-letters. The behavior of a mixed-case range such as ‘A-z’ is
somewhat ill-defined, and it may change in future Emacs versions.

[^ ... ]

‘[^’ begins a complemented character set, which matches any character except the ones specified. Thus, ‘[^a-z0-9A-Z]’ matches all
characters except ASCII letters and digits.

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‘^’ is not special in a character set unless it is the first character. The
character following the ‘^’ is treated as if it were first (in other words,
‘-’ and ‘]’ are not special there).
A complemented character set can match a newline, unless newline is
mentioned as one of the characters not to match. This is in contrast
to the handling of regexps in programs such as grep.
^

is a special character that matches the empty string, but only at the
beginning of a line in the text being matched. Otherwise it fails to
match anything. Thus, ‘^foo’ matches a ‘foo’ that occurs at the
beginning of a line.
For historical compatibility reasons, ‘^’ can be used with this meaning
only at the beginning of the regular expression, or after ‘\(’ or ‘\|’.

$

is similar to ‘^’ but matches only at the end of a line. Thus, ‘x+$’
matches a string of one ‘x’ or more at the end of a line.
For historical compatibility reasons, ‘$’ can be used with this meaning
only at the end of the regular expression, or before ‘\)’ or ‘\|’.

\

has two functions: it quotes the special characters (including ‘\’), and
it introduces additional special constructs.
Because ‘\’ quotes special characters, ‘\$’ is a regular expression that
matches only ‘$’, and ‘\[’ is a regular expression that matches only
‘[’, and so on.
See the following section for the special constructs that begin with ‘\’.

Note: for historical compatibility, special characters are treated as ordinary ones
if they are in contexts where their special meanings make no sense. For example,
‘*foo’ treats ‘*’ as ordinary since there is no preceding expression on which the ‘*’
can act. It is poor practice to depend on this behavior; it is better to quote the
special character anyway, regardless of where it appears.
As a ‘\’ is not special inside a character alternative, it can never remove the
special meaning of ‘-’ or ‘]’. So you should not quote these characters when they
have no special meaning either. This would not clarify anything, since backslashes
can legitimately precede these characters where they have special meaning, as in
‘[^\]’ ("[^\\]" for Lisp string syntax), which matches any single character except
a backslash.

12.6 Backslash in Regular Expressions
For the most part, ‘\’ followed by any character matches only that character. However, there are several exceptions: two-character sequences starting with ‘\’ that
have special meanings. The second character in the sequence is always an ordinary
character when used on its own. Here is a table of ‘\’ constructs.
\|

specifies an alternative. Two regular expressions a and b with ‘\|’ in
between form an expression that matches some text if either a matches

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it or b matches it. It works by trying to match a, and if that fails, by
trying to match b.
Thus, ‘foo\|bar’ matches either ‘foo’ or ‘bar’ but no other string.
‘\|’ applies to the largest possible surrounding expressions. Only a
surrounding ‘\( ... \)’ grouping can limit the grouping power of ‘\|’.
Full backtracking capability exists to handle multiple uses of ‘\|’.
\( ... \)

is a grouping construct that serves three purposes:
1. To enclose a set of ‘\|’ alternatives for other operations. Thus,
‘\(foo\|bar\)x’ matches either ‘foox’ or ‘barx’.
2. To enclose a complicated expression for the postfix operators ‘*’,
‘+’ and ‘?’ to operate on. Thus, ‘ba\(na\)*’ matches ‘bananana’,
etc., with any (zero or more) number of ‘na’ strings.
3. To record a matched substring for future reference.
This last application is not a consequence of the idea of a parenthetical
grouping; it is a separate feature that is assigned as a second meaning
to the same ‘\( ... \)’ construct. In practice there is usually no
conflict between the two meanings; when there is a conflict, you can
use a “shy” group.

\(?: ... \)
specifies a “shy” group that does not record the matched substring;
you can’t refer back to it with ‘\d ’. This is useful in mechanically
combining regular expressions, so that you can add groups for syntactic
purposes without interfering with the numbering of the groups that
are meant to be referred to.
\d

matches the same text that matched the dth occurrence of a ‘\( ...
\)’ construct. This is called a back reference.
After the end of a ‘\( ... \)’ construct, the matcher remembers the
beginning and end of the text matched by that construct. Then, later
on in the regular expression, you can use ‘\’ followed by the digit d to
mean “match the same text matched the dth time by the ‘\( ... \)’
construct”.
The strings matching the first nine ‘\( ... \)’ constructs appearing
in a regular expression are assigned numbers 1 through 9 in the order
that the open-parentheses appear in the regular expression. So you can
use ‘\1’ through ‘\9’ to refer to the text matched by the corresponding
‘\( ... \)’ constructs.
For example, ‘\(.*\)\1’ matches any newline-free string that is composed of two identical halves. The ‘\(.*\)’ matches the first half,
which may be anything, but the ‘\1’ that follows must match the
same exact text.
If a particular ‘\( ... \)’ construct matches more than once (which
can easily happen if it is followed by ‘*’), only the last match is
recorded.

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\‘

matches the empty string, but only at the beginning of the string or
buffer (or its accessible portion) being matched against.

\’

matches the empty string, but only at the end of the string or buffer
(or its accessible portion) being matched against.

\=

matches the empty string, but only at point.

\b

matches the empty string, but only at the beginning or end of a word.
Thus, ‘\bfoo\b’ matches any occurrence of ‘foo’ as a separate word.
‘\bballs?\b’ matches ‘ball’ or ‘balls’ as a separate word.
‘\b’ matches at the beginning or end of the buffer regardless of what
text appears next to it.

\B

matches the empty string, but not at the beginning or end of a word.

\<

matches the empty string, but only at the beginning of a word. ‘\<’
matches at the beginning of the buffer only if a word-constituent character follows.

\>

matches the empty string, but only at the end of a word. ‘\>’ matches
at the end of the buffer only if the contents end with a word-constituent
character.

\w

matches any word-constituent character. The syntax table determines
which characters these are. See Section “Syntax Tables” in The Emacs
Lisp Reference Manual.

\W

matches any character that is not a word-constituent.

\_<

matches the empty string, but only at the beginning of a symbol. A
symbol is a sequence of one or more symbol-constituent characters. A
symbol-constituent character is a character whose syntax is either ‘w’
or ‘_’. ‘\_<’ matches at the beginning of the buffer only if a symbolconstituent character follows.

\_>

matches the empty string, but only at the end of a symbol. ‘\_>’
matches at the end of the buffer only if the contents end with a symbolconstituent character.

\sc

matches any character whose syntax is c. Here c is a character that
designates a particular syntax class: thus, ‘w’ for word constituent, ‘-’
or ‘ ’ for whitespace, ‘.’ for ordinary punctuation, etc. See Section
“Syntax Tables” in The Emacs Lisp Reference Manual.

\Sc

matches any character whose syntax is not c.

\cc

matches any character that belongs to the category c. For example, ‘\cc’ matches Chinese characters, ‘\cg’ matches Greek characters, etc. For the description of the known categories, type M-x describe-categories RET.

\Cc

matches any character that does not belong to category c.

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The constructs that pertain to words and syntax are controlled by the setting
of the syntax table. See Section “Syntax Tables” in The Emacs Lisp Reference
Manual.

12.7 Regular Expression Example
Here is an example of a regexp—similar to the regexp that Emacs uses, by default, to
recognize the end of a sentence, not including the following space (i.e., the variable
sentence-end-base):
[.?!][]\"’)}]*
This contains two parts in succession: a character set matching period, ‘?’, or ‘!’,
and a character set matching close-brackets, quotes, or parentheses, repeated zero
or more times.

12.8 Searching and Case
Searches in Emacs normally ignore the case of the text they are searching through, if
you specify the text in lower case. Thus, if you specify searching for ‘foo’, then ‘Foo’
and ‘foo’ also match. Regexps, and in particular character sets, behave likewise:
‘[ab]’ matches ‘a’ or ‘A’ or ‘b’ or ‘B’.
An upper-case letter anywhere in the incremental search string makes the search
case-sensitive. Thus, searching for ‘Foo’ does not find ‘foo’ or ‘FOO’. This applies to
regular expression search as well as to string search. The effect ceases if you delete
the upper-case letter from the search string.
Typing M-c within an incremental search toggles the case sensitivity of that
search. The effect does not extend beyond the current incremental search to the
next one, but it does override the effect of adding or removing an upper-case letter
in the current search.
If you set the variable case-fold-search to nil, then all letters must match
exactly, including case. This is a per-buffer variable; altering the variable normally
affects only the current buffer, unless you change its default value. See Section 33.2.3
[Locals], page 446. This variable applies to nonincremental searches also, including
those performed by the replace commands (see Section 12.9 [Replace], page 103)
and the minibuffer history matching commands (see Section 5.4 [Minibuffer History],
page 34).
Several related variables control case-sensitivity of searching and matching for
specific commands or activities. For instance, tags-case-fold-search controls
case sensitivity for find-tag. To find these variables, do M-x apropos-variable
RET case-fold-search RET.

12.9 Replacement Commands
Emacs provides several commands for performing search-and-replace operations.
In addition to the simple M-x replace-string command, there is M-% (queryreplace), which presents each occurrence of the pattern and asks you whether to
replace it.

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The replace commands normally operate on the text from point to the end of
the buffer. When the region is active, they operate on it instead (see Chapter 8
[Mark], page 47). The basic replace commands replace one search string (or regexp) with one replacement string. It is possible to perform several replacements in
parallel, using the command expand-region-abbrevs (see Section 26.3 [Expanding
Abbrevs], page 323).
12.9.1 Unconditional Replacement
M-x replace-string RET string RET newstring RET
Replace every occurrence of string with newstring.
To replace every instance of ‘foo’ after point with ‘bar’, use the command M-x
replace-string with the two arguments ‘foo’ and ‘bar’. Replacement happens
only in the text after point, so if you want to cover the whole buffer you must go
to the beginning first. All occurrences up to the end of the buffer are replaced; to
limit replacement to part of the buffer, activate the region around that part. When
the region is active, replacement is limited to the region (see Chapter 8 [Mark],
page 47).
When replace-string exits, it leaves point at the last occurrence replaced. It
adds the prior position of point (where the replace-string command was issued)
to the mark ring, without activating the mark; use C-u C-SPC to move back there.
See Section 8.4 [Mark Ring], page 51.
A prefix argument restricts replacement to matches that are surrounded by word
boundaries.
See Section 12.9.3 [Replacement and Case], page 105, for details about casesensitivity in replace commands.
12.9.2 Regexp Replacement
The M-x replace-string command replaces exact matches for a single string. The
similar command M-x replace-regexp replaces any match for a specified pattern.
M-x replace-regexp RET regexp RET newstring RET
Replace every match for regexp with newstring.
In replace-regexp, the newstring need not be constant: it can refer to all or
part of what is matched by the regexp. ‘\&’ in newstring stands for the entire match
being replaced. ‘\d ’ in newstring, where d is a digit, stands for whatever matched
the dth parenthesized grouping in regexp. (This is called a “back reference”.) ‘\#’
refers to the count of replacements already made in this command, as a decimal
number. In the first replacement, ‘\#’ stands for ‘0’; in the second, for ‘1’; and so
on. For example,
M-x replace-regexp RET c[ad]+r RET \&-safe RET
replaces (for example) ‘cadr’ with ‘cadr-safe’ and ‘cddr’ with ‘cddr-safe’.
M-x replace-regexp RET \(c[ad]+r\)-safe RET \1 RET
performs the inverse transformation. To include a ‘\’ in the text to replace with,
you must enter ‘\\’.

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If you want to enter part of the replacement string by hand each time, use ‘\?’
in the replacement string. Each replacement will ask you to edit the replacement
string in the minibuffer, putting point where the ‘\?’ was.
The remainder of this subsection is intended for specialized tasks and requires
knowledge of Lisp. Most readers can skip it.
You can use Lisp expressions to calculate parts of the replacement string. To
do this, write ‘\,’ followed by the expression in the replacement string. Each
replacement calculates the value of the expression and converts it to text without
quoting (if it’s a string, this means using the string’s contents), and uses it in the
replacement string in place of the expression itself. If the expression is a symbol,
one space in the replacement string after the symbol name goes with the symbol
name, so the value replaces them both.
Inside such an expression, you can use some special sequences. ‘\&’ and ‘\n ’
refer here, as usual, to the entire match as a string, and to a submatch as a string.
n may be multiple digits, and the value of ‘\n ’ is nil if subexpression n did not
match. You can also use ‘\#&’ and ‘\#n ’ to refer to those matches as numbers (this
is valid when the match or submatch has the form of a numeral). ‘\#’ here too
stands for the number of already-completed replacements.
Repeating our example to exchange ‘x’ and ‘y’, we can thus do it also this way:
M-x replace-regexp RET \(x\)\|y RET
\,(if \1 "y" "x") RET
For computing replacement strings for ‘\,’, the format function is often useful
(see Section “Formatting Strings” in The Emacs Lisp Reference Manual). For
example, to add consecutively numbered strings like ‘ABC00042’ to columns 73 to 80
(unless they are already occupied), you can use
M-x replace-regexp RET ^.\{0,72\}$ RET
\,(format "%-72sABC%05d" \& \#) RET
12.9.3 Replace Commands and Case
If the first argument of a replace command is all lower case, the command ignores
case while searching for occurrences to replace—provided case-fold-search is nonnil. If case-fold-search is set to nil, case is always significant in all searches.
In addition, when the newstring argument is all or partly lower case, replacement
commands try to preserve the case pattern of each occurrence. Thus, the command
M-x replace-string RET foo RET bar RET
replaces a lower case ‘foo’ with a lower case ‘bar’, an all-caps ‘FOO’ with ‘BAR’, and
a capitalized ‘Foo’ with ‘Bar’. (These three alternatives—lower case, all caps, and
capitalized, are the only ones that replace-string can distinguish.)
If upper-case letters are used in the replacement string, they remain upper case
every time that text is inserted. If upper-case letters are used in the first argument,
the second argument is always substituted exactly as given, with no case conversion.
Likewise, if either case-replace or case-fold-search is set to nil, replacement
is done without case conversion.

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12.9.4 Query Replace
M-% string RET newstring RET
Replace some occurrences of string with newstring.
C-M-% regexp RET newstring RET
Replace some matches for regexp with newstring.
If you want to change only some of the occurrences of ‘foo’ to ‘bar’, not all of
them, use M-% (query-replace). This command finds occurrences of ‘foo’ one by
one, displays each occurrence and asks you whether to replace it. Aside from querying, query-replace works just like replace-string (see Section 12.9.1 [Unconditional Replace], page 104). In particular, it preserves case provided case-replace
is non-nil, as it normally is (see Section 12.9.3 [Replacement and Case], page 105).
A numeric argument means to consider only occurrences that are bounded by worddelimiter characters.
C-M-% performs regexp search and replace (query-replace-regexp). It works
like replace-regexp except that it queries like query-replace.
These commands highlight the current match using the face query-replace.
They highlight other matches using lazy-highlight just like incremental search
(see Section 12.1 [Incremental Search], page 91). By default, query-replaceregexp will show the substituted replacement string for the current match in the
minibuffer. If you want to keep special sequences ‘\&’ and ‘\n ’ unexpanded, customize query-replace-show-replacement variable.
The characters you can type when you are shown a match for the string or
regexp are:
SPC

to replace the occurrence with newstring.

DEL

to skip to the next occurrence without replacing this one.

, (Comma) to replace this occurrence and display the result. You are then asked
for another input character to say what to do next. Since the replacement has already been made, DEL and SPC are equivalent in this
situation; both move to the next occurrence.
You can type C-r at this point (see below) to alter the replaced text.
You can also type C-x u to undo the replacement; this exits the queryreplace, so if you want to do further replacement you must use C-x
ESC ESC RET to restart (see Section 5.5 [Repetition], page 35).
RET

to exit without doing any more replacements.

. (Period)

to replace this occurrence and then exit without searching for more
occurrences.

!

to replace all remaining occurrences without asking again.

^

to go back to the position of the previous occurrence (or what used
to be an occurrence), in case you changed it by mistake or want to
reexamine it.

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C-r

to enter a recursive editing level, in case the occurrence needs to be
edited rather than just replaced with newstring. When you are done,
exit the recursive editing level with C-M-c to proceed to the next occurrence. See Section 31.9 [Recursive Edit], page 424.

C-w

to delete the occurrence, and then enter a recursive editing level as
in C-r. Use the recursive edit to insert text to replace the deleted
occurrence of string. When done, exit the recursive editing level with
C-M-c to proceed to the next occurrence.

e

to edit the replacement string in the minibuffer. When you exit the
minibuffer by typing RET, the minibuffer contents replace the current
occurrence of the pattern. They also become the new replacement
string for any further occurrences.

C-l

to redisplay the screen. Then you must type another character to
specify what to do with this occurrence.

C-h

to display a message summarizing these options. Then you must type
another character to specify what to do with this occurrence.

Some other characters are aliases for the ones listed above: y, n and q are
equivalent to SPC, DEL and RET.
Aside from this, any other character exits the query-replace, and is then reread
as part of a key sequence. Thus, if you type C-k, it exits the query-replace and
then kills to end of line.
To restart a query-replace once it is exited, use C-x ESC ESC, which repeats the
query-replace because it used the minibuffer to read its arguments. See Section 5.5
[Repetition], page 35.
See Section 27.7 [Operating on Files], page 335, for the Dired Q command which
performs query replace on selected files. See also Section 27.9 [Transforming File
Names], page 338, for Dired commands to rename, copy, or link files by replacing
regexp matches in file names.

12.10 Other Search-and-Loop Commands
Here are some other commands that find matches for a regular expression. They
all ignore case in matching, if the pattern contains no upper-case letters and casefold-search is non-nil. Aside from occur and its variants, all operate on the text
from point to the end of the buffer, or on the region if it is active.
M-x multi-isearch-buffers
Prompt for one or more buffer names, ending with RET; then, begin a
multi-buffer incremental search in those buffers. (If the search fails in
one buffer, the next C-s tries searching the next specified buffer, and
so forth.) With a prefix argument, prompt for a regexp and begin a
multi-buffer incremental search in buffers matching that regexp.
M-x multi-isearch-buffers-regexp
This command is just like multi-isearch-buffers, except it performs an incremental regexp search.

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M-x occur

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Prompt for a regexp, and display a list showing each line in the buffer
that contains a match for it. To limit the search to part of the buffer,
narrow to that part (see Section 11.5 [Narrowing], page 74). A numeric
argument n specifies that n lines of context are to be displayed before
and after each matching line.
In the ‘*Occur*’ buffer, you can click on each entry, or move point
there and type RET, to visit the corresponding position in the buffer
that was searched. o and C-o display the match in another window;
C-o does not select it. Alternatively, you can use the C-x ‘ (nexterror) command to visit the occurrences one by one (see Section 24.2
[Compilation Mode], page 272).
Typing e in the ‘*Occur*’ buffer switches to Occur Edit mode, in
which edits made to the entries are also applied to the text in the
originating buffer. Type C-c C-c to return to Occur mode.
The command M-x list-matching-lines is a synonym for M-x
occur.

M-s o

Run occur using the search string of the last incremental string search.
You can also run M-s o when an incremental search is active; this uses
the current search string.

M-x multi-occur
This command is just like occur, except it is able to search through
multiple buffers. It asks you to specify the buffer names one by one.
M-x multi-occur-in-matching-buffers
This command is similar to multi-occur, except the buffers to search
are specified by a regular expression that matches visited file names.
With a prefix argument, it uses the regular expression to match buffer
names instead.
M-x how-many
Prompt for a regexp, and print the number of matches for it in the
buffer after point. If the region is active, this operates on the region
instead.
M-x flush-lines
Prompt for a regexp, and delete each line that contains a match for it,
operating on the text after point. This command deletes the current
line if it contains a match starting after point. If the region is active,
it operates on the region instead; if a line partially contained in the
region contains a match entirely contained in the region, it is deleted.
If a match is split across lines, flush-lines deletes all those lines.
It deletes the lines before starting to look for the next match; hence,
it ignores a match starting on the same line at which another match
ended.

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M-x keep-lines
Prompt for a regexp, and delete each line that does not contain a
match for it, operating on the text after point. If point is not at the
beginning of a line, this command always keeps the current line. If the
region is active, the command operates on the region instead; it never
deletes lines that are only partially contained in the region (a newline
that ends a line counts as part of that line).
If a match is split across lines, this command keeps all those lines.

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13 Commands for Fixing Typos
In this chapter we describe commands that are useful when you catch a mistake
while editing. The most fundamental of these commands is the undo command
C-/ (also bound to C-x u and C-_). This undoes a single command, or a part of
a command (as in the case of query-replace), or several consecutive character
insertions. Consecutive repetitions of C-/ undo earlier and earlier changes, back to
the limit of the undo information available.
Aside from the commands described here, you can erase text using deletion
commands such as DEL (delete-backward-char). These were described earlier in
this manual. See Section 4.3 [Erasing], page 20.

13.1 Undo
The undo command reverses recent changes in the buffer’s text. Each buffer records
changes individually, and the undo command always applies to the current buffer.
You can undo all the changes in a buffer for as far back as the buffer’s records go.
Usually, each editing command makes a separate entry in the undo records, but
some commands such as query-replace divide their changes into multiple entries
for flexibility in undoing. Consecutive character insertion commands are usually
grouped together into a single undo record, to make undoing less tedious.
C-/
C-x u
C-_

Undo one entry in the current buffer’s undo records (undo).

To begin to undo, type C-/ (or its aliases, C-_ or C-x u)1 . This undoes the
most recent change in the buffer, and moves point back to where it was before
that change. Consecutive repetitions of C-/ (or its aliases) undo earlier and earlier
changes in the current buffer. If all the recorded changes have already been undone,
the undo command signals an error.
Any command other than an undo command breaks the sequence of undo commands. Starting from that moment, the entire sequence of undo commands that
you have just performed are themselves placed into the undo record, as a single set
of changes. Therefore, to re-apply changes you have undone, type C-f or any other
command that harmlessly breaks the sequence of undoing; then type C-/ to undo
the undo command.
Alternatively, if you want to resume undoing, without redoing previous undo
commands, use M-x undo-only. This is like undo, but will not redo changes you
have just undone.
If you notice that a buffer has been modified accidentally, the easiest way to
recover is to type C-/ repeatedly until the stars disappear from the front of the
mode line (see Section 1.3 [Mode Line], page 8). Whenever an undo command
1

Aside from C-/, the undo command is also bound to C-x u because that is more straightforward for beginners to remember: ‘u’ stands for “undo”. It is also bound to C-_
because typing C-/ on some text terminals actually enters C-_.

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makes the stars disappear from the mode line, it means that the buffer contents
are the same as they were when the file was last read in or saved. If you do not
remember whether you changed the buffer deliberately, type C-/ once. When you
see the last change you made undone, you will see whether it was an intentional
change. If it was an accident, leave it undone. If it was deliberate, redo the change
as described above.
When there is an active region, any use of undo performs selective undo: it
undoes the most recent change within the region, instead of the entire buffer. However, when Transient Mark mode is off (see Section 8.7 [Disabled Transient Mark],
page 52), C-/ always operates on the entire buffer, ignoring the region. In this
case, you can perform selective undo by supplying a prefix argument to the undo
command: C-u C-/. To undo further changes in the same region, repeat the undo
command (no prefix argument is needed).
Some specialized buffers do not make undo records. Buffers whose names start
with spaces never do; these buffers are used internally by Emacs to hold text that
users don’t normally look at or edit.
When the undo information for a buffer becomes too large, Emacs discards the
oldest records from time to time (during garbage collection). You can specify how
much undo information to keep by setting the variables undo-limit, undo-stronglimit, and undo-outer-limit. Their values are expressed in bytes.
The variable undo-limit sets a soft limit: Emacs keeps undo data for enough
commands to reach this size, and perhaps exceed it, but does not keep data for
any earlier commands beyond that. Its default value is 80000. The variable undostrong-limit sets a stricter limit: any previous command (though not the most
recent one) that pushes the size past this amount is forgotten. The default value of
undo-strong-limit is 120000.
Regardless of the values of those variables, the most recent change is never
discarded unless it gets bigger than undo-outer-limit (normally 12,000,000). At
that point, Emacs discards the undo data and warns you about it. This is the only
situation in which you cannot undo the last command. If this happens, you can
increase the value of undo-outer-limit to make it even less likely to happen in the
future. But if you didn’t expect the command to create such large undo data, then
it is probably a bug and you should report it. See Section 34.3 [Reporting Bugs],
page 473.

13.2 Transposing Text
C-t

Transpose two characters (transpose-chars).

M-t

Transpose two words (transpose-words).

C-M-t

Transpose two balanced expressions (transpose-sexps).

C-x C-t

Transpose two lines (transpose-lines).

The common error of transposing two characters can be fixed, when they are
adjacent, with the C-t command (transpose-chars). Normally, C-t transposes
the two characters on either side of point. When given at the end of a line, rather

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than transposing the last character of the line with the newline, which would be
useless, C-t transposes the last two characters on the line. So, if you catch your
transposition error right away, you can fix it with just a C-t. If you don’t catch
it so fast, you must move the cursor back between the two transposed characters
before you type C-t. If you transposed a space with the last character of the word
before it, the word motion commands are a good way of getting there. Otherwise,
a reverse search (C-r) is often the best way. See Chapter 12 [Search], page 91.
M-t transposes the word before point with the word after point (transposewords). It moves point forward over a word, dragging the word preceding or containing point forward as well. The punctuation characters between the words do not
move. For example, ‘FOO, BAR’ transposes into ‘BAR, FOO’ rather than ‘BAR FOO,’.
C-M-t (transpose-sexps) is a similar command for transposing two expressions (see Section 23.4.1 [Expressions], page 256), and C-x C-t (transpose-lines)
exchanges lines. They work like M-t except as regards what units of text they
transpose.
A numeric argument to a transpose command serves as a repeat count: it tells
the transpose command to move the character (word, expression, line) before or
containing point across several other characters (words, expressions, lines). For
example, C-u 3 C-t moves the character before point forward across three other
characters. It would change ‘f?oobar’ into ‘oobf?ar’. This is equivalent to repeating C-t three times. C-u - 4 M-t moves the word before point backward across four
words. C-u - C-M-t would cancel the effect of plain C-M-t.
A numeric argument of zero is assigned a special meaning (because otherwise a
command with a repeat count of zero would do nothing): to transpose the character
(word, expression, line) ending after point with the one ending after the mark.

13.3 Case Conversion
M-- M-l

Convert last word to lower case. Note Meta-- is Meta-minus.

M-- M-u

Convert last word to all upper case.

M-- M-c

Convert last word to lower case with capital initial.

A very common error is to type words in the wrong case. Because of this, the
word case-conversion commands M-l, M-u and M-c have a special feature when used
with a negative argument: they do not move the cursor. As soon as you see you
have mistyped the last word, you can simply case-convert it and go on typing. See
Section 22.6 [Case], page 223.

13.4 Checking and Correcting Spelling
This section describes the commands to check the spelling of a single word or of
a portion of a buffer. These commands only work if the spelling checker program
Aspell, Ispell or Hunspell is installed. These programs are not part of Emacs, but
one of them is usually installed in GNU/Linux and other free operating systems.

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M-$

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Check and correct spelling of the word at point (ispell-word). If the
region is active, do it for all words in the region instead.

M-x ispell Check and correct spelling of all words in the buffer. If the region is
active, do it for all words in the region instead.
M-x ispell-buffer
Check and correct spelling in the buffer.
M-x ispell-region
Check and correct spelling in the region.
M-x ispell-message
Check and correct spelling in a draft mail message, excluding cited
material.
M-x ispell-change-dictionary RET dict RET
Restart the Aspell/Ispell/Hunspell process, using dict as the dictionary.
M-x ispell-kill-ispell
Kill the Aspell/Ispell/Hunspell subprocess.
M-TAB
ESC TAB

Complete the word before point based on the spelling dictionary
(ispell-complete-word).

M-x flyspell-mode
Enable Flyspell mode, which highlights all misspelled words.
M-x flyspell-prog-mode
Enable Flyspell mode for comments and strings only.
To check the spelling of the word around or before point, and optionally correct
it as well, type M-$ (ispell-word). If a region is active, M-$ checks the spelling
of all words within the region. See Chapter 8 [Mark], page 47. (When Transient
Mark mode is off, M-$ always acts on the word around or before point, ignoring the
region; see Section 8.7 [Disabled Transient Mark], page 52.)
Similarly, the command M-x ispell performs spell-checking in the region if one
is active, or in the entire buffer otherwise. The commands M-x ispell-buffer and
M-x ispell-region explicitly perform spell-checking on the entire buffer or the
region respectively. To check spelling in an email message you are writing, use M-x
ispell-message; that command checks the whole buffer, except for material that
is indented or appears to be cited from other messages. See Chapter 29 [Sending
Mail], page 367.
When one of these commands encounters what appears to be an incorrect word,
it asks you what to do. It usually displays a list of numbered “near-misses”—
words that are close to the incorrect word. Then you must type a single-character
response. Here are the valid responses:
digit

Replace the word, just this time, with one of the displayed near-misses.
Each near-miss is listed with a digit; type that digit to select it.

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SPC

Skip this word—continue to consider it incorrect, but don’t change it
here.

r new RET

Replace the word, just this time, with new. (The replacement string
will be rescanned for more spelling errors.)

R new RET

Replace the word with new, and do a query-replace so you can
replace it elsewhere in the buffer if you wish. (The replacements will
be rescanned for more spelling errors.)

a

Accept the incorrect word—treat it as correct, but only in this editing
session.

A

Accept the incorrect word—treat it as correct, but only in this editing
session and for this buffer.

i

Insert this word in your private dictionary file so that Aspell or Ispell or
Hunspell will consider it correct from now on, even in future sessions.

m

Like i, but you can also specify dictionary completion information.

u

Insert the lower-case version of this word in your private dictionary
file.

l word RET Look in the dictionary for words that match word. These words become the new list of “near-misses”; you can select one of them as the
replacement by typing a digit. You can use ‘*’ in word as a wildcard.
C-g
X

Quit interactive spell checking, leaving point at the word that was
being checked. You can restart checking again afterward with C-u
M-$.

x

Quit interactive spell checking and move point back to where it was
when you started spell checking.

q

Quit interactive spell checking and kill the spell-checker subprocess.

?

Show the list of options.

In Text mode and related modes, M-TAB (ispell-complete-word) performs inbuffer completion based on spelling correction. Insert the beginning of a word,
and then type M-TAB; this shows a list of completions. (If your window manager
intercepts M-TAB, type ESC TAB or C-M-i.) Each completion is listed with a digit or
character; type that digit or character to choose it.
Once started, the Aspell or Ispell or Hunspell subprocess continues to run, waiting for something to do, so that subsequent spell checking commands complete more
quickly. If you want to get rid of the process, use M-x ispell-kill-ispell. This
is not usually necessary, since the process uses no processor time except when you
do spelling correction.
Ispell, Aspell and Hunspell look up spelling in two dictionaries: the standard
dictionary and your personal dictionary. The standard dictionary is specified by

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the variable ispell-local-dictionary or, if that is nil, by the variable ispelldictionary. If both are nil, the spelling program’s default dictionary is used.
The command M-x ispell-change-dictionary sets the standard dictionary for
the buffer and then restarts the subprocess, so that it will use a different standard
dictionary. Your personal dictionary is specified by the variable ispell-personaldictionary. If that is nil, the spelling program looks for a personal dictionary in
a default location.
A separate dictionary is used for word completion. The variable ispellcomplete-word-dict specifies the file name of this dictionary. The completion
dictionary must be different because it cannot use root and affix information. For
some languages, there is a spell checking dictionary but no word completion dictionary.
Flyspell mode is a minor mode that performs automatic spell checking as you
type. When it finds a word that it does not recognize, it highlights that word.
Type M-x flyspell-mode to toggle Flyspell mode in the current buffer. To enable
Flyspell mode in all text mode buffers, add flyspell-mode to text-mode-hook.
See Section 33.2.2 [Hooks], page 445.
When Flyspell mode highlights a word as misspelled, you can click on it with
Mouse-2 to display a menu of possible corrections and actions. You can also correct
the word by editing it manually in any way you like.
Flyspell Prog mode works just like ordinary Flyspell mode, except that it only
checks words in comments and string constants. This feature is useful for editing programs. Type M-x flyspell-prog-mode to enable or disable this mode in
the current buffer. To enable this mode in all programming mode buffers, add
flyspell-prog-mode to prog-mode-hook (see Section 33.2.2 [Hooks], page 445).

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14 Keyboard Macros
In this chapter we describe how to record a sequence of editing commands so you
can repeat it conveniently later.
A keyboard macro is a command defined by an Emacs user to stand for another
sequence of keys. For example, if you discover that you are about to type C-n M-d
C-d forty times, you can speed your work by defining a keyboard macro to do C-n
M-d C-d, and then executing it 39 more times.
You define a keyboard macro by executing and recording the commands which
are its definition. Put differently, as you define a keyboard macro, the definition
is being executed for the first time. This way, you can see the effects of your
commands, so that you don’t have to figure them out in your head. When you close
the definition, the keyboard macro is defined and also has been, in effect, executed
once. You can then do the whole thing over again by invoking the macro.
Keyboard macros differ from ordinary Emacs commands in that they are written
in the Emacs command language rather than in Lisp. This makes it easier for
the novice to write them, and makes them more convenient as temporary hacks.
However, the Emacs command language is not powerful enough as a programming
language to be useful for writing anything intelligent or general. For such things,
Lisp must be used.

14.1 Basic Use
F3

Start defining a keyboard macro (kmacro-start-macro-or-insertcounter).

F4

If a keyboard macro is being defined, end the definition; otherwise, execute the most recent keyboard macro (kmacro-end-or-call-macro).

C-u F3

Re-execute last keyboard macro, then append keys to its definition.

C-u C-u F3 Append keys to the last keyboard macro without re-executing it.
C-x C-k r

Run the last keyboard macro on each line that begins in the region
(apply-macro-to-region-lines).

To start defining a keyboard macro, type F3. From then on, your keys continue
to be executed, but also become part of the definition of the macro. ‘Def’ appears
in the mode line to remind you of what is going on. When you are finished, type
F4 (kmacro-end-or-call-macro) to terminate the definition. For example,
F3 M-f foo F4
defines a macro to move forward a word and then insert ‘foo’. Note that F3 and
F4 do not become part of the macro.
After defining the macro, you can call it with F4. For the above example,
this has the same effect as typing M-f foo again. (Note the two roles of the F4
command: it ends the macro if you are in the process of defining one, or calls the
last macro otherwise.) You can also supply F4 with a numeric prefix argument ‘n’,

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which means to invoke the macro ‘n’ times. An argument of zero repeats the macro
indefinitely, until it gets an error or you type C-g (or, on MS-DOS, C-BREAK).
The above example demonstrates a handy trick that you can employ with keyboard macros: if you wish to repeat an operation at regularly spaced places in the
text, include a motion command as part of the macro. In this case, repeating the
macro inserts the string ‘foo’ after each successive word.
After terminating the definition of a keyboard macro, you can append more
keystrokes to its definition by typing C-u F3. This is equivalent to plain F3 followed
by retyping the whole definition so far. As a consequence, it re-executes the macro as
previously defined. If you change the variable kmacro-execute-before-append to
nil, the existing macro will not be re-executed before appending to it (the default
is t). You can also add to the end of the definition of the last keyboard macro
without re-executing it by typing C-u C-u F3.
When a command reads an argument with the minibuffer, your minibuffer input
becomes part of the macro along with the command. So when you replay the macro,
the command gets the same argument as when you entered the macro. For example,
F3 C-a C-k C-x b foo RET C-y C-x b RET F4
defines a macro that kills the current line, yanks it into the buffer ‘foo’, then returns
to the original buffer.
Most keyboard commands work as usual in a keyboard macro definition, with
some exceptions. Typing C-g (keyboard-quit) quits the keyboard macro definition.
Typing C-M-c (exit-recursive-edit) can be unreliable: it works as you’d expect
if exiting a recursive edit that started within the macro, but if it exits a recursive
edit that started before you invoked the keyboard macro, it also necessarily exits
the keyboard macro too. Mouse events are also unreliable, even though you can use
them in a keyboard macro: when the macro replays the mouse event, it uses the
original mouse position of that event, the position that the mouse had while you
were defining the macro. The effect of this may be hard to predict.
The command C-x C-k r (apply-macro-to-region-lines) repeats the last defined keyboard macro on each line that begins in the region. It does this line by
line, by moving point to the beginning of the line and then executing the macro.
In addition to the F3 and F4 commands described above, Emacs also supports
an older set of key bindings for defining and executing keyboard macros. To begin a
macro definition, type C-x ( (kmacro-start-macro); as with F3, a prefix argument
appends this definition to the last keyboard macro. To end a macro definition,
type C-x ) (kmacro-end-macro). To execute the most recent macro, type C-x e
(kmacro-end-and-call-macro). If you enter C-x e while defining a macro, the
macro is terminated and executed immediately. Immediately after typing C-x e,
you can type E repeatedly to immediately repeat the macro one or more times.
You can also give C-x e a repeat argument, just like F4.
C-x ) can be given a repeat count as an argument. This means to repeat the
macro right after defining it. The macro definition itself counts as the first repetition, since it is executed as you define it, so C-u 4 C-x ) executes the macro
immediately 3 additional times.

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14.2 The Keyboard Macro Ring
All defined keyboard macros are recorded in the keyboard macro ring. There is
only one keyboard macro ring, shared by all buffers.
C-x C-k C-k
Execute the keyboard macro at the head of the ring (kmacro-end-orcall-macro-repeat).
C-x C-k C-n
Rotate the keyboard macro ring to the next macro (defined earlier)
(kmacro-cycle-ring-next).
C-x C-k C-p
Rotate the keyboard macro ring to the previous macro (defined later)
(kmacro-cycle-ring-previous).
All commands which operate on the keyboard macro ring use the same C-x C-k
prefix. Most of these commands can be executed and repeated immediately after
each other without repeating the C-x C-k prefix. For example,
C-x C-k C-p C-p C-k C-k C-k C-n C-n C-k C-p C-k C-d
will rotate the keyboard macro ring to the “second previous” macro, execute the
resulting head macro three times, rotate back to the original head macro, execute
that once, rotate to the “previous” macro, execute that, and finally delete it from
the macro ring.
The command C-x C-k C-k (kmacro-end-or-call-macro-repeat) executes the
keyboard macro at the head of the macro ring. You can repeat the macro immediately by typing another C-k, or you can rotate the macro ring immediately by
typing C-n or C-p.
When a keyboard macro is being defined, C-x C-k C-k behaves like F4 except
that, immediately afterward, you can use most key bindings of this section without
the C-x C-k prefix. For instance, another C-k will re-execute the macro.
The commands C-x C-k C-n (kmacro-cycle-ring-next) and C-x C-k C-p
(kmacro-cycle-ring-previous) rotate the macro ring, bringing the next or
previous keyboard macro to the head of the macro ring. The definition of the new
head macro is displayed in the echo area. You can continue to rotate the macro
ring immediately by repeating just C-n and C-p until the desired macro is at the
head of the ring. To execute the new macro ring head immediately, just type C-k.
Note that Emacs treats the head of the macro ring as the “last defined keyboard
macro”. For instance, F4 will execute that macro, and C-x C-k n will give it a name.
The maximum number of macros stored in the keyboard macro ring is determined by the customizable variable kmacro-ring-max.

14.3 The Keyboard Macro Counter
Each keyboard macro has an associated counter, which is initialized to 0 when you
start defining the macro. This counter allows you to insert a number into the buffer
that depends on the number of times the macro has been called. The counter is
incremented each time its value is inserted into the buffer.

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F3

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In a keyboard macro definition, insert the keyboard macro counter
value in the buffer (kmacro-start-macro-or-insert-counter).

C-x C-k C-i
Insert the keyboard macro counter value in the buffer (kmacroinsert-counter).
C-x C-k C-c
Set the keyboard macro counter (kmacro-set-counter).
C-x C-k C-a
Add the prefix arg to the keyboard macro counter (kmacro-addcounter).
C-x C-k C-f
Specify the format for inserting the keyboard macro counter (kmacroset-format).
When you are defining a keyboard macro, the command F3 (kmacro-startmacro-or-insert-counter) inserts the current value of the keyboard macro’s
counter into the buffer, and increments the counter by 1. (If you are not defining
a macro, F3 begins a macro definition instead. See Section 14.1 [Basic Keyboard
Macro], page 116.) You can use a numeric prefix argument to specify a different
increment. If you just specify a C-u prefix, that is the same as an increment of zero:
it inserts the current counter value without changing it.
As an example, let us show how the keyboard macro counter can be used to
build a numbered list. Consider the following key sequence:
F3 C-a F3 . SPC F4
As part of this keyboard macro definition, the string ‘0. ’ was inserted into the
beginning of the current line. If you now move somewhere else in the buffer and
type F4 to invoke the macro, the string ‘1. ’ is inserted at the beginning of that
line. Subsequent invocations insert ‘2. ’, ‘3. ’, and so forth.
The command C-x C-k C-i (kmacro-insert-counter) does the same thing as
F3, but it can be used outside a keyboard macro definition. When no keyboard
macro is being defined or executed, it inserts and increments the counter of the
macro at the head of the keyboard macro ring.
The command C-x C-k C-c (kmacro-set-counter) sets the current macro
counter to the value of the numeric argument. If you use it inside the macro,
it operates on each repetition of the macro. If you specify just C-u as the prefix,
while executing the macro, that resets the counter to the value it had at the beginning of the current repetition of the macro (undoing any increments so far in this
repetition).
The command C-x C-k C-a (kmacro-add-counter) adds the prefix argument to
the current macro counter. With just C-u as argument, it resets the counter to the
last value inserted by any keyboard macro. (Normally, when you use this, the last
insertion will be in the same macro and it will be the same counter.)
The command C-x C-k C-f (kmacro-set-format) prompts for the format to use
when inserting the macro counter. The default format is ‘%d’, which means to insert

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the number in decimal without any padding. You can exit with empty minibuffer to
reset the format to this default. You can specify any format string that the format
function accepts and that makes sense with a single integer extra argument (see
Section “Formatting Strings” in The Emacs Lisp Reference Manual). Do not put
the format string inside double quotes when you insert it in the minibuffer.
If you use this command while no keyboard macro is being defined or executed,
the new format affects all subsequent macro definitions. Existing macros continue
to use the format in effect when they were defined. If you set the format while
defining a keyboard macro, this affects the macro being defined from that point
on, but it does not affect subsequent macros. Execution of the macro will, at each
step, use the format in effect at that step during its definition. Changes to the
macro format during execution of a macro, like the corresponding changes during
its definition, have no effect on subsequent macros.
The format set by C-x C-k C-f does not affect insertion of numbers stored in
registers.
If you use a register as a counter, incrementing it on each repetition of the macro,
that accomplishes the same thing as a keyboard macro counter. See Section 10.5
[Number Registers], page 68. For most purposes, it is simpler to use a keyboard
macro counter.

14.4 Executing Macros with Variations
In a keyboard macro, you can create an effect similar to that of query-replace, in
that the macro asks you each time around whether to make a change.
C-x q

When this point is reached during macro execution, ask for confirmation (kbd-macro-query).

While defining the macro, type C-x q at the point where you want the query
to occur. During macro definition, the C-x q does nothing, but when you run the
macro later, C-x q asks you interactively whether to continue.
The valid responses when C-x q asks are:
SPC (or y) Continue executing the keyboard macro.
DEL (or n) Skip the remainder of this repetition of the macro, and start right
away with the next repetition.
RET (or q) Skip the remainder of this repetition and cancel further repetitions.
C-r

Enter a recursive editing level, in which you can perform editing which
is not part of the macro. When you exit the recursive edit using C-M-c,
you are asked again how to continue with the keyboard macro. If you
type a SPC at this time, the rest of the macro definition is executed.
It is up to you to leave point and the text in a state such that the rest
of the macro will do what you want.

C-u C-x q, which is C-x q with a numeric argument, performs a completely
different function. It enters a recursive edit reading input from the keyboard, both
when you type it during the definition of the macro, and when it is executed from

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the macro. During definition, the editing you do inside the recursive edit does not
become part of the macro. During macro execution, the recursive edit gives you
a chance to do some particularized editing on each repetition. See Section 31.9
[Recursive Edit], page 424.

14.5 Naming and Saving Keyboard Macros
C-x C-k n

Give a command name (for the duration of the Emacs session) to the
most recently defined keyboard macro (kmacro-name-last-macro).

C-x C-k b

Bind the most recently defined keyboard macro to a key sequence (for
the duration of the session) (kmacro-bind-to-key).

M-x insert-kbd-macro
Insert in the buffer a keyboard macro’s definition, as Lisp code.
If you wish to save a keyboard macro for later use, you can give it a name using
C-x C-k n (kmacro-name-last-macro). This reads a name as an argument using
the minibuffer and defines that name to execute the last keyboard macro, in its
current form. (If you later add to the definition of this macro, that does not alter
the name’s definition as a macro.) The macro name is a Lisp symbol, and defining
it in this way makes it a valid command name for calling with M-x or for binding
a key to with global-set-key (see Section 33.3.1 [Keymaps], page 452). If you
specify a name that has a prior definition other than a keyboard macro, an error
message is shown and nothing is changed.
You can also bind the last keyboard macro (in its current form) to a key, using
C-x C-k b (kmacro-bind-to-key) followed by the key sequence you want to bind.
You can bind to any key sequence in the global keymap, but since most key sequences
already have other bindings, you should select the key sequence carefully. If you try
to bind to a key sequence with an existing binding (in any keymap), this command
asks you for confirmation before replacing the existing binding.
To avoid problems caused by overriding existing bindings, the key sequences C-x
C-k 0 through C-x C-k 9 and C-x C-k A through C-x C-k Z are reserved for your
own keyboard macro bindings. In fact, to bind to one of these key sequences, you
only need to type the digit or letter rather than the whole key sequences. For
example,
C-x C-k b 4
will bind the last keyboard macro to the key sequence C-x C-k 4.
Once a macro has a command name, you can save its definition in a file. Then
it can be used in another editing session. First, visit the file you want to save the
definition in. Then use this command:
M-x insert-kbd-macro RET macroname RET
This inserts some Lisp code that, when executed later, will define the same macro
with the same definition it has now. (You need not understand Lisp code to do
this, because insert-kbd-macro writes the Lisp code for you.) Then save the
file. You can load the file later with load-file (see Section 24.8 [Lisp Libraries],

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page 287). If the file you save in is your init file ‘~/.emacs’ (see Section 33.4 [Init
File], page 461) then the macro will be defined each time you run Emacs.
If you give insert-kbd-macro a numeric argument, it makes additional Lisp
code to record the keys (if any) that you have bound to macroname, so that the
macro will be reassigned the same keys when you load the file.

14.6 Editing a Keyboard Macro
C-x C-k C-e
Edit the last defined keyboard macro (kmacro-edit-macro).
C-x C-k e name RET
Edit a previously defined keyboard macro name (edit-kbd-macro).
C-x C-k l

Edit the last 300 keystrokes as a keyboard macro (kmacro-editlossage).

You can edit the last keyboard macro by typing C-x C-k C-e or C-x C-k RET
(kmacro-edit-macro). This formats the macro definition in a buffer and enters a
specialized major mode for editing it. Type C-h m once in that buffer to display
details of how to edit the macro. When you are finished editing, type C-c C-c.
You can edit a named keyboard macro or a macro bound to a key by typing C-x
C-k e (edit-kbd-macro). Follow that with the keyboard input that you would use
to invoke the macro—C-x e or M-x name or some other key sequence.
You can edit the last 300 keystrokes as a macro by typing C-x C-k l (kmacroedit-lossage).

14.7 Stepwise Editing a Keyboard Macro
You can interactively replay and edit the last keyboard macro, one command at
a time, by typing C-x C-k SPC (kmacro-step-edit-macro). Unless you quit the
macro using q or C-g, the edited macro replaces the last macro on the macro ring.
This macro editing feature shows the last macro in the minibuffer together with
the first (or next) command to be executed, and prompts you for an action. You
can enter ? to get a summary of your options. These actions are available:
• SPC and y execute the current command, and advance to the next command
in the keyboard macro.
• n, d, and DEL skip and delete the current command.
• f skips the current command in this execution of the keyboard macro, but
doesn’t delete it from the macro.
• TAB executes the current command, as well as all similar commands immediately following the current command; for example, TAB may be used to insert a
sequence of characters (corresponding to a sequence of self-insert-command
commands).
• c continues execution (without further editing) until the end of the keyboard
macro. If execution terminates normally, the edited macro replaces the original
keyboard macro.

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• C-k skips and deletes the rest of the keyboard macro, terminates step-editing,
and replaces the original keyboard macro with the edited macro.
• q and C-g cancels the step-editing of the keyboard macro; discarding any
changes made to the keyboard macro.
• i KEY... C-j reads and executes a series of key sequences (not including the
final C-j), and inserts them before the current command in the keyboard
macro, without advancing over the current command.
• I KEY... reads one key sequence, executes it, and inserts it before the current command in the keyboard macro, without advancing over the current
command.
• r KEY... C-j reads and executes a series of key sequences (not including the
final C-j), and replaces the current command in the keyboard macro with
them, advancing over the inserted key sequences.
• R KEY... reads one key sequence, executes it, and replaces the current command in the keyboard macro with that key sequence, advancing over the inserted key sequence.
• a KEY... C-j executes the current command, then reads and executes a series
of key sequences (not including the final C-j), and inserts them after the
current command in the keyboard macro; it then advances over the current
command and the inserted key sequences.
• A KEY... C-j executes the rest of the commands in the keyboard macro, then
reads and executes a series of key sequences (not including the final C-j),
and appends them at the end of the keyboard macro; it then terminates the
step-editing and replaces the original keyboard macro with the edited macro.

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15 File Handling
The operating system stores data permanently in named files, so most of the text
you edit with Emacs comes from a file and is ultimately stored in a file.
To edit a file, you must tell Emacs to read the file and prepare a buffer containing
a copy of the file’s text. This is called visiting the file. Editing commands apply
directly to text in the buffer; that is, to the copy inside Emacs. Your changes appear
in the file itself only when you save the buffer back into the file.
In addition to visiting and saving files, Emacs can delete, copy, rename, and
append to files, keep multiple versions of them, and operate on file directories.

15.1 File Names
Many Emacs commands that operate on a file require you to specify the file name,
using the minibuffer (see Section 5.1 [Minibuffer File], page 27).
While in the minibuffer, you can use the usual completion and history commands
(see Chapter 5 [Minibuffer], page 27). Note that file name completion ignores file
names whose extensions appear in the variable completion-ignored-extensions
(see Section 5.3.5 [Completion Options], page 33). Note also that most commands
use “permissive completion with confirmation” for reading file names: you are allowed to submit a nonexistent file name, but if you type RET immediately after
completing up to a nonexistent file name, Emacs prints ‘[Confirm]’ and you must
type a second RET to confirm. See Section 5.3.3 [Completion Exit], page 31, for
details.
Each buffer has a default directory, stored in the buffer-local variable defaultdirectory. Whenever Emacs reads a file name using the minibuffer, it usually
inserts the default directory into the minibuffer as the initial contents. You can
inhibit this insertion by changing the variable insert-default-directory to nil
(see Section 5.1 [Minibuffer File], page 27). Regardless, Emacs always assumes that
any relative file name is relative to the default directory, e.g. entering a file name
without a directory specifies a file in the default directory.
When you visit a file, Emacs sets default-directory in the visiting buffer to
the directory of its file. When you create a new buffer that is not visiting a file,
via a command like C-x b, its default directory is usually copied from the buffer
that was current at the time (see Section 16.1 [Select Buffer], page 150). You can
use the command M-x pwd to see the value of default-directory in the current
buffer. The command M-x cd prompts for a directory name, and sets the buffer’s
default-directory to that directory (doing this does not change the buffer’s file
name, if any).
As an example, when you visit the file ‘/u/rms/gnu/gnu.tasks’, the default
directory is set to ‘/u/rms/gnu/’. If you invoke a command that reads a file name,
entering just ‘foo’ in the minibuffer, with a directory omitted, specifies the file
‘/u/rms/gnu/foo’; entering ‘../.login’ specifies ‘/u/rms/.login’; and entering
‘new/foo’ specifies ‘/u/rms/gnu/new/foo’.
When typing a file name into the minibuffer, you can make use of a couple of
shortcuts: a double slash is interpreted as “ignore everything before the second

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slash in the pair”, and ‘~/’ is interpreted as your home directory. See Section 5.1
[Minibuffer File], page 27.
The character ‘$’ is used to substitute an environment variable into a file name.
The name of the environment variable consists of all the alphanumeric characters
after the ‘$’; alternatively, it can be enclosed in braces after the ‘$’. For example,
if you have used the shell command export FOO=rms/hacks to set up an environment variable named FOO, then both ‘/u/$FOO/test.c’ and ‘/u/${FOO}/test.c’
are abbreviations for ‘/u/rms/hacks/test.c’. If the environment variable is not
defined, no substitution occurs, so that the character ‘$’ stands for itself. Note that
environment variables affect Emacs only if they are applied before Emacs is started.
To access a file with ‘$’ in its name, if the ‘$’ causes expansion, type ‘$$’.
This pair is converted to a single ‘$’ at the same time that variable substitution is
performed for a single ‘$’. Alternatively, quote the whole file name with ‘/:’ (see
Section 15.14 [Quoted File Names], page 146). File names which begin with a literal
‘~’ should also be quoted with ‘/:’.
You can include non-ASCII characters in file names. See Section 19.12 [File
Name Coding], page 195.

15.2 Visiting Files
C-x C-f

Visit a file (find-file).

C-x C-r

Visit a file for viewing, without allowing changes to it (find-fileread-only).

C-x C-v

Visit a different file instead of the one visited last (find-alternatefile).

C-x 4 f

Visit a file, in another window (find-file-other-window). Don’t
alter what is displayed in the selected window.

C-x 5 f

Visit a file, in a new frame (find-file-other-frame). Don’t alter
what is displayed in the selected frame.

M-x find-file-literally
Visit a file with no conversion of the contents.
Visiting a file means reading its contents into an Emacs buffer so you can edit
them. Emacs makes a new buffer for each file that you visit.
To visit a file, type C-x C-f (find-file) and use the minibuffer to enter the
name of the desired file. While in the minibuffer, you can abort the command by
typing C-g. See Section 15.1 [File Names], page 124, for details about entering file
names into minibuffers.
If the specified file exists but the system does not allow you to read it, an error
message is displayed in the echo area. Otherwise, you can tell that C-x C-f has
completed successfully by the appearance of new text on the screen, and by the
buffer name shown in the mode line (see Section 1.3 [Mode Line], page 8). Emacs
normally constructs the buffer name from the file name, omitting the directory
name. For example, a file named ‘/usr/rms/emacs.tex’ is visited in a buffer named

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‘emacs.tex’. If there is already a buffer with that name, Emacs constructs a unique
name; the normal method is to append ‘<2>’, ‘<3>’, and so on, but you can select
other methods. See Section 16.7.1 [Uniquify], page 157.
To create a new file, just visit it using the same command, C-x C-f. Emacs
displays ‘(New file)’ in the echo area, but in other respects behaves as if you had
visited an existing empty file.
After visiting a file, the changes you make with editing commands are made in
the Emacs buffer. They do not take effect in the visited file, until you save the
buffer (see Section 15.3 [Saving], page 128). If a buffer contains changes that have
not been saved, we say the buffer is modified. This implies that some changes will
be lost if the buffer is not saved. The mode line displays two stars near the left
margin to indicate that the buffer is modified.
If you visit a file that is already in Emacs, C-x C-f switches to the existing
buffer instead of making another copy. Before doing so, it checks whether the file
has changed since you last visited or saved it. If the file has changed, Emacs offers
to reread it.
If you try to visit a file larger than large-file-warning-threshold (the default
is 10000000, which is about 10 megabytes), Emacs asks you for confirmation first.
You can answer y to proceed with visiting the file. Note, however, that Emacs
cannot visit files that are larger than the maximum Emacs buffer size, which is
limited by the amount of memory Emacs can allocate and by the integers that
Emacs can represent (see Chapter 16 [Buffers], page 150). If you try, Emacs displays
an error message saying that the maximum buffer size has been exceeded.
If the file name you specify contains shell-style wildcard characters, Emacs visits
all the files that match it. (On case-insensitive filesystems, Emacs matches the
wildcards disregarding the letter case.) Wildcards include ‘?’, ‘*’, and ‘[...]’
sequences. To enter the wild card ‘?’ in a file name in the minibuffer, you need
to type C-q ?. See Section 15.14 [Quoted File Names], page 146, for information
on how to visit a file whose name actually contains wildcard characters. You can
disable the wildcard feature by customizing find-file-wildcards.
If you visit the wrong file unintentionally by typing its name incorrectly, type
C-x C-v (find-alternate-file) to visit the file you really wanted. C-x C-v is
similar to C-x C-f, but it kills the current buffer (after first offering to save it if it
is modified). When C-x C-v reads the file name to visit, it inserts the entire default
file name in the buffer, with point just after the directory part; this is convenient if
you made a slight error in typing the name.
If you “visit” a file that is actually a directory, Emacs invokes Dired, the Emacs
directory browser. See Chapter 27 [Dired], page 329. You can disable this behavior
by setting the variable find-file-run-dired to nil; in that case, it is an error to
try to visit a directory.
Files which are actually collections of other files, or file archives, are visited in
special modes which invoke a Dired-like environment to allow operations on archive
members. See Section 15.12 [File Archives], page 144, for more about these features.
If you visit a file that the operating system won’t let you modify, or that is
marked read-only, Emacs makes the buffer read-only too, so that you won’t go ahead

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and make changes that you’ll have trouble saving afterward. You can make the
buffer writable with C-x C-q (toggle-read-only). See Section 16.3 [Misc Buffer],
page 152.
If you want to visit a file as read-only in order to protect yourself from entering
changes accidentally, visit it with the command C-x C-r (find-file-read-only)
instead of C-x C-f.
C-x 4 f (find-file-other-window) is like C-x C-f except that the buffer containing the specified file is selected in another window. The window that was
selected before C-x 4 f continues to show the same buffer it was already showing.
If this command is used when only one window is being displayed, that window is
split in two, with one window showing the same buffer as before, and the other one
showing the newly requested file. See Chapter 17 [Windows], page 159.
C-x 5 f (find-file-other-frame) is similar, but opens a new frame, or selects
any existing frame showing the specified file. See Chapter 18 [Frames], page 165.
On graphical displays, there are two additional methods for visiting files. Firstly,
when Emacs is built with a suitable GUI toolkit, commands invoked with the mouse
(by clicking on the menu bar or tool bar) use the toolkit’s standard “File Selection”
dialog instead of prompting for the file name in the minibuffer. On GNU/Linux and
Unix platforms, Emacs does this when built with GTK, LessTif, and Motif toolkits;
on MS-Windows and Mac, the GUI version does that by default. For information
on how to customize this, see Section 18.16 [Dialog Boxes], page 177.
Secondly, Emacs supports “drag and drop”: dropping a file into an ordinary
Emacs window visits the file using that window. As an exception, dropping a file
into a window displaying a Dired buffer moves or copies the file into the displayed directory. For details, see Section 18.13 [Drag and Drop], page 176, and Section 27.18
[Misc Dired Features], page 344.
Each time you visit a file, Emacs automatically scans its contents to detect
what character encoding and end-of-line convention it uses, and converts these to
Emacs’s internal encoding and end-of-line convention within the buffer. When you
save the buffer, Emacs performs the inverse conversion, writing the file to disk with
its original encoding and end-of-line convention. See Section 19.6 [Coding Systems],
page 188.
If you wish to edit a file as a sequence of ASCII characters with no special encoding or conversion, use the M-x find-file-literally command. This visits a file,
like C-x C-f, but does not do format conversion (see Section “Format Conversion”
in the Emacs Lisp Reference Manual), character code conversion (see Section 19.6
[Coding Systems], page 188), or automatic uncompression (see Section 15.11 [Compressed Files], page 144), and does not add a final newline because of requirefinal-newline (see Section 15.3.3 [Customize Save], page 132). If you have already visited the same file in the usual (non-literal) manner, this command asks
you whether to visit it literally instead.
Two special hook variables allow extensions to modify the operation of visiting
files. Visiting a file that does not exist runs the functions in find-file-not-foundfunctions; this variable holds a list of functions, which are called one by one (with

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no arguments) until one of them returns non-nil. This is not a normal hook, and
the name ends in ‘-functions’ rather than ‘-hook’ to indicate that fact.
Successful visiting of any file, whether existing or not, calls the functions in
find-file-hook, with no arguments. This variable is a normal hook. In the
case of a nonexistent file, the find-file-not-found-functions are run first. See
Section 33.2.2 [Hooks], page 445.
There are several ways to specify automatically the major mode for editing the
file (see Section 20.3 [Choosing Modes], page 207), and to specify local variables
defined for that file (see Section 33.2.4 [File Variables], page 447).

15.3 Saving Files
Saving a buffer in Emacs means writing its contents back into the file that was
visited in the buffer.
15.3.1 Commands for Saving Files
These are the commands that relate to saving and writing files.
C-x C-s

Save the current buffer to its file (save-buffer).

C-x s

Save any or all buffers to their files (save-some-buffers).

M-~

Forget that the current buffer has been changed (not-modified).
With prefix argument (C-u), mark the current buffer as changed.

C-x C-w

Save the current buffer with a specified file name (write-file).

M-x set-visited-file-name
Change the file name under which the current buffer will be saved.
When you wish to save the file and make your changes permanent, type C-x C-s
(save-buffer). After saving is finished, C-x C-s displays a message like this:
Wrote /u/rms/gnu/gnu.tasks
If the current buffer is not modified (no changes have been made in it since the
buffer was created or last saved), saving is not really done, because it would have
no effect. Instead, C-x C-s displays a message like this in the echo area:
(No changes need to be saved)
With a prefix argument, C-u C-x C-s, Emacs also marks the buffer to be backed
up when the next save is done. See Section 15.3.2 [Backup], page 130.
The command C-x s (save-some-buffers) offers to save any or all modified
buffers. It asks you what to do with each buffer. The possible responses are analogous to those of query-replace:
y

Save this buffer and ask about the rest of the buffers.

n

Don’t save this buffer, but ask about the rest of the buffers.

!

Save this buffer and all the rest with no more questions.

RET

Terminate save-some-buffers without any more saving.

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.

Save this buffer, then exit save-some-buffers without even asking
about other buffers.

C-r

View the buffer that you are currently being asked about. When you
exit View mode, you get back to save-some-buffers, which asks the
question again.

d

Diff the buffer against its corresponding file, so you can see what
changes you would be saving. This calls the command diff-bufferwith-file (see Section 15.8 [Comparing Files], page 140).

C-h

Display a help message about these options.

C-x C-c, the key sequence to exit Emacs, invokes save-some-buffers and therefore asks the same questions.
If you have changed a buffer but do not wish to save the changes, you should
take some action to prevent it. Otherwise, each time you use C-x s or C-x C-c,
you are liable to save this buffer by mistake. One thing you can do is type M-~
(not-modified), which clears out the indication that the buffer is modified. If you
do this, none of the save commands will believe that the buffer needs to be saved.
(‘~’ is often used as a mathematical symbol for ‘not’; thus M-~ is ‘not’, metafied.)
Alternatively, you can cancel all the changes made since the file was visited or saved,
by reading the text from the file again. This is called reverting. See Section 15.4
[Reverting], page 135. (You could also undo all the changes by repeating the undo
command C-x u until you have undone all the changes; but reverting is easier.)
M-x set-visited-file-name alters the name of the file that the current buffer
is visiting. It reads the new file name using the minibuffer. Then it marks the
buffer as visiting that file name, and changes the buffer name correspondingly.
set-visited-file-name does not save the buffer in the newly visited file; it just
alters the records inside Emacs in case you do save later. It also marks the buffer
as “modified” so that C-x C-s in that buffer will save.
If you wish to mark the buffer as visiting a different file and save it right away,
use C-x C-w (write-file). This is equivalent to set-visited-file-name followed
by C-x C-s, except that C-x C-w asks for confirmation if the file exists. C-x C-s
used on a buffer that is not visiting a file has the same effect as C-x C-w; that is,
it reads a file name, marks the buffer as visiting that file, and saves it there. The
default file name in a buffer that is not visiting a file is made by combining the buffer
name with the buffer’s default directory (see Section 15.1 [File Names], page 124).
If the new file name implies a major mode, then C-x C-w switches to that major
mode, in most cases. The command set-visited-file-name also does this. See
Section 20.3 [Choosing Modes], page 207.
If Emacs is about to save a file and sees that the date of the latest version on
disk does not match what Emacs last read or wrote, Emacs notifies you of this fact,
because it probably indicates a problem caused by simultaneous editing and requires
your immediate attention. See Section 15.3.4 [Simultaneous Editing], page 133.

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15.3.2 Backup Files
On most operating systems, rewriting a file automatically destroys all record of
what the file used to contain. Thus, saving a file from Emacs throws away the old
contents of the file—or it would, except that Emacs carefully copies the old contents
to another file, called the backup file, before actually saving.
Emacs makes a backup for a file only the first time the file is saved from a buffer.
No matter how many times you subsequently save the file, its backup remains
unchanged. However, if you kill the buffer and then visit the file again, a new
backup file will be made.
For most files, the variable make-backup-files determines whether to make
backup files. On most operating systems, its default value is t, so that Emacs does
write backup files.
For files managed by a version control system (see Section 25.1 [Version Control],
page 292), the variable vc-make-backup-files determines whether to make backup
files. By default it is nil, since backup files are redundant when you store all the
previous versions in a version control system. See Section “General VC Options”
in Specialized Emacs Features.
At your option, Emacs can keep either a single backup for each file, or make
a series of numbered backup files for each file that you edit. See Section 15.3.2.1
[Backup Names], page 130.
The default value of the backup-enable-predicate variable prevents backup
files being written for files in the directories used for temporary files, specified by
temporary-file-directory or small-temporary-file-directory.
You can explicitly tell Emacs to make another backup file from a buffer, even
though that buffer has been saved before. If you save the buffer with C-u C-x C-s,
the version thus saved will be made into a backup file if you save the buffer again.
C-u C-u C-x C-s saves the buffer, but first makes the previous file contents into a
new backup file. C-u C-u C-u C-x C-s does both things: it makes a backup from
the previous contents, and arranges to make another from the newly saved contents
if you save again.
15.3.2.1 Single or Numbered Backups
When Emacs makes a backup file, its name is normally constructed by appending ‘~’
to the file name being edited; thus, the backup file for ‘eval.c’ would be ‘eval.c~’.
If access control stops Emacs from writing backup files under the usual names,
it writes the backup file as ‘~/.emacs.d/%backup%~’. Only one such file can exist,
so only the most recently made such backup is available.
Emacs can also make numbered backup files. Numbered backup file names
contain ‘.~’, the number, and another ‘~’ after the original file name. Thus, the
backup files of ‘eval.c’ would be called ‘eval.c.~1~’, ‘eval.c.~2~’, and so on, all
the way through names like ‘eval.c.~259~’ and beyond.
The variable version-control determines whether to make single backup files
or multiple numbered backup files. Its possible values are:

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nil

Make numbered backups for files that have numbered backups already.
Otherwise, make single backups. This is the default.

t

Make numbered backups.

never

Never make numbered backups; always make single backups.

The usual way to set this variable is globally, through your init file or the customization buffer. However, you can set version-control locally in an individual buffer
to control the making of backups for that buffer’s file (see Section 33.2.3 [Locals],
page 446). You can have Emacs set version-control locally whenever you visit a
given file (see Section 33.2.4 [File Variables], page 447). Some modes, such as Rmail
mode, set this variable.
If you set the environment variable VERSION_CONTROL, to tell various GNU utilities what to do with backup files, Emacs also obeys the environment variable by
setting the Lisp variable version-control accordingly at startup. If the environment variable’s value is ‘t’ or ‘numbered’, then version-control becomes t; if the
value is ‘nil’ or ‘existing’, then version-control becomes nil; if it is ‘never’ or
‘simple’, then version-control becomes never.
You can customize the variable backup-directory-alist to specify that files
matching certain patterns should be backed up in specific directories. This variable
applies to both single and numbered backups. A typical use is to add an element
("." . dir ) to make all backups in the directory with absolute name dir; Emacs
modifies the backup file names to avoid clashes between files with the same names
originating in different directories. Alternatively, adding, ("." . ".~") would make
backups in the invisible subdirectory ‘.~’ of the original file’s directory. Emacs
creates the directory, if necessary, to make the backup.
If you define the variable make-backup-file-name-function to a suitable Lisp
function, that overrides the usual way Emacs constructs backup file names.
15.3.2.2 Automatic Deletion of Backups
To prevent excessive consumption of disk space, Emacs can delete numbered backup
versions automatically. Generally Emacs keeps the first few backups and the latest
few backups, deleting any in between. This happens every time a new backup is
made.
The two variables kept-old-versions and kept-new-versions control this
deletion. Their values are, respectively, the number of oldest (lowest-numbered)
backups to keep and the number of newest (highest-numbered) ones to keep, each
time a new backup is made. The backups in the middle (excluding those oldest and
newest) are the excess middle versions—those backups are deleted. These variables’
values are used when it is time to delete excess versions, just after a new backup
version is made; the newly made backup is included in the count in kept-newversions. By default, both variables are 2.
If delete-old-versions is t, Emacs deletes the excess backup files silently. If
it is nil, the default, Emacs asks you whether it should delete the excess backup
versions. If it has any other value, then Emacs never automatically deletes backups.

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Dired’s . (Period) command can also be used to delete old versions.
Section 27.3 [Dired Deletion], page 330.

See

15.3.2.3 Copying vs. Renaming
Backup files can be made by copying the old file or by renaming it. This makes a
difference when the old file has multiple names (hard links). If the old file is renamed
into the backup file, then the alternate names become names for the backup file.
If the old file is copied instead, then the alternate names remain names for the file
that you are editing, and the contents accessed by those names will be the new
contents.
The method of making a backup file may also affect the file’s owner and group.
If copying is used, these do not change. If renaming is used, you become the file’s
owner, and the file’s group becomes the default (different operating systems have
different defaults for the group).
The choice of renaming or copying is made as follows:
• If the variable backup-by-copying is non-nil (the default is nil), use copying.
• Otherwise, if the variable backup-by-copying-when-linked is non-nil (the
default is nil), and the file has multiple names, use copying.
• Otherwise, if the variable backup-by-copying-when-mismatch is non-nil (the
default is t), and renaming would change the file’s owner or group, use copying.
If you change backup-by-copying-when-mismatch to nil, Emacs checks the
numeric user-id of the file’s owner. If this is higher than backup-by-copyingwhen-privileged-mismatch, then it behaves as though backup-by-copyingwhen-mismatch is non-nil anyway.
• Otherwise, renaming is the default choice.
When a file is managed with a version control system (see Section 25.1 [Version
Control], page 292), Emacs does not normally make backups in the usual way for
that file. But check-in and check-out are similar in some ways to making backups.
One unfortunate similarity is that these operations typically break hard links, disconnecting the file name you visited from any alternate names for the same file.
This has nothing to do with Emacs—the version control system does it.
15.3.3 Customizing Saving of Files
If the value of the variable require-final-newline is t, saving or writing a file
silently puts a newline at the end if there isn’t already one there. If the value is
visit, Emacs adds a newline at the end of any file that doesn’t have one, just after
it visits the file. (This marks the buffer as modified, and you can undo it.) If the
value is visit-save, Emacs adds such newlines both on visiting and on saving. If
the value is nil, Emacs leaves the end of the file unchanged; any other non-nil
value means to asks you whether to add a newline. The default is nil.
Some major modes are designed for specific kinds of files that are always supposed to end in newlines. Such major modes set the variable require-finalnewline to the value of mode-require-final-newline, which defaults to t. By
setting the latter variable, you can control how these modes handle final newlines.

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When Emacs saves a file, it invokes the fsync system call to force the data
immediately out to disk. This is important for safety if the system crashes or in
case of power outage. However, it can be disruptive on laptops using power saving,
as it may force a disk spin-up each time you save a file. If you accept an increased
risk of data loss, you can set write-region-inhibit-fsync to a non-nil value to
disable the synchronization.
15.3.4 Protection against Simultaneous Editing
Simultaneous editing occurs when two users visit the same file, both make changes,
and then both save them. If nobody is informed that this is happening, whichever
user saves first would later find that his changes were lost.
On some systems, Emacs notices immediately when the second user starts to
change the file, and issues an immediate warning. On all systems, Emacs checks
when you save the file, and warns if you are about to overwrite another user’s
changes. You can prevent loss of the other user’s work by taking the proper corrective action instead of saving the file.
When you make the first modification in an Emacs buffer that is visiting a file,
Emacs records that the file is locked by you. (It does this by creating a speciallynamed symbolic link in the same directory.) Emacs removes the lock when you save
the changes. The idea is that the file is locked whenever an Emacs buffer visiting
it has unsaved changes.
If you begin to modify the buffer while the visited file is locked by someone else,
this constitutes a collision. When Emacs detects a collision, it asks you what to do,
by calling the Lisp function ask-user-about-lock. You can redefine this function
for the sake of customization. The standard definition of this function asks you a
question and accepts three possible answers:
s

Steal the lock. Whoever was already changing the file loses the lock,
and you gain the lock.

p

Proceed. Go ahead and edit the file despite its being locked by someone
else.

q

Quit. This causes an error (file-locked), and the buffer contents
remain unchanged—the modification you were trying to make does
not actually take place.

If Emacs or the operating system crashes, this may leave behind lock files which
are stale, so you may occasionally get warnings about spurious collisions. When
you determine that the collision is spurious, just use p to tell Emacs to go ahead
anyway.
Note that locking works on the basis of a file name; if a file has multiple names,
Emacs does not prevent two users from editing it simultaneously under different
names.
A lock file cannot be written in some circumstances, e.g. if Emacs lacks the
system permissions or the system does not support symbolic links. In these cases,
Emacs can still detect the collision when you try to save a file, by checking the file’s

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last-modification date. If the file has changed since the last time Emacs visited or
saved it, that implies that changes have been made in some other way, and will be
lost if Emacs proceeds with saving. Emacs then displays a warning message and
asks for confirmation before saving; answer yes to save, and no or C-g cancel the
save.
If you are notified that simultaneous editing has already taken place, one way
to compare the buffer to its file is the M-x diff-buffer-with-file command. See
Section 15.8 [Comparing Files], page 140.
15.3.5 Shadowing Files
M-x shadow-initialize
Set up file shadowing.
M-x shadow-define-literal-group
Declare a single file to be shared between sites.
M-x shadow-define-regexp-group
Make all files that match each of a group of files be shared between
hosts.
M-x shadow-define-cluster RET name RET
Define a shadow file cluster name.
M-x shadow-copy-files
Copy all pending shadow files.
M-x shadow-cancel
Cancel the instruction to shadow some files.
You can arrange to keep identical shadow copies of certain files in more than one
place—possibly on different machines. To do this, first you must set up a shadow
file group, which is a set of identically-named files shared between a list of sites.
The file group is permanent and applies to further Emacs sessions as well as the
current one. Once the group is set up, every time you exit Emacs, it will copy the
file you edited to the other files in its group. You can also do the copying without
exiting Emacs, by typing M-x shadow-copy-files.
To set up a shadow file group, use M-x shadow-define-literal-group or M-x
shadow-define-regexp-group. See their documentation strings for further information.
Before copying a file to its shadows, Emacs asks for confirmation. You can
answer “no” to bypass copying of this file, this time. If you want to cancel the
shadowing permanently for a certain file, use M-x shadow-cancel to eliminate or
change the shadow file group.
A shadow cluster is a group of hosts that share directories, so that copying to or
from one of them is sufficient to update the file on all of them. Each shadow cluster
has a name, and specifies the network address of a primary host (the one we copy
files to), and a regular expression that matches the host names of all the other hosts
in the cluster. You can define a shadow cluster with M-x shadow-define-cluster.

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15.3.6 Updating Time Stamps Automatically
You can arrange to put a time stamp in a file, so that it is updated automatically
each time you edit and save the file. The time stamp must be in the first eight lines
of the file, and you should insert it like this:
Time-stamp: <>
or like this:
Time-stamp: " "
Then add the function time-stamp to the hook before-save-hook (see
Section 33.2.2 [Hooks], page 445). When you save the file, this function then
automatically updates the time stamp with the current date and time. You can
also use the command M-x time-stamp to update the time stamp manually. For
other customizations, see the Custom group time-stamp. Note that the time
stamp is formatted according to your locale setting (see Section C.4 [Environment],
page 509).

15.4 Reverting a Buffer
If you have made extensive changes to a file-visiting buffer and then change your
mind, you can revert the changes and go back to the saved version of the file. To
do this, type M-x revert-buffer. Since reverting unintentionally could lose a lot
of work, Emacs asks for confirmation first.
The revert-buffer command tries to position point in such a way that, if the
file was edited only slightly, you will be at approximately the same part of the text
as before. But if you have made major changes, point may end up in a totally
different location.
Reverting marks the buffer as “not modified”. It also clears the buffer’s undo
history (see Section 13.1 [Undo], page 110). Thus, the reversion cannot be undone—
if you change your mind yet again, you can’t use the undo commands to bring the
reverted changes back.
Some kinds of buffers that are not associated with files, such as Dired buffers, can
also be reverted. For them, reverting means recalculating their contents. Buffers
created explicitly with C-x b cannot be reverted; revert-buffer reports an error
if you try.
When you edit a file that changes automatically and frequently—for example,
a log of output from a process that continues to run—it may be useful for Emacs
to revert the file without querying you. To request this behavior, set the variable
revert-without-query to a list of regular expressions. When a file name matches
one of these regular expressions, find-file and revert-buffer will revert it automatically if it has changed—provided the buffer itself is not modified. (If you have
edited the text, it would be wrong to discard your changes.)
You can also tell Emacs to revert buffers periodically. To do this for a specific
buffer, enable the minor mode Auto-Revert mode by typing M-x auto-revert-mode.
This automatically reverts the current buffer every five seconds; you can change the
interval through the variable auto-revert-interval. To do the same for all file
buffers, type M-x global-auto-revert-mode to enable Global Auto-Revert mode.

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These minor modes do not check or revert remote files, because that is usually too
slow.
One use of Auto-Revert mode is to “tail” a file such as a system log, so that
changes made to that file by other programs are continuously displayed. To do
this, just move the point to the end of the buffer, and it will stay there as the file
contents change. However, if you are sure that the file will only change by growing
at the end, use Auto-Revert Tail mode instead (auto-revert-tail-mode). It is
more efficient for this. Auto-Revert Tail mode works also for remote files.
See Section 25.1.8 [VC Undo], page 304, for commands to revert to earlier versions of files under version control. See Section 25.1.2 [VC Mode Line], page 296,
for Auto Revert peculiarities when visiting files under version control.

15.5 Auto-Saving: Protection Against Disasters
From time to time, Emacs automatically saves each visited file in a separate file,
without altering the file you actually use. This is called auto-saving. It prevents
you from losing more than a limited amount of work if the system crashes.
When Emacs determines that it is time for auto-saving, it considers each buffer,
and each is auto-saved if auto-saving is enabled for it and it has been changed since
the last time it was auto-saved. The message ‘Auto-saving...’ is displayed in the
echo area during auto-saving, if any files are actually auto-saved. Errors occurring
during auto-saving are caught so that they do not interfere with the execution of
commands you have been typing.
15.5.1 Auto-Save Files
Auto-saving does not normally save in the files that you visited, because it can
be very undesirable to save a change that you did not want to make permanent.
Instead, auto-saving is done in a different file called the auto-save file, and the
visited file is changed only when you request saving explicitly (such as with C-x
C-s).
Normally, the auto-save file name is made by appending ‘#’ to the front and rear
of the visited file name. Thus, a buffer visiting file ‘foo.c’ is auto-saved in a file
‘#foo.c#’. Most buffers that are not visiting files are auto-saved only if you request
it explicitly; when they are auto-saved, the auto-save file name is made by appending
‘#’ to the front and rear of buffer name, then adding digits and letters at the end for
uniqueness. For example, the ‘*mail*’ buffer in which you compose messages to be
sent might be auto-saved in a file named ‘#*mail*#704juu’. Auto-save file names
are made this way unless you reprogram parts of Emacs to do something different
(the functions make-auto-save-file-name and auto-save-file-name-p). The
file name to be used for auto-saving in a buffer is calculated when auto-saving is
turned on in that buffer.
The variable auto-save-file-name-transforms allows a degree of control over
the auto-save file name. It lets you specify a series of regular expressions and
replacements to transform the auto save file name. The default value puts the

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auto-save files for remote files (see Section 15.13 [Remote Files], page 145) into the
temporary file directory on the local machine.
When you delete a substantial part of the text in a large buffer, auto save turns
off temporarily in that buffer. This is because if you deleted the text unintentionally,
you might find the auto-save file more useful if it contains the deleted text. To
reenable auto-saving after this happens, save the buffer with C-x C-s, or use C-u 1
M-x auto-save-mode.
If you want auto-saving to be done in the visited file rather than in a separate
auto-save file, set the variable auto-save-visited-file-name to a non-nil value.
In this mode, there is no real difference between auto-saving and explicit saving.
A buffer’s auto-save file is deleted when you save the buffer in its visited file.
(You can inhibit this by setting the variable delete-auto-save-files to nil.)
Changing the visited file name with C-x C-w or set-visited-file-name renames
any auto-save file to go with the new visited name.
15.5.2 Controlling Auto-Saving
Each time you visit a file, auto-saving is turned on for that file’s buffer if the
variable auto-save-default is non-nil (but not in batch mode; see Section C.2
[Initial Options], page 507). The default for this variable is t, so auto-saving is the
usual practice for file-visiting buffers. To toggle auto-saving in the current buffer,
type M-x auto-save-mode. Auto Save mode acts as a buffer-local minor mode (see
Section 20.2 [Minor Modes], page 205).
Emacs auto-saves periodically based on how many characters you have typed
since the last auto-save. The variable auto-save-interval specifies how many
characters there are between auto-saves. By default, it is 300. Emacs doesn’t
accept values that are too small: if you customize auto-save-interval to a value
less than 20, Emacs will behave as if the value is 20.
Auto-saving also takes place when you stop typing for a while. By default,
it does this after 30 seconds of idleness (at this time, Emacs may also perform
garbage collection; see Section “Garbage Collection” in The Emacs Lisp Reference
Manual). To change this interval, customize the variable auto-save-timeout. The
actual time period is longer if the current buffer is long; this is a heuristic which
aims to keep out of your way when you are editing long buffers, in which auto-save
takes an appreciable amount of time. Auto-saving during idle periods accomplishes
two things: first, it makes sure all your work is saved if you go away from the
terminal for a while; second, it may avoid some auto-saving while you are actually
typing.
Emacs also does auto-saving whenever it gets a fatal error. This includes killing
the Emacs job with a shell command such as ‘kill %emacs’, or disconnecting a
phone line or network connection.
You can perform an auto-save explicitly with the command M-x do-auto-save.
15.5.3 Recovering Data from Auto-Saves
You can use the contents of an auto-save file to recover from a loss of data with the
command M-x recover-file RET file RET. This visits file and then (after your

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confirmation) restores the contents from its auto-save file ‘#file #’. You can then
save with C-x C-s to put the recovered text into file itself. For example, to recover
file ‘foo.c’ from its auto-save file ‘#foo.c#’, do:
M-x recover-file RET foo.c RET
yes RET
C-x C-s
Before asking for confirmation, M-x recover-file displays a directory listing
describing the specified file and the auto-save file, so you can compare their sizes
and dates. If the auto-save file is older, M-x recover-file does not offer to read
it.
If Emacs or the computer crashes, you can recover all the files you were editing
from their auto save files with the command M-x recover-session. This first shows
you a list of recorded interrupted sessions. Move point to the one you choose, and
type C-c C-c.
Then recover-session asks about each of the files that were being edited during
that session, asking whether to recover that file. If you answer y, it calls recoverfile, which works in its normal fashion. It shows the dates of the original file and
its auto-save file, and asks once again whether to recover that file.
When recover-session is done, the files you’ve chosen to recover are present
in Emacs buffers. You should then save them. Only this—saving them—updates
the files themselves.
Emacs records information about interrupted sessions in files named
‘.saves-pid-hostname ’ in the directory ‘~/.emacs.d/auto-save-list/’. This
directory is determined by the variable auto-save-list-file-prefix. If you set
auto-save-list-file-prefix to nil, sessions are not recorded for recovery.

15.6 File Name Aliases
Symbolic links and hard links both make it possible for several file names to refer to
the same file. Hard links are alternate names that refer directly to the file; all the
names are equally valid, and no one of them is preferred. By contrast, a symbolic
link is a kind of defined alias: when ‘foo’ is a symbolic link to ‘bar’, you can use
either name to refer to the file, but ‘bar’ is the real name, while ‘foo’ is just an
alias. More complex cases occur when symbolic links point to directories.
Normally, if you visit a file which Emacs is already visiting under a different
name, Emacs displays a message in the echo area and uses the existing buffer
visiting that file. This can happen on systems that support hard or symbolic links,
or if you use a long file name on a system that truncates long file names, or on a
case-insensitive file system. You can suppress the message by setting the variable
find-file-suppress-same-file-warnings to a non-nil value. You can disable
this feature entirely by setting the variable find-file-existing-other-name to
nil: then if you visit the same file under two different names, you get a separate
buffer for each file name.
If the variable find-file-visit-truename is non-nil, then the file name
recorded for a buffer is the file’s truename (made by replacing all symbolic links

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with their target names), rather than the name you specify. Setting find-filevisit-truename also implies the effect of find-file-existing-other-name.
Sometimes, a directory is ordinarily accessed through a symbolic link, and you
may want Emacs to preferentially show its “linked” name. To do this, customize
directory-abbrev-alist. Each element in this list should have the form (from
. to ), which means to replace from with to whenever from appears in a directory
name. The from string is a regular expression (see Section 12.5 [Regexps], page 97).
It is matched against directory names anchored at the first character, and should
start with ‘\‘’ (to support directory names with embedded newlines, which would
defeat ‘^’). The to string should be an ordinary absolute directory name pointing
to the same directory. Do not use ‘~’ to stand for a home directory in the to string;
Emacs performs these substitutions separately. Here’s an example, from a system
on which ‘/home/fsf’ is normally accessed through a symbolic link named ‘/fsf’:
(("\\‘/home/fsf" . "/fsf"))

15.7 File Directories
The file system groups files into directories. A directory listing is a list of all the files
in a directory. Emacs provides commands to create and delete directories, and to
make directory listings in brief format (file names only) and verbose format (sizes,
dates, and authors included). Emacs also includes a directory browser feature called
Dired; see Chapter 27 [Dired], page 329.
C-x C-d dir-or-pattern RET
Display a brief directory listing (list-directory).
C-u C-x C-d dir-or-pattern RET
Display a verbose directory listing.
M-x make-directory RET dirname RET
Create a new directory named dirname.
M-x delete-directory RET dirname RET
Delete the directory named dirname. If it isn’t empty, you will be
asked whether you want to delete it recursively.
The command to display a directory listing is C-x C-d (list-directory). It
reads using the minibuffer a file name which is either a directory to be listed or a
wildcard-containing pattern for the files to be listed. For example,
C-x C-d /u2/emacs/etc RET
lists all the files in directory ‘/u2/emacs/etc’. Here is an example of specifying a
file name pattern:
C-x C-d /u2/emacs/src/*.c RET
Normally, C-x C-d displays a brief directory listing containing just file names.
A numeric argument (regardless of value) tells it to make a verbose listing including
sizes, dates, and owners (like ‘ls -l’).
The text of a directory listing is mostly obtained by running ls in an inferior
process. Two Emacs variables control the switches passed to ls: list-directorybrief-switches is a string giving the switches to use in brief listings ("-CF" by

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default), and list-directory-verbose-switches is a string giving the switches
to use in a verbose listing ("-l" by default).
In verbose directory listings, Emacs adds information about the amount of free
space on the disk that contains the directory. To do this, it runs the program
specified by directory-free-space-program with arguments directory-freespace-args.
The command M-x delete-directory prompts for a directory name using the
minibuffer, and deletes the directory if it is empty. If the directory is not empty,
you will be asked whether you want to delete it recursively. On systems that have a
“Trash” (or “Recycle Bin”) feature, you can make this command move the specified
directory to the Trash instead of deleting it outright, by changing the variable
delete-by-moving-to-trash to t. See Section 15.10 [Misc File Ops], page 143,
for more information about using the Trash.

15.8 Comparing Files
The command M-x diff prompts for two file names, using the minibuffer, and
displays the differences between the two files in a buffer named ‘*diff*’. This
works by running the diff program, using options taken from the variable diffswitches. The value of diff-switches should be a string; the default is "-c" to
specify a context diff. See Section “Diff” in Comparing and Merging Files, for more
information about the diff program.
The output of the diff command is shown using a major mode called Diff mode.
See Section 15.9 [Diff Mode], page 141.
The command M-x diff-backup compares a specified file with its most recent
backup. If you specify the name of a backup file, diff-backup compares it with
the source file that it is a backup of. In all other respects, this behaves like M-x
diff.
The command M-x diff-buffer-with-file compares a specified buffer with
its corresponding file. This shows you what changes you would make to the file if
you save the buffer.
The command M-x compare-windows compares the text in the current window
with that in the next window. (For more information about windows in Emacs,
Chapter 17 [Windows], page 159.) Comparison starts at point in each window,
after pushing each initial point value on the mark ring in its respective buffer.
Then it moves point forward in each window, one character at a time, until it
reaches characters that don’t match. Then the command exits.
If point in the two windows is followed by non-matching text when the command
starts, M-x compare-windows tries heuristically to advance up to matching text in
the two windows, and then exits. So if you use M-x compare-windows repeatedly,
each time it either skips one matching range or finds the start of another.
With a numeric argument, compare-windows ignores changes in whitespace. If
the variable compare-ignore-case is non-nil, the comparison ignores differences
in case as well. If the variable compare-ignore-whitespace is non-nil, compare-

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windows normally ignores changes in whitespace, and a prefix argument turns that
off.
You can use M-x smerge-mode to turn on Smerge mode, a minor mode for editing
output from the diff3 program. This is typically the result of a failed merge from
a version control system “update” outside VC, due to conflicting changes to a file.
Smerge mode provides commands to resolve conflicts by selecting specific changes.
See Section “Emerge” in Specialized Emacs Features, for the Emerge facility,
which provides a powerful interface for merging files.

15.9 Diff Mode
Diff mode is a major mode used for the output of M-x diff and other similar
commands. This kind of output is called a patch, because it can be passed to the
patch command to automatically apply the specified changes. To select Diff mode
manually, type M-x diff-mode.
The changes specified in a patch are grouped into hunks, which are contiguous
chunks of text that contain one or more changed lines. Hunks can also include
unchanged lines to provide context for the changes. Each hunk is preceded by a
hunk header, which specifies the old and new line numbers at which the hunk occurs.
Diff mode highlights each hunk header, to distinguish it from the actual contents
of the hunk.
You can edit a Diff mode buffer like any other buffer. (If it is read-only, you
need to make it writable first. See Section 16.3 [Misc Buffer], page 152.) Whenever
you change a hunk, Diff mode attempts to automatically correct the line numbers
in the hunk headers, to ensure that the diff remains “correct”. To disable automatic
line number correction, change the variable diff-update-on-the-fly to nil.
Diff mode treats each hunk as an “error message”, similar to Compilation mode.
Thus, you can use commands such as C-x ’ to visit the corresponding source locations. See Section 24.2 [Compilation Mode], page 272.
In addition, Diff mode provides the following commands to navigate, manipulate
and apply parts of patches:
M-n

Move to the next hunk-start (diff-hunk-next).
This command has a side effect: it refines the hunk you move to, highlighting its changes with better granularity. To disable this feature,
type M-x diff-auto-refine-mode to toggle off the minor mode Diff
Auto-Refine mode. To disable Diff Auto Refine mode by default, add
this to your init file (see Section 33.2.2 [Hooks], page 445):
(add-hook ’diff-mode-hook
(lambda () (diff-auto-refine-mode -1)))

M-p

Move to the previous hunk-start (diff-hunk-prev). Like M-n, this
has the side-effect of refining the hunk you move to, unless you disable
Diff Auto-Refine mode.

M-}

Move to the next file-start, in a multi-file patch (diff-file-next).

M-{

Move to the previous file-start, in a multi-file patch (diff-file-prev).

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M-k

Kill the hunk at point (diff-hunk-kill).

M-K

In a multi-file patch, kill the current file part. (diff-file-kill).

C-c C-a

Apply this hunk to its target file (diff-apply-hunk). With a prefix
argument of C-u, revert this hunk.

C-c C-b

Highlight the changes of the hunk at point with a finer granularity
(diff-refine-hunk). This allows you to see exactly which parts of
each changed line were actually changed.

C-c C-c

Go to the source file and line corresponding to this hunk (diff-gotosource).

C-c C-e

Start an Ediff session with the patch (diff-ediff-patch). See Section
“Ediff” in The Ediff Manual.

C-c C-n

Restrict the view to the current hunk (diff-restrict-view). See
Section 11.5 [Narrowing], page 74. With a prefix argument of C-u,
restrict the view to the current file of a multiple-file patch. To widen
again, use C-x n w (widen).

C-c C-r

Reverse the direction of comparison for the entire buffer (diffreverse-direction).

C-c C-s

Split the hunk at point (diff-split-hunk). This is for manually
editing patches, and only works with the unified diff format produced
by the ‘-u’ or ‘--unified’ options to the diff program. If you need
to split a hunk in the context diff format produced by the ‘-c’ or
‘--context’ options to diff, first convert the buffer to the unified diff
format with C-c C-u.

C-c C-d

Convert the entire buffer to the context diff format (diff-unified>context). With a prefix argument, convert only the text within the
region.

C-c C-u

Convert the entire buffer to unified diff format (diff-context>unified). With a prefix argument, convert unified format to context
format. When the mark is active, convert only the text within the
region.

C-c C-w

Refine the current hunk so that it disregards changes in whitespace
(diff-refine-hunk).

C-x 4 A

Generate a ChangeLog entry, like C-x 4 a does (see Section 25.2
[Change Log], page 309), for each one of the hunks (diff-add-changelog-entries-other-window). This creates a skeleton of the log of
changes that you can later fill with the actual descriptions of the
changes. C-x 4 a itself in Diff mode operates on behalf of the current hunk’s file, but gets the function name from the patch itself. This
is useful for making log entries for functions that are deleted by the
patch.

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By default, Diff mode highlights trailing whitespace on modified lines, so that
they are more obvious. This is done by enabling Whitespace mode in the Diff buffer
(see Section 11.16 [Useless Whitespace], page 84). Diff mode buffers are set up so
that Whitespace mode avoids highlighting trailing whitespace occurring in the diff
context.

15.10 Miscellaneous File Operations
Emacs has commands for performing many other operations on files. All operate
on one file; they do not accept wildcard file names.
M-x delete-file prompts for a file and deletes it. If you are deleting many files
in one directory, it may be more convenient to use Dired rather than delete-file.
See Section 27.3 [Dired Deletion], page 330.
M-x move-file-to-trash moves a file into the system Trash (or Recycle Bin).
This is a facility available on most operating systems; files that are moved into the
Trash can be brought back later if you change your mind.
By default, Emacs deletion commands do not use the Trash. To use the Trash
(when it is available) for common deletion commands, change the variable deleteby-moving-to-trash to t. This affects the commands M-x delete-file and M-x
delete-directory (see Section 15.7 [Directories], page 139), as well as the deletion
commands in Dired (see Section 27.3 [Dired Deletion], page 330). Supplying a
prefix argument to M-x delete-file or M-x delete-directory makes them delete
outright, instead of using the Trash, regardless of delete-by-moving-to-trash.
M-x copy-file reads the file old and writes a new file named new with the same
contents.
M-x copy-directory copies directories, similar to the cp -r shell command. It
prompts for a directory old and a destination new. If new is an existing directory,
it creates a copy of the old directory and puts it in new. If new is not an existing
directory, it copies all the contents of old into a new directory named new.
M-x rename-file reads two file names old and new using the minibuffer, then
renames file old as new. If the file name new already exists, you must confirm with
yes or renaming is not done; this is because renaming causes the old meaning of the
name new to be lost. If old and new are on different file systems, the file old is copied
and deleted. If the argument new is just a directory name, the real new name is
in that directory, with the same non-directory component as old. For example, M-x
rename-file RET ~/foo RET /tmp RET renames ‘~/foo’ to ‘/tmp/foo’. The same
rule applies to all the remaining commands in this section. All of them ask for
confirmation when the new file name already exists, too.
M-x add-name-to-file adds an additional name to an existing file without removing its old name. The new name is created as a “hard link” to the existing
file. The new name must belong on the same file system that the file is on. On
MS-Windows, this command works only if the file resides in an NTFS file system.
On MS-DOS, it works by copying the file.
M-x make-symbolic-link reads two file names target and linkname, then creates a symbolic link named linkname, which points at target. The effect is that

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future attempts to open file linkname will refer to whatever file is named target at
the time the opening is done, or will get an error if the name target is nonexistent
at that time. This command does not expand the argument target, so that it allows
you to specify a relative name as the target of the link. Not all systems support
symbolic links; on systems that don’t support them, this command is not defined.
M-x insert-file (also C-x i) inserts a copy of the contents of the specified file
into the current buffer at point, leaving point unchanged before the contents. The
position after the inserted contents is added to the mark ring, without activating
the mark (see Section 8.4 [Mark Ring], page 51).
M-x insert-file-literally is like M-x insert-file, except the file is inserted
“literally”: it is treated as a sequence of ASCII characters with no special encoding
or conversion, similar to the M-x find-file-literally command (see Section 15.2
[Visiting], page 125).
M-x write-region is the inverse of M-x insert-file; it copies the contents of
the region into the specified file. M-x append-to-file adds the text of the region
to the end of the specified file. See Section 9.4 [Accumulating Text], page 61.
The variable write-region-inhibit-fsync applies to these commands, as well as
saving files; see Section 15.3.3 [Customize Save], page 132.
M-x set-file-modes reads a file name followed by a file mode, and applies that
file mode to the specified file. File modes, also called file permissions, determine
whether a file can be read, written to, or executed, and by whom. This command
reads file modes using the same symbolic or octal format accepted by the chmod
command; for instance, ‘u+x’ means to add execution permission for the user who
owns the file. It has no effect on operating systems that do not support file modes.
chmod is a convenience alias for this function.

15.11 Accessing Compressed Files
Emacs automatically uncompresses compressed files when you visit them, and automatically recompresses them if you alter them and save them. Emacs recognizes
compressed files by their file names. File names ending in ‘.gz’ indicate a file
compressed with gzip. Other endings indicate other compression programs.
Automatic uncompression and compression apply to all the operations in which
Emacs uses the contents of a file. This includes visiting it, saving it, inserting its
contents into a buffer, loading it, and byte compiling it.
To disable this feature, type the command M-x auto-compression-mode. You
can disable it permanently by customizing the variable auto-compression-mode.

15.12 File Archives
A file whose name ends in ‘.tar’ is normally an archive made by the tar program.
Emacs views these files in a special mode called Tar mode which provides a Diredlike list of the contents (see Chapter 27 [Dired], page 329). You can move around
through the list just as you would in Dired, and visit the subfiles contained in the
archive. However, not all Dired commands are available in Tar mode.

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If Auto Compression mode is enabled (see Section 15.11 [Compressed Files],
page 144), then Tar mode is used also for compressed archives—files with extensions
‘.tgz’, .tar.Z and .tar.gz.
The keys e, f and RET all extract a component file into its own buffer. You can
edit it there, and if you save the buffer, the edited version will replace the version
in the Tar buffer. Clicking with the mouse on the file name in the Tar buffer does
likewise. v extracts a file into a buffer in View mode (see Section 11.6 [View Mode],
page 75). o extracts the file and displays it in another window, so you could edit
the file and operate on the archive simultaneously.
d marks a file for deletion when you later use x, and u unmarks a file, as in Dired.
C copies a file from the archive to disk and R renames a file within the archive. g
reverts the buffer from the archive on disk. The keys M, G, and O change the file’s
permission bits, group, and owner, respectively.
Saving the Tar buffer writes a new version of the archive to disk with the changes
you made to the components.
You don’t need the tar program to use Tar mode—Emacs reads the archives
directly. However, accessing compressed archives requires the appropriate uncompression program.
A separate but similar Archive mode is used for arc, jar, lzh, zip, rar, 7z,
and zoo archives, as well as exe files that are self-extracting executables.
The key bindings of Archive mode are similar to those in Tar mode, with the
addition of the m key which marks a file for subsequent operations, and M-DEL
which unmarks all the marked files. Also, the a key toggles the display of detailed
file information, for those archive types where it won’t fit in a single line. Operations
such as renaming a subfile, or changing its mode or owner, are supported only for
some of the archive formats.
Unlike Tar mode, Archive mode runs the archiving programs to unpack and
repack archives. However, you don’t need these programs to look at the archive
table of contents, only to extract or manipulate the subfiles in the archive. Details
of the program names and their options can be set in the ‘Archive’ Customize
group.

15.13 Remote Files
You can refer to files on other machines using a special file name syntax:
/host :filename
/user @host :filename
/user @host #port :filename
/method :user @host :filename
/method :user @host #port :filename
To carry out this request, Emacs uses a remote-login program such as ftp,
ssh, rlogin, or telnet. You can always specify in the file name which
method to use—for example, ‘/ftp:user @host :filename ’ uses FTP, whereas
‘/ssh:user @host :filename ’ uses ssh. When you don’t specify a method in the
file name, Emacs chooses the method as follows:

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1. If the host name starts with ‘ftp.’ (with dot), Emacs uses FTP.
2. If the user name is ‘ftp’ or ‘anonymous’, Emacs uses FTP.
3. If the variable tramp-default-method is set to ‘ftp’, Emacs uses FTP.
4. If ssh-agent is running, Emacs uses scp.
5. Otherwise, Emacs uses ssh.
You can entirely turn off the remote file name feature by setting the variable trampmode to nil. You can turn off the feature in individual cases by quoting the file
name with ‘/:’ (see Section 15.14 [Quoted File Names], page 146).
Remote file access through FTP is handled by the Ange-FTP package, which
is documented in the following. Remote file access through the other methods is
handled by the Tramp package, which has its own manual. See Section “Top” in
The Tramp Manual.
When the Ange-FTP package is used, Emacs logs in through FTP using the
name user, if that is specified in the remote file name. If user is unspecified, Emacs
logs in using your user name on the local system; but if you set the variable angeftp-default-user to a string, that string is used instead. When logging in, Emacs
may also ask for a password.
For performance reasons, Emacs does not make backup files for files accessed via
FTP by default. To make it do so, change the variable ange-ftp-make-backupfiles to a non-nil value.
By default, auto-save files for remote files are made in the temporary file directory on the local machine, as specified by the variable auto-save-file-nametransforms. See Section 15.5.1 [Auto Save Files], page 136.
To visit files accessible by anonymous FTP, you use special user names
‘anonymous’ or ‘ftp’. Passwords for these user names are handled specially. The
variable ange-ftp-generate-anonymous-password controls what happens: if
the value of this variable is a string, then that string is used as the password; if
non-nil (the default), then the value of user-mail-address is used; if nil, then
Emacs prompts you for a password as usual (see Section 5.6 [Passwords], page 36).
Sometimes you may be unable to access files on a remote machine because a
firewall in between blocks the connection for security reasons. If you can log in on a
gateway machine from which the target files are accessible, and whose FTP server
supports gatewaying features, you can still use remote file names; all you have to
do is specify the name of the gateway machine by setting the variable ange-ftpgateway-host, and set ange-ftp-smart-gateway to t. Otherwise you may be able
to make remote file names work, but the procedure is complex. You can read the
instructions by typing M-x finder-commentary RET ange-ftp RET.

15.14 Quoted File Names
You can quote an absolute file name to prevent special characters and syntax in it
from having their special effects. The way to do this is to add ‘/:’ at the beginning.
For example, you can quote a local file name which appears remote, to prevent it from being treated as a remote file name. Thus, if you have a directory

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named ‘/foo:’ and a file named ‘bar’ in it, you can refer to that file in Emacs as
‘/:/foo:/bar’.
‘/:’ can also prevent ‘~’ from being treated as a special character for a user’s
home directory. For example, ‘/:/tmp/~hack’ refers to a file whose name is ‘~hack’
in directory ‘/tmp’.
Quoting with ‘/:’ is also a way to enter in the minibuffer a file name that contains
‘$’. In order for this to work, the ‘/:’ must be at the beginning of the minibuffer
contents. (You can also double each ‘$’; see [File Names with $], page 125.)
You can also quote wildcard characters with ‘/:’, for visiting. For example,
‘/:/tmp/foo*bar’ visits the file ‘/tmp/foo*bar’.
Another method of getting the same result is to enter ‘/tmp/foo[*]bar’, which
is a wildcard specification that matches only ‘/tmp/foo*bar’. However, in many
cases there is no need to quote the wildcard characters because even unquoted they
give the right result. For example, if the only file name in ‘/tmp’ that starts with
‘foo’ and ends with ‘bar’ is ‘foo*bar’, then specifying ‘/tmp/foo*bar’ will visit
only ‘/tmp/foo*bar’.

15.15 File Name Cache
You can use the file name cache to make it easy to locate a file by name, without
having to remember exactly where it is located. When typing a file name in the
minibuffer, C-TAB (file-cache-minibuffer-complete) completes it using the file
name cache. If you repeat C-TAB, that cycles through the possible completions of
what you had originally typed. (However, note that the C-TAB character cannot be
typed on most text terminals.)
The file name cache does not fill up automatically. Instead, you load file names
into the cache using these commands:
M-x file-cache-add-directory RET directory RET
Add each file name in directory to the file name cache.
M-x file-cache-add-directory-using-find RET directory RET
Add each file name in directory and all of its nested subdirectories to
the file name cache.
M-x file-cache-add-directory-using-locate RET directory RET
Add each file name in directory and all of its nested subdirectories to
the file name cache, using locate to find them all.
M-x file-cache-add-directory-list RET variable RET
Add each file name in each directory listed in variable to the file name
cache. variable should be a Lisp variable whose value is a list of
directory names, like load-path.
M-x file-cache-clear-cache RET
Clear the cache; that is, remove all file names from it.
The file name cache is not persistent: it is kept and maintained only for the
duration of the Emacs session. You can view the contents of the cache with the
file-cache-display command.

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15.16 Convenience Features for Finding Files
In this section, we introduce some convenient facilities for finding recently-opened
files, reading file names from a buffer, and viewing image files.
If you enable Recentf mode, with M-x recentf-mode, the ‘File’ menu includes
a submenu containing a list of recently opened files. M-x recentf-save-list saves
the current recent-file-list to a file, and M-x recentf-edit-list edits it.
The M-x ffap command generalizes find-file with more powerful heuristic
defaults (see Section 31.11.3 [FFAP], page 427), often based on the text at point.
Partial Completion mode offers other features extending find-file, which can be
used with ffap. See Section 5.3.5 [Completion Options], page 33.
Visiting image files automatically selects Image mode. In this major mode, you
can type C-c C-c (image-toggle-display) to toggle between displaying the file
as an image in the Emacs buffer, and displaying its underlying text (or raw byte)
representation. Displaying the file as an image works only if Emacs is compiled
with support for displaying such images. If the displayed image is wider or taller
than the frame, the usual point motion keys (C-f, C-p, and so forth) cause different
parts of the image to be displayed. If the image can be animated, the command
RET (image-toggle-animation) starts or stops the animation. Animation plays
once, unless the option image-animate-loop is non-nil. Currently, Emacs only
supports animation in GIF files.
If your Emacs was compiled with ImageMagick support, it is possible to view
a much wider variety of image types in Image mode, by rendering the images via
ImageMagick. However, this feature is currently disabled by default. To enable it,
add the following line to your init file:
(imagemagick-register-types)
The Image-Dired package can also be used to view images as thumbnails. See
Section 27.17 [Image-Dired], page 343.

15.17 Filesets
If you regularly edit a certain group of files, you can define them as a fileset. This
lets you perform certain operations, such as visiting, query-replace, and shell
commands on all the files at once. To make use of filesets, you must first add the
expression (filesets-init) to your init file (see Section 33.4 [Init File], page 461).
This adds a ‘Filesets’ menu to the menu bar.
The simplest way to define a fileset is by adding files to it one at a time. To add
a file to fileset name, visit the file and type M-x filesets-add-buffer RET name
RET. If there is no fileset name, this creates a new one, which initially contains only
the current file. The command M-x filesets-remove-buffer removes the current
file from a fileset.
You can also edit the list of filesets directly, with M-x filesets-edit (or by
choosing ‘Edit Filesets’ from the ‘Filesets’ menu). The editing is performed in
a Customize buffer (see Section 33.1 [Easy Customization], page 434). Normally, a
fileset is a simple list of files, but you can also define a fileset as a regular expression
matching file names. Some examples of these more complicated filesets are shown

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in the Customize buffer. Remember to select ‘Save for future sessions’ if you
want to use the same filesets in future Emacs sessions.
You can use the command M-x filesets-open to visit all the files in a fileset,
and M-x filesets-close to close them. Use M-x filesets-run-cmd to run a shell
command on all the files in a fileset. These commands are also available from the
‘Filesets’ menu, where each existing fileset is represented by a submenu.
See Section 25.1 [Version Control], page 292, for a different concept of “filesets”:
groups of files bundled together for version control operations. Filesets of that type
are unnamed, and do not persist across Emacs sessions.

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16 Using Multiple Buffers
The text you are editing in Emacs resides in an object called a buffer. Each time
you visit a file, a buffer is used to hold the file’s text. Each time you invoke Dired,
a buffer is used to hold the directory listing. If you send a message with C-x m,
a buffer is used to hold the text of the message. When you ask for a command’s
documentation, that appears in a buffer named ‘*Help*’.
Each buffer has a unique name, which can be of any length. When a buffer is
displayed in a window, its name is shown in the mode line (see Section 1.3 [Mode
Line], page 8). The distinction between upper and lower case matters in buffer
names. Most buffers are made by visiting files, and their names are derived from
the files’ names; however, you can also create an empty buffer with any name you
want. A newly started Emacs has several buffers, including one named ‘*scratch*’,
which can be used for evaluating Lisp expressions and is not associated with any
file (see Section 24.10 [Lisp Interaction], page 290).
At any time, one and only one buffer is selected; we call it the current buffer.
We sometimes say that a command operates on “the buffer”; this really means that
it operates on the current buffer. When there is only one Emacs window, the buffer
displayed in that window is current. When there are multiple windows, the buffer
displayed in the selected window is current. See Chapter 17 [Windows], page 159.
Aside from its textual contents, each buffer records several pieces of information,
such as what file it is visiting (if any), whether it is modified, and what major mode
and minor modes are in effect (see Chapter 20 [Modes], page 204). These are stored
in buffer-local variables—variables that can have a different value in each buffer.
See Section 33.2.3 [Locals], page 446.
A buffer’s size cannot be larger than some maximum, which is defined by the
largest buffer position representable by Emacs integers. This is because Emacs
tracks buffer positions using that data type. For typical 64-bit machines, this maximum buffer size is 26 1 − 2 bytes, or about 2 EiB. For typical 32-bit machines, the
maximum is usually 22 9 − 2 bytes, or about 512 MiB. Buffer sizes are also limited
by the amount of memory in the system.

16.1 Creating and Selecting Buffers
C-x b buffer RET
Select or create a buffer named buffer (switch-to-buffer).
C-x 4 b buffer RET
Similar, but select buffer in another window (switch-to-bufferother-window).
C-x 5 b buffer RET
Similar, but select buffer in a separate frame (switch-to-bufferother-frame).
C-x LEFT

Select the previous buffer in the buffer list (previous-buffer).

C-x RIGHT

Select the next buffer in the buffer list (next-buffer).

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C-u M-g M-g
C-u M-g g Read a number n and move to line n in the most recently selected
buffer other than the current buffer.
The C-x b (switch-to-buffer) command reads a buffer name using the minibuffer. Then it makes that buffer current, and displays it in the currently-selected
window. An empty input specifies the buffer that was current most recently among
those not now displayed in any window.
While entering the buffer name, you can use the usual completion and history
commands (see Chapter 5 [Minibuffer], page 27). Note that C-x b, and related commands, use “permissive completion with confirmation” for minibuffer completion:
if you type RET immediately after completing up to a nonexistent buffer name,
Emacs prints ‘[Confirm]’ and you must type a second RET to submit that buffer
name. See Section 5.3.3 [Completion Exit], page 31, for details.
If you specify a buffer that does not exist, C-x b creates a new, empty buffer
that is not visiting any file, and selects it for editing. The default value of the
variable major-mode determines the new buffer’s major mode; the default value
is Fundamental mode. See Section 20.1 [Major Modes], page 204. One reason to
create a new buffer is to use it for making temporary notes. If you try to save it,
Emacs asks for the file name to use, and the buffer’s major mode is re-established
taking that file name into account (see Section 20.3 [Choosing Modes], page 207).
For conveniently switching between a few buffers, use the commands C-x LEFT
and C-x RIGHT. C-x LEFT (previous-buffer) selects the previous buffer (following
the order of most recent selection in the current frame), while C-x RIGHT (nextbuffer) moves through buffers in the reverse direction.
To select a buffer in a window other than the current one, type C-x 4 b (switchto-buffer-other-window). This prompts for a buffer name using the minibuffer,
displays that buffer in another window, and selects that window.
Similarly, C-x 5 b (switch-to-buffer-other-frame) prompts for a buffer
name, displays that buffer in another frame, and selects that frame. If the buffer
is already being shown in a window on another frame, Emacs selects that window
and frame instead of creating a new frame.
See Section 17.6 [Displaying Buffers], page 163, for how the C-x 4 b and C-x 5
b commands get the window and/or frame to display in.
In addition, C-x C-f, and any other command for visiting a file, can also be used
to switch to an existing file-visiting buffer. See Section 15.2 [Visiting], page 125.
C-u M-g M-g, that is goto-line with a plain prefix argument, reads a number n
using the minibuffer, selects the most recently selected buffer other than the current
buffer in another window, and then moves point to the beginning of line number
n in that buffer. This is mainly useful in a buffer that refers to line numbers in
another buffer: if point is on or just after a number, goto-line uses that number as
the default for n. Note that prefix arguments other than just C-u behave differently.
C-u 4 M-g M-g goes to line 4 in the current buffer, without reading a number from
the minibuffer. (Remember that M-g M-g without prefix argument reads a number
n and then moves to line number n in the current buffer. See Section 4.2 [Moving
Point], page 18.)

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Emacs uses buffer names that start with a space for internal purposes. It treats
these buffers specially in minor ways—for example, by default they do not record
undo information. It is best to avoid using such buffer names yourself.

16.2 Listing Existing Buffers
C-x C-b

List the existing buffers (list-buffers).

To display a list of existing buffers, type C-x C-b. Each line in the list shows
one buffer’s name, major mode and visited file. The buffers are listed in the order
that they were current; the buffers that were current most recently come first.
‘.’ in the first field of a line indicates that the buffer is current. ‘%’ indicates
a read-only buffer. ‘*’ indicates that the buffer is “modified”. If several buffers
are modified, it may be time to save some with C-x s (see Section 15.3.1 [Save
Commands], page 128). Here is an example of a buffer list:
CRM Buffer
. * .emacs
% *Help*
search.c
% src
* *mail*
% HELLO
% NEWS
*scratch*
* *Messages*

Size
3294
101
86055
20959
42
1607
481184
191
1554

Mode
Emacs-Lisp
Help
C
Dired by name
Mail
Fundamental
Outline
Lisp Interaction
Fundamental

File
~/.emacs
~/cvs/emacs/src/search.c
~/cvs/emacs/src/
~/cvs/emacs/etc/HELLO
~/cvs/emacs/etc/NEWS

The buffer ‘*Help*’ was made by a help request (see Chapter 7 [Help], page 38);
it is not visiting any file. The buffer src was made by Dired on the directory
‘~/cvs/emacs/src/’. You can list only buffers that are visiting files by giving the
command a prefix argument, as in C-u C-x C-b.
list-buffers omits buffers whose names begin with a space, unless they visit
files: such buffers are used internally by Emacs.

16.3 Miscellaneous Buffer Operations
C-x C-q

Toggle read-only status of buffer (toggle-read-only).

M-x rename-buffer RET name RET
Change the name of the current buffer.
M-x rename-uniquely
Rename the current buffer by adding ‘’ to the end.
M-x view-buffer RET buffer RET
Scroll through buffer buffer. See Section 11.6 [View Mode], page 75.
A buffer can be read-only, which means that commands to change its contents
are not allowed. The mode line indicates read-only buffers with ‘%%’ or ‘%*’ near
the left margin. Read-only buffers are usually made by subsystems such as Dired
and Rmail that have special commands to operate on the text; also by visiting a
file whose access control says you cannot write it.

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The command C-x C-q (toggle-read-only) makes a read-only buffer writable,
and makes a writable buffer read-only. This works by setting the variable bufferread-only, which has a local value in each buffer and makes the buffer read-only
if its value is non-nil.
M-x rename-buffer changes the name of the current buffer. You specify the
new name as a minibuffer argument; there is no default. If you specify a name that
is in use for some other buffer, an error happens and no renaming is done.
M-x rename-uniquely renames the current buffer to a similar name with a numeric suffix added to make it both different and unique. This command does not
need an argument. It is useful for creating multiple shell buffers: if you rename
the ‘*shell*’ buffer, then do M-x shell again, it makes a new shell buffer named
‘*shell*’; meanwhile, the old shell buffer continues to exist under its new name.
This method is also good for mail buffers, compilation buffers, and most Emacs
features that create special buffers with particular names. (With some of these
features, such as M-x compile, M-x grep, you need to switch to some other buffer
before using the command again, otherwise it will reuse the current buffer despite
the name change.)
The commands M-x append-to-buffer and M-x insert-buffer can also be
used to copy text from one buffer to another. See Section 9.4 [Accumulating Text],
page 61.

16.4 Killing Buffers
If you continue an Emacs session for a while, you may accumulate a large number
of buffers. You may then find it convenient to kill the buffers you no longer need.
On most operating systems, killing a buffer releases its space back to the operating
system so that other programs can use it. Here are some commands for killing
buffers:
C-x k bufname RET
Kill buffer bufname (kill-buffer).
M-x kill-some-buffers
Offer to kill each buffer, one by one.
M-x kill-matching-buffers
Offer to kill all buffers matching a regular expression.
C-x k (kill-buffer) kills one buffer, whose name you specify in the minibuffer.
The default, used if you type just RET in the minibuffer, is to kill the current
buffer. If you kill the current buffer, another buffer becomes current: one that was
current in the recent past but is not displayed in any window now. If you ask to
kill a file-visiting buffer that is modified, then you must confirm with yes before
the buffer is killed.
The command M-x kill-some-buffers asks about each buffer, one by one. An
answer of y means to kill the buffer, just like kill-buffer. This command ignores
buffers whose names begin with a space, which are used internally by Emacs.

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The command M-x kill-matching-buffers prompts for a regular expression
and kills all buffers whose names match that expression. See Section 12.5 [Regexps],
page 97. Like kill-some-buffers, it asks for confirmation before each kill. This
command normally ignores buffers whose names begin with a space, which are used
internally by Emacs. To kill internal buffers as well, call kill-matching-buffers
with a prefix argument.
The buffer menu feature is also convenient for killing various buffers. See
Section 16.5 [Several Buffers], page 154.
If you want to do something special every time a buffer is killed, you can add hook
functions to the hook kill-buffer-hook (see Section 33.2.2 [Hooks], page 445).
If you run one Emacs session for a period of days, as many people do, it can fill up
with buffers that you used several days ago. The command M-x clean-buffer-list
is a convenient way to purge them; it kills all the unmodified buffers that you have
not used for a long time. An ordinary buffer is killed if it has not been displayed
for three days; however, you can specify certain buffers that should never be killed
automatically, and others that should be killed if they have been unused for a mere
hour.
You can also have this buffer purging done for you, once a day, by enabling
Midnight mode. Midnight mode operates each day at midnight; at that time, it
runs clean-buffer-list, or whichever functions you have placed in the normal
hook midnight-hook (see Section 33.2.2 [Hooks], page 445). To enable Midnight
mode, use the Customization buffer to set the variable midnight-mode to t. See
Section 33.1 [Easy Customization], page 434.

16.5 Operating on Several Buffers
M-x buffer-menu
Begin editing a buffer listing all Emacs buffers.
M-x buffer-menu-other-window.
Similar, but do it in another window.
The buffer menu opened by C-x C-b (see Section 16.2 [List Buffers], page 152)
does not merely list buffers. It also allows you to perform various operations on
buffers, through an interface similar to Dired (see Chapter 27 [Dired], page 329).
You can save buffers, kill them (here called deleting them, for consistency with
Dired), or display them.
To use the buffer menu, type C-x C-b and switch to the window displaying
the ‘*Buffer List*’ buffer.
You can also type M-x buffer-menu to open
the buffer menu in the selected window. Alternatively, the command M-x
buffer-menu-other-window opens the buffer menu in another window, and selects
that window.
The buffer menu is a read-only buffer, and can be changed only through the
special commands described in this section. The usual cursor motion commands
can be used in this buffer. The following commands apply to the buffer described
on the current line:

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d

Request to delete (kill) the buffer, then move down. The request shows
as a ‘D’ on the line, before the buffer name. Requested deletions take
place when you type the x command.

C-d

Like d but move up afterwards instead of down.

s

Request to save the buffer. The request shows as an ‘S’ on the line.
Requested saves take place when you type the x command. You may
request both saving and deletion for the same buffer.

x

Perform previously requested deletions and saves.

u

Remove any request made for the current line, and move down.

DEL

Move to previous line and remove any request made for that line.

The d, C-d, s and u commands to add or remove flags also move down (or up)
one line. They accept a numeric argument as a repeat count.
These commands operate immediately on the buffer listed on the current line:
~

Mark the buffer “unmodified”. The command ~ does this immediately
when you type it.

%

Toggle the buffer’s read-only flag. The command % does this immediately when you type it.

t

Visit the buffer as a tags table. See Section 25.3.4 [Select Tags Table],
page 317.
There are also commands to select another buffer or buffers:

q
RET
f

Quit the buffer menu—immediately display the most recent formerly
visible buffer in its place.
Immediately select this line’s buffer in place of the ‘*Buffer List*’
buffer.

o

Immediately select this line’s buffer in another window as if by C-x 4
b, leaving ‘*Buffer List*’ visible.

C-o

Immediately display this line’s buffer in another window, but don’t
select the window.

1

Immediately select this line’s buffer in a full-screen window.

2

Immediately set up two windows, with this line’s buffer selected in
one, and the previously current buffer (aside from the buffer ‘*Buffer
List*’) displayed in the other.

b

Bury the buffer listed on this line.

m

Mark this line’s buffer to be displayed in another window if you exit
with the v command. The request shows as a ‘>’ at the beginning of
the line. (A single buffer may not have both a delete request and a
display request.)

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Immediately select this line’s buffer, and also display in other windows
any buffers previously marked with the m command. If you have not
marked any buffers, this command is equivalent to 1.

v

There is also a command that affects the entire buffer list:
T

Delete, or reinsert, lines for non-file buffers. This command toggles
the inclusion of such buffers in the buffer list.

What buffer-menu actually does is create and switch to a suitable buffer, and
turn on Buffer Menu mode in it. Everything else described above is implemented
by the special commands provided in Buffer Menu mode. One consequence of this
is that you can switch from the ‘*Buffer List*’ buffer to another Emacs buffer,
and edit there. You can reselect the ‘*Buffer List*’ buffer later, to perform the
operations already requested, or you can kill it, or pay no further attention to it.
Normally, the buffer ‘*Buffer List*’ is not updated automatically when buffers
are created and killed; its contents are just text. If you have created, deleted or
renamed buffers, the way to update ‘*Buffer List*’ to show what you have done
is to type g (revert-buffer). You can make this happen regularly every autorevert-interval seconds if you enable Auto Revert mode in this buffer, as long
as it is not marked modified. Global Auto Revert mode applies to the ‘*Buffer
List*’ buffer only if global-auto-revert-non-file-buffers is non-nil. See Info
file ‘emacs-xtra’, node ‘Autorevert’, for details.

16.6 Indirect Buffers
An indirect buffer shares the text of some other buffer, which is called the base
buffer of the indirect buffer. In some ways it is a buffer analogue of a symbolic link
between files.
M-x make-indirect-buffer RET base-buffer RET indirect-name RET
Create an indirect buffer named indirect-name with base buffer basebuffer.
M-x clone-indirect-buffer RET
Create an indirect buffer that is a twin copy of the current buffer.
C-x 4 c

Create an indirect buffer that is a twin copy of the current buffer,
and select it in another window (clone-indirect-buffer-otherwindow).

The text of the indirect buffer is always identical to the text of its base buffer;
changes made by editing either one are visible immediately in the other. But in all
other respects, the indirect buffer and its base buffer are completely separate. They
can have different names, different values of point, different narrowing, different
markers, different major modes, and different local variables.
An indirect buffer cannot visit a file, but its base buffer can. If you try to save
the indirect buffer, that actually works by saving the base buffer. Killing the base
buffer effectively kills the indirect buffer, but killing an indirect buffer has no effect
on its base buffer.

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One way to use indirect buffers is to display multiple views of an outline. See
Section 22.8.4 [Outline Views], page 228.
A quick and handy way to make an indirect buffer is with the command M-x
clone-indirect-buffer. It creates and selects an indirect buffer whose base buffer
is the current buffer. With a numeric argument, it prompts for the name of the
indirect buffer; otherwise it uses the name of the current buffer, with a ‘’
suffix added. C-x 4 c (clone-indirect-buffer-other-window) works like M-x
clone-indirect-buffer, but it selects the new buffer in another window. These
functions run the hook clone-indirect-buffer-hook after creating the indirect
buffer.
The more general way to make an indirect buffer is with the command M-x
make-indirect-buffer. It creates an indirect buffer named indirect-name from a
buffer base-buffer, prompting for both using the minibuffer.

16.7 Convenience Features and Customization of Buffer
Handling
This section describes several modes and features that make it more convenient to
switch between buffers.
16.7.1 Making Buffer Names Unique
When several buffers visit identically-named files, Emacs must give the buffers distinct names. The usual method for making buffer names unique adds ‘<2>’, ‘<3>’,
etc. to the end of the buffer names (all but one of them).
Other methods work by adding parts of each file’s directory to the buffer name.
To select one, load the library ‘uniquify’ (e.g. using (require ’uniquify)), and
customize the variable uniquify-buffer-name-style (see Section 33.1 [Easy Customization], page 434).
To begin with, the forward naming method includes part of the file’s directory
name at the beginning of the buffer name; using this method, buffers visiting the files
‘/u/rms/tmp/Makefile’ and ‘/usr/projects/zaphod/Makefile’ would be named
‘tmp/Makefile’ and ‘zaphod/Makefile’, respectively (instead of ‘Makefile’ and
‘Makefile<2>’).
In contrast, the post-forward naming method would call the buffers
‘Makefile|tmp’ and ‘Makefile|zaphod’, and the reverse naming method would
call them ‘Makefile\tmp’ and ‘Makefile\zaphod’. The nontrivial difference
between post-forward and reverse occurs when just one directory name is
not enough to distinguish two files; then reverse puts the directory names
in reverse order, so that ‘/top/middle/file’ becomes ‘file\middle\top’,
while post-forward puts them in forward order after the file name, as in
‘file|top/middle’.
Which rule to follow for putting the directory names in the buffer name is not
very important if you are going to look at the buffer names before you type one.
But as an experienced user, if you know the rule, you won’t have to look. And

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then you may find that one rule or another is easier for you to remember and apply
quickly.
16.7.2 Switching Between Buffers using Substrings
Iswitchb global minor mode provides convenient switching between buffers using
substrings of their names. It replaces the normal definitions of C-x b, C-x 4 b, C-x
5 b, and C-x 4 C-o with alternative commands that are somewhat “smarter”.
When one of these commands prompts you for a buffer name, you can type
in just a substring of the name you want to choose. As you enter the substring,
Iswitchb mode continuously displays a list of buffers that match the substring you
have typed.
At any time, you can type RET to select the first buffer in the list. So the way
to select a particular buffer is to make it the first in the list. There are two ways
to do this. You can type more of the buffer name and thus narrow down the list,
excluding unwanted buffers above the desired one. Alternatively, you can use C-s
and C-r to rotate the list until the desired buffer is first.
TAB while entering the buffer name performs completion on the string you have
entered, based on the displayed list of buffers.
To enable Iswitchb mode, type M-x iswitchb-mode, or customize the variable
iswitchb-mode to t (see Section 33.1 [Easy Customization], page 434).
16.7.3 Customizing Buffer Menus
M-x bs-show
Make a list of buffers similarly to M-x list-buffers but customizable.
M-x bs-show pops up a buffer list similar to the one normally displayed by C-x
C-b but which you can customize. If you prefer this to the usual buffer list, you can
bind this command to C-x C-b. To customize this buffer list, use the bs Custom
group (see Section 33.1 [Easy Customization], page 434).
MSB global minor mode (“MSB” stands for “mouse select buffer”) provides a
different and customizable mouse buffer menu which you may prefer. It replaces
the bindings of mouse-buffer-menu, normally on C-Down-Mouse-1, and the menu
bar buffer menu. You can customize the menu in the msb Custom group.

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17 Multiple Windows
Emacs can split a frame into two or many windows. Multiple windows can display
parts of different buffers, or different parts of one buffer. Multiple frames always
imply multiple windows, because each frame has its own set of windows. Each
window belongs to one and only one frame.

17.1 Concepts of Emacs Windows
Each Emacs window displays one Emacs buffer at any time. A single buffer may
appear in more than one window; if it does, any changes in its text are displayed
in all the windows where it appears. But these windows can show different parts of
the buffer, because each window has its own value of point.
At any time, one Emacs window is the selected window; the buffer this window
is displaying is the current buffer. On graphical displays, the point is indicated by
a solid blinking cursor in the selected window, and by a hollow box in non-selected
windows. On text terminals, the cursor is drawn only in the selected window. See
Section 11.20 [Cursor Display], page 88.
Commands to move point affect the value of point for the selected Emacs window
only. They do not change the value of point in other Emacs windows, even those
showing the same buffer. The same is true for buffer-switching commands such as
C-x b; they do not affect other windows at all. However, there are other commands
such as C-x 4 b that select a different window and switch buffers in it. Also, all
commands that display information in a window, including (for example) C-h f
(describe-function) and C-x C-b (list-buffers), work by switching buffers in
a nonselected window without affecting the selected window.
When multiple windows show the same buffer, they can have different regions,
because they can have different values of point. However, they all have the same
value for the mark, because each buffer has only one mark position.
Each window has its own mode line, which displays the buffer name, modification
status and major and minor modes of the buffer that is displayed in the window.
The selected window’s mode line appears in a different color. See Section 1.3 [Mode
Line], page 8, for details.

17.2 Splitting Windows
C-x 2

Split the selected window into two windows, one above the other
(split-window-below).

C-x 3

Split the selected window into two windows, positioned side by side
(split-window-right).

C-Mouse-2

In the mode line of a window, split that window.

C-x 2 (split-window-below) splits the selected window into two windows, one
above the other. After splitting, the selected window is the upper one, and the
newly split-off window is below. Both windows have the same value of point as

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before, and display the same portion of the buffer (or as close to it as possible).
If necessary, the windows are scrolled to keep point on-screen. By default, the
two windows each get half the height of the original window. A positive numeric
argument specifies how many lines to give to the top window; a negative numeric
argument specifies how many lines to give to the bottom window.
If you change the variable split-window-keep-point to nil, C-x 2 instead
adjusts the portion of the buffer displayed by the two windows, as well as the value
of point in each window, in order to keep the text on the screen as close as possible
to what it was before; furthermore, if point was in the lower half of the original
window, the bottom window is selected instead of the upper one.
C-x 3 (split-window-right) splits the selected window into two side-by-side
windows. The left window is the selected one; the right window displays the same
portion of the same buffer, and has the same value of point. A positive numeric
argument specifies how many columns to give the left window; a negative numeric
argument specifies how many columns to give the right window.
When you split a window with C-x 3, each resulting window occupies less than
the full width of the frame. If it becomes too narrow, the buffer may be difficult to
read if continuation lines are in use (see Section 4.8 [Continuation Lines], page 23).
Therefore, Emacs automatically switches to line truncation if the window width
becomes narrower than 50 columns. This truncation occurs regardless of the value
of the variable truncate-lines (see Section 11.21 [Line Truncation], page 89); it is
instead controlled by the variable truncate-partial-width-windows. If the value
of this variable is a positive integer (the default is 50), that specifies the minimum
width for a partial-width window before automatic line truncation occurs; if the
value is nil, automatic line truncation is disabled; and for any other non-nil value,
Emacs truncates lines in every partial-width window regardless of its width.
On text terminals, side-by-side windows are separated by a vertical divider which
is drawn using the vertical-border face.
If you click C-Mouse-2 in the mode line of a window, that splits the window,
putting a vertical divider where you click. Depending on how Emacs is compiled,
you can also split a window by clicking C-Mouse-2 in the scroll bar, which puts
a horizontal divider where you click (this feature does not work when Emacs uses
GTK+ scroll bars).

17.3 Using Other Windows
C-x o

Select another window (other-window).

C-M-v

Scroll the next window (scroll-other-window).

Mouse-1

Mouse-1, in the text area of a window, selects the window and moves
point to the position clicked. Clicking in the mode line selects the
window without moving point in it.

With the keyboard, you can switch windows by typing C-x o (other-window).
That is an o, for “other”, not a zero. When there are more than two windows,
this command moves through all the windows in a cyclic order, generally top to

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bottom and left to right. After the rightmost and bottommost window, it goes
back to the one at the upper left corner. A numeric argument means to move
several steps in the cyclic order of windows. A negative argument moves around
the cycle in the opposite order. When the minibuffer is active, the minibuffer is the
last window in the cycle; you can switch from the minibuffer window to one of the
other windows, and later switch back and finish supplying the minibuffer argument
that is requested. See Section 5.2 [Minibuffer Edit], page 28.
The usual scrolling commands (see Chapter 11 [Display], page 70) apply to
the selected window only, but there is one command to scroll the next window.
C-M-v (scroll-other-window) scrolls the window that C-x o would select. It takes
arguments, positive and negative, like C-v. (In the minibuffer, C-M-v scrolls the help
window associated with the minibuffer, if any, rather than the next window in the
standard cyclic order; see Section 5.2 [Minibuffer Edit], page 28.)
If you set mouse-autoselect-window to a non-nil value, moving the mouse
over a different window selects that window. This feature is off by default.

17.4 Displaying in Another Window
C-x 4 is a prefix key for a variety of commands that switch to a buffer in a different
window—either another existing window, or a new window created by splitting the
selected window. See Section 17.6.1 [Window Choice], page 163, for how Emacs
picks or creates the window to use.
C-x 4 b bufname RET
Select buffer bufname in another window (switch-to-buffer-otherwindow).
C-x 4 C-o bufname RET
Display buffer bufname in some window, without trying to select it
(display-buffer). See Section 17.6 [Displaying Buffers], page 163,
for details about how the window is chosen.
C-x 4 f filename RET
Visit file filename and select its buffer in another window (find-fileother-window). See Section 15.2 [Visiting], page 125.
C-x 4 d directory RET
Select a Dired buffer for directory directory in another window
(dired-other-window). See Chapter 27 [Dired], page 329.
C-x 4 m

Start composing a mail message, similar to C-x m (see Chapter 29
[Sending Mail], page 367), but in another window (mail-otherwindow).

C-x 4 .

Find a tag in the current tags table, similar to M-. (see Section 25.3
[Tags], page 311), but in another window (find-tag-other-window).

C-x 4 r filename RET
Visit file filename read-only, and select its buffer in another window
(find-file-read-only-other-window). See Section 15.2 [Visiting],
page 125.

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17.5 Deleting and Rearranging Windows
C-x 0

Delete the selected window (delete-window).

C-x 1

Delete all windows in the selected frame except the selected window
(delete-other-windows).

C-x 4 0

Delete the selected window and kill the buffer that was showing in it
(kill-buffer-and-window). The last character in this key sequence
is a zero.

C-x ^

Make selected window taller (enlarge-window).

C-x }

Make selected window wider (enlarge-window-horizontally).

C-x {

Make selected window narrower (shrink-window-horizontally).

C-x -

Shrink this window if its buffer doesn’t need so many lines (shrinkwindow-if-larger-than-buffer).

C-x +

Make all windows the same height (balance-windows).

To delete the selected window, type C-x 0 (delete-window). (That is a zero.)
Once a window is deleted, the space that it occupied is given to an adjacent window
(but not the minibuffer window, even if that is active at the time). Deleting the
window has no effect on the buffer it used to display; the buffer continues to exist,
and you can still switch to with C-x b.
C-x 4 0 (kill-buffer-and-window) is a stronger command than C-x 0; it kills
the current buffer and then deletes the selected window.
C-x 1 (delete-other-windows) deletes all the windows, except the selected one;
the selected window expands to use the whole frame. (This command cannot be
used while the minibuffer window is active; attempting to do so signals an error.)
The command C-x ^ (enlarge-window) makes the selected window one line
taller, taking space from a vertically adjacent window without changing the height of
the frame. With a positive numeric argument, this command increases the window
height by that many lines; with a negative argument, it reduces the height by that
many lines. If there are no vertically adjacent windows (i.e. the window is at the
full frame height), that signals an error. The command also signals an error if you
attempt to reduce the height of any window below a certain minimum number of
lines, specified by the variable window-min-height (the default is 4).
Similarly, C-x } (enlarge-window-horizontally) makes the selected window
wider, and C-x { (shrink-window-horizontally) makes it narrower. These commands signal an error if you attempt to reduce the width of any window below a
certain minimum number of columns, specified by the variable window-min-width
(the default is 10).
C-x - (shrink-window-if-larger-than-buffer) reduces the height of the selected window, if it is taller than necessary to show the whole text of the buffer it
is displaying. It gives the extra lines to other windows in the frame.
You can also use C-x + (balance-windows) to even out the heights of all the
windows in the selected frame.

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Mouse clicks on the mode line provide another way to change window heights
and to delete windows. See Section 18.5 [Mode Line Mouse], page 169.

17.6 Displaying a Buffer in a Window
It is a common Emacs operation to display or “pop up” some buffer in response to
a user command. There are several different ways in which commands do this.
Many commands, like C-x C-f (find-file), display the buffer by “taking over”
the selected window, expecting that the user’s attention will be diverted to that
buffer. These commands usually work by calling switch-to-buffer internally (see
Section 16.1 [Select Buffer], page 150).
Some commands try to display “intelligently”, trying not to take over the selected window, e.g. by splitting off a new window and displaying the desired buffer
there. Such commands, which include the various help commands (see Chapter 7
[Help], page 38), work by calling display-buffer internally. See Section 17.6.1
[Window Choice], page 163, for details.
Other commands do the same as display-buffer, and additionally select the
displaying window so that you can begin editing its buffer. The command C-x
‘ (next-error) is one example (see Section 24.2 [Compilation Mode], page 272).
Such commands work by calling the function pop-to-buffer internally. See Section
“Switching to a Buffer in a Window” in The Emacs Lisp Reference Manual.
Commands with names ending in -other-window behave like display-buffer,
except that they never display in the selected window. Several of these commands
are bound in the C-x 4 prefix key (see Section 17.4 [Pop Up Window], page 161).
Commands with names ending in -other-frame behave like display-buffer,
except that they (i) never display in the selected window and (ii) prefer to create a
new frame to display the desired buffer instead of splitting a window—as though the
variable pop-up-frames is set to t (see Section 17.6.1 [Window Choice], page 163).
Several of these commands are bound in the C-x 5 prefix key.
17.6.1 How display-buffer works
The display-buffer command (as well as commands that call it internally) chooses
a window to display by following the steps given below. See Section “Choosing a
Window for Display” in The Emacs Lisp Reference Manual, for details about how
to alter this sequence of steps.
• First, check if the buffer should be displayed in the selected window regardless
of other considerations. You can tell Emacs to do this by adding the desired
buffer’s name to the list same-window-buffer-names, or adding a matching
regular expression to the list same-window-regexps. By default, these variables are nil, so this step is skipped.
• Otherwise, if the buffer is already displayed in an existing window, “reuse”
that window. Normally, only windows on the selected frame are considered,
but windows on other frames are also reusable if you change display-bufferreuse-frames to t, or if you change pop-up-frames (see below) to t.

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• Otherwise, if you specified that the buffer should be displayed in a special
frame by customizing special-display-buffer-names or special-displayregexps, do so. See Section “Choosing Window Options” in The Emacs Lisp
Reference Manual.
• Otherwise, optionally create a new frame and display the buffer there. By
default, this step is skipped. To enable it, change the variable pop-up-frames
to a non-nil value. The special value graphic-only means to do this only on
graphical displays.
• Otherwise, try to create a new window by splitting the selected window, and
display the buffer in that new window.
The split can be either vertical or horizontal, depending on the variables
split-height-threshold and split-width-threshold. These variables
should have integer values. If split-height-threshold is smaller than the
selected window’s height, the split puts the new window below. Otherwise, if
split-width-threshold is smaller than the window’s width, the split puts
the new window on the right. If neither condition holds, Emacs tries to split
so that the new window is below—but only if the window was not split before
(to avoid excessive splitting).
• Otherwise, display the buffer in an existing window on the selected frame.
• If all the above methods fail for whatever reason, create a new frame and
display the buffer there.

17.7 Convenience Features for Window Handling
Winner mode is a global minor mode that records the changes in the window configuration (i.e. how the frames are partitioned into windows), so that you can “undo”
them. You can toggle Winner mode with M-x winner-mode, or by customizing the
variable winner-mode. When the mode is enabled, C-c left (winner-undo) undoes
the last window configuration change. If you change your mind while undoing, you
can redo the changes you had undone using C-c right (M-x winner-redo).
Follow mode (M-x follow-mode) synchronizes several windows on the same
buffer so that they always display adjacent sections of that buffer. See Section 11.7
[Follow Mode], page 75.
The Windmove package defines commands for moving directionally between
neighboring windows in a frame. M-x windmove-right selects the window immediately to the right of the currently selected one, and similarly for the “left”,
“up”, and “down” counterparts. M-x windmove-default-keybindings binds these
commands to S-right etc.; doing so disables shift selection for those keys (see
Section 8.6 [Shift Selection], page 52).
The command M-x compare-windows lets you compare the text shown in different windows. See Section 15.8 [Comparing Files], page 140.
Scroll All mode (M-x scroll-all-mode) is a global minor mode that causes
scrolling commands and point motion commands to apply to every single window.

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18 Frames and Graphical Displays
When Emacs is started on a graphical display, e.g. on the X Window System, it
occupies a graphical system-level “window”. In this manual, we call this a frame,
reserving the word “window” for the part of the frame used for displaying a buffer. A
frame initially contains one window, but it can be subdivided into multiple windows
(see Chapter 17 [Windows], page 159). A frame normally also contains a menu bar,
tool bar, and echo area.
You can also create additional frames (see Section 18.6 [Creating Frames],
page 169). All frames created in the same Emacs session have access to the same
underlying buffers and other data. For instance, if a buffer is being shown in more
than one frame, any changes made to it in one frame show up immediately in the
other frames too.
Typing C-x C-c closes all the frames on the current display, and ends the Emacs
session if it has no frames open on any other displays (see Section 3.2 [Exiting],
page 15). To close just the selected frame, type C-x 5 0 (that is zero, not o).
This chapter describes Emacs features specific to graphical displays (particularly
mouse commands), and features for managing multiple frames. On text terminals,
many of these features are unavailable. However, it is still possible to create multiple
“frames” on text terminals; such frames are displayed one at a time, filling the entire
terminal screen (see Section 18.19 [Non-Window Terminals], page 179). It is also
possible to use the mouse on some text terminals (see Section 18.20 [Text-Only
Mouse], page 179, for doing so on GNU and Unix systems; and see Section “MSDOS Mouse” in Specialized Emacs Features, for doing so on MS-DOS).

18.1 Mouse Commands for Editing
Mouse-1

Move point to where you click (mouse-set-point).

Drag-Mouse-1
Activate the region around the text selected by dragging, and copy it
to the kill ring (mouse-set-region).
Mouse-2

Move point to where you click, and insert the contents of the primary
selection there (mouse-yank-primary).

Mouse-3

If the region is active, move the nearer end of the region to the click
position; otherwise, set mark at the current value of point and point
at the click position. Save the resulting region in the kill ring; on a
second click, kill it (mouse-save-then-kill).

The most basic mouse command is mouse-set-point, which is invoked by clicking with the left mouse button, Mouse-1, in the text area of a window. This moves
point to the position where you clicked. If that window was not the selected window,
it becomes the selected window.
Normally, if the frame you clicked in was not the selected frame, it is made the
selected frame, in addition to selecting the window and setting the cursor. On the

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X Window System, you can change this by setting the variable x-mouse-clickfocus-ignore-position to t. In that case, the initial click on an unselected frame
just selects the frame, without doing anything else; clicking again selects the window
and sets the cursor position.
Holding down Mouse-1 and “dragging” the mouse over a stretch of text activates the region around that text (mouse-set-region), placing the mark where
you started holding down the mouse button, and point where you release it (see
Chapter 8 [Mark], page 47). In addition, the text in the region becomes the primary
selection (see Section 9.3.2 [Primary Selection], page 60).
If you change the variable mouse-drag-copy-region to a non-nil value, dragging the mouse over a stretch of text also adds the text to the kill ring. The default
is nil.
If you move the mouse off the top or bottom of the window while dragging, the
window scrolls at a steady rate until you move the mouse back into the window.
This way, you can select regions that don’t fit entirely on the screen. The number
of lines scrolled per step depends on how far away from the window edge the mouse
has gone; the variable mouse-scroll-min-lines specifies a minimum step size.
Clicking with the middle mouse button, Mouse-2, moves point to the position
where you clicked and inserts the contents of the primary selection (mouse-yankprimary). See Section 9.3.2 [Primary Selection], page 60. This behavior is consistent with other X applications. Alternatively, you can rebind Mouse-2 to mouseyank-at-click, which performs a yank at point.
If you change the variable mouse-yank-at-point to a non-nil value, Mouse-2
does not move point; it inserts the text at point, regardless of where you clicked
or even which of the frame’s windows you clicked on. This variable affects both
mouse-yank-primary and mouse-yank-at-click.
Clicking with the right mouse button, Mouse-3, runs the command mouse-savethen-kill. This performs several actions depending on where you click and the
status of the region:
• If no region is active, clicking Mouse-3 activates the region, placing the mark
where point was and point at the clicked position.
• If a region is active, clicking Mouse-3 adjusts the nearer end of the region by
moving it to the clicked position. The adjusted region’s text is copied to the
kill ring; if the text in the original region was already on the kill ring, it replaces
it there.
• If you originally specified the region using a double or triple Mouse-1, so that
the region is defined to consist of entire words or lines (see Section 18.2 [Word
and Line Mouse], page 167), then adjusting the region with Mouse-3 also proceeds by entire words or lines.
• If you use Mouse-3 a second time consecutively, at the same place, that kills
the region already selected. Thus, the simplest way to kill text with the mouse
is to click Mouse-1 at one end, then click Mouse-3 twice at the other end.
To copy the text into the kill ring without deleting it from the buffer, press
Mouse-3 just once—or just drag across the text with Mouse-1. Then you can
copy it elsewhere by yanking it.

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The mouse-save-then-kill command also obeys the variable mouse-dragcopy-region (described above). If the value is non-nil, then whenever the command sets or adjusts the active region, the text in the region is also added to the
kill ring. If the latest kill ring entry had been added the same way, that entry is
replaced rather than making a new entry.
Whenever you set the region using any of the mouse commands described above,
the mark will be deactivated by any subsequent unshifted cursor motion command,
in addition to the usual ways of deactivating the mark. See Section 8.6 [Shift
Selection], page 52.
Some mice have a “wheel” which can be used for scrolling. Emacs supports
scrolling windows with the mouse wheel, by default, on most graphical displays.
To toggle this feature, use M-x mouse-wheel-mode. The variables mouse-wheelfollow-mouse and mouse-wheel-scroll-amount determine where and by how
much buffers are scrolled. The variable mouse-wheel-progressive-speed determines whether the scroll speed is linked to how fast you move the wheel.

18.2 Mouse Commands for Words and Lines
These variants of Mouse-1 select entire words or lines at a time. Emacs activates
the region around the selected text, which is also copied to the kill ring.
Double-Mouse-1
Select the text around the word which you click on.
Double-clicking on a character with “symbol” syntax (such as underscore, in C mode) selects the symbol surrounding that character.
Double-clicking on a character with open- or close-parenthesis syntax
selects the parenthetical grouping which that character starts or ends.
Double-clicking on a character with string-delimiter syntax (such as a
single-quote or double-quote in C) selects the string constant (Emacs
uses heuristics to figure out whether that character is the beginning
or the end of it).
Double-Drag-Mouse-1
Select the text you drag across, in the form of whole words.
Triple-Mouse-1
Select the line you click on.
Triple-Drag-Mouse-1
Select the text you drag across, in the form of whole lines.

18.3 Following References with the Mouse
Some Emacs buffers include buttons, or hyperlinks: pieces of text that perform
some action (e.g. following a reference) when activated (e.g. by clicking on them).
Usually, a button’s text is visually highlighted: it is underlined, or a box is drawn
around it. If you move the mouse over a button, the shape of the mouse cursor

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changes and the button lights up. If you change the variable mouse-highlight to
nil, Emacs disables this highlighting.
You can activate a button by moving point to it and typing RET, or by clicking
either Mouse-1 or Mouse-2 on the button. For example, in a Dired buffer, each
file name is a button; activating it causes Emacs to visit that file (see Chapter 27
[Dired], page 329). In a ‘*Compilation*’ buffer, each error message is a button, and
activating it visits the source code for that error (see Section 24.1 [Compilation],
page 271).
Although clicking Mouse-1 on a button usually activates the button, if you hold
the mouse button down for a period of time before releasing it (specifically, for
more than 450 milliseconds), then Emacs moves point where you clicked, without
activating the button. In this way, you can use the mouse to move point over a
button without activating it. Dragging the mouse over or onto a button has its
usual behavior of setting the region, and does not activate the button.
You can change how Mouse-1 applies to buttons by customizing the variable
mouse-1-click-follows-link. If the value is a positive integer, that determines
how long you need to hold the mouse button down for, in milliseconds, to cancel
button activation; the default is 450, as described in the previous paragraph. If
the value is nil, Mouse-1 just sets point where you clicked, and does not activate
buttons. If the value is double, double clicks activate buttons but single clicks just
set point.
Normally, Mouse-1 on a button activates the button even if it is in a non-selected
window. If you change the variable mouse-1-click-in-non-selected-windows to
nil, Mouse-1 on a button in an unselected window moves point to the clicked
position and selects that window, without activating the button.

18.4 Mouse Clicks for Menus
Several mouse clicks with the CTRL and SHIFT modifiers bring up menus.
C-Mouse-1

This menu is for selecting a buffer.
The MSB (“mouse select buffer”) global minor mode makes this menu
smarter and more customizable. See Section 16.7.3 [Buffer Menus],
page 158.

C-Mouse-2

This menu contains entries for examining faces and other text properties, and well as for setting them (the latter is mainly useful when
editing enriched text; see Section 22.13 [Enriched Text], page 237).

C-Mouse-3

This menu is mode-specific. For most modes if Menu-bar mode is
on, this menu has the same items as all the mode-specific menu-bar
menus put together. Some modes may specify a different menu for
this button. If Menu Bar mode is off, this menu contains all the items
which would be present in the menu bar—not just the mode-specific
ones—so that you can access them without having to display the menu
bar.

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This menu is for changing the default face within the window’s buffer.
See Section 11.11 [Text Scale], page 79.

Some graphical applications use Mouse-3 for a mode-specific menu. If you prefer
Mouse-3 in Emacs to bring up such a menu instead of running the mouse-savethen-kill command, rebind Mouse-3 by adding the following line to your init file
(see Section 33.3.6 [Init Rebinding], page 455):
(global-set-key [mouse-3] ’mouse-popup-menubar-stuff)

18.5 Mode Line Mouse Commands
You can use mouse clicks on window mode lines to select and manipulate windows.
Some areas of the mode line, such as the buffer name, and major and minor
mode names, have their own special mouse bindings. These areas are highlighted
when you hold the mouse over them, and information about the special bindings
will be displayed (see Section 18.17 [Tooltips], page 178). This section’s commands
do not apply in those areas.
Mouse-1

Mouse-1 on a mode line selects the window it belongs to. By dragging
Mouse-1 on the mode line, you can move it, thus changing the height
of the windows above and below. Changing heights with the mouse
in this way never deletes windows, it just refuses to make any window
smaller than the minimum height.

Mouse-2

Mouse-2 on a mode line expands that window to fill its frame.

Mouse-3

Mouse-3 on a mode line deletes the window it belongs to. If the frame
has only one window, it does nothing.

C-Mouse-2

C-Mouse-2 on a mode line splits that window, producing two side-byside windows with the boundary running through the click position
(see Section 17.2 [Split Window], page 159).

Furthermore, by clicking and dragging Mouse-1 on the divider between two
side-by-side mode lines, you can move the vertical boundary to the left or right.

18.6 Creating Frames
The prefix key C-x 5 is analogous to C-x 4. Whereas each C-x 4 command pops
up a buffer in a different window in the selected frame (see Section 17.4 [Pop Up
Window], page 161), the C-x 5 commands use a different frame. If an existing
visible or iconified (“minimized”) frame already displays the requested buffer, that
frame is raised and deiconified (“un-minimized”); otherwise, a new frame is created
on the current display terminal.
The various C-x 5 commands differ in how they find or create the buffer to
select:
C-x 5 2

Create a new frame (make-frame-command).

C-x 5 b bufname RET
Select buffer bufname in another frame.
buffer-other-frame.

This runs switch-to-

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C-x 5 f filename RET
Visit file filename and select its buffer in another frame. This runs
find-file-other-frame. See Section 15.2 [Visiting], page 125.
C-x 5 d directory RET
Select a Dired buffer for directory directory in another frame. This
runs dired-other-frame. See Chapter 27 [Dired], page 329.
C-x 5 m

Start composing a mail message in another frame. This runs mailother-frame. It is the other-frame variant of C-x m. See Chapter 29
[Sending Mail], page 367.

C-x 5 .

Find a tag in the current tag table in another frame. This runs findtag-other-frame, the multiple-frame variant of M-.. See Section 25.3
[Tags], page 311.

C-x 5 r filename RET
Visit file filename read-only, and select its buffer in another frame.
This runs find-file-read-only-other-frame. See Section 15.2 [Visiting], page 125.
You can control the appearance and behavior of the newly-created frames by
specifying frame parameters. See Section 18.11 [Frame Parameters], page 175.

18.7 Frame Commands
The following commands are used to delete and operate on frames:
C-x 5 0

Delete the selected frame (delete-frame). This signals an error if
there is only one frame.

C-z

Minimize (or “iconify) the selected Emacs frame (suspend-frame).
See Section 3.2 [Exiting], page 15.

C-x 5 o

Select another frame, and raise it. If you repeat this command, it
cycles through all the frames on your terminal.

C-x 5 1

Delete all frames on the current terminal, except the selected one.

The C-x 5 0 (delete-frame) command deletes the selected frame. However, it
will refuse to delete the last frame in an Emacs session, to prevent you from losing
the ability to interact with the Emacs session. Note that when Emacs is run as
a daemon (see Section 31.4 [Emacs Server], page 412), there is always a “virtual
frame” that remains after all the ordinary, interactive frames are deleted. In this
case, C-x 5 0 can delete the last interactive frame; you can use emacsclient to
reconnect to the Emacs session.
The C-x 5 1 (delete-other-frames) command deletes all other frames on the
current terminal (this terminal refers to either a graphical display, or a text terminal;
see Section 18.19 [Non-Window Terminals], page 179). If the Emacs session has
frames open on other graphical displays or text terminals, those are not deleted.
The C-x 5 o (other-frame) command selects the next frame on the current
terminal. If you are using Emacs on the X Window System with a window manager

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that selects (or gives focus to) whatever frame the mouse cursor is over, you have to
change the variable focus-follows-mouse to t in order for this command to work
properly. Then invoking C-x 5 o will also warp the mouse cursor to the chosen
frame.

18.8 Fonts
By default, Emacs displays text on graphical displays using a 12-point monospace
font. There are several different ways to specify a different font:
• Click on ‘Set Default Font’ in the ‘Options’ menu. To save this for future
sessions, click on ‘Save Options’ in the ‘Options’ menu.
• Add a line to your init file, modifying the variable default-frame-alist to
specify the font parameter (see Section 18.11 [Frame Parameters], page 175),
like this:
(add-to-list ’default-frame-alist
’(font . "DejaVu Sans Mono-10"))
• Add an ‘emacs.font’ X resource setting to your X resource file, like this:
emacs.font: DejaVu Sans Mono-12
You must restart X, or use the xrdb command, for the X resources file to take
effect. See Section D.1 [Resources], page 521. Do not quote font names in X
resource files.
• If you are running Emacs on the GNOME desktop, you can tell Emacs to use
the default system font by setting the variable font-use-system-font to t
(the default is nil). For this to work, Emacs must have been compiled with
Gconf support.
• Use the command line option ‘-fn’ (or ‘--font’). See Section C.6 [Font X],
page 515.
To check what font you’re currently using, the C-u C-x = command can be helpful. It describes the character at point, and names the font that it’s rendered in.
On X, there are four different ways to express a “font name”. The first is to use
a Fontconfig pattern. Fontconfig patterns have the following form:
fontname [-fontsize ][:name1 =values1 ][:name2 =values2 ]...
Within this format, any of the elements in braces may be omitted. Here, fontname
is the family name of the font, such as ‘Monospace’ or ‘DejaVu Sans Mono’; fontsize
is the point size of the font (one printer’s point is about 1/72 of an inch); and
the ‘name =values ’ entries specify settings such as the slant and weight of the font.
Each values may be a single value, or a list of values separated by commas. In
addition, some property values are valid with only one kind of property name, in
which case the ‘name =’ part may be omitted.
Here is a list of common font properties:
‘slant’

One of ‘italic’, ‘oblique’, or ‘roman’.

‘weight’

One of ‘light’, ‘medium’, ‘demibold’, ‘bold’ or ‘black’.

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‘style’

Some fonts define special styles which are a combination of slant and
weight. For instance, ‘Dejavu Sans’ defines the ‘book’ style, which
overrides the slant and weight properties.

‘width’

One of ‘condensed’, ‘normal’, or ‘expanded’.

‘spacing’

One of ‘monospace’, ‘proportional’, ‘dual-width’, or ‘charcell’.

Here are some examples of Fontconfig patterns:
Monospace
Monospace-12
Monospace-12:bold
DejaVu Sans Mono:bold:italic
Monospace-12:weight=bold:slant=italic
For a more detailed description of Fontconfig patterns, see the Fontconfig manual, which is distributed with Fontconfig and available online at
http://fontconfig.org/fontconfig-user.html.
The second way to specify a font is to use a GTK font pattern. These have the
syntax
fontname [properties ] [fontsize ]
where fontname is the family name, properties is a list of property values separated
by spaces, and fontsize is the point size. The properties that you may specify for
GTK font patterns are as follows:
• Slant properties: ‘Italic’ or ‘Oblique’. If omitted, the default (roman) slant
is implied.
• Weight properties: ‘Bold’, ‘Book’, ‘Light’, ‘Medium’, ‘Semi-bold’, or
‘Ultra-light’. If omitted, ‘Medium’ weight is implied.
• Width properties: ‘Semi-Condensed’ or ‘Condensed’. If omitted, a default
width is used.
Here are some examples of GTK font patterns:
Monospace 12
Monospace Bold Italic 12
The third way to specify a font is to use an XLFD (X Logical Font Description).
This is the traditional method for specifying fonts under X. Each XLFD consists of
fourteen words or numbers, separated by dashes, like this:
-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1
A wildcard character (‘*’) in an XLFD matches any sequence of characters (including none), and ‘?’ matches any single character. However, matching is
implementation-dependent, and can be inaccurate when wildcards match dashes
in a long name. For reliable results, supply all 14 dashes and use wildcards only
within a field. Case is insignificant in an XLFD. The syntax for an XLFD is as
follows:
-maker-family-weight-slant-widthtype-style ...
...-pixels-height-horiz-vert-spacing-width-registry-encoding
The entries have the following meanings:

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maker

The name of the font manufacturer.

family

The name of the font family (e.g. ‘courier’).

weight

The font weight—normally either ‘bold’, ‘medium’ or ‘light’. Some
font names support other values.

slant

The font slant—normally ‘r’ (roman), ‘i’ (italic), ‘o’ (oblique), ‘ri’
(reverse italic), or ‘ot’ (other). Some font names support other values.

widthtype

The font width—normally ‘normal’, ‘condensed’, ‘semicondensed’,
or ‘extended’. Some font names support other values.

style

An optional additional style name. Usually it is empty—most XLFDs
have two hyphens in a row at this point.

pixels

The font height, in pixels.

height

The font height on the screen, measured in tenths of a printer’s point.
This is the point size of the font, times ten. For a given vertical
resolution, height and pixels are proportional; therefore, it is common
to specify just one of them and use ‘*’ for the other.

horiz

The horizontal resolution, in pixels per inch, of the screen for which
the font is intended.

vert

The vertical resolution, in pixels per inch, of the screen for which the
font is intended. Normally the resolution of the fonts on your system
is the right value for your screen; therefore, you normally specify ‘*’
for this and horiz.

spacing

This is ‘m’ (monospace), ‘p’ (proportional) or ‘c’ (character cell).

width

The average character width, in pixels, multiplied by ten.

registry
encoding

The X font character set that the font depicts. (X font character
sets are not the same as Emacs character sets, but they are similar.)
You can use the xfontsel program to check which choices you have.
Normally you should use ‘iso8859’ for registry and ‘1’ for encoding.

The fourth and final method of specifying a font is to use a “font nickname”.
Certain fonts have shorter nicknames, which you can use instead of a normal font
specification. For instance, ‘6x13’ is equivalent to
-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1
On X, Emacs recognizes two types of fonts: client-side fonts, which are provided
by the Xft and Fontconfig libraries, and server-side fonts, which are provided by
the X server itself. Most client-side fonts support advanced font features such as
antialiasing and subpixel hinting, while server-side fonts do not. Fontconfig and
GTK patterns match only client-side fonts.
You will probably want to use a fixed-width default font—that is, a font in which
all characters have the same width. For Xft and Fontconfig fonts, you can use the
fc-list command to list the available fixed-width fonts, like this:

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fc-list :spacing=mono fc-list :spacing=charcell
For server-side X fonts, you can use the xlsfonts program to list the available
fixed-width fonts, like this:
xlsfonts -fn ’*x*’ | egrep "^[0-9]+x[0-9]+"
xlsfonts -fn ’*-*-*-*-*-*-*-*-*-*-*-m*’
xlsfonts -fn ’*-*-*-*-*-*-*-*-*-*-*-c*’
Any font with ‘m’ or ‘c’ in the spacing field of the XLFD is a fixed-width font. To
see what a particular font looks like, use the xfd command. For example:
xfd -fn 6x13
displays the entire font ‘6x13’.
While running Emacs, you can also set the font of a specific kind of text (see
Section 11.8 [Faces], page 75), or a particular frame (see Section 18.11 [Frame
Parameters], page 175).

18.9 Speedbar Frames
The speedbar is a special frame for conveniently navigating in or operating on
another frame. The speedbar, when it exists, is always associated with a specific
frame, called its attached frame; all speedbar operations act on that frame.
Type M-x speedbar to create the speedbar and associate it with the current
frame. To dismiss the speedbar, type M-x speedbar again, or select the speedbar
and type q. (You can also delete the speedbar frame like any other Emacs frame.)
If you wish to associate the speedbar with a different frame, dismiss it and call M-x
speedbar from that frame.
The speedbar can operate in various modes. Its default mode is File Display
mode, which shows the files in the current directory of the selected window of the
attached frame, one file per line. Clicking on a file name visits that file in the
selected window of the attached frame, and clicking on a directory name shows that
directory in the speedbar (see Section 18.3 [Mouse References], page 167). Each line
also has a box, ‘[+]’ or ‘<+>’, that you can click on to expand the contents of that
item. Expanding a directory adds the contents of that directory to the speedbar
display, underneath the directory’s own line. Expanding an ordinary file adds a list
of the tags in that file to the speedbar display; you can click on a tag name to jump
to that tag in the selected window of the attached frame. When a file or directory
is expanded, the ‘[+]’ changes to ‘[-]’; you can click on that box to contract the
item, hiding its contents.
You navigate through the speedbar using the keyboard, too. Typing RET while
point is on a line in the speedbar is equivalent to clicking the item on the current
line, and SPC expands or contracts the item. U displays the parent directory of the
current directory. To copy, delete, or rename the file on the current line, type C, D,
and R respectively. To create a new directory, type M.
Another general-purpose speedbar mode is Buffer Display mode; in this mode,
the speedbar displays a list of Emacs buffers. To switch to this mode, type b in the
speedbar. To return to File Display mode, type f. You can also change the display

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mode by clicking mouse-3 anywhere in the speedbar window (or mouse-1 on the
mode-line) and selecting ‘Displays’ in the pop-up menu.
Some major modes, including Rmail mode, Info, and GUD, have specialized
ways of putting useful items into the speedbar for you to select. For example, in
Rmail mode, the speedbar shows a list of Rmail files, and lets you move the current
message to another Rmail file by clicking on its ‘’ box.
For more details on using and programming the speedbar, See Section “Top” in
Speedbar Manual.

18.10 Multiple Displays
A single Emacs can talk to more than one X display. Initially, Emacs uses just
one display—the one specified with the DISPLAY environment variable or with the
‘--display’ option (see Section C.2 [Initial Options], page 507). To connect to
another display, use the command make-frame-on-display:
M-x make-frame-on-display RET display RET
Create a new frame on display display.
A single X server can handle more than one screen. When you open frames on
two screens belonging to one server, Emacs knows they share a single keyboard, and
it treats all the commands arriving from these screens as a single stream of input.
When you open frames on different X servers, Emacs makes a separate input
stream for each server. Each server also has its own selected frame. The commands
you enter with a particular X server apply to that server’s selected frame.

18.11 Frame Parameters
You can control the default appearance and behavior of all frames by specifying a
default list of frame parameters in the variable default-frame-alist. Its value
should be a list of entries, each specifying a parameter name and a value for that
parameter. These entries take effect whenever Emacs creates a new frame, including
the initial frame.
For example, you can add the following lines to your init file (see Section 33.4
[Init File], page 461) to set the default frame width to 90 character columns, the
default frame height to 40 character rows, and the default font to ‘Monospace-10’:
(add-to-list ’default-frame-alist ’(width . 90))
(add-to-list ’default-frame-alist ’(height . 40))
(add-to-list ’default-frame-alist ’(font . "Monospace-10"))
For a list of frame parameters and their effects, see Section “Frame Parameters”
in The Emacs Lisp Reference Manual.
You can also specify a list of frame parameters which apply to just the initial
frame, by customizing the variable initial-frame-alist.
If Emacs is compiled to use an X toolkit, frame parameters that specify colors
and fonts don’t affect menus and the menu bar, since those are drawn by the toolkit
and not directly by Emacs.

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18.12 Scroll Bars
On graphical displays, there is a scroll bar on the side of each Emacs window.
Clicking Mouse-1 on the scroll bar’s up and down buttons scrolls the window by
one line at a time. Clicking Mouse-1 above or below the scroll bar’s inner box
scrolls the window by nearly the entire height of the window, like M-v and C-v
respectively (see Section 4.2 [Moving Point], page 18). Dragging the inner box
scrolls continuously.
If Emacs is compiled on the X Window System without X toolkit support, the
scroll bar behaves differently. Clicking Mouse-1 anywhere on the scroll bar scrolls
forward like C-v, while Mouse-3 scrolls backward like M-v. Clicking Mouse-2 in the
scroll bar lets you drag the inner box up and down.
To toggle the use of scroll bars, type M-x scroll-bar-mode. This command
applies to all frames, including frames yet to be created. To toggle scroll bars for
just the selected frame, use the command M-x toggle-scroll-bar.
To control the use of scroll bars at startup, customize the variable scrollbar-mode. Its value should be either right (put scroll bars on the right side of
windows), left (put them on the left), or nil (disable scroll bars). By default,
Emacs puts scroll bars on the right if it was compiled with GTK+ support on the
X Window System, and on MS-Windows or Mac OS; Emacs puts scroll bars on the
left if compiled on the X Window System without GTK+ support (following the old
convention for X applications).
You can also use the X resource ‘verticalScrollBars’ to enable or disable the
scroll bars (see Section D.1 [Resources], page 521). To control the scroll bar width,
change the scroll-bar-width frame parameter (see Section “Frame Parameters”
in The Emacs Lisp Reference Manual).

18.13 Drag and Drop
In most graphical desktop environments, Emacs has basic support for drag and
drop operations. For instance, dropping text onto an Emacs frame inserts the text
where it is dropped. Dropping a file onto an Emacs frame visits that file. As a
special case, dropping the file on a Dired buffer moves or copies the file (according
to the conventions of the application it came from) into the directory displayed in
that buffer.
Dropping a file normally visits it in the window you drop it on. If you prefer
to visit the file in a new window in such cases, customize the variable dnd-openfile-other-window.
The XDND and Motif drag and drop protocols, and the old KDE 1.x protocol,
are currently supported.

18.14 Menu Bars
You can toggle the use of menu bars with M-x menu-bar-mode. With no argument,
this command toggles Menu Bar mode, a global minor mode. With an argument, the
command turns Menu Bar mode on if the argument is positive, off if the argument

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is not positive. To control the use of menu bars at startup, customize the variable
menu-bar-mode.
Expert users often turn off the menu bar, especially on text terminals, where
this makes one additional line available for text. If the menu bar is off, you can still
pop up a menu of its contents with C-Mouse-3 on a display which supports pop-up
menus. See Section 18.4 [Menu Mouse Clicks], page 168.
See Section 1.4 [Menu Bar], page 10, for information on how to invoke commands
with the menu bar. See Appendix D [X Resources], page 521, for how to customize
the menu bar menus’ visual appearance.

18.15 Tool Bars
On graphical displays, Emacs puts a tool bar at the top of each frame, just below
the menu bar. This is a row of icons which you can click on with the mouse to
invoke various commands.
The global (default) tool bar contains general commands. Some major modes
define their own tool bars; whenever a buffer with such a major mode is current,
the mode’s tool bar replaces the global tool bar.
To toggle the use of tool bars, type M-x tool-bar-mode. This command applies
to all frames, including frames yet to be created. To control the use of tool bars at
startup, customize the variable tool-bar-mode.
When Emacs is compiled with GTK+ support, each tool bar item can consist of
an image, or a text label, or both. By default, Emacs follows the Gnome desktop’s
tool bar style setting; if none is defined, it displays tool bar items as just images.
To impose a specific tool bar style, customize the variable tool-bar-style.
You can also control the placement of the tool bar for the GTK+ tool bar with
the frame parameter tool-bar-position. See Section “Frame Parameters” in The
Emacs Lisp Reference Manual.

18.16 Using Dialog Boxes
A dialog box is a special kind of menu for asking you a yes-or-no question or some
other special question. Many Emacs commands use a dialog box to ask a yes-or-no
question, if you used the mouse to invoke the command that led to the question.
To disable the use of dialog boxes, change the variable use-dialog-box to nil.
In that case, Emacs always performs yes-or-no prompts using the echo area and
keyboard input. This variable also controls whether to use file selection windows
(but those are not supported on all platforms).
A file selection window is a special kind of dialog box for asking for file names.
You can customize the variable use-file-dialog to suppress the use of file selection
windows, even if you still want other kinds of dialogs. This variable has no effect if
you have suppressed all dialog boxes with the variable use-dialog-box.
When Emacs is compiled with GTK+ support, it uses the GTK+ “file chooser”
dialog. Emacs adds an additional toggle button to this dialog, which you can use
to enable or disable the display of hidden files (files starting with a dot) in that

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dialog. If you want this toggle to be activated by default, change the variable xgtk-show-hidden-files to t. In addition, Emacs adds help text to the GTK+ file
chooser dialog; to disable this help text, change the variable x-gtk-file-dialoghelp-text to nil.

18.17 Tooltips
Tooltips are small windows that display text information at the current mouse position. They activate when there is a pause in mouse movement over some significant
piece of text in a window, or the mode line, or some other part of the Emacs frame
such as a tool bar button or menu item.
You can toggle the use of tooltips with the command M-x tooltip-mode. When
Tooltip mode is disabled, the help text is displayed in the echo area instead. To
control the use of tooltips at startup, customize the variable tooltip-mode.
The variables tooltip-delay specifies how long Emacs should wait before displaying a tooltip. For additional customization options for displaying tooltips, use
M-x customize-group RET tooltip RET.
If Emacs is built with GTK+ support, it displays tooltips via GTK+, using the
default appearance of GTK+ tooltips. To disable this, change the variable x-gtkuse-system-tooltips to nil. If you do this, or if Emacs is built without GTK+
support, most attributes of the tooltip text are specified by the tooltip face, and
by X resources (see Appendix D [X Resources], page 521).
GUD tooltips are special tooltips that show the values of variables when debugging a program with GUD. See Section 24.6.2 [Debugger Operation], page 277.

18.18 Mouse Avoidance
On graphical terminals, the mouse pointer may obscure the text in the Emacs frame.
Emacs provides two methods to avoid this problem.
Firstly, Emacs hides the mouse pointer each time you type a self-inserting character, if the pointer lies inside an Emacs frame; moving the mouse pointer makes it
visible again. To disable this feature, set the variable make-pointer-invisible to
nil.
Secondly, you can use Mouse Avoidance mode, a minor mode, to keep the mouse
pointer away from point. To use Mouse Avoidance mode, customize the variable
mouse-avoidance-mode. You can set this to various values to move the mouse in
several ways:
banish

Move the mouse to the upper-right corner on any key-press;

exile

Move the mouse to the corner only if the cursor gets too close, and
allow it to return once the cursor is out of the way;

jump

If the cursor gets too close to the mouse, displace the mouse a random
distance & direction;

animate

As jump, but shows steps along the way for illusion of motion;

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cat-and-mouse
The same as animate;
proteus

As animate, but changes the shape of the mouse pointer too.

You can also use the command M-x mouse-avoidance-mode to enable the mode.
Whenever Mouse Avoidance mode moves the mouse, it also raises the frame.

18.19 Non-Window Terminals
On a text terminal, Emacs can display only one Emacs frame at a time. However,
you can still create multiple Emacs frames, and switch between them. Switching
frames on these terminals is much like switching between different window configurations.
Use C-x 5 2 to create a new frame and switch to it; use C-x 5 o to cycle through
the existing frames; use C-x 5 0 to delete the current frame.
Each frame has a number to distinguish it. If your terminal can display only
one frame at a time, the selected frame’s number n appears near the beginning of
the mode line, in the form ‘Fn ’.
‘Fn ’ is in fact the frame’s initial name. You can give frames more meaningful
names if you wish, and you can select a frame by its name. Use the command M-x
set-frame-name RET name RET to specify a new name for the selected frame, and
use M-x select-frame-by-name RET name RET to select a frame according to its
name. The name you specify appears in the mode line when the frame is selected.

18.20 Using a Mouse in Text Terminals
Some text terminals support mouse clicks in the terminal window.
In a terminal emulator which is compatible with xterm, you can use M-x
xterm-mouse-mode to give Emacs control over simple uses of the mouse—basically,
only non-modified single clicks are supported. The normal xterm mouse functionality for such clicks is still available by holding down the SHIFT key when you press
the mouse button. Xterm Mouse mode is a global minor mode (see Section 20.2
[Minor Modes], page 205). Repeating the command turns the mode off again.
In the console on GNU/Linux, you can use M-x gpm-mouse-mode to enable mouse
support. You must have the gpm server installed and running on your system in
order for this to work.
See Section “MS-DOS Mouse” in Specialized Emacs Features, for information
about mouse support on MS-DOS.

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19 International Character Set Support
Emacs supports a wide variety of international character sets, including European
and Vietnamese variants of the Latin alphabet, as well as Cyrillic, Devanagari (for
Hindi and Marathi), Ethiopic, Greek, Han (for Chinese and Japanese), Hangul
(for Korean), Hebrew, IPA, Kannada, Lao, Malayalam, Tamil, Thai, Tibetan, and
Vietnamese scripts. Emacs also supports various encodings of these characters that
are used by other internationalized software, such as word processors and mailers.
Emacs allows editing text with international characters by supporting all the
related activities:
• You can visit files with non-ASCII characters, save non-ASCII text, and pass
non-ASCII text between Emacs and programs it invokes (such as compilers, spell-checkers, and mailers). Setting your language environment (see
Section 19.3 [Language Environments], page 183) takes care of setting up the
coding systems and other options for a specific language or culture. Alternatively, you can specify how Emacs should encode or decode text for each
command; see Section 19.10 [Text Coding], page 193.
• You can display non-ASCII characters encoded by the various scripts. This
works by using appropriate fonts on graphics displays (see Section 19.15 [Defining Fontsets], page 198), and by sending special codes to text displays (see
Section 19.13 [Terminal Coding], page 196). If some characters are displayed
incorrectly, refer to Section 19.17 [Undisplayable Characters], page 200, which
describes possible problems and explains how to solve them.
• Characters from scripts whose natural ordering of text is from right to left
are reordered for display (see Section 19.20 [Bidirectional Editing], page 202).
These scripts include Arabic, Hebrew, Syriac, Thaana, and a few others.
• You can insert non-ASCII characters or search for them. To do that, you can
specify an input method (see Section 19.5 [Select Input Method], page 186)
suitable for your language, or use the default input method set up when
you chose your language environment. If your keyboard can produce nonASCII characters, you can select an appropriate keyboard coding system (see
Section 19.13 [Terminal Coding], page 196), and Emacs will accept those characters. Latin-1 characters can also be input by using the C-x 8 prefix, see
Section 19.18 [Unibyte Mode], page 200.
With the X Window System, your locale should be set to an appropriate
value to make sure Emacs interprets keyboard input correctly; see Section 19.3
[Language Environments], page 183.
The rest of this chapter describes these issues in detail.

19.1 Introduction to International Character Sets
The users of international character sets and scripts have established many moreor-less standard coding systems for storing files. These coding systems are typically
multibyte, meaning that sequences of two or more bytes are used to represent individual non-ASCII characters.

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Internally, Emacs uses its own multibyte character encoding, which is a superset
of the Unicode standard. This internal encoding allows characters from almost every
known script to be intermixed in a single buffer or string. Emacs translates between
the multibyte character encoding and various other coding systems when reading
and writing files, and when exchanging data with subprocesses.
The command C-h h (view-hello-file) displays the file ‘etc/HELLO’, which
illustrates various scripts by showing how to say “hello” in many languages. If
some characters can’t be displayed on your terminal, they appear as ‘?’ or as hollow
boxes (see Section 19.17 [Undisplayable Characters], page 200).
Keyboards, even in the countries where these character sets are used, generally
don’t have keys for all the characters in them. You can insert characters that
your keyboard does not support, using C-q (quoted-insert) or C-x 8 RET (ucsinsert). See Section 4.1 [Inserting Text], page 17. Emacs also supports various
input methods, typically one for each script or language, which make it easier to
type characters in the script. See Section 19.4 [Input Methods], page 185.
The prefix key C-x RET is used for commands that pertain to multibyte characters, coding systems, and input methods.
The command C-x = (what-cursor-position) shows information about the
character at point. In addition to the character position, which was described
in Section 4.9 [Position Info], page 23, this command displays how the character
is encoded. For instance, it displays the following line in the echo area for the
character ‘c’:
Char: c (99, #o143, #x63) point=28062 of 36168 (78%) column=53

The four values after ‘Char:’ describe the character that follows point, first by
showing it and then by giving its character code in decimal, octal and hex. For
a non-ASCII multibyte character, these are followed by ‘file’ and the character’s
representation, in hex, in the buffer’s coding system, if that coding system encodes
the character safely and with a single byte (see Section 19.6 [Coding Systems],
page 188). If the character’s encoding is longer than one byte, Emacs shows ‘file
...’.
As a special case, if the character lies in the range 128 (0200 octal) through 159
(0237 octal), it stands for a “raw” byte that does not correspond to any specific
displayable character. Such a “character” lies within the eight-bit-control character set, and is displayed as an escaped octal character code. In this case, C-x =
shows ‘part of display ...’ instead of ‘file’.
With a prefix argument (C-u C-x =), this command displays a detailed description of the character in a window:
• The character set name, and the codes that identify the character within that
character set; ASCII characters are identified as belonging to the ascii character set.
• The character’s syntax and categories.
• The character’s encodings, both internally in the buffer, and externally if you
were to save the file.
• What keys to type to input the character in the current input method (if it

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supports the character).
• If you are running Emacs on a graphical display, the font name and glyph code
for the character. If you are running Emacs on a text terminal, the code(s)
sent to the terminal.
• The character’s text properties (see Section “Text Properties” in the Emacs
Lisp Reference Manual), including any non-default faces used to display the
character, and any overlays containing it (see Section “Overlays” in the same
manual).
Here’s an example showing the Latin-1 character A with grave accent, in a buffer
whose coding system is utf-8-unix:
position:
character:
preferred charset:
code point in charset:
syntax:
category:

1 of 1 (0%), column: 0
À (displayed as À) (codepoint 192, #o300, #xc0)
unicode (Unicode (ISO10646))
0xC0
w
which means: word
.:Base, L:Left-to-right (strong),
j:Japanese, l:Latin, v:Viet
buffer code: #xC3 #x80
file code: not encodable by coding system undecided-unix
display: by this font (glyph code)
xft:-unknown-DejaVu Sans Mono-normal-normalnormal-*-13-*-*-*-m-0-iso10646-1 (#x82)

Character code properties: customize what to show
name: LATIN CAPITAL LETTER A WITH GRAVE
old-name: LATIN CAPITAL LETTER A GRAVE
general-category: Lu (Letter, Uppercase)
decomposition: (65 768) (’A’ ’‘’)

19.2 Disabling Multibyte Characters
By default, Emacs starts in multibyte mode: it stores the contents of buffers and
strings using an internal encoding that represents non-ASCII characters using multibyte sequences. Multibyte mode allows you to use all the supported languages and
scripts without limitations.
Under very special circumstances, you may want to disable multibyte character
support, for a specific buffer. When multibyte characters are disabled in a buffer,
we call that unibyte mode. In unibyte mode, each character in the buffer has a
character code ranging from 0 through 255 (0377 octal); 0 through 127 (0177 octal)
represent ASCII characters, and 128 (0200 octal) through 255 (0377 octal) represent
non-ASCII characters.
To edit a particular file in unibyte representation, visit it using find-fileliterally. See Section 15.2 [Visiting], page 125. You can convert a multibyte
buffer to unibyte by saving it to a file, killing the buffer, and visiting the file again
with find-file-literally. Alternatively, you can use C-x RET c (universalcoding-system-argument) and specify ‘raw-text’ as the coding system with which
to visit or save a file. See Section 19.10 [Text Coding], page 193. Unlike find-

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file-literally, finding a file as ‘raw-text’ doesn’t disable format conversion,
uncompression, or auto mode selection.
Emacs normally loads Lisp files as multibyte. This includes the Emacs initialization file, ‘.emacs’, and the initialization files of packages such as Gnus. However, you
can specify unibyte loading for a particular Lisp file, by adding an entry ‘unibyte:
t’ in a file local variables section (see Section 33.2.4 [File Variables], page 447).
Then that file is always loaded as unibyte text. Note that this does not represent
a real unibyte variable, rather it just acts as an indicator to Emacs in the same
way as coding does (see Section 19.8 [Specify Coding], page 192). Note also that
this feature only applies to loading Lisp files for evaluation, not to visiting them for
editing. You can also load a Lisp file as unibyte, on any one occasion, by typing
C-x RET c raw-text RET immediately before loading it.
The buffer-local variable enable-multibyte-characters is non-nil in multibyte buffers, and nil in unibyte ones. The mode line also indicates whether a buffer
is multibyte or not. See Section 1.3 [Mode Line], page 8. With a graphical display,
in a multibyte buffer, the portion of the mode line that indicates the character
set has a tooltip that (amongst other things) says that the buffer is multibyte. In
a unibyte buffer, the character set indicator is absent. Thus, in a unibyte buffer
(when using a graphical display) there is normally nothing before the indication of
the visited file’s end-of-line convention (colon, backslash, etc.), unless you are using
an input method.
You can turn off multibyte support in a specific buffer by invoking the command
toggle-enable-multibyte-characters in that buffer.

19.3 Language Environments
All supported character sets are supported in Emacs buffers whenever multibyte
characters are enabled; there is no need to select a particular language in order
to display its characters. However, it is important to select a language environment in order to set various defaults. Roughly speaking, the language environment
represents a choice of preferred script rather than a choice of language.
The language environment controls which coding systems to recognize when
reading text (see Section 19.7 [Recognize Coding], page 190). This applies to files,
incoming mail, and any other text you read into Emacs. It may also specify the
default coding system to use when you create a file. Each language environment
also specifies a default input method.
To select a language environment, customize current-language-environment
or use the command M-x set-language-environment. It makes no difference which
buffer is current when you use this command, because the effects apply globally
to the Emacs session. The supported language environments (see the variable
language-info-alist) include:
ASCII, Belarusian, Bengali, Brazilian Portuguese, Bulgarian, Cham,
Chinese-BIG5, Chinese-CNS, Chinese-EUC-TW, Chinese-GB, ChineseGBK, Chinese-GB18030, Croatian, Cyrillic-ALT, Cyrillic-ISO, CyrillicKOI8, Czech, Devanagari, Dutch, English, Esperanto, Ethiopic, French,
Georgian, German, Greek, Gujarati, Hebrew, IPA, Italian, Japanese,

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Kannada, Khmer, Korean, Lao, Latin-1, Latin-2, Latin-3, Latin-4, Latin5, Latin-6, Latin-7, Latin-8 (Celtic), Latin-9 (updated Latin-1 with the
Euro sign), Latvian, Lithuanian, Malayalam, Oriya, Polish, Punjabi, Romanian, Russian, Sinhala, Slovak, Slovenian, Spanish, Swedish, TaiViet,
Tajik, Tamil, Telugu, Thai, Tibetan, Turkish, UTF-8 (for a setup which
prefers Unicode characters and files encoded in UTF-8), Ukrainian, Vietnamese, Welsh, and Windows-1255 (for a setup which prefers Cyrillic
characters and files encoded in Windows-1255).
To display the script(s) used by your language environment on a graphical display, you need to have suitable fonts. See Section 19.14 [Fontsets], page 197, for
more details about setting up your fonts.
Some operating systems let you specify the character-set locale you are using
by setting the locale environment variables LC_ALL, LC_CTYPE, or LANG. (If more
than one of these is set, the first one that is nonempty specifies your locale for this
purpose.) During startup, Emacs looks up your character-set locale’s name in the
system locale alias table, matches its canonical name against entries in the value of
the variables locale-charset-language-names and locale-language-names (the
former overrides the latter), and selects the corresponding language environment if
a match is found. It also adjusts the display table and terminal coding system, the
locale coding system, the preferred coding system as needed for the locale, and—last
but not least—the way Emacs decodes non-ASCII characters sent by your keyboard.
If you modify the LC_ALL, LC_CTYPE, or LANG environment variables while running Emacs (by using M-x setenv), you may want to invoke the set-localeenvironment function afterwards to readjust the language environment from the
new locale.
The set-locale-environment function normally uses the preferred coding system established by the language environment to decode system messages. But if
your locale matches an entry in the variable locale-preferred-coding-systems,
Emacs uses the corresponding coding system instead. For example, if the locale ‘ja_JP.PCK’ matches japanese-shift-jis in locale-preferred-codingsystems, Emacs uses that encoding even though it might normally use japaneseiso-8bit.
You can override the language environment chosen at startup with explicit use
of the command set-language-environment, or with customization of currentlanguage-environment in your init file.
To display information about the effects of a certain language environment langenv, use the command C-h L lang-env RET (describe-language-environment).
This tells you which languages this language environment is useful for, and lists
the character sets, coding systems, and input methods that go with it. It also
shows some sample text to illustrate scripts used in this language environment. If
you give an empty input for lang-env, this command describes the chosen language
environment.
You can customize any language environment with the normal hook setlanguage-environment-hook. The command set-language-environment runs
that hook after setting up the new language environment. The hook functions

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can test for a specific language environment by checking the variable currentlanguage-environment. This hook is where you should put non-default settings
for specific language environments, such as coding systems for keyboard input and
terminal output, the default input method, etc.
Before it starts to set up the new language environment, set-languageenvironment first runs the hook exit-language-environment-hook.
This
hook is useful for undoing customizations that were made with set-languageenvironment-hook. For instance, if you set up a special key binding in a specific
language environment using set-language-environment-hook, you should set up
exit-language-environment-hook to restore the normal binding for that key.

19.4 Input Methods
An input method is a kind of character conversion designed specifically for interactive input. In Emacs, typically each language has its own input method; sometimes
several languages that use the same characters can share one input method. A few
languages support several input methods.
The simplest kind of input method works by mapping ASCII letters into another
alphabet; this allows you to use one other alphabet instead of ASCII. The Greek
and Russian input methods work this way.
A more powerful technique is composition: converting sequences of characters
into one letter. Many European input methods use composition to produce a single
non-ASCII letter from a sequence that consists of a letter followed by accent characters (or vice versa). For example, some methods convert the sequence o ^ into
a single accented letter. These input methods have no special commands of their
own; all they do is compose sequences of printing characters.
The input methods for syllabic scripts typically use mapping followed by composition. The input methods for Thai and Korean work this way. First, letters are
mapped into symbols for particular sounds or tone marks; then, sequences of these
that make up a whole syllable are mapped into one syllable sign.
Chinese and Japanese require more complex methods. In Chinese input methods, first you enter the phonetic spelling of a Chinese word (in input method
chinese-py, among others), or a sequence of portions of the character (input methods chinese-4corner and chinese-sw, and others). One input sequence typically
corresponds to many possible Chinese characters. You select the one you mean
using keys such as C-f, C-b, C-n, C-p (or the arrow keys), and digits, which have
special meanings in this situation.
The possible characters are conceptually arranged in several rows, with each row
holding up to 10 alternatives. Normally, Emacs displays just one row at a time, in
the echo area; (i /j ) appears at the beginning, to indicate that this is the ith row
out of a total of j rows. Type C-n or C-p to display the next row or the previous
row.
Type C-f and C-b to move forward and backward among the alternatives in
the current row. As you do this, Emacs highlights the current alternative with
a special color; type C-SPC to select the current alternative and use it as input.

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The alternatives in the row are also numbered; the number appears before the
alternative. Typing a number selects the associated alternative of the current row
and uses it as input.
TAB in these Chinese input methods displays a buffer showing all the possible
characters at once; then clicking Mouse-2 on one of them selects that alternative.
The keys C-f, C-b, C-n, C-p, and digits continue to work as usual, but they do the
highlighting in the buffer showing the possible characters, rather than in the echo
area.
In Japanese input methods, first you input a whole word using phonetic spelling;
then, after the word is in the buffer, Emacs converts it into one or more characters
using a large dictionary. One phonetic spelling corresponds to a number of different Japanese words; to select one of them, use C-n and C-p to cycle through the
alternatives.
Sometimes it is useful to cut off input method processing so that the characters
you have just entered will not combine with subsequent characters. For example,
in input method latin-1-postfix, the sequence o ^ combines to form an ‘o’ with
an accent. What if you want to enter them as separate characters?
One way is to type the accent twice; this is a special feature for entering the
separate letter and accent. For example, o ^ ^ gives you the two characters ‘o^’.
Another way is to type another letter after the o—something that won’t combine
with that—and immediately delete it. For example, you could type o o DEL ^ to
get separate ‘o’ and ‘^’.
Another method, more general but not quite as easy to type, is to use C-\ C-\
between two characters to stop them from combining. This is the command C-\
(toggle-input-method) used twice.
C-\ C-\ is especially useful inside an incremental search, because it stops waiting
for more characters to combine, and starts searching for what you have already
entered.
To find out how to input the character after point using the current input
method, type C-u C-x =. See Section 4.9 [Position Info], page 23.
The variables input-method-highlight-flag and input-method-verboseflag control how input methods explain what is happening. If input-methodhighlight-flag is non-nil, the partial sequence is highlighted in the buffer (for
most input methods—some disable this feature). If input-method-verbose-flag
is non-nil, the list of possible characters to type next is displayed in the echo area
(but not when you are in the minibuffer).
Another facility for typing characters not on your keyboard is by using C-x 8 RET
(ucs-insert) to insert a single character based on its Unicode name or code-point;
see Section 4.1 [Inserting Text], page 17.

19.5 Selecting an Input Method
C-\

Enable or disable use of the selected input method (toggle-inputmethod).

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C-x RET C-\ method RET
Select a new input method for the current buffer (set-input-method).
C-h I method RET
C-h C-\ method RET
Describe the input method method (describe-input-method). By
default, it describes the current input method (if any). This description should give you the full details of how to use any particular input
method.
M-x list-input-methods
Display a list of all the supported input methods.
To choose an input method for the current buffer, use C-x RET C-\ (set-inputmethod). This command reads the input method name from the minibuffer; the
name normally starts with the language environment that it is meant to be used
with. The variable current-input-method records which input method is selected.
Input methods use various sequences of ASCII characters to stand for non-ASCII
characters. Sometimes it is useful to turn off the input method temporarily. To do
this, type C-\ (toggle-input-method). To reenable the input method, type C-\
again.
If you type C-\ and you have not yet selected an input method, it prompts you
to specify one. This has the same effect as using C-x RET C-\ to specify an input
method.
When invoked with a numeric argument, as in C-u C-\, toggle-input-method
always prompts you for an input method, suggesting the most recently selected one
as the default.
Selecting a language environment specifies a default input method for use in
various buffers. When you have a default input method, you can select it in the
current buffer by typing C-\. The variable default-input-method specifies the
default input method (nil means there is none).
In some language environments, which support several different input methods,
you might want to use an input method different from the default chosen by setlanguage-environment. You can instruct Emacs to select a different default input
method for a certain language environment, if you wish, by using set-languageenvironment-hook (see Section 19.3 [Language Environments], page 183). For
example:
(defun my-chinese-setup ()
"Set up my private Chinese environment."
(if (equal current-language-environment "Chinese-GB")
(setq default-input-method "chinese-tonepy")))
(add-hook ’set-language-environment-hook ’my-chinese-setup)
This sets the default input method to be chinese-tonepy whenever you choose a
Chinese-GB language environment.
You can instruct Emacs to activate a certain input method automatically. For
example:
(add-hook ’text-mode-hook

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(lambda () (set-input-method "german-prefix")))
This automatically activates the input method “german-prefix” in Text mode.
Some input methods for alphabetic scripts work by (in effect) remapping
the keyboard to emulate various keyboard layouts commonly used for those
scripts. How to do this remapping properly depends on your actual keyboard
layout. To specify which layout your keyboard has, use the command M-x
quail-set-keyboard-layout.
You can use the command M-x quail-show-key to show what key (or key sequence) to type in order to input the character following point, using the selected
keyboard layout. The command C-u C-x = also shows that information, in addition
to other information about the character.
M-x list-input-methods displays a list of all the supported input methods.
The list gives information about each input method, including the string that stands
for it in the mode line.

19.6 Coding Systems
Users of various languages have established many more-or-less standard coding systems for representing them. Emacs does not use these coding systems internally;
instead, it converts from various coding systems to its own system when reading
data, and converts the internal coding system to other coding systems when writing
data. Conversion is possible in reading or writing files, in sending or receiving from
the terminal, and in exchanging data with subprocesses.
Emacs assigns a name to each coding system. Most coding systems are used for
one language, and the name of the coding system starts with the language name.
Some coding systems are used for several languages; their names usually start with
‘iso’. There are also special coding systems, such as no-conversion, raw-text,
and emacs-internal.
A special class of coding systems, collectively known as codepages, is designed to
support text encoded by MS-Windows and MS-DOS software. The names of these
coding systems are cpnnnn , where nnnn is a 3- or 4-digit number of the codepage.
You can use these encodings just like any other coding system; for example, to visit
a file encoded in codepage 850, type C-x RET c cp850 RET C-x C-f filename RET.
In addition to converting various representations of non-ASCII characters, a
coding system can perform end-of-line conversion. Emacs handles three different
conventions for how to separate lines in a file: newline (“unix”), carriage-return
linefeed (“dos”), and just carriage-return (“mac”).
C-h C coding RET
Describe coding system coding (describe-coding-system).
C-h C RET

Describe the coding systems currently in use.

M-x list-coding-systems
Display a list of all the supported coding systems.
The command C-h C (describe-coding-system) displays information about
particular coding systems, including the end-of-line conversion specified by those

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coding systems. You can specify a coding system name as the argument; alternatively, with an empty argument, it describes the coding systems currently selected
for various purposes, both in the current buffer and as the defaults, and the priority
list for recognizing coding systems (see Section 19.7 [Recognize Coding], page 190).
To display a list of all the supported coding systems, type M-x
list-coding-systems.
The list gives information about each coding system, including the letter that stands for it in the mode line (see Section 1.3 [Mode
Line], page 8).
Each of the coding systems that appear in this list—except for no-conversion,
which means no conversion of any kind—specifies how and whether to convert printing characters, but leaves the choice of end-of-line conversion to be decided based
on the contents of each file. For example, if the file appears to use the sequence
carriage-return linefeed to separate lines, DOS end-of-line conversion will be used.
Each of the listed coding systems has three variants, which specify exactly what
to do for end-of-line conversion:
...-unix

Don’t do any end-of-line conversion; assume the file uses newline to
separate lines. (This is the convention normally used on Unix and
GNU systems, and Mac OS X.)

...-dos

Assume the file uses carriage-return linefeed to separate lines, and do
the appropriate conversion. (This is the convention normally used on
Microsoft systems.1 )

...-mac

Assume the file uses carriage-return to separate lines, and do the appropriate conversion. (This was the convention used on the Macintosh
system prior to OS X.)

These variant coding systems are omitted from the list-coding-systems display for brevity, since they are entirely predictable. For example, the coding system
iso-latin-1 has variants iso-latin-1-unix, iso-latin-1-dos and iso-latin1-mac.
The coding systems unix, dos, and mac are aliases for undecided-unix,
undecided-dos, and undecided-mac, respectively. These coding systems specify only the end-of-line conversion, and leave the character code conversion to be
deduced from the text itself.
The coding system raw-text is good for a file which is mainly ASCII text,
but may contain byte values above 127 that are not meant to encode non-ASCII
characters. With raw-text, Emacs copies those byte values unchanged, and sets
enable-multibyte-characters to nil in the current buffer so that they will be
interpreted properly. raw-text handles end-of-line conversion in the usual way,
based on the data encountered, and has the usual three variants to specify the kind
of end-of-line conversion to use.
In contrast, the coding system no-conversion specifies no character code conversion at all—none for non-ASCII byte values and none for end of line. This is
1

It is also specified for MIME ‘text/*’ bodies and in other network transport contexts.
It is different from the SGML reference syntax record-start/record-end format, which
Emacs doesn’t support directly.

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useful for reading or writing binary files, tar files, and other files that must be
examined verbatim. It, too, sets enable-multibyte-characters to nil.
The easiest way to edit a file with no conversion of any kind is with the M-x
find-file-literally command. This uses no-conversion, and also suppresses
other Emacs features that might convert the file contents before you see them. See
Section 15.2 [Visiting], page 125.
The coding system emacs-internal (or utf-8-emacs, which is equivalent)
means that the file contains non-ASCII characters stored with the internal Emacs
encoding. This coding system handles end-of-line conversion based on the data
encountered, and has the usual three variants to specify the kind of end-of-line
conversion.

19.7 Recognizing Coding Systems
Whenever Emacs reads a given piece of text, it tries to recognize which coding
system to use. This applies to files being read, output from subprocesses, text from
X selections, etc. Emacs can select the right coding system automatically most of
the time—once you have specified your preferences.
Some coding systems can be recognized or distinguished by which byte sequences
appear in the data. However, there are coding systems that cannot be distinguished,
not even potentially. For example, there is no way to distinguish between Latin-1
and Latin-2; they use the same byte values with different meanings.
Emacs handles this situation by means of a priority list of coding systems. Whenever Emacs reads a file, if you do not specify the coding system to use, Emacs checks
the data against each coding system, starting with the first in priority and working
down the list, until it finds a coding system that fits the data. Then it converts the
file contents assuming that they are represented in this coding system.
The priority list of coding systems depends on the selected language environment
(see Section 19.3 [Language Environments], page 183). For example, if you use
French, you probably want Emacs to prefer Latin-1 to Latin-2; if you use Czech,
you probably want Latin-2 to be preferred. This is one of the reasons to specify a
language environment.
However, you can alter the coding system priority list in detail with the command
M-x prefer-coding-system. This command reads the name of a coding system
from the minibuffer, and adds it to the front of the priority list, so that it is preferred
to all others. If you use this command several times, each use adds one element to
the front of the priority list.
If you use a coding system that specifies the end-of-line conversion type, such
as iso-8859-1-dos, what this means is that Emacs should attempt to recognize
iso-8859-1 with priority, and should use DOS end-of-line conversion when it does
recognize iso-8859-1.
Sometimes a file name indicates which coding system to use for the file. The variable file-coding-system-alist specifies this correspondence. There is a special
function modify-coding-system-alist for adding elements to this list. For exam-

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ple, to read and write all ‘.txt’ files using the coding system chinese-iso-8bit,
you can execute this Lisp expression:
(modify-coding-system-alist ’file "\\.txt\\’" ’chinese-iso-8bit)

The first argument should be file, the second argument should be a regular expression that determines which files this applies to, and the third argument says
which coding system to use for these files.
Emacs recognizes which kind of end-of-line conversion to use based on the contents of the file: if it sees only carriage-returns, or only carriage-return linefeed
sequences, then it chooses the end-of-line conversion accordingly. You can inhibit
the automatic use of end-of-line conversion by setting the variable inhibit-eolconversion to non-nil. If you do that, DOS-style files will be displayed with
the ‘^M’ characters visible in the buffer; some people prefer this to the more subtle
‘(DOS)’ end-of-line type indication near the left edge of the mode line (see Section 1.3
[Mode Line], page 8).
By default, the automatic detection of coding system is sensitive to escape sequences. If Emacs sees a sequence of characters that begin with an escape character,
and the sequence is valid as an ISO-2022 code, that tells Emacs to use one of the
ISO-2022 encodings to decode the file.
However, there may be cases that you want to read escape sequences in a file
as is. In such a case, you can set the variable inhibit-iso-escape-detection to
non-nil. Then the code detection ignores any escape sequences, and never uses an
ISO-2022 encoding. The result is that all escape sequences become visible in the
buffer.
The default value of inhibit-iso-escape-detection is nil. We recommend
that you not change it permanently, only for one specific operation. That’s because
some Emacs Lisp source files in the Emacs distribution contain non-ASCII characters
encoded in the coding system iso-2022-7bit, and they won’t be decoded correctly
when you visit those files if you suppress the escape sequence detection.
The variables auto-coding-alist and auto-coding-regexp-alist are the
strongest way to specify the coding system for certain patterns of file names, or
for files containing certain patterns, respectively. These variables even override
‘-*-coding:-*-’ tags in the file itself (see Section 19.8 [Specify Coding], page 192).
For example, Emacs uses auto-coding-alist for tar and archive files, to prevent
it from being confused by a ‘-*-coding:-*-’ tag in a member of the archive and
thinking it applies to the archive file as a whole.
Another way to specify a coding system is with the variable auto-codingfunctions. For example, one of the builtin auto-coding-functions detects the
encoding for XML files. Unlike the previous two, this variable does not override
any ‘-*-coding:-*-’ tag.
When you get new mail in Rmail, each message is translated automatically
from the coding system it is written in, as if it were a separate file. This uses the
priority list of coding systems that you have specified. If a MIME message specifies
a character set, Rmail obeys that specification. For reading and saving Rmail files
themselves, Emacs uses the coding system specified by the variable rmail-file-

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coding-system. The default value is nil, which means that Rmail files are not
translated (they are read and written in the Emacs internal character code).

19.8 Specifying a File’s Coding System
If Emacs recognizes the encoding of a file incorrectly, you can reread the file using
the correct coding system with C-x RET r (revert-buffer-with-coding-system).
This command prompts for the coding system to use. To see what coding system
Emacs actually used to decode the file, look at the coding system mnemonic letter
near the left edge of the mode line (see Section 1.3 [Mode Line], page 8), or type
C-h C (describe-coding-system).
You can specify the coding system for a particular file in the file itself, using
the ‘-*-...-*-’ construct at the beginning, or a local variables list at the end (see
Section 33.2.4 [File Variables], page 447). You do this by defining a value for the
“variable” named coding. Emacs does not really have a variable coding; instead
of setting a variable, this uses the specified coding system for the file. For example,
‘-*-mode: C; coding: latin-1;-*-’ specifies use of the Latin-1 coding system, as
well as C mode. When you specify the coding explicitly in the file, that overrides
file-coding-system-alist.

19.9 Choosing Coding Systems for Output
Once Emacs has chosen a coding system for a buffer, it stores that coding system
in buffer-file-coding-system. That makes it the default for operations that
write from this buffer into a file, such as save-buffer and write-region. You
can specify a different coding system for further file output from the buffer using
set-buffer-file-coding-system (see Section 19.10 [Text Coding], page 193).
You can insert any character Emacs supports into any Emacs buffer, but most
coding systems can only handle a subset of these characters. Therefore, it’s possible
that the characters you insert cannot be encoded with the coding system that will be
used to save the buffer. For example, you could visit a text file in Polish, encoded
in iso-8859-2, and add some Russian words to it. When you save that buffer,
Emacs cannot use the current value of buffer-file-coding-system, because the
characters you added cannot be encoded by that coding system.
When that happens, Emacs tries the most-preferred coding system (set by M-x
prefer-coding-system or M-x set-language-environment). If that coding system can safely encode all of the characters in the buffer, Emacs uses it, and stores its
value in buffer-file-coding-system. Otherwise, Emacs displays a list of coding
systems suitable for encoding the buffer’s contents, and asks you to choose one of
those coding systems.
If you insert the unsuitable characters in a mail message, Emacs behaves a
bit differently. It additionally checks whether the most-preferred coding system is
recommended for use in MIME messages; if not, it informs you of this fact and
prompts you for another coding system. This is so you won’t inadvertently send
a message encoded in a way that your recipient’s mail software will have difficulty

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decoding. (You can still use an unsuitable coding system if you enter its name at
the prompt.)
When you send a mail message (see Chapter 29 [Sending Mail], page 367),
Emacs has four different ways to determine the coding system to use for encoding
the message text. It tries the buffer’s own value of buffer-file-coding-system, if
that is non-nil. Otherwise, it uses the value of sendmail-coding-system, if that
is non-nil. The third way is to use the default coding system for new files, which
is controlled by your choice of language environment, if that is non-nil. If all of
these three values are nil, Emacs encodes outgoing mail using the Latin-1 coding
system.

19.10 Specifying a Coding System for File Text
In cases where Emacs does not automatically choose the right coding system for a
file’s contents, you can use these commands to specify one:
C-x RET f coding RET
Use coding system coding to save or revisit the file in the current
buffer (set-buffer-file-coding-system).
C-x RET c coding RET
Specify coding system coding for the immediately following command
(universal-coding-system-argument).
C-x RET r coding RET
Revisit the current file using the coding system coding (revertbuffer-with-coding-system).
M-x recode-region RET right RET wrong RET
Convert a region that was decoded using coding system wrong, decoding it using coding system right instead.
The command C-x RET f (set-buffer-file-coding-system) sets the file coding system for the current buffer—in other words, it says which coding system to
use when saving or reverting the visited file. You specify which coding system using
the minibuffer. If you specify a coding system that cannot handle all of the characters in the buffer, Emacs warns you about the troublesome characters when you
actually save the buffer.
You can also use this command to specify the end-of-line conversion (see
Section 19.6 [Coding Systems], page 188) for encoding the current buffer. For
example, C-x RET f dos RET will cause Emacs to save the current buffer’s text with
DOS-style carriage-return linefeed line endings.
Another way to specify the coding system for a file is when you visit the file.
First use the command C-x RET c (universal-coding-system-argument); this
command uses the minibuffer to read a coding system name. After you exit the
minibuffer, the specified coding system is used for the immediately following command.
So if the immediately following command is C-x C-f, for example, it reads the
file using that coding system (and records the coding system for when you later

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save the file). Or if the immediately following command is C-x C-w, it writes the
file using that coding system. When you specify the coding system for saving in this
way, instead of with C-x RET f, there is no warning if the buffer contains characters
that the coding system cannot handle.
Other file commands affected by a specified coding system include C-x i and
C-x C-v, as well as the other-window variants of C-x C-f. C-x RET c also affects
commands that start subprocesses, including M-x shell (see Section 31.3 [Shell],
page 401). If the immediately following command does not use the coding system,
then C-x RET c ultimately has no effect.
An easy way to visit a file with no conversion is with the M-x
find-file-literally command. See Section 15.2 [Visiting], page 125.
The default value of the variable buffer-file-coding-system specifies the
choice of coding system to use when you create a new file. It applies when you
find a new file, and when you create a buffer and then save it in a file. Selecting a
language environment typically sets this variable to a good choice of default coding
system for that language environment.
If you visit a file with a wrong coding system, you can correct this with C-x RET
r (revert-buffer-with-coding-system). This visits the current file again, using
a coding system you specify.
If a piece of text has already been inserted into a buffer using the wrong coding
system, you can redo the decoding of it using M-x recode-region. This prompts
you for the proper coding system, then for the wrong coding system that was
actually used, and does the conversion. It first encodes the region using the wrong
coding system, then decodes it again using the proper coding system.

19.11 Coding Systems for Interprocess Communication
This section explains how to specify coding systems for use in communication with
other processes.
C-x RET x coding RET
Use coding system coding for transferring selections to and from other
graphical applications (set-selection-coding-system).
C-x RET X coding RET
Use coding system coding for transferring one selection—the next
one—to or from another graphical application (set-next-selectioncoding-system).
C-x RET p input-coding RET output-coding RET
Use coding systems input-coding and output-coding for subprocess input and output in the current buffer (set-buffer-process-codingsystem).
The command C-x RET x (set-selection-coding-system) specifies the coding
system for sending selected text to other windowing applications, and for receiving
the text of selections made in other applications. This command applies to all
subsequent selections, until you override it by using the command again. The

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command C-x RET X (set-next-selection-coding-system) specifies the coding
system for the next selection made in Emacs or read by Emacs.
The variable x-select-request-type specifies the data type to request from
the X Window System for receiving text selections from other applications. If the
value is nil (the default), Emacs tries UTF8_STRING and COMPOUND_TEXT, in this
order, and uses various heuristics to choose the more appropriate of the two results;
if none of these succeed, Emacs falls back on STRING. If the value of x-selectrequest-type is one of the symbols COMPOUND_TEXT, UTF8_STRING, STRING, or
TEXT, Emacs uses only that request type. If the value is a list of some of these
symbols, Emacs tries only the request types in the list, in order, until one of them
succeeds, or until the list is exhausted.
The command C-x RET p (set-buffer-process-coding-system) specifies the
coding system for input and output to a subprocess. This command applies to the
current buffer; normally, each subprocess has its own buffer, and thus you can use
this command to specify translation to and from a particular subprocess by giving
the command in the corresponding buffer.
You can also use C-x RET c (universal-coding-system-argument) just before
the command that runs or starts a subprocess, to specify the coding system for
communicating with that subprocess. See Section 19.10 [Text Coding], page 193.
The default for translation of process input and output depends on the current
language environment.
The variable locale-coding-system specifies a coding system to use when encoding and decoding system strings such as system error messages and formattime-string formats and time stamps. That coding system is also used for decoding non-ASCII keyboard input on the X Window System. You should choose a
coding system that is compatible with the underlying system’s text representation,
which is normally specified by one of the environment variables LC_ALL, LC_CTYPE,
and LANG. (The first one, in the order specified above, whose value is nonempty is
the one that determines the text representation.)

19.12 Coding Systems for File Names
C-x RET F coding RET
Use coding system coding for encoding and decoding file names (setfile-name-coding-system).
The command C-x RET F (set-file-name-coding-system) specifies a coding
system to use for encoding file names. It has no effect on reading and writing the
contents of files.
In fact, all this command does is set the value of the variable file-namecoding-system. If you set the variable to a coding system name (as a Lisp symbol
or a string), Emacs encodes file names using that coding system for all file operations. This makes it possible to use non-ASCII characters in file names—or, at
least, those non-ASCII characters that the specified coding system can encode.
If file-name-coding-system is nil, Emacs uses a default coding system determined by the selected language environment, and stored in the default-file-

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name-coding-system variable. In the default language environment, non-ASCII
characters in file names are not encoded specially; they appear in the file system
using the internal Emacs representation.
Warning: if you change file-name-coding-system (or the language environment) in the middle of an Emacs session, problems can result if you have already
visited files whose names were encoded using the earlier coding system and cannot
be encoded (or are encoded differently) under the new coding system. If you try
to save one of these buffers under the visited file name, saving may use the wrong
file name, or it may encounter an error. If such a problem happens, use C-x C-w to
specify a new file name for that buffer.
If a mistake occurs when encoding a file name, use the command M-x
recode-file-name to change the file name’s coding system. This prompts for an
existing file name, its old coding system, and the coding system to which you wish
to convert.

19.13 Coding Systems for Terminal I/O
C-x RET t coding RET
Use coding system coding for terminal output (set-terminalcoding-system).
C-x RET k coding RET
Use coding system coding for keyboard input (set-keyboardcoding-system).
The command C-x RET t (set-terminal-coding-system) specifies the coding
system for terminal output. If you specify a character code for terminal output, all
characters output to the terminal are translated into that coding system.
This feature is useful for certain character-only terminals built to support specific
languages or character sets—for example, European terminals that support one of
the ISO Latin character sets. You need to specify the terminal coding system
when using multibyte text, so that Emacs knows which characters the terminal can
actually handle.
By default, output to the terminal is not translated at all, unless Emacs can
deduce the proper coding system from your terminal type or your locale specification
(see Section 19.3 [Language Environments], page 183).
The command C-x RET k (set-keyboard-coding-system), or the variable
keyboard-coding-system, specifies the coding system for keyboard input.
Character-code translation of keyboard input is useful for terminals with keys that
send non-ASCII graphic characters—for example, some terminals designed for ISO
Latin-1 or subsets of it.
By default, keyboard input is translated based on your system locale setting.
If your terminal does not really support the encoding implied by your locale (for
example, if you find it inserts a non-ASCII character if you type M-i), you will need
to set keyboard-coding-system to nil to turn off encoding. You can do this by
putting

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(set-keyboard-coding-system nil)
in your init file.
There is a similarity between using a coding system translation for keyboard
input, and using an input method: both define sequences of keyboard input that
translate into single characters. However, input methods are designed to be convenient for interactive use by humans, and the sequences that are translated are
typically sequences of ASCII printing characters. Coding systems typically translate
sequences of non-graphic characters.

19.14 Fontsets
A font typically defines shapes for a single alphabet or script. Therefore, displaying
the entire range of scripts that Emacs supports requires a collection of many fonts.
In Emacs, such a collection is called a fontset. A fontset is defined by a list of font
specifications, each assigned to handle a range of character codes, and may fall back
on another fontset for characters that are not covered by the fonts it specifies.
Each fontset has a name, like a font. However, while fonts are stored in the
system and the available font names are defined by the system, fontsets are defined
within Emacs itself. Once you have defined a fontset, you can use it within Emacs
by specifying its name, anywhere that you could use a single font. Of course, Emacs
fontsets can use only the fonts that the system supports. If some characters appear
on the screen as empty boxes or hex codes, this means that the fontset in use for
them has no font for those characters. In this case, or if the characters are shown,
but not as well as you would like, you may need to install extra fonts. Your operating
system may have optional fonts that you can install; or you can install the GNU
Intlfonts package, which includes fonts for most supported scripts.2
Emacs creates three fontsets automatically: the standard fontset, the startup
fontset and the default fontset. The default fontset is most likely to have fonts for
a wide variety of non-ASCII characters, and is the default fallback for the other two
fontsets, and if you set a default font rather than fontset. However, it does not
specify font family names, so results can be somewhat random if you use it directly.
You can specify use of a particular fontset by starting Emacs with the ‘-fn’ option.
For example,
emacs -fn fontset-standard
You can also specify a fontset with the ‘Font’ resource (see Appendix D [X Resources], page 521).
If no fontset is specified for use, then Emacs uses an ASCII font, with
‘fontset-default’ as a fallback for characters the font does not cover. The standard fontset is only used if explicitly requested, despite its name.
2

If you run Emacs on X, you may need to inform the X server about the location of the
newly installed fonts with commands such as:
xset fp+ /usr/local/share/emacs/fonts
xset fp rehash

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A fontset does not necessarily specify a font for every character code. If a fontset
specifies no font for a certain character, or if it specifies a font that does not exist
on your system, then it cannot display that character properly. It will display that
character as a hex code or thin space or an empty box instead. (See Section 11.19
[glyphless characters], page 87, for details.)

19.15 Defining fontsets
When running on X, Emacs creates a standard fontset automatically according to
the value of standard-fontset-spec. This fontset’s name is
-*-fixed-medium-r-normal-*-16-*-*-*-*-*-fontset-standard
or just ‘fontset-standard’ for short.
On GNUstep and Mac OS X, the standard fontset is created using the value of
ns-standard-fontset-spec, and on MS Windows it is created using the value of
w32-standard-fontset-spec.
Bold, italic, and bold-italic variants of the standard fontset are created automatically. Their names have ‘bold’ instead of ‘medium’, or ‘i’ instead of ‘r’, or
both.
Emacs generates a fontset automatically, based on any default ASCII font that
you specify with the ‘Font’ resource or the ‘-fn’ argument, or the default font that
Emacs found when it started. This is the startup fontset and its name is fontsetstartup. It does this by replacing the charset registry field with ‘fontset’, and
replacing charset encoding field with ‘startup’, then using the resulting string to
specify a fontset.
For instance, if you start Emacs with a font of this form,
emacs -fn "*courier-medium-r-normal--14-140-*-iso8859-1"
Emacs generates the following fontset and uses it for the initial X window frame:
-*-courier-medium-r-normal-*-14-140-*-*-*-*-fontset-startup
The startup fontset will use the font that you specify, or a variant with a different
registry and encoding, for all the characters that are supported by that font, and
fallback on ‘fontset-default’ for other characters.
With the X resource ‘Emacs.Font’, you can specify a fontset name just like an
actual font name. But be careful not to specify a fontset name in a wildcard resource
like ‘Emacs*Font’—that wildcard specification matches various other resources, such
as for menus, and menus cannot handle fontsets. See Appendix D [X Resources],
page 521.
You can specify additional fontsets using X resources named ‘Fontset-n ’, where
n is an integer starting from 0. The resource value should have this form:
fontpattern, [charset :font ]. . .

fontpattern should have the form of a standard X font name (see the previous
fontset-startup example), except for the last two fields. They should have the form
‘fontset-alias ’.
The fontset has two names, one long and one short. The long name is fontpattern. The short name is ‘fontset-alias ’. You can refer to the fontset by either
name.

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The construct ‘charset :font ’ specifies which font to use (in this fontset) for
one particular character set. Here, charset is the name of a character set, and font
is the font to use for that character set. You can use this construct any number of
times in defining one fontset.
For the other character sets, Emacs chooses a font based on fontpattern. It
replaces ‘fontset-alias ’ with values that describe the character set. For the ASCII
character font, ‘fontset-alias ’ is replaced with ‘ISO8859-1’.
In addition, when several consecutive fields are wildcards, Emacs collapses them
into a single wildcard. This is to prevent use of auto-scaled fonts. Fonts made by
scaling larger fonts are not usable for editing, and scaling a smaller font is not also
useful, because it is better to use the smaller font in its own size, which is what
Emacs does.
Thus if fontpattern is this,
-*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24
the font specification for ASCII characters would be this:
-*-fixed-medium-r-normal-*-24-*-ISO8859-1
and the font specification for Chinese GB2312 characters would be this:
-*-fixed-medium-r-normal-*-24-*-gb2312*-*
You may not have any Chinese font matching the above font specification. Most
X distributions include only Chinese fonts that have ‘song ti’ or ‘fangsong ti’ in
the family field. In such a case, ‘Fontset-n ’ can be specified as:
Emacs.Fontset-0: -*-fixed-medium-r-normal-*-24-*-*-*-*-*-fontset-24,\
chinese-gb2312:-*-*-medium-r-normal-*-24-*-gb2312*-*

Then, the font specifications for all but Chinese GB2312 characters have ‘fixed’
in the family field, and the font specification for Chinese GB2312 characters has a
wild card ‘*’ in the family field.
The function that processes the fontset resource value to create the fontset is
called create-fontset-from-fontset-spec. You can also call this function explicitly to create a fontset.
See Section 18.8 [Fonts], page 171, for more information about font naming.

19.16 Modifying Fontsets
Fontsets do not always have to be created from scratch. If only minor changes are required it may be easier to modify an existing fontset. Modifying ‘fontset-default’
will also affect other fontsets that use it as a fallback, so can be an effective way of
fixing problems with the fonts that Emacs chooses for a particular script.
Fontsets can be modified using the function set-fontset-font, specifying a
character, a charset, a script, or a range of characters to modify the font for, and a
font specification for the font to be used. Some examples are:
;; Use Liberation Mono for latin-3 charset.
(set-fontset-font "fontset-default" ’iso-8859-3
"Liberation Mono")
;; Prefer a big5 font for han characters

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(set-fontset-font "fontset-default"
’han (font-spec :registry "big5")
nil ’prepend)
;; Use DejaVu Sans Mono as a fallback in fontset-startup
;; before resorting to fontset-default.
(set-fontset-font "fontset-startup" nil "DejaVu Sans Mono"
nil ’append)
;; Use MyPrivateFont for the Unicode private use area.
(set-fontset-font "fontset-default" ’(#xe000 . #xf8ff)
"MyPrivateFont")

19.17 Undisplayable Characters
There may be some non-ASCII characters that your terminal cannot display. Most
text terminals support just a single character set (use the variable defaultterminal-coding-system to tell Emacs which one, Section 19.13 [Terminal Coding], page 196); characters that can’t be encoded in that coding system are displayed
as ‘?’ by default.
Graphical displays can display a broader range of characters, but you may not
have fonts installed for all of them; characters that have no font appear as a hollow
box.
If you use Latin-1 characters but your terminal can’t display Latin-1, you can
arrange to display mnemonic ASCII sequences instead, e.g. ‘"o’ for o-umlaut. Load
the library ‘iso-ascii’ to do this.
If your terminal can display Latin-1, you can display characters from other
European character sets using a mixture of equivalent Latin-1 characters and ASCII
mnemonics. Customize the variable latin1-display to enable this. The mnemonic
ASCII sequences mostly correspond to those of the prefix input methods.

19.18 Unibyte Editing Mode
The ISO 8859 Latin-n character sets define character codes in the range 0240 to
0377 octal (160 to 255 decimal) to handle the accented letters and punctuation
needed by various European languages (and some non-European ones). Note that
Emacs considers bytes with codes in this range as raw bytes, not as characters,
even in a unibyte buffer, i.e. if you disable multibyte characters. However, Emacs
can still handle these character codes as if they belonged to one of the singlebyte character sets at a time. To specify which of these codes to use, invoke M-x
set-language-environment and specify a suitable language environment such as
‘Latin-n ’.
For more information about unibyte operation, see Section 19.2 [Disabling Multibyte], page 182.

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Emacs can also display bytes in the range 160 to 255 as readable characters,
provided the terminal or font in use supports them. This works automatically. On
a graphical display, Emacs can also display single-byte characters through fontsets,
in effect by displaying the equivalent multibyte characters according to the current
language environment. To request this, set the variable unibyte-display-vialanguage-environment to a non-nil value. Note that setting this only affects how
these bytes are displayed, but does not change the fundamental fact that Emacs
treats them as raw bytes, not as characters.
If your terminal does not support display of the Latin-1 character set, Emacs
can display these characters as ASCII sequences which at least give you a clear idea
of what the characters are. To do this, load the library iso-ascii. Similar libraries
for other Latin-n character sets could be implemented, but have not been so far.
Normally non-ISO-8859 characters (decimal codes between 128 and 159 inclusive) are displayed as octal escapes. You can change this for non-standard
“extended” versions of ISO-8859 character sets by using the function standarddisplay-8bit in the disp-table library.
There are two ways to input single-byte non-ASCII characters:
• You can use an input method for the selected language environment. See
Section 19.4 [Input Methods], page 185. When you use an input method in
a unibyte buffer, the non-ASCII character you specify with it is converted to
unibyte.
• If your keyboard can generate character codes 128 (decimal) and up, representing non-ASCII characters, you can type those character codes directly.
On a graphical display, you should not need to do anything special to use
these keys; they should simply work. On a text terminal, you should use
the command M-x set-keyboard-coding-system or customize the variable
keyboard-coding-system to specify which coding system your keyboard uses
(see Section 19.13 [Terminal Coding], page 196). Enabling this feature will
probably require you to use ESC to type Meta characters; however, on a console
terminal or in xterm, you can arrange for Meta to be converted to ESC and
still be able type 8-bit characters present directly on the keyboard or using
Compose or AltGr keys. See Section 2.1 [User Input], page 11.
• For Latin-1 only, you can use the key C-x 8 as a “compose character” prefix
for entry of non-ASCII Latin-1 printing characters. C-x 8 is good for insertion
(in the minibuffer as well as other buffers), for searching, and in any other
context where a key sequence is allowed.
C-x 8 works by loading the iso-transl library. Once that library is loaded,
the ALT modifier key, if the keyboard has one, serves the same purpose as C-x
8: use ALT together with an accent character to modify the following letter.
In addition, if the keyboard has keys for the Latin-1 “dead accent characters”,
they too are defined to compose with the following character, once iso-transl
is loaded.
Use C-x 8 C-h to list all the available C-x 8 translations.

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19.19 Charsets
In Emacs, charset is short for “character set”. Emacs supports most popular
charsets (such as ascii, iso-8859-1, cp1250, big5, and unicode), in addition
to some charsets of its own (such as emacs, unicode-bmp, and eight-bit). All
supported characters belong to one or more charsets.
Emacs normally “does the right thing” with respect to charsets, so that you
don’t have to worry about them. However, it is sometimes helpful to know some of
the underlying details about charsets.
One example is font selection (see Section 18.8 [Fonts], page 171). Each language environment (see Section 19.3 [Language Environments], page 183) defines
a “priority list” for the various charsets. When searching for a font, Emacs initially attempts to find one that can display the highest-priority charsets. For instance, in the Japanese language environment, the charset japanese-jisx0208
has the highest priority, so Emacs tries to use a font whose registry property is
‘JISX0208.1983-0’.
There are two commands that can be used to obtain information about
charsets.
The command M-x list-charset-chars prompts for a charset
name, and displays all the characters in that character set. The command M-x
describe-character-set prompts for a charset name, and displays information
about that charset, including its internal representation within Emacs.
M-x list-character-sets displays a list of all supported charsets. The list
gives the names of charsets and additional information to identity each charset; see
the International Register of Coded Character Sets for more details. In this list,
charsets are divided into two categories: normal charsets are listed first, followed
by supplementary charsets. A supplementary charset is one that is used to define
another charset (as a parent or a subset), or to provide backward-compatibility for
older Emacs versions.
To find out which charset a character in the buffer belongs to, put point before
it and type C-u C-x = (see Section 19.1 [International Chars], page 180).

19.20 Bidirectional Editing
Emacs supports editing text written in scripts, such as Arabic and Hebrew, whose
natural ordering of horizontal text for display is from right to left. However, digits
and Latin text embedded in these scripts are still displayed left to right. It is also
not uncommon to have small portions of text in Arabic or Hebrew embedded in an
otherwise Latin document; e.g., as comments and strings in a program source file.
For these reasons, text that uses these scripts is actually bidirectional: a mixture
of runs of left-to-right and right-to-left characters.
This section describes the facilities and options provided by Emacs for editing
bidirectional text.
Emacs stores right-to-left and bidirectional text in the so-called logical (or reading) order: the buffer or string position of the first character you read precedes that
of the next character. Reordering of bidirectional text into the visual order happens
at display time. As result, character positions no longer increase monotonically with

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their positions on display. Emacs implements the Unicode Bidirectional Algorithm
described in the Unicode Standard Annex #9, for reordering of bidirectional text
for display.
The buffer-local variable bidi-display-reordering controls whether text in
the buffer is reordered for display. If its value is non-nil, Emacs reorders characters
that have right-to-left directionality when they are displayed. The default value is
t.
Each paragraph of bidirectional text can have its own base direction, either rightto-left or left-to-right. (Paragraph boundaries are empty lines, i.e. lines consisting
entirely of whitespace characters.) Text in left-to-right paragraphs begins on the
screen at the left margin of the window and is truncated or continued when it
reaches the right margin. By contrast, text in right-to-left paragraphs is displayed
starting at the right margin and is continued or truncated at the left margin.
Emacs determines the base direction of each paragraph dynamically, based on
the text at the beginning of the paragraph. However, sometimes a buffer may need
to force a certain base direction for its paragraphs. The variable bidi-paragraphdirection, if non-nil, disables the dynamic determination of the base direction,
and instead forces all paragraphs in the buffer to have the direction specified by its
buffer-local value. The value can be either right-to-left or left-to-right. Any
other value is interpreted as nil.
Alternatively, you can control the base direction of a paragraph by inserting special formatting characters in front of the paragraph. The special character RIGHTTO-LEFT MARK, or rlm, forces the right-to-left direction on the following paragraph,
while LEFT-TO-RIGHT MARK, or lrm forces the left-to-right direction. (You can use
C-x 8 RET to insert these characters.) In a GUI session, the lrm and rlm characters
display as very thin blank characters; on text terminals they display as blanks.
Because characters are reordered for display, Emacs commands that operate in
the logical order or on stretches of buffer positions may produce unusual effects.
For example, C-f and C-b commands move point in the logical order, so the cursor
will sometimes jump when point traverses reordered bidirectional text. Similarly,
a highlighted region covering a contiguous range of character positions may look
discontinuous if the region spans reordered text. This is normal and similar to the
behavior of other programs that support bidirectional text.

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20 Major and Minor Modes
Emacs contains many editing modes that alter its basic behavior in useful ways.
These are divided into major modes and minor modes.
Major modes provide specialized facilities for working on a particular file type,
such as a C source file (see Chapter 23 [Programs], page 249), or a particular type
of non-file buffer, such as a shell buffer (see Section 31.3 [Shell], page 401). Major
modes are mutually exclusive; each buffer has one and only one major mode at any
time.
Minor modes are optional features which you can turn on or off, not necessarily
specific to a type of file or buffer. For example, Auto Fill mode is a minor mode in
which SPC breaks lines between words as you type (see Section 22.5.1 [Auto Fill],
page 218). Minor modes are independent of one another, and of the selected major
mode.

20.1 Major Modes
Every buffer possesses a major mode, which determines the editing behavior of
Emacs while that buffer is current. The mode line normally shows the name of the
current major mode, in parentheses (see Section 1.3 [Mode Line], page 8).
The least specialized major mode is called Fundamental mode. This mode has
no mode-specific redefinitions or variable settings, so that each Emacs command
behaves in its most general manner, and each user option variable is in its default
state.
For editing text of a specific type that Emacs knows about, such as Lisp code
or English text, you typically use a more specialized major mode, such as Lisp
mode or Text mode. Most major modes fall into three major groups. The first
group contains modes for normal text, either plain or with mark-up. It includes
Text mode, HTML mode, SGML mode, TEX mode and Outline mode. The second
group contains modes for specific programming languages. These include Lisp mode
(which has several variants), C mode, Fortran mode, and others. The third group
consists of major modes that are not associated directly with files; they are used
in buffers created for specific purposes by Emacs, such as Dired mode for buffers
made by Dired (see Chapter 27 [Dired], page 329), Message mode for buffers made
by C-x m (see Chapter 29 [Sending Mail], page 367), and Shell mode for buffers used
to communicate with an inferior shell process (see Section 31.3.2 [Interactive Shell],
page 403).
Usually, the major mode is automatically set by Emacs, when you first visit
a file or create a buffer (see Section 20.3 [Choosing Modes], page 207). You can
explicitly select a new major mode by using an M-x command. Take the name of
the mode and add -mode to get the name of the command to select that mode (e.g.,
M-x lisp-mode enters Lisp mode).
The value of the buffer-local variable major-mode is a symbol with the same
name as the major mode command (e.g. lisp-mode). This variable is set automatically; you should not change it yourself.

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The default value of major-mode determines the major mode to use for files that
do not specify a major mode, and for new buffers created with C-x b. Normally, this
default value is the symbol fundamental-mode, which specifies Fundamental mode.
You can change this default value via the Customization interface (see Section 33.1
[Easy Customization], page 434), or by adding a line like this to your init file (see
Section 33.4 [Init File], page 461):
(setq-default major-mode ’text-mode)
If the default value of major-mode is nil, the major mode is taken from the previously current buffer.
Specialized major modes often change the meanings of certain keys to do something more suitable for the mode. For instance, programming language modes bind
TAB to indent the current line according to the rules of the language (see Chapter 21
[Indentation], page 210). The keys that are commonly changed are TAB, DEL, and
C-j. Many modes also define special commands of their own, usually bound in
the prefix key C-c. Major modes can also alter user options and variables; for
instance, programming language modes typically set a buffer-local value for the
variable comment-start, which determines how source code comments are delimited (see Section 23.5 [Comments], page 258).
To view the documentation for the current major mode, including a list of its
key bindings, type C-h m (describe-mode).
Every major mode, apart from Fundamental mode, defines a mode hook, a customizable list of Lisp functions to run each time the mode is enabled in a buffer.
See Section 33.2.2 [Hooks], page 445, for more information about hooks. Each mode
hook is named after its major mode, e.g. Fortran mode has fortran-mode-hook.
Furthermore, all text-based major modes run text-mode-hook, and all programming language modes run prog-mode-hook, prior to running their own mode hooks.
Hook functions can look at the value of the variable major-mode to see which mode
is actually being entered.
Mode hooks are commonly used to enable minor modes (see Section 20.2 [Minor
Modes], page 205). For example, you can put the following lines in your init file
to enable Flyspell minor mode in all text-based major modes (see Section 13.4
[Spelling], page 112), and Eldoc minor mode in Emacs Lisp mode (see Section 23.6.3
[Lisp Doc], page 263):
(add-hook ’text-mode-hook ’flyspell-mode)
(add-hook ’emacs-lisp-mode-hook ’eldoc-mode)

20.2 Minor Modes
A minor mode is an optional editing mode that alters the behavior of Emacs in some
well-defined way. Unlike major modes, any number of minor modes can be in effect
at any time. Some minor modes are buffer-local, and can be turned on (enabled)
in certain buffers and off (disabled) in others. Other minor modes are global: while
enabled, they affect everything you do in the Emacs session, in all buffers. Most
minor modes are disabled by default, but a few are enabled by default.

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Most buffer-local minor modes say in the mode line when they are enabled, just
after the major mode indicator. For example, ‘Fill’ in the mode line means that
Auto Fill mode is enabled. See Section 1.3 [Mode Line], page 8.
Like major modes, each minor mode is associated with a mode command, whose
name consists of the mode name followed by ‘-mode’. For instance, the mode command for Auto Fill mode is auto-fill-mode. But unlike a major mode command,
which simply enables the mode, the mode command for a minor mode can either
enable or disable it:
• If you invoke the mode command directly with no prefix argument (either via
M-x, or by binding it to a key and typing that key; see Section 33.3 [Key
Bindings], page 452), that toggles the minor mode. The minor mode is turned
on if it was off, and turned off if it was on.
• If you invoke the mode command with a prefix argument, the minor mode is
unconditionally turned off if that argument is zero or negative; otherwise, it is
unconditionally turned on.
• If the mode command is called via Lisp, the minor mode is unconditionally
turned on if the argument is omitted or nil. This makes it easy to turn on a
minor mode from a major mode’s mode hook (see Section 20.1 [Major Modes],
page 204). A non-nil argument is handled like an interactive prefix argument,
as described above.
Most minor modes also have a mode variable, with the same name as the mode
command. Its value is non-nil if the mode is enabled, and nil if it is disabled. In
general, you should not try to enable or disable the mode by changing the value of
the mode variable directly in Lisp; you should run the mode command instead. However, setting the mode variable through the Customize interface (see Section 33.1
[Easy Customization], page 434) will always properly enable or disable the mode,
since Customize automatically runs the mode command for you.
The following is a list of some buffer-local minor modes:
• Abbrev mode automatically expands text based on pre-defined abbreviation
definitions. See Chapter 26 [Abbrevs], page 322.
• Auto Fill mode inserts newlines as you type to prevent lines from becoming
too long. See Section 22.5 [Filling], page 218.
• Auto Save mode saves the buffer contents periodically to reduce the amount
of work you can lose in case of a crash. See Section 15.5 [Auto Save], page 136.
• Enriched mode enables editing and saving of formatted text. See Section 22.13
[Enriched Text], page 237.
• Flyspell mode automatically highlights misspelled words. See Section 13.4
[Spelling], page 112.
• Font-Lock mode automatically highlights certain textual units found in programs. It is enabled globally by default, but you can disable it in individual
buffers. See Section 11.8 [Faces], page 75.
• Linum mode displays each line’s line number in the window’s left margin.

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• Outline minor mode provides similar facilities to the major mode called Outline
mode. See Section 22.8 [Outline Mode], page 224.
• Overwrite mode causes ordinary printing characters to replace existing text
instead of shoving it to the right. For example, if point is in front of the ‘B’ in
‘FOOBAR’, then in Overwrite mode typing a G changes it to ‘FOOGAR’, instead of
producing ‘FOOGBAR’ as usual. In Overwrite mode, the command C-q inserts
the next character whatever it may be, even if it is a digit—this gives you a
way to insert a character instead of replacing an existing character. The mode
command, overwrite-mode, is bound to the INSERT key.
• Binary Overwrite mode is a variant of Overwrite mode for editing binary files;
it treats newlines and tabs like other characters, so that they overwrite other
characters and can be overwritten by them. In Binary Overwrite mode, digits
after C-q specify an octal character code, as usual.
• Visual Line mode performs “word wrapping”, causing long lines to be wrapped
at word boundaries. See Section 11.22 [Visual Line Mode], page 89.
And here are some useful global minor modes:
• Column Number mode enables display of the current column number in the
mode line. See Section 1.3 [Mode Line], page 8.
• Delete Selection mode causes text insertion to first delete the text in the region,
if the region is active. See Section 8.3 [Using Region], page 50.
• Icomplete mode displays an indication of available completions when you are
in the minibuffer and completion is active. See Section 5.3.5 [Completion
Options], page 33.
• Line Number mode enables display of the current line number in the mode
line. It is enabled by default. See Section 1.3 [Mode Line], page 8.
• Menu Bar mode gives each frame a menu bar. It is enabled by default. See
Section 18.14 [Menu Bars], page 176.
• Scroll Bar mode gives each window a scroll bar. It is enabled by default, but
the scroll bar is only displayed on graphical terminals. See Section 18.12 [Scroll
Bars], page 176.
• Tool Bar mode gives each frame a tool bar. It is enabled by default, but the
tool bar is only displayed on graphical terminals. See Section 18.15 [Tool Bars],
page 177.
• Transient Mark mode highlights the region, and makes many Emacs commands
operate on the region when the mark is active. It is enabled by default. See
Chapter 8 [Mark], page 47.

20.3 Choosing File Modes
When you visit a file, Emacs chooses a major mode automatically. Normally, it
makes the choice based on the file name—for example, files whose names end in ‘.c’
are normally edited in C mode—but sometimes it chooses the major mode based
on special text in the file. This special text can also be used to enable buffer-local
minor modes.

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Here is the exact procedure:
First, Emacs checks whether the file contains file-local mode variables. See
Section 33.2.4 [File Variables], page 447. If there is a file-local variable that specifies
a major mode, then Emacs uses that major mode, ignoring all other criteria. There
are several methods to specify a major mode using a file-local variable; the simplest
is to put the mode name in the first nonblank line, preceded and followed by ‘-*-’.
Other text may appear on the line as well. For example,
; -*-Lisp-*tells Emacs to use Lisp mode. Note how the semicolon is used to make Lisp treat
this line as a comment. You could equivalently write
; -*- mode: Lisp;-*You can also use file-local variables to specify buffer-local minor modes, by using
eval specifications. For example, this first nonblank line puts the buffer in Lisp
mode and enables Auto-Fill mode:
; -*- mode: Lisp; eval: (auto-fill-mode 1); -*Note, however, that it is usually inappropriate to enable minor modes this way,
since most minor modes represent individual user preferences. If you personally
want to use a minor mode for a particular file type, it is better to enable the minor
mode via a major mode hook (see Section 20.1 [Major Modes], page 204).
Second, if there is no file variable specifying a major mode, Emacs checks
whether the file’s contents begin with ‘#!’. If so, that indicates that the file can serve
as an executable shell command, which works by running an interpreter named on
the file’s first line (the rest of the file is used as input to the interpreter). Therefore,
Emacs tries to use the interpreter name to choose a mode. For instance, a file that
begins with ‘#!/usr/bin/perl’ is opened in Perl mode. The variable interpretermode-alist specifies the correspondence between interpreter program names and
major modes.
When the first line starts with ‘#!’, you usually cannot use the ‘-*-’ feature on
the first line, because the system would get confused when running the interpreter.
So Emacs looks for ‘-*-’ on the second line in such files as well as on the first line.
The same is true for man pages which start with the magic string ‘’\"’ to specify
a list of troff preprocessors.
Third, Emacs tries to determine the major mode by looking at the text at
the start of the buffer, based on the variable magic-mode-alist. By default, this
variable is nil (an empty list), so Emacs skips this step; however, you can customize
it in your init file (see Section 33.4 [Init File], page 461). The value should be a list
of elements of the form
(regexp . mode-function )
where regexp is a regular expression (see Section 12.5 [Regexps], page 97), and
mode-function is a major mode command. If the text at the beginning of the file
matches regexp, Emacs chooses the major mode specified by mode-function.
Alternatively, an element of magic-mode-alist may have the form
(match-function . mode-function )

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where match-function is a Lisp function that is called at the beginning of the buffer;
if the function returns non-nil, Emacs set the major mode with mode-function.
Fourth—if Emacs still hasn’t found a suitable major mode—it looks at the file’s
name. The correspondence between file names and major modes is controlled by
the variable auto-mode-alist. Its value is a list in which each element has this
form,
(regexp . mode-function )
or this form,
(regexp mode-function flag )
For example, one element normally found in the list has the form ("\\.c\\’" .
c-mode), and it is responsible for selecting C mode for files whose names end in
‘.c’. (Note that ‘\\’ is needed in Lisp syntax to include a ‘\’ in the string, which
must be used to suppress the special meaning of ‘.’ in regexps.) If the element has
the form (regexp mode-function flag ) and flag is non-nil, then after calling
mode-function, Emacs discards the suffix that matched regexp and searches the list
again for another match.
On GNU/Linux and other systems with case-sensitive file names, Emacs performs a case-sensitive search through auto-mode-alist; if this search fails, it performs a second case-insensitive search through the alist. To suppress the second
search, change the variable auto-mode-case-fold to nil. On systems with caseinsensitive file names, such as Microsoft Windows, Emacs performs a single caseinsensitive search through auto-mode-alist.
Finally, if Emacs still hasn’t found a major mode to use, it compares the text at
the start of the buffer to the variable magic-fallback-mode-alist. This variable
works like magic-mode-alist, described above, except that is consulted only after
auto-mode-alist. By default, magic-fallback-mode-alist contains forms that
check for image files, HTML/XML/SGML files, and PostScript files.
If you have changed the major mode of a buffer, you can return to the major
mode Emacs would have chosen automatically, by typing M-x normal-mode. This is
the same function that find-file calls to choose the major mode. It also processes
the file’s ‘-*-’ line or local variables list (if any). See Section 33.2.4 [File Variables],
page 447.
The commands C-x C-w and set-visited-file-name change to a new major
mode if the new file name implies a mode (see Section 15.3 [Saving], page 128). (C-x
C-s does this too, if the buffer wasn’t visiting a file.) However, this does not happen
if the buffer contents specify a major mode, and certain “special” major modes do
not allow the mode to change. You can turn off this mode-changing feature by
setting change-major-mode-with-file-name to nil.

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21 Indentation
Indentation refers to inserting or adjusting whitespace characters (space and/or tab
characters) at the beginning of a line of text. This chapter documents indentation
commands and options which are common to Text mode and related modes, as well
as programming language modes. See Section 23.3 [Program Indent], page 252, for
additional documentation about indenting in programming modes.
The simplest way to perform indentation is the TAB key. In most major modes,
this runs the command indent-for-tab-command. (In C and related modes, TAB
runs the command c-indent-line-or-region, which behaves similarly).
TAB

Insert whitespace, or indent the current line, in a mode-appropriate
way (indent-for-tab-command). If the region is active, indent all the
lines within it.

The exact behavior of TAB depends on the major mode. In Text mode and
related major modes, TAB normally inserts some combination of space and tab
characters to advance point to the next tab stop (see Section 21.2 [Tab Stops],
page 211). For this purpose, the position of the first non-whitespace character on
the preceding line is treated as an additional tab stop, so you can use TAB to
“align” point with the preceding line. If the region is active (see Section 8.3 [Using
Region], page 50), TAB acts specially: it indents each line in the region so that its
first non-whitespace character is aligned with the preceding line.
In programming modes, TAB indents the current line of code in a way that
makes sense given the code in the preceding lines. If the region is active, all the
lines in the region are indented this way. If point was initially within the current
line’s indentation, it is repositioned to the first non-whitespace character on the
line.
If you just want to insert a tab character in the buffer, type C-q TAB (see
Section 4.1 [Inserting Text], page 17).

21.1 Indentation Commands
Apart from the TAB (indent-for-tab-command) command, Emacs provides a variety of commands to perform indentation in other ways.
C-j

Perform RET followed by TAB (newline-and-indent).

C-M-o

Split the current line at point (split-line). The text on the line after
point becomes a new line, indented to the same column where point
is located. This command first moves point forward over any spaces
and tabs. Afterward, point is positioned before the inserted newline.

M-m

Move (forward or back) to the first non-whitespace character on the
current line (back-to-indentation). If there are no non-whitespace
characters on the line, move to the end of the line.

M-i

Indent whitespace at point, up to the next tab stop (tab-to-tabstop). See Section 21.2 [Tab Stops], page 211.

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M-x indent-relative
Insert whitespace at point, until point is aligned with the first nonwhitespace character on the previous line (actually, the last non-blank
line). If point is already farther right than that, run tab-to-tabstop instead—unless called with a numeric argument, in which case
do nothing.
M-^

Merge the previous and the current line (delete-indentation). This
“joins” the two lines cleanly, by replacing any indentation at the front
of the current line, together with the line boundary, with a single
space.
As a special case (useful for Lisp code), the single space is omitted if
the characters to be joined are consecutive opening and closing parentheses, or if the junction follows another newline.
If there is a fill prefix, M-^ deletes the fill prefix if it appears after the
newline that is deleted. See Section 22.5.3 [Fill Prefix], page 220.

C-M-\

Indent all the lines in the region, as though you had typed TAB at the
beginning of each line (indent-region).
If a numeric argument is supplied, indent every line in the region to
that column number.

C-x TAB

Shift each line in the region by a fixed distance, to the right or left
(indent-rigidly). The distance to move is determined by the numeric argument (positive to move rightward, negative to move leftward).
This command can be used to remove all indentation from the lines
in the region, by invoking it with a large negative argument, e.g. C-u
-1000 C-x TAB.

21.2 Tab Stops
Emacs defines certain column numbers to be tab stops. These are used as stopping
points by TAB when inserting whitespace in Text mode and related modes (see
Chapter 21 [Indentation], page 210), and by commands like M-i (see Section 21.1
[Indentation Commands], page 210). By default, tab stops are located every 8
columns. These positions are stored in the variable tab-stop-list, whose value is
a list of column numbers in increasing order.
Instead of customizing the variable tab-stop-list directly, a convenient way
to view and set tab stops is via the command M-x edit-tab-stops. This switches
to a buffer containing a description of the tab stop settings, which looks like this:
:
:
:
:
:
:
0
1
2
3
4
0123456789012345678901234567890123456789012345678
To install changes, type C-c C-c
The first line contains a colon at each tab stop. The numbers on the next two lines
are present just to indicate where the colons are.

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You can edit this buffer to specify different tab stops by placing colons on the
desired columns. The buffer uses Overwrite mode (see Section 20.2 [Minor Modes],
page 205). When you are done, type C-c C-c to make the new tab stops take
effect. Normally, the new tab stop settings apply to all buffers. However, if you
have made the tab-stop-list variable local to the buffer where you called M-x
edit-tab-stops (see Section 33.2.3 [Locals], page 446), then the new tab stop settings apply only to that buffer. To save the tab stop settings for future Emacs
sessions, use the Customize interface to save the value of tab-stop-list (see
Section 33.1 [Easy Customization], page 434).
Note that the tab stops discussed in this section have nothing to do with how
tab characters are displayed in the buffer. Tab characters are always displayed
as empty spaces extending to the next display tab stop. See Section 11.19 [Text
Display], page 87.

21.3 Tabs vs. Spaces
Normally, indentation commands insert (or remove) an optimal mix of space characters and tab characters to align to the desired column. Tab characters are displayed
as a stretch of empty space extending to the next display tab stop. By default, there
is one display tab stop every tab-width columns (the default is 8). See Section 11.19
[Text Display], page 87.
If you prefer, all indentation can be made from spaces only. To request this,
set the buffer-local variable indent-tabs-mode to nil. See Section 33.2.3 [Locals],
page 446, for information about setting buffer-local variables. Note, however, that
C-q TAB always inserts a tab character, regardless of the value of indent-tabsmode.
One reason to set indent-tabs-mode to nil is that not all editors display tab
characters in the same way. Emacs users, too, may have different customized values
of tab-width. By using spaces only, you can make sure that your file always
looks the same. If you only care about how it looks within Emacs, another way
to tackle this problem is to set the tab-width variable in a file-local variable (see
Section 33.2.4 [File Variables], page 447).
There are also commands to convert tabs to spaces or vice versa, always preserving the columns of all non-whitespace text. M-x tabify scans the region for
sequences of spaces, and converts sequences of at least two spaces to tabs if that
can be done without changing indentation. M-x untabify changes all tabs in the
region to appropriate numbers of spaces.

21.4 Convenience Features for Indentation
The variable tab-always-indent tweaks the behavior of the TAB (indent-fortab-command) command. The default value, t, gives the behavior described in
Chapter 21 [Indentation], page 210. If you change the value to the symbol complete,
then TAB first tries to indent the current line, and if the line was already indented, it
tries to complete the text at point (see Section 23.8 [Symbol Completion], page 264).

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If the value is nil, then TAB indents the current line only if point is at the left
margin or in the line’s indentation; otherwise, it inserts a tab character.
Electric Indent mode is a global minor mode that automatically indents
the line after every RET you type. To toggle this minor mode, type M-x
electric-indent-mode.

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22 Commands for Human Languages
This chapter describes Emacs commands that act on text, by which we mean sequences of characters in a human language (as opposed to, say, a computer programming language). These commands act in ways that take into account the syntactic
and stylistic conventions of human languages: conventions involving words, sentences, paragraphs, and capital letters. There are also commands for filling, which
means rearranging the lines of a paragraph to be approximately equal in length.
These commands, while intended primarily for editing text, are also often useful for
editing programs.
Emacs has several major modes for editing human-language text. If the file
contains ordinary text, use Text mode, which customizes Emacs in small ways for
the syntactic conventions of text. Outline mode provides special commands for
operating on text with an outline structure. Org mode extends Outline mode and
turn Emacs into a full-fledged organizer: you can manage TODO lists, store notes
and publish them in many formats.
See Section 22.8 [Outline Mode], page 224.
Emacs has other major modes for text which contains “embedded” commands,
such as TEX and LaTEX (see Section 22.10 [TeX Mode], page 231); HTML and
SGML (see Section 22.11 [HTML Mode], page 236); XML (see the nXML mode Info
manual, which is distributed with Emacs); and Groff and Nroff (see Section 22.12
[Nroff Mode], page 237).
If you need to edit pictures made out of text characters (commonly referred to
as “ASCII art”), use Picture mode, a special major mode for editing such pictures.
See Section “Picture Mode” in Specialized Emacs Features.

22.1 Words
Emacs defines several commands for moving over or operating on words:
M-f

Move forward over a word (forward-word).

M-b

Move backward over a word (backward-word).

M-d

Kill up to the end of a word (kill-word).

M-DEL

Kill back to the beginning of a word (backward-kill-word).

M-@

Mark the end of the next word (mark-word).

M-t

Transpose two words or drag a word across others (transpose-words).

Notice how these keys form a series that parallels the character-based C-f, C-b,
C-d, DEL and C-t. M-@ is cognate to C-@, which is an alias for C-SPC.
The commands M-f (forward-word) and M-b (backward-word) move forward
and backward over words. These META-based key sequences are analogous to the
key sequences C-f and C-b, which move over single characters. The analogy extends
to numeric arguments, which serve as repeat counts. M-f with a negative argument
moves backward, and M-b with a negative argument moves forward. Forward motion

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stops right after the last letter of the word, while backward motion stops right before
the first letter.
M-d (kill-word) kills the word after point. To be precise, it kills everything
from point to the place M-f would move to. Thus, if point is in the middle of a
word, M-d kills just the part after point. If some punctuation comes between point
and the next word, it is killed along with the word. (If you wish to kill only the
next word but not the punctuation before it, simply do M-f to get the end, and kill
the word backwards with M-DEL.) M-d takes arguments just like M-f.
M-DEL (backward-kill-word) kills the word before point. It kills everything
from point back to where M-b would move to. For instance, if point is after the
space in ‘FOO, BAR’, it kills ‘FOO, ’. If you wish to kill just ‘FOO’, and not the comma
and the space, use M-b M-d instead of M-DEL.
M-t (transpose-words) exchanges the word before or containing point with
the following word. The delimiter characters between the words do not move.
For example, ‘FOO, BAR’ transposes into ‘BAR, FOO’ rather than ‘BAR FOO,’. See
Section 13.2 [Transpose], page 111, for more on transposition.
To operate on words with an operation which acts on the region, use the command M-@ (mark-word). This command sets the mark where M-f would move to.
See Section 8.2 [Marking Objects], page 49, for more information about this command.
The word commands’ understanding of word boundaries is controlled by the
syntax table. Any character can, for example, be declared to be a word delimiter.
See Section “Syntax Tables” in The Emacs Lisp Reference Manual.
In addition, see Section 4.9 [Position Info], page 23 for the M-= (count-wordsregion) and M-x count-words commands, which count and report the number of
words in the region or buffer.

22.2 Sentences
The Emacs commands for manipulating sentences and paragraphs are mostly on
Meta keys, like the word-handling commands.
M-a

Move back to the beginning of the sentence (backward-sentence).

M-e

Move forward to the end of the sentence (forward-sentence).

M-k

Kill forward to the end of the sentence (kill-sentence).

C-x DEL

Kill back to the beginning of the sentence (backward-killsentence).

The commands M-a (backward-sentence) and M-e (forward-sentence) move
to the beginning and end of the current sentence, respectively. Their bindings were
chosen to resemble C-a and C-e, which move to the beginning and end of a line.
Unlike them, M-a and M-e move over successive sentences if repeated.
Moving backward over a sentence places point just before the first character of
the sentence; moving forward places point right after the punctuation that ends the
sentence. Neither one moves over the whitespace at the sentence boundary.

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Just as C-a and C-e have a kill command, C-k, to go with them, M-a and
M-e have a corresponding kill command: M-k (kill-sentence) kills from point to
the end of the sentence. With a positive numeric argument n, it kills the next n
sentences; with a negative argument −n, it kills back to the beginning of the nth
preceding sentence.
The C-x DEL (backward-kill-sentence) kills back to the beginning of a sentence.
The sentence commands assume that you follow the American typist’s convention of putting two spaces at the end of a sentence. That is, a sentence ends wherever
there is a ‘.’, ‘?’ or ‘!’ followed by the end of a line or two spaces, with any number
of ‘)’, ‘]’, ‘’’, or ‘"’ characters allowed in between. A sentence also begins or ends
wherever a paragraph begins or ends. It is useful to follow this convention, because
it allows the Emacs sentence commands to distinguish between periods that end a
sentence and periods that indicate abbreviations.
If you want to use just one space between sentences, you can set the variable
sentence-end-double-space to nil to make the sentence commands stop for single
spaces. However, this has a drawback: there is no way to distinguish between
periods that end sentences and those that indicate abbreviations. For convenient
and reliable editing, we therefore recommend you follow the two-space convention.
The variable sentence-end-double-space also affects filling (see Section 22.5.2
[Fill Commands], page 219).
The variable sentence-end controls how to recognize the end of a sentence. If
non-nil, its value should be a regular expression, which is used to match the last
few characters of a sentence, together with the whitespace following the sentence
(see Section 12.5 [Regexps], page 97). If the value is nil, the default, then Emacs
computes sentence ends according to various criteria such as the value of sentenceend-double-space.
Some languages, such as Thai, do not use periods to indicate the end of a
sentence. Set the variable sentence-end-without-period to t in such cases.

22.3 Paragraphs
The Emacs commands for manipulating paragraphs are also on Meta keys.
M-{

Move back to previous paragraph beginning (backward-paragraph).

M-}

Move forward to next paragraph end (forward-paragraph).

M-h

Put point and mark around this or next paragraph (mark-paragraph).

M-{ (backward-paragraph) moves to the beginning of the current or previous
paragraph (see below for the definition of a paragraph). M-} (forward-paragraph)
moves to the end of the current or next paragraph. If there is a blank line before
the paragraph, M-{ moves to the blank line.
When you wish to operate on a paragraph, type M-h (mark-paragraph) to set
the region around it. For example, M-h C-w kills the paragraph around or after
point. M-h puts point at the beginning and mark at the end of the paragraph point
was in. If point is between paragraphs (in a run of blank lines, or at a boundary),

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M-h sets the region around the paragraph following point. If there are blank lines
preceding the first line of the paragraph, one of these blank lines is included in the
region. If the region is already active, the command sets the mark without changing
point, and each subsequent M-h further advances the mark by one paragraph.
The definition of a paragraph depends on the major mode. In Fundamental
mode, as well as Text mode and related modes, a paragraph is separated each
neighboring paragraph another by one or more blank lines—lines that are either
empty, or consist solely of space, tab and/or formfeed characters. In programming
language modes, paragraphs are usually defined in a similar way, so that you can
use the paragraph commands even though there are no paragraphs as such in a
program.
Note that an indented line is not itself a paragraph break in Text mode. If
you want indented lines to separate paragraphs, use Paragraph-Indent Text mode
instead. See Section 22.7 [Text Mode], page 223.
If you set a fill prefix, then paragraphs are delimited by all lines which don’t
start with the fill prefix. See Section 22.5 [Filling], page 218.
The precise definition of a paragraph boundary is controlled by the variables
paragraph-separate and paragraph-start. The value of paragraph-start is
a regular expression that should match lines that either start or separate paragraphs (see Section 12.5 [Regexps], page 97). The value of paragraph-separate is
another regular expression that should match lines that separate paragraphs without being part of any paragraph (for example, blank lines). Lines that start a
new paragraph and are contained in it must match only paragraph-start, not
paragraph-separate. For example, in Fundamental mode, paragraph-start is
"\f\\|[ \t]*$", and paragraph-separate is "[ \t\f]*$".

22.4 Pages
Within some text files, text is divided into pages delimited by the formfeed character
(ASCII code 12, also denoted as CONTROL-L), which is displayed in Emacs as the
escape sequence ‘^L’ (see Section 11.19 [Text Display], page 87). Traditionally, when
such text files are printed to hardcopy, each formfeed character forces a page break.
Most Emacs commands treat it just like any other character, so you can insert it
with C-q C-l, delete it with DEL, etc. In addition, Emacs provides commands to
move over pages and operate on them.
M-x what-page
Display the page number of point, and the line number within that
page.
C-x [

Move point to previous page boundary (backward-page).

C-x ]

Move point to next page boundary (forward-page).

C-x C-p

Put point and mark around this page (or another page) (mark-page).

C-x l

Count the lines in this page (count-lines-page).

M-x what-page counts pages from the beginning of the file, and counts lines
within the page, showing both numbers in the echo area.

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The C-x [ (backward-page) command moves point to immediately after the
previous page delimiter. If point is already right after a page delimiter, it skips that
one and stops at the previous one. A numeric argument serves as a repeat count.
The C-x ] (forward-page) command moves forward past the next page delimiter.
The C-x C-p command (mark-page) puts point at the beginning of the current
page (after that page delimiter at the front), and the mark at the end of the page
(after the page delimiter at the end).
C-x C-p C-w is a handy way to kill a page to move it elsewhere. If you move
to another page delimiter with C-x [ and C-x ], then yank the killed page, all the
pages will be properly delimited once again. The reason C-x C-p includes only the
following page delimiter in the region is to ensure that.
A numeric argument to C-x C-p specifies which page to go to, relative to the
current one. Zero means the current page, one the next page, and −1 the previous
one.
The C-x l command (count-lines-page) is good for deciding where to break a
page in two. It displays in the echo area the total number of lines in the current page,
and then divides it up into those preceding the current line and those following, as
in
Page has 96 (72+25) lines
Notice that the sum is off by one; this is correct if point is not at the beginning of
a line.
The variable page-delimiter controls where pages begin. Its value is a regular
expression that matches the beginning of a line that separates pages (see Section 12.5
[Regexps], page 97). The normal value of this variable is "^\f", which matches a
formfeed character at the beginning of a line.

22.5 Filling Text
Filling text means breaking it up into lines that fit a specified width. Emacs does
filling in two ways. In Auto Fill mode, inserting text with self-inserting characters
also automatically fills it. There are also explicit fill commands that you can use
when editing text.
22.5.1 Auto Fill Mode
Auto Fill mode is a buffer-local minor mode (see Section 20.2 [Minor Modes],
page 205) in which lines are broken automatically when they become too wide.
Breaking happens only when you type a SPC or RET.
M-x auto-fill-mode
Enable or disable Auto Fill mode.
SPC
RET

In Auto Fill mode, break lines when appropriate.

The mode command M-x auto-fill-mode toggles Auto Fill mode in the current
buffer. With a positive numeric argument, it enables Auto Fill mode, and with a
negative argument it disables it. If auto-fill-mode is called from Lisp with an

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omitted or nil argument, it enables Auto Fill mode. To enable Auto Fill mode
automatically in certain major modes, add auto-fill-mode to the mode hooks
(see Section 20.1 [Major Modes], page 204). When Auto Fill mode is enabled,
the mode indicator ‘Fill’ appears in the mode line (see Section 1.3 [Mode Line],
page 8).
Auto Fill mode breaks lines automatically at spaces whenever they get longer
than the desired width. This line breaking occurs only when you type SPC or RET.
If you wish to insert a space or newline without permitting line-breaking, type C-q
SPC or C-q C-j respectively. Also, C-o inserts a newline without line breaking.
When Auto Fill mode breaks a line, it tries to obey the adaptive fill prefix: if a fill
prefix can be deduced from the first and/or second line of the current paragraph, it is
inserted into the new line (see Section 22.5.4 [Adaptive Fill], page 222). Otherwise
the new line is indented, as though you had typed TAB on it (see Chapter 21
[Indentation], page 210). In a programming language mode, if a line is broken in
the middle of a comment, the comment is split by inserting new comment delimiters
as appropriate.
Auto Fill mode does not refill entire paragraphs; it breaks lines but does not
merge lines. Therefore, editing in the middle of a paragraph can result in a paragraph that is not correctly filled. To fill it, call the explicit fill commands described
in the next section.
22.5.2 Explicit Fill Commands
M-q

Fill current paragraph (fill-paragraph).

C-x f

Set the fill column (set-fill-column).

M-x fill-region
Fill each paragraph in the region (fill-region).
M-x fill-region-as-paragraph
Fill the region, considering it as one paragraph.
M-o M-s

Center a line.

The command M-q (fill-paragraph) fills the current paragraph. It redistributes the line breaks within the paragraph, and deletes any excess space and
tab characters occurring within the paragraph, in such a way that the lines end up
fitting within a certain maximum width.
Normally, M-q acts on the paragraph where point is, but if point is between
paragraphs, it acts on the paragraph after point. If the region is active, it acts
instead on the text in the region. You can also call M-x fill-region to specifically
fill the text in the region.
M-q and fill-region use the usual Emacs criteria for finding paragraph boundaries (see Section 22.3 [Paragraphs], page 216). For more control, you can use M-x
fill-region-as-paragraph, which refills everything between point and mark as
a single paragraph. This command deletes any blank lines within the region, so
separate blocks of text end up combined into one block.

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A numeric argument to M-q tells it to justify the text as well as filling it. This
means that extra spaces are inserted to make the right margin line up exactly at
the fill column. To remove the extra spaces, use M-q with no argument. (Likewise
for fill-region.)
The maximum line width for filling is specified by the buffer-local variable fillcolumn. The default value (see Section 33.2.3 [Locals], page 446) is 70. The easiest
way to set fill-column in the current buffer is to use the command C-x f (setfill-column). With a numeric argument, it uses that as the new fill column. With
just C-u as argument, it sets fill-column to the current horizontal position of
point.
The command M-o M-s (center-line) centers the current line within the current fill column. With an argument n, it centers n lines individually and moves past
them. This binding is made by Text mode and is available only in that and related
modes (see Section 22.7 [Text Mode], page 223).
By default, Emacs considers a period followed by two spaces or by a newline as
the end of a sentence; a period followed by just one space indicates an abbreviation,
not the end of a sentence. Accordingly, the fill commands will not break a line
after a period followed by just one space. If you set the variable sentence-enddouble-space to nil, the fill commands will break a line after a period followed by
one space, and put just one space after each period. See Section 22.2 [Sentences],
page 215, for other effects and possible drawbacks of this.
If the variable colon-double-space is non-nil, the fill commands put two spaces after a colon.
To specify additional conditions where line-breaking is not allowed, customize
the abnormal hook variable fill-nobreak-predicate (see Section 33.2.2 [Hooks],
page 445). Each function in this hook is called with no arguments, with point
positioned where Emacs is considering breaking a line. If a function returns a nonnil value, Emacs will not break the line there. Two functions you can use are
fill-single-word-nobreak-p (don’t break after the first word of a sentence or
before the last) and fill-french-nobreak-p (don’t break after ‘(’ or before ‘)’,
‘:’ or ‘?’).
22.5.3 The Fill Prefix
The fill prefix feature allows paragraphs to be filled so that each line starts with
a special string of characters (such as a sequence of spaces, giving an indented
paragraph). You can specify a fill prefix explicitly; otherwise, Emacs tries to deduce
one automatically (see Section 22.5.4 [Adaptive Fill], page 222).
C-x .

Set the fill prefix (set-fill-prefix).

M-q

Fill a paragraph using current fill prefix (fill-paragraph).

M-x fill-individual-paragraphs
Fill the region, considering each change of indentation as starting a
new paragraph.

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M-x fill-nonuniform-paragraphs
Fill the region, considering only paragraph-separator lines as starting
a new paragraph.
To specify a fill prefix for the current buffer, move to a line that starts with
the desired prefix, put point at the end of the prefix, and type C-x . (set-fillprefix). (That’s a period after the C-x.) To turn off the fill prefix, specify an
empty prefix: type C-x . with point at the beginning of a line.
When a fill prefix is in effect, the fill commands remove the fill prefix from each
line of the paragraph before filling, and insert it on each line after filling. (The
beginning of the first line of the paragraph is left unchanged, since often that is intentionally different.) Auto Fill mode also inserts the fill prefix automatically when
it makes a new line (see Section 22.5.1 [Auto Fill], page 218). The C-o command inserts the fill prefix on new lines it creates, when you use it at the beginning of a line
(see Section 4.7 [Blank Lines], page 22). Conversely, the command M-^ deletes the
prefix (if it occurs) after the newline that it deletes (see Chapter 21 [Indentation],
page 210).
For example, if fill-column is 40 and you set the fill prefix to ‘;; ’, then M-q
in the following text
;; This is an
;; example of a paragraph
;; inside a Lisp-style comment.
produces this:
;; This is an example of a paragraph
;; inside a Lisp-style comment.
Lines that do not start with the fill prefix are considered to start paragraphs,
both in M-q and the paragraph commands; this gives good results for paragraphs
with hanging indentation (every line indented except the first one). Lines which
are blank or indented once the prefix is removed also separate or start paragraphs;
this is what you want if you are writing multi-paragraph comments with a comment
delimiter on each line.
You can use M-x fill-individual-paragraphs to set the fill prefix for each
paragraph automatically. This command divides the region into paragraphs, treating every change in the amount of indentation as the start of a new paragraph, and
fills each of these paragraphs. Thus, all the lines in one “paragraph” have the same
amount of indentation. That indentation serves as the fill prefix for that paragraph.
M-x fill-nonuniform-paragraphs is a similar command that divides the region
into paragraphs in a different way. It considers only paragraph-separating lines (as
defined by paragraph-separate) as starting a new paragraph. Since this means
that the lines of one paragraph may have different amounts of indentation, the fill
prefix used is the smallest amount of indentation of any of the lines of the paragraph.
This gives good results with styles that indent a paragraph’s first line more or less
that the rest of the paragraph.
The fill prefix is stored in the variable fill-prefix. Its value is a string, or
nil when there is no fill prefix. This is a per-buffer variable; altering the variable

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affects only the current buffer, but there is a default value which you can change as
well. See Section 33.2.3 [Locals], page 446.
The indentation text property provides another way to control the amount
of indentation paragraphs receive. See Section 22.13.5 [Enriched Indentation],
page 240.
22.5.4 Adaptive Filling
The fill commands can deduce the proper fill prefix for a paragraph automatically in
certain cases: either whitespace or certain punctuation characters at the beginning
of a line are propagated to all lines of the paragraph.
If the paragraph has two or more lines, the fill prefix is taken from the paragraph’s second line, but only if it appears on the first line as well.
If a paragraph has just one line, fill commands may take a prefix from that line.
The decision is complicated because there are three reasonable things to do in such
a case:
• Use the first line’s prefix on all the lines of the paragraph.
• Indent subsequent lines with whitespace, so that they line up under the text
that follows the prefix on the first line, but don’t actually copy the prefix from
the first line.
• Don’t do anything special with the second and following lines.
All three of these styles of formatting are commonly used. So the fill commands
try to determine what you would like, based on the prefix that appears and on the
major mode. Here is how.
If the prefix found on the first line matches adaptive-fill-first-lineregexp, or if it appears to be a comment-starting sequence (this depends on the
major mode), then the prefix found is used for filling the paragraph, provided it
would not act as a paragraph starter on subsequent lines.
Otherwise, the prefix found is converted to an equivalent number of spaces, and
those spaces are used as the fill prefix for the rest of the lines, provided they would
not act as a paragraph starter on subsequent lines.
In Text mode, and other modes where only blank lines and page delimiters
separate paragraphs, the prefix chosen by adaptive filling never acts as a paragraph
starter, so it can always be used for filling.
The variable adaptive-fill-regexp determines what kinds of line beginnings
can serve as a fill prefix: any characters at the start of the line that match this
regular expression are used. If you set the variable adaptive-fill-mode to nil,
the fill prefix is never chosen automatically.
You can specify more complex ways of choosing a fill prefix automatically by
setting the variable adaptive-fill-function to a function. This function is called
with point after the left margin of a line, and it should return the appropriate fill
prefix based on that line. If it returns nil, adaptive-fill-regexp gets a chance
to find a prefix.

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22.6 Case Conversion Commands
Emacs has commands for converting either a single word or any arbitrary range of
text to upper case or to lower case.
M-l

Convert following word to lower case (downcase-word).

M-u

Convert following word to upper case (upcase-word).

M-c

Capitalize the following word (capitalize-word).

C-x C-l

Convert region to lower case (downcase-region).

C-x C-u

Convert region to upper case (upcase-region).

M-l (downcase-word) converts the word after point to lower case, moving past
it. Thus, repeating M-l converts successive words. M-u (upcase-word) converts to
all capitals instead, while M-c (capitalize-word) puts the first letter of the word
into upper case and the rest into lower case. All these commands convert several
words at once if given an argument. They are especially convenient for converting
a large amount of text from all upper case to mixed case, because you can move
through the text using M-l, M-u or M-c on each word as appropriate, occasionally
using M-f instead to skip a word.
When given a negative argument, the word case conversion commands apply
to the appropriate number of words before point, but do not move point. This is
convenient when you have just typed a word in the wrong case: you can give the
case conversion command and continue typing.
If a word case conversion command is given in the middle of a word, it applies
only to the part of the word which follows point. (This is comparable to what M-d
(kill-word) does.) With a negative argument, case conversion applies only to the
part of the word before point.
The other case conversion commands are C-x C-u (upcase-region) and C-x
C-l (downcase-region), which convert everything between point and mark to the
specified case. Point and mark do not move.
The region case conversion commands upcase-region and downcase-region
are normally disabled. This means that they ask for confirmation if you try to use
them. When you confirm, you may enable the command, which means it will not
ask for confirmation again. See Section 33.3.11 [Disabling], page 460.

22.7 Text Mode
Text mode is a major mode for editing files of text in a human language. Files
which have names ending in the extension ‘.txt’ are usually opened in Text mode
(see Section 20.3 [Choosing Modes], page 207). To explicitly switch to Text mode,
type M-x text-mode.
In Text mode, only blank lines and page delimiters separate paragraphs. As a
result, paragraphs can be indented, and adaptive filling determines what indentation
to use when filling a paragraph. See Section 22.5.4 [Adaptive Fill], page 222.

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In Text mode, the TAB (indent-for-tab-command) command usually inserts
whitespace up to the next tab stop, instead of indenting the current line. See
Chapter 21 [Indentation], page 210, for details.
Text mode turns off the features concerned with comments except when you
explicitly invoke them. It changes the syntax table so that single-quotes are considered part of words (e.g. ‘don’t’ is considered one word). However, if a word starts
with a single-quote, it is treated as a prefix for the purposes of capitalization (e.g.
M-c converts ‘’hello’’ into ‘’Hello’’, as expected).
If you indent the first lines of paragraphs, then you should use Paragraph-Indent
Text mode (M-x paragraph-indent-text-mode) rather than Text mode. In that
mode, you do not need to have blank lines between paragraphs, because the firstline indentation is sufficient to start a paragraph; however paragraphs in which
every line is indented are not supported. Use M-x paragraph-indent-minor-mode
to enable an equivalent minor mode for situations where you shouldn’t change the
major mode—in mail composition, for instance.
Text mode binds M-TAB to ispell-complete-word. This command performs
completion of the partial word in the buffer before point, using the spelling dictionary as the space of possible words. See Section 13.4 [Spelling], page 112. If your
window manager defines M-TAB to switch windows, you can type ESC TAB or C-M-i
instead.
Entering Text mode runs the mode hook text-mode-hook (see Section 20.1
[Major Modes], page 204).
The following sections describe several major modes that are derived from Text
mode. These derivatives share most of the features of Text mode described above.
In particular, derivatives of Text mode run text-mode-hook prior to running their
own mode hooks.

22.8 Outline Mode
Outline mode is a major mode derived from Text mode, which is specialized for
editing outlines. It provides commands to navigate between entries in the outline
structure, and commands to make parts of a buffer temporarily invisible, so that
the outline structure may be more easily viewed. Type M-x outline-mode to switch
to Outline mode. Entering Outline mode runs the hook text-mode-hook followed
by the hook outline-mode-hook (see Section 33.2.2 [Hooks], page 445).
When you use an Outline mode command to make a line invisible (see
Section 22.8.3 [Outline Visibility], page 226), the line disappears from the screen.
An ellipsis (three periods in a row) is displayed at the end of the previous visible
line, to indicate the hidden text. Multiple consecutive invisible lines produce just
one ellipsis.
Editing commands that operate on lines, such as C-n and C-p, treat the text of
the invisible line as part of the previous visible line. Killing the ellipsis at the end of
a visible line really kills all the following invisible text associated with the ellipsis.
Outline minor mode is a buffer-local minor mode which provides the same commands as the major mode, Outline mode, but can be used in conjunction with

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other major modes. You can type M-x outline-minor-mode to toggle Outline minor mode in the current buffer, or use a file-local variable setting to enable it in a
specific file (see Section 33.2.4 [File Variables], page 447).
The major mode, Outline mode, provides special key bindings on the C-c prefix.
Outline minor mode provides similar bindings with C-c @ as the prefix; this is
to reduce the conflicts with the major mode’s special commands. (The variable
outline-minor-mode-prefix controls the prefix used.)
22.8.1 Format of Outlines
Outline mode assumes that the lines in the buffer are of two types: heading lines
and body lines. A heading line represents a topic in the outline. Heading lines start
with one or more asterisk (‘*’) characters; the number of asterisks determines the
depth of the heading in the outline structure. Thus, a heading line with one ‘*’ is
a major topic; all the heading lines with two ‘*’s between it and the next one-‘*’
heading are its subtopics; and so on. Any line that is not a heading line is a body
line. Body lines belong with the preceding heading line. Here is an example:
* Food
This is the body,
which says something about the topic of food.
** Delicious Food
This is the body of the second-level header.
** Distasteful Food
This could have
a body too, with
several lines.
*** Dormitory Food
* Shelter
Another first-level topic with its header line.
A heading line together with all following body lines is called collectively an
entry. A heading line together with all following deeper heading lines and their
body lines is called a subtree.
You can customize the criterion for distinguishing heading lines by setting the
variable outline-regexp. (The recommended ways to do this are in a major mode
function or with a file local variable.) Any line whose beginning has a match for
this regexp is considered a heading line. Matches that start within a line (not at
the left margin) do not count.
The length of the matching text determines the level of the heading; longer
matches make a more deeply nested level. Thus, for example, if a text formatter
has commands ‘@chapter’, ‘@section’ and ‘@subsection’ to divide the document
into chapters and sections, you could make those lines count as heading lines by
setting outline-regexp to ‘"@chap\\|@\\(sub\\)*section"’. Note the trick: the

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two words ‘chapter’ and ‘section’ are equally long, but by defining the regexp
to match only ‘chap’ we ensure that the length of the text matched on a chapter
heading is shorter, so that Outline mode will know that sections are contained in
chapters. This works as long as no other command starts with ‘@chap’.
You can explicitly specify a rule for calculating the level of a heading line by
setting the variable outline-level. The value of outline-level should be a
function that takes no arguments and returns the level of the current heading. The
recommended ways to set this variable are in a major mode command or with a file
local variable.
22.8.2 Outline Motion Commands
Outline mode provides special motion commands that move backward and forward
to heading lines.
C-c C-n

Move point to the next visible heading line (outline-next-visibleheading).

C-c C-p

Move point to the previous visible heading line (outline-previousvisible-heading).

C-c C-f

Move point to the next visible heading line at the same level as the
one point is on (outline-forward-same-level).

C-c C-b

Move point to the previous visible heading line at the same level
(outline-backward-same-level).

C-c C-u

Move point up to a lower-level (more inclusive) visible heading line
(outline-up-heading).

C-c C-n (outline-next-visible-heading) moves down to the next heading
line. C-c C-p (outline-previous-visible-heading) moves similarly backward.
Both accept numeric arguments as repeat counts.
C-c C-f (outline-forward-same-level) and C-c C-b (outline-backwardsame-level) move from one heading line to another visible heading at the same
depth in the outline. C-c C-u (outline-up-heading) moves backward to another
heading that is less deeply nested.
22.8.3 Outline Visibility Commands
Outline mode provides several commands for temporarily hiding or revealing parts
of the buffer, based on the outline structure. These commands are not undoable;
their effects are simply not recorded by the undo mechanism, so you can undo right
past them (see Section 13.1 [Undo], page 110).
Many of these commands act on the “current” heading line. If point is on a
heading line, that is the current heading line; if point is on a body line, the current
heading line is the nearest preceding header line.
C-c C-c

Make the current heading line’s body invisible (hide-entry).

C-c C-e

Make the current heading line’s body visible (show-entry).

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C-c C-d

Make everything under the current heading invisible, not including the
heading itself (hide-subtree).

C-c C-s

Make everything under the current heading visible, including body,
subheadings, and their bodies (show-subtree).

C-c C-l

Make the body of the current heading line, and of all its subheadings,
invisible (hide-leaves).

C-c C-k

Make all subheadings of the current heading line, at all levels, visible
(show-branches).

C-c C-i

Make immediate subheadings (one level down) of the current heading
line visible (show-children).

C-c C-t

Make all body lines in the buffer invisible (hide-body).

C-c C-a

Make all lines in the buffer visible (show-all).

C-c C-q

Hide everything except the top n levels of heading lines (hidesublevels).

C-c C-o

Hide everything except for the heading or body that point is in, plus
the headings leading up from there to the top level of the outline
(hide-other).

The simplest of these commands are C-c C-c (hide-entry), which hides the
body lines directly following the current heading line, and C-c C-e (show-entry),
which reveals them. Subheadings and their bodies are not affected.
The commands C-c C-d (hide-subtree) and C-c C-s (show-subtree) are more
powerful. They apply to the current heading line’s subtree: its body, all of its
subheadings, both direct and indirect, and all of their bodies.
The command C-c C-l (hide-leaves) hides the body of the current heading
line as well as all the bodies in its subtree; the subheadings themselves are left visible. The command C-c C-k (show-branches) reveals the subheadings, if they had
previously been hidden (e.g. by C-c C-d). The command C-c C-i (show-children)
is a weaker version of this; it reveals just the direct subheadings, i.e. those one level
down.
The command C-c C-o (hide-other) hides everything except the entry that
point is in, plus its parents (the headers leading up from there to top level in the
outline) and the top level headings.
The remaining commands affect the whole buffer. C-c C-t (hide-body) makes
all body lines invisible, so that you see just the outline structure (as a special
exception, it will not hide lines at the top of the file, preceding the first header
line, even though these are technically body lines). C-c C-a (show-all) makes all
lines visible. C-c C-q (hide-sublevels) hides all but the top level headings; with
a numeric argument n, it hides everything except the top n levels of heading lines.
When incremental search finds text that is hidden by Outline mode, it makes
that part of the buffer visible. If you exit the search at that position, the text
remains visible. You can also automatically make text visible as you navigate in it
by using Reveal mode (M-x reveal-mode), a buffer-local minor mode.

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22.8.4 Viewing One Outline in Multiple Views
You can display two views of a single outline at the same time, in different windows.
To do this, you must create an indirect buffer using M-x make-indirect-buffer.
The first argument of this command is the existing outline buffer name, and its
second argument is the name to use for the new indirect buffer. See Section 16.6
[Indirect Buffers], page 156.
Once the indirect buffer exists, you can display it in a window in the normal
fashion, with C-x 4 b or other Emacs commands. The Outline mode commands to
show and hide parts of the text operate on each buffer independently; as a result,
each buffer can have its own view. If you want more than two views on the same
outline, create additional indirect buffers.
22.8.5 Folding Editing
The Foldout package extends Outline mode and Outline minor mode with “folding”
commands. The idea of folding is that you zoom in on a nested portion of the outline,
while hiding its relatives at higher levels.
Consider an Outline mode buffer with all the text and subheadings under level-1
headings hidden. To look at what is hidden under one of these headings, you could
use C-c C-e (M-x show-entry) to expose the body, or C-c C-i to expose the child
(level-2) headings.
With Foldout, you use C-c C-z (M-x foldout-zoom-subtree). This exposes the
body and child subheadings, and narrows the buffer so that only the level-1 heading,
the body and the level-2 headings are visible. Now to look under one of the level-2
headings, position the cursor on it and use C-c C-z again. This exposes the level-2
body and its level-3 child subheadings and narrows the buffer again. Zooming in
on successive subheadings can be done as much as you like. A string in the mode
line shows how deep you’ve gone.
When zooming in on a heading, to see only the child subheadings specify a
numeric argument: C-u C-c C-z. The number of levels of children can be specified too (compare M-x show-children), e.g. M-2 C-c C-z exposes two levels of
child subheadings. Alternatively, the body can be specified with a negative argument: M-- C-c C-z. The whole subtree can be expanded, similarly to C-c C-s
(M-x show-subtree), by specifying a zero argument: M-0 C-c C-z.
While you’re zoomed in, you can still use Outline mode’s exposure and hiding
functions without disturbing Foldout. Also, since the buffer is narrowed, “global”
editing actions will only affect text under the zoomed-in heading. This is useful for
restricting changes to a particular chapter or section of your document.
To unzoom (exit) a fold, use C-c C-x (M-x foldout-exit-fold). This hides
all the text and subheadings under the top-level heading and returns you to the
previous view of the buffer. Specifying a numeric argument exits that many levels
of folds. Specifying a zero argument exits all folds.
To cancel the narrowing of a fold without hiding the text and subheadings,
specify a negative argument. For example, M--2 C-c C-x exits two folds and leaves
the text and subheadings exposed.

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Foldout mode also provides mouse commands for entering and exiting folds, and
for showing and hiding text:
C-M-Mouse-1 zooms in on the heading clicked on
single click: expose body.
double click: expose subheadings.
triple click: expose body and subheadings.
quad click: expose entire subtree.
C-M-Mouse-2 exposes text under the heading clicked on
single click: expose body.
double click: expose subheadings.
triple click: expose body and subheadings.
quad click: expose entire subtree.
C-M-Mouse-3 hides text under the heading clicked on or exits fold
single click: hide subtree.
double click: exit fold and hide text.
triple click: exit fold without hiding text.
quad click: exit all folds and hide text.
You can specify different modifier keys (instead of Control-Meta-) by setting
foldout-mouse-modifiers; but if you have already loaded the ‘foldout.el’ library, you must reload it in order for this to take effect.
To use the Foldout package, you can type M-x load-library RET foldout RET;
or you can arrange for to do that automatically by putting the following in your
init file:
(eval-after-load "outline" ’(require ’foldout))

22.9 Org Mode
Org mode is a variant of Outline mode for using Emacs as an organizer and/or
authoring system. Files with names ending in the extension ‘.org’ are opened in
Org mode (see Section 20.3 [Choosing Modes], page 207). To explicitly switch to
Org mode, type M-x org-mode.
In Org mode, as in Outline mode, each entry has a heading line that starts
with one or more ‘*’ characters. See Section 22.8.1 [Outline Format], page 225. In
addition, any line that begins with the ‘#’ character is treated as a comment.
Org mode provides commands for easily viewing and manipulating the outline
structure. The simplest of these commands is TAB (org-cycle). If invoked on
a heading line, it cycles through the different visibility states of the subtree: (i)
showing only that heading line, (ii) showing only the heading line and the heading
lines of its direct children, if any, and (iii) showing the entire subtree. If invoked in
a body line, the global binding for TAB is executed.
Typing S-TAB (org-shifttab) anywhere in an Org mode buffer cycles the
visibility of the entire outline structure, between (i) showing only top-level heading
lines, (ii) showing all heading lines but no body lines, and (iii) showing everything.

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You can move an entire entry up or down in the buffer, including its body lines
and subtree (if any), by typing M- (org-metaup) or M- (org-metadown)
on the heading line. Similarly, you can promote or demote a heading line with
M- (org-metaleft) and M- (org-metaright). These commands execute their global bindings if invoked on a body line.
The following subsections give basic instructions for using Org mode as an organizer and as an authoring system. For details, see Section “Introduction” in The
Org Manual.
22.9.1 Org as an organizer
You can tag an Org entry as a TODO item by typing C-c C-t (org-todo) anywhere
in the entry. This adds the keyword ‘TODO’ to the heading line. Typing C-c C-t
again switches the keyword to ‘DONE’; another C-c C-t removes the keyword entirely,
and so forth. You can customize the keywords used by C-c C-t via the variable
org-todo-keywords.
Apart from marking an entry as TODO, you can attach a date to it, by typing
C-c C-s (org-schedule) in the entry. This prompts for a date by popping up the
Emacs Calendar (see Chapter 28 [Calendar/Diary], page 346), and then adds the
tag ‘SCHEDULED’, together with the selected date, beneath the heading line. The
command C-c C-d (org-deadline) has the same effect, except that it uses the tag
DEADLINE.
Once you have some TODO items planned in an Org file, you can add that
file to the list of agenda files by typing C-c [ (org-agenda-file-to-front). Org
mode is designed to let you easily maintain multiple agenda files, e.g. for organizing
different aspects of your life. The list of agenda files is stored in the variable orgagenda-files.
To view items coming from your agenda files, type M-x org-agenda. This command prompts for what you want to see: a list of things to do this week, a list of
TODO items with specific keywords, etc.
22.9.2 Org as an authoring system
You may want to format your Org notes nicely and to prepare them for export and
publication. To export the current buffer, type C-c C-e (org-export) anywhere in
an Org buffer. This command prompts for an export format; currently supported
formats include HTML, LaTEX, OpenDocument (‘.odt’), and PDF. Some formats,
such as PDF, require certain system tools to be installed.
To export several files at once to a specific directory, either locally or over the
network, you must define a list of projects through the variable org-publishproject-alist. See its documentation for details.
Org supports a simple markup scheme for applying text formatting to exported
documents:
- This text is /emphasized/
- This text is *in bold*
- This text is _underlined_
- This text uses =a teletype font=

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#+begin_quote
‘‘This is a quote.’’
#+end_quote
#+begin_example
This is an example.
#+end_example
For further details, see Section “Exporting” in The Org Manual and Section
“Publishing” in The Org Manual.

22.10 TEX Mode
Emacs provides special major modes for editing files written in TEX and its related
formats. TEX is a powerful text formatter written by Donald Knuth; like GNU
Emacs, it is free software. LaTEX is a simplified input format for TEX, implemented
using TEX macros. DocTEX is a special file format in which the LaTEX sources are
written, combining sources with documentation. SliTEX is an obsolete special form
of LaTEX.1
TEX mode has four variants: Plain TEX mode, LaTEX mode, DocTEX mode, and
SliTEX mode. These distinct major modes differ only slightly, and are designed for
editing the four different formats. Emacs selects the appropriate mode by looking
at the contents of the buffer. (This is done by the tex-mode command, which
is normally called automatically when you visit a TEX-like file. See Section 20.3
[Choosing Modes], page 207.) If the contents are insufficient to determine this,
Emacs chooses the mode specified by the variable tex-default-mode; its default
value is latex-mode. If Emacs does not guess right, you can select the correct
variant of TEX mode using the command M-x plain-tex-mode, M-x latex-mode,
M-x slitex-mode, or doctex-mode.
The following sections document the features of TEX mode and its variants.
There are several other TEX-related Emacs packages, which are not documented in
this manual:
• BibTEX mode is a major mode for BibTEX files, which are commonly used for
keeping bibliographic references for LaTEX documents. For more information,
see the documentation string for the command bibtex-mode.
• The RefTEX package provides a minor mode which can be used with LaTEX
mode to manage bibliographic references. For more information, see the
RefTEX Info manual, which is distributed with Emacs.
• The AUCTEX package provides more advanced features for editing TEX and its
related formats, including the ability to preview TEX equations within Emacs
buffers. Unlike BibTEX mode and the RefTEX package, AUCTEX is not distributed with Emacs by default. It can be downloaded via the Package Menu
(see Chapter 32 [Packages], page 430); once installed, see the AUCTEX manual,
which is included with the package.
1

It has been replaced by the ‘slides’ document class, which comes with LaTEX.

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22.10.1 TEX Editing Commands
"

Insert, according to context, either ‘‘‘’ or ‘"’ or ‘’’’ (tex-insertquote).

C-j

Insert a paragraph break (two newlines) and check the previous
paragraph for unbalanced braces or dollar signs (tex-terminateparagraph).

M-x tex-validate-region
Check each paragraph in the region for unbalanced braces or dollar
signs.
C-c {

Insert ‘{}’ and position point between them (tex-insert-braces).

C-c }

Move forward past the next unmatched close brace (up-list).

In TEX, the character ‘"’ is not normally used; instead, quotations begin with
‘‘‘’ and end with ‘’’’. TEX mode therefore binds the " key to the tex-insertquote command. This inserts ‘‘‘’ after whitespace or an open brace, ‘"’ after a
backslash, and ‘’’’ after any other character.
As a special exception, if you type " when the text before point is either ‘‘‘’
or ‘’’’, Emacs replaces that preceding text with a single ‘"’ character. You can
therefore type "" to insert ‘"’, should you ever need to do so. (You can also use C-q
" to insert this character.)
In TEX mode, ‘$’ has a special syntax code which attempts to understand the
way TEX math mode delimiters match. When you insert a ‘$’ that is meant to exit
math mode, the position of the matching ‘$’ that entered math mode is displayed
for a second. This is the same feature that displays the open brace that matches a
close brace that is inserted. However, there is no way to tell whether a ‘$’ enters
math mode or leaves it; so when you insert a ‘$’ that enters math mode, the previous
‘$’ position is shown as if it were a match, even though they are actually unrelated.
TEX uses braces as delimiters that must match. Some users prefer to keep braces
balanced at all times, rather than inserting them singly. Use C-c { (tex-insertbraces) to insert a pair of braces. It leaves point between the two braces so you can
insert the text that belongs inside. Afterward, use the command C-c } (up-list)
to move forward past the close brace.
There are two commands for checking the matching of braces. C-j (texterminate-paragraph) checks the paragraph before point, and inserts two newlines
to start a new paragraph. It outputs a message in the echo area if any mismatch is
found. M-x tex-validate-region checks a region, paragraph by paragraph. The
errors are listed in an ‘*Occur*’ buffer; you can use the usual Occur mode commands
in that buffer, such as C-c C-c, to visit a particular mismatch (see Section 12.10
[Other Repeating Search], page 107).
Note that Emacs commands count square brackets and parentheses in TEX
mode, not just braces. This is not strictly correct for the purpose of checking
TEX syntax. However, parentheses and square brackets are likely to be used in
text as matching delimiters, and it is useful for the various motion commands and
automatic match display to work with them.

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22.10.2 LaTEX Editing Commands
LaTEX mode provides a few extra features not applicable to plain TEX:
C-c C-o

Insert ‘\begin’ and ‘\end’ for LaTEX block and position point on a
line between them (tex-latex-block).

C-c C-e

Close the innermost LaTEX block not yet closed (tex-close-latexblock).

In LaTEX input, ‘\begin’ and ‘\end’ tags are used to group blocks of text. To
insert a block, type C-c C-o (tex-latex-block). This prompts for a block type,
and inserts the appropriate matching ‘\begin’ and ‘\end’ tags, leaving a blank line
between the two and moving point there.
When entering the block type argument to C-c C-o, you can use the usual completion commands (see Section 5.3 [Completion], page 29). The default completion
list contains the standard LaTEX block types. If you want additional block types
for completion, customize the list variable latex-block-names.
In LaTEX input, ‘\begin’ and ‘\end’ tags must balance. You can use C-c
C-e (tex-close-latex-block) to insert an ‘\end’ tag which matches the last unmatched ‘\begin’. It also indents the ‘\end’ to match the corresponding ‘\begin’,
and inserts a newline after the ‘\end’ tag if point is at the beginning of a line. The
minor mode latex-electric-env-pair-mode automatically inserts an ‘\end’ or
‘\begin’ tag for you when you type the corresponding one.
22.10.3 TEX Printing Commands
You can invoke TEX as an subprocess of Emacs, supplying either the entire contents
of the buffer or just part of it (e.g. one chapter of a larger document).
C-c C-b

Invoke TEX on the entire current buffer (tex-buffer).

C-c C-r

Invoke TEX on the current region, together with the buffer’s header
(tex-region).

C-c C-f

Invoke TEX on the current file (tex-file).

C-c C-v

Preview the output from the last C-c C-r, C-c C-b, or C-c C-f command (tex-view).

C-c C-p

Print the output from the last C-c C-b, C-c C-r, or C-c C-f command
(tex-print).

C-c TAB

Invoke BibTEX on the current file (tex-bibtex-file).

C-c C-l

Recenter the window showing output from TEX so that the last line
can be seen (tex-recenter-output-buffer).

C-c C-k

Kill the TEX subprocess (tex-kill-job).

C-c C-c

Invoke some other compilation command on the entire current buffer
(tex-compile).

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To pass the current buffer through TEX, type C-c C-b (tex-buffer). The formatted output goes in a temporary file, normally a ‘.dvi’ file. Afterwards, you
can type C-c C-v (tex-view) to launch an external program, such as xdvi, to view
this output file. You can also type C-c C-p (tex-print) to print a hardcopy of the
output file.
By default, C-c C-b runs TEX in the current directory. The output of TEX also
goes in this directory. To run TEX in a different directory, change the variable texdirectory to the desired directory name. If your environment variable TEXINPUTS
contains relative directory names, or if your files contains ‘\input’ commands with
relative file names, then tex-directory must be "." or you will get the wrong
results. Otherwise, it is safe to specify some other directory, such as "/tmp".
The buffer’s TEX variant determines what shell command C-c C-b actually runs.
In Plain TEX mode, it is specified by the variable tex-run-command, which defaults
to "tex". In LaTEX mode, it is specified by latex-run-command, which defaults
to "latex". The shell command that C-c C-v runs to view the ‘.dvi’ output is
determined by the variable tex-dvi-view-command, regardless of the TEX variant.
The shell command that C-c C-p runs to print the output is determined by the
variable tex-dvi-print-command.
Normally, Emacs automatically appends the output file name to the shell command strings described in the preceding paragraph. For example, if tex-dvi-viewcommand is "xdvi", C-c C-v runs xdvi output-file-name . In some cases, however,
the file name needs to be embedded in the command, e.g. if you need to provide
the file name as an argument to one command whose output is piped to another.
You can specify where to put the file name with ‘*’ in the command string. For
example,
(setq tex-dvi-print-command "dvips -f * | lpr")
The terminal output from TEX, including any error messages, appears in a buffer
called ‘*tex-shell*’. If TEX gets an error, you can switch to this buffer and feed it
input (this works as in Shell mode; see Section 31.3.2 [Interactive Shell], page 403).
Without switching to this buffer you can scroll it so that its last line is visible by
typing C-c C-l.
Type C-c C-k (tex-kill-job) to kill the TEX process if you see that its output is
no longer useful. Using C-c C-b or C-c C-r also kills any TEX process still running.
You can also pass an arbitrary region through TEX by typing C-c C-r (texregion). This is tricky, however, because most files of TEX input contain commands
at the beginning to set parameters and define macros, without which no later part
of the file will format correctly. To solve this problem, C-c C-r allows you to
designate a part of the file as containing essential commands; it is included before
the specified region as part of the input to TEX. The designated part of the file is
called the header.
To indicate the bounds of the header in Plain TEX mode, you insert two special
strings in the file. Insert ‘%**start of header’ before the header, and ‘%**end of
header’ after it. Each string must appear entirely on one line, but there may be
other text on the line before or after. The lines containing the two strings are

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included in the header. If ‘%**start of header’ does not appear within the first
100 lines of the buffer, C-c C-r assumes that there is no header.
In LaTEX mode, the header begins with ‘\documentclass’ or ‘\documentstyle’
and ends with ‘\begin{document}’. These are commands that LaTEX requires you
to use in any case, so nothing special needs to be done to identify the header.
The commands (tex-buffer) and (tex-region) do all of their work in a temporary directory, and do not have available any of the auxiliary files needed by TEX
for cross-references; these commands are generally not suitable for running the final
copy in which all of the cross-references need to be correct.
When you want the auxiliary files for cross references, use C-c C-f (tex-file)
which runs TEX on the current buffer’s file, in that file’s directory. Before running
TEX, it offers to save any modified buffers. Generally, you need to use (tex-file)
twice to get the cross-references right.
The value of the variable tex-start-options specifies options for the TEX run.
The value of the variable tex-start-commands specifies TEX commands for
starting TEX. The default value causes TEX to run in nonstop mode. To run TEX
interactively, set the variable to "".
Large TEX documents are often split into several files—one main file, plus subfiles. Running TEX on a subfile typically does not work; you have to run it on the
main file. In order to make tex-file useful when you are editing a subfile, you can
set the variable tex-main-file to the name of the main file. Then tex-file runs
TEX on that file.
The most convenient way to use tex-main-file is to specify it in a local variable
list in each of the subfiles. See Section 33.2.4 [File Variables], page 447.
For LaTEX files, you can use BibTEX to process the auxiliary file for the current
buffer’s file. BibTEX looks up bibliographic citations in a data base and prepares the
cited references for the bibliography section. The command C-c TAB (tex-bibtexfile) runs the shell command (tex-bibtex-command) to produce a ‘.bbl’ file for
the current buffer’s file. Generally, you need to do C-c C-f (tex-file) once to
generate the ‘.aux’ file, then do C-c TAB (tex-bibtex-file), and then repeat C-c
C-f (tex-file) twice more to get the cross-references correct.
To invoke some other compilation program on the current TEX buffer, type C-c
C-c (tex-compile). This command knows how to pass arguments to many common
programs, including ‘pdflatex’, ‘yap’, ‘xdvi’, and ‘dvips’. You can select your
desired compilation program using the standard completion keys (see Section 5.3
[Completion], page 29).
22.10.4 TEX Mode Miscellany
Entering any variant of TEX mode runs the hooks text-mode-hook and tex-modehook. Then it runs either plain-tex-mode-hook, latex-mode-hook, or slitexmode-hook, whichever is appropriate. Starting the TEX shell runs the hook texshell-hook. See Section 33.2.2 [Hooks], page 445.
The commands M-x iso-iso2tex, M-x iso-tex2iso, M-x iso-iso2gtex and
M-x iso-gtex2iso can be used to convert between Latin-1 encoded files and TEXencoded equivalents.

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22.11 SGML and HTML Modes
The major modes for SGML and HTML provide indentation support and commands
for operating on tags. HTML mode is a slightly customized variant of SGML mode.
C-c C-n

Interactively specify a special character and insert the SGML ‘&’command for that character (sgml-name-char).

C-c C-t

Interactively specify a tag and its attributes (sgml-tag). This command asks you for a tag name and for the attribute values, then inserts
both the opening tag and the closing tag, leaving point between them.
With a prefix argument n, the command puts the tag around the n
words already present in the buffer after point. Whenever a region is
active, it puts the tag around the region (when Transient Mark mode
is off, it does this when a numeric argument of −1 is supplied.)

C-c C-a

Interactively insert attribute values for the current tag (sgmlattributes).

C-c C-f

Skip across a balanced tag group (which extends from an opening tag
through its corresponding closing tag) (sgml-skip-tag-forward). A
numeric argument acts as a repeat count.

C-c C-b

Skip backward across a balanced tag group (which extends from an
opening tag through its corresponding closing tag) (sgml-skip-tagbackward). A numeric argument acts as a repeat count.

C-c C-d

Delete the tag at or after point, and delete the matching tag too (sgmldelete-tag). If the tag at or after point is an opening tag, delete the
closing tag too; if it is a closing tag, delete the opening tag too.

C-c ? tag RET
Display a description of the meaning of tag tag (sgml-tag-help). If
the argument tag is empty, describe the tag at point.
C-c /

Insert a close tag for the innermost unterminated tag (sgml-closetag). If called within a tag or a comment, close it instead of inserting
a close tag.

C-c 8

Toggle a minor mode in which Latin-1 characters insert the corresponding SGML commands that stand for them, instead of the characters themselves (sgml-name-8bit-mode).

C-c C-v

Run a shell command (which you must specify) to validate the current
buffer as SGML (sgml-validate).

C-c TAB

Toggle the visibility of existing tags in the buffer. This can be used as
a cheap preview (sgml-tags-invisible).

The major mode for editing XML documents is called nXML mode. This is
a powerful major mode that can recognize many existing XML schema and use
them to provide completion of XML elements via C-RET or M-TAB, as well as “onthe-fly” XML validation with error highlighting. To enable nXML mode in an

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existing buffer, type M-x nxml-mode, or, equivalently, M-x xml-mode. Emacs uses
nXML mode for files which have the extension ‘.xml’. For XHTML files, which
have the extension ‘.xhtml’, Emacs uses HTML mode by default; you can make it
use nXML mode by customizing the variable auto-mode-alist (see Section 20.3
[Choosing Modes], page 207). nXML mode is described in an Info manual, which
is distributed with Emacs.
You may choose to use the less powerful SGML mode for editing XML, since
XML is a strict subset of SGML. To enable SGML mode in an existing buffer, type
M-x sgml-mode. On enabling SGML mode, Emacs examines the buffer to determine
whether it is XML; if so, it sets the variable sgml-xml-mode to a non-nil value.
This causes SGML mode’s tag insertion commands, described above, to always
insert explicit closing tags as well.

22.12 Nroff Mode
Nroff mode, a major mode derived from Text mode, is specialized for editing
nroff files (e.g. Unix man pages). Type M-x nroff-mode to enter this mode. Entering Nroff mode runs the hook text-mode-hook, then nroff-mode-hook (see
Section 33.2.2 [Hooks], page 445).
In Nroff mode, nroff command lines are treated as paragraph separators, pages
are separated by ‘.bp’ commands, and comments start with backslash-doublequote.
It also defines these commands:
M-n

Move to the beginning of the next line that isn’t an nroff command
(forward-text-line). An argument is a repeat count.

M-p

Like M-n but move up (backward-text-line).

M-?

Displays in the echo area the number of text lines (lines that are not
nroff commands) in the region (count-text-lines).

Electric Nroff mode is a buffer-local minor mode that can be used with Nroff
mode. To toggle this minor mode, type M-x electric-nroff-mode (see Section 20.2
[Minor Modes], page 205). When the mode is on, each time you type RET to end a
line containing an nroff command that opens a kind of grouping, the nroff command
to close that grouping is automatically inserted on the following line.
If you use Outline minor mode with Nroff mode (see Section 22.8 [Outline Mode],
page 224), heading lines are lines of the form ‘.H’ followed by a number (the header
level).

22.13 Enriched Text
Enriched mode is a minor mode for editing formatted text files in a WYSIWYG
(“what you see is what you get”) fashion. When Enriched mode is enabled, you
can apply various formatting properties to the text in the buffer, such as fonts and
colors; upon saving the buffer, those properties are saved together with the text,
using the MIME ‘text/enriched’ file format.
Enriched mode is typically used with Text mode (see Section 22.7 [Text Mode],
page 223). It is not compatible with Font Lock mode, which is used by many major

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modes, including most programming language modes, for syntax highlighting (see
Section 11.12 [Font Lock], page 80). Unlike Enriched mode, Font Lock mode assigns
text properties automatically, based on the current buffer contents; those properties
are not saved to disk.
The file ‘etc/enriched.doc’ in the Emacs distribution serves as an example of
the features of Enriched mode.
22.13.1 Enriched Mode
Enriched mode is a buffer-local minor mode (see Section 20.2 [Minor Modes],
page 205). When you visit a file that has been saved in the ‘text/enriched’ format,
Emacs automatically enables Enriched mode, and applies the formatting information in the file to the buffer text. When you save a buffer with Enriched mode
enabled, it is saved using the ‘text/enriched’ format, including the formatting
information.
To create a new file of formatted text, visit the nonexistent file and type M-x
enriched-mode. This command actually toggles Enriched mode. With a prefix argument, it enables Enriched mode if the argument is positive, and disables Enriched
mode otherwise. If you disable Enriched mode, Emacs no longer saves the buffer
using the ‘text/enriched’ format; any formatting properties that have been added
to the buffer remain in the buffer, but they are not saved to disk.
Enriched mode does not save all Emacs text properties, only those specified in
the variable enriched-translations. These include properties for fonts, colors,
indentation, and justification.
If you visit a file and Emacs fails to recognize that it is in the ‘text/enriched’
format, type M-x format-decode-buffer. This command prompts for a file format, and re-reads the file in that format. Specifying the ‘text/enriched’ format
automatically enables Enriched mode.
To view a ‘text/enriched’ file in raw form (as plain text with markup tags
rather than formatted text), use M-x find-file-literally (see Section 15.2 [Visiting], page 125).
See Section “Format Conversion” in the Emacs Lisp Reference Manual, for details of how Emacs recognizes and converts file formats like ‘text/enriched’. See
Section “Text Properties” in the Emacs Lisp Reference Manual, for more information about text properties.
22.13.2 Hard and Soft Newlines
In Enriched mode, Emacs distinguishes between two different kinds of newlines,
hard newlines and soft newlines. You can also enable or disable this feature in
other buffers, by typing M-x use-hard-newlines.
Hard newlines are used to separate paragraphs, or anywhere there needs to be
a line break regardless of how the text is filled; soft newlines are used for filling.
The RET (newline) and C-o (open-line) commands insert hard newlines. The
fill commands, including Auto Fill (see Section 22.5.1 [Auto Fill], page 218), insert
only soft newlines and delete only soft newlines, leaving hard newlines alone.

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Thus, when editing with Enriched mode, you should not use RET or C-o to
break lines in the middle of filled paragraphs. Use Auto Fill mode or explicit fill
commands (see Section 22.5.2 [Fill Commands], page 219) instead. Use RET or C-o
where line breaks should always remain, such as in tables and lists. For such lines,
you may also want to set the justification style to unfilled (see Section 22.13.6
[Enriched Justification], page 241).
22.13.3 Editing Format Information
The easiest way to alter properties is with the Text Properties menu. You can get
to this menu from the Edit menu in the menu bar (see Section 1.4 [Menu Bar],
page 10), or with C-Mouse-2 (see Section 18.4 [Menu Mouse Clicks], page 168).
Some of the commands in the Text Properties menu are listed below (you can also
invoke them with M-x):
Remove Face Properties
Remove face properties from the region (facemenu-remove-faceprops).
Remove Text Properties
Remove all text properties from the region, including face properties
(facemenu-remove-all).
Describe Properties
List all text properties and other information about the character following point (describe-text-properties).
Display Faces
Display a list of defined faces (list-faces-display). See Section 11.8
[Faces], page 75.
Display Colors
Display a list of defined colors (list-colors-display).
Section 11.9 [Colors], page 76.

See

The other menu entries are described in the following sections.
22.13.4 Faces in Enriched Text
The following commands can be used to add or remove faces (see Section 11.8
[Faces], page 75). Each applies to the text in the region if the mark is active, and
to the next self-inserting character if the mark is inactive. With a prefix argument,
each command applies to the next self-inserting character even if the region is active.
M-o d

Remove all face properties (facemenu-set-default).

M-o b

Apply the bold face (facemenu-set-bold).

M-o i

Apply the italic face (facemenu-set-italic).

M-o l

Apply the bold-italic face (facemenu-set-bold-italic).

M-o u

Apply the underline face (facemenu-set-underline).

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M-o o face RET
Apply the face face (facemenu-set-face).
M-x facemenu-set-foreground
Prompt for a color (see Section 11.9 [Colors], page 76), and apply it
as a foreground color.
M-x facemenu-set-background
Prompt for a color, and apply it as a background color.
These command are also available via the Text Properties menu.
A self-inserting character normally inherits the face properties (and most other
text properties) from the preceding character in the buffer. If you use one of the
above commands to specify the face for the next self-inserting character, that character will not inherit the faces properties from the preceding character, but it will
still inherit other text properties.
Enriched mode defines two additional faces: excerpt and fixed. These correspond to codes used in the text/enriched file format. The excerpt face is intended
for quotations; by default, it appears the same as italic. The fixed face specifies
fixed-width text; by default, it appears the same as bold.
22.13.5 Indentation in Enriched Text
In Enriched mode, you can specify different amounts of indentation for the right or
left margin of a paragraph or a part of a paragraph. These margins also affect fill
commands such as M-q (see Section 22.5 [Filling], page 218).
The Indentation submenu of Text Properties offers commands for specifying
indentation:
Indent More
Indent the region by 4 columns (increase-left-margin). In Enriched
mode, this command is also available on C-x TAB; if you supply a
numeric argument, that says how many columns to add to the margin
(a negative argument reduces the number of columns).
Indent Less
Remove 4 columns of indentation from the region.
Indent Right More
Make the text narrower by indenting 4 columns at the right margin.
Indent Right Less
Remove 4 columns of indentation from the right margin.
The variable standard-indent specifies how many columns these commands
should add to or subtract from the indentation. The default value is 4. The default
right margin for Enriched mode is controlled by the variable fill-column, as usual.
You can also type C-c [ (set-left-margin) and C-c ] (set-right-margin) to
set the left and right margins. You can specify the margin width with a numeric
argument; otherwise these commands prompt for a value via the minibuffer.

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The fill prefix, if any, works in addition to the specified paragraph indentation:
C-x . does not include the specified indentation’s whitespace in the new value for
the fill prefix, and the fill commands look for the fill prefix after the indentation on
each line. See Section 22.5.3 [Fill Prefix], page 220.
22.13.6 Justification in Enriched Text
In Enriched mode, you can use the following commands to specify various justification styles for filling. These commands apply to the paragraph containing point,
or, if the region is active, to all paragraphs overlapping the region.
M-j l

Align lines to the left margin (set-justification-left).

M-j r

Align lines to the right margin (set-justification-right).

M-j b

Align lines to both margins, inserting spaces in the middle of the line
to achieve this (set-justification-full).

M-j c
M-S
M-j u

Center lines between the margins (set-justification-center).
Turn off filling entirely (set-justification-none). The fill commands do nothing on text with this setting. You can, however, still
indent the left margin.

You can also specify justification styles using the Justification submenu in the
Text Properties menu. The default justification style is specified by the per-buffer
variable default-justification. Its value should be one of the symbols left,
right, full, center, or none.
22.13.7 Setting Other Text Properties
The Special Properties submenu of Text Properties has entries for adding or removing three other text properties: read-only, (which disallows alteration of the
text), invisible (which hides text), and intangible (which disallows moving point
within the text). The ‘Remove Special’ menu item removes all of these special
properties from the text in the region.
The invisible and intangible properties are not saved.

22.14 Editing Text-based Tables
The table package provides commands to easily edit text-based tables. Here is an
example of what such a table looks like:

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+-----------------+--------------------------------+-----------------+
|
Command
|
Description
|
Key Binding
|
+-----------------+--------------------------------+-----------------+
| forward-char
|Move point right N characters
|
C-f
|
|
|(left if N is negative).
|
|
|
|
|
|
+-----------------+--------------------------------+-----------------+
| backward-char |Move point left N characters
|
C-b
|
|
|(right if N is negative).
|
|
|
|
|
|
+-----------------+--------------------------------+-----------------+

When Emacs recognizes such a stretch of text as a table (see Section 22.14.3
[Table Recognition], page 243), editing the contents of each table cell will automatically resize the table, whenever the contents become too large to fit in the cell. You
can use the commands defined in the following sections for navigating and editing
the table layout.
Type M-x table-fixed-width-mode to toggle the automatic table resizing feature.
22.14.1 What is a Text-based Table?
A table consists of a rectangular text area which is divided into cells. Each cell
must be at least one character wide and one character high, not counting its border
lines. A cell can be subdivided into more cells, but they cannot overlap.
Cell border lines are drawn with three special characters, specified by the following variables:
table-cell-vertical-char
The character used for vertical lines. The default is ‘|’.
table-cell-horizontal-chars
The characters used for horizontal lines. The default is ‘"-="’.
table-cell-intersection-char
The character used for the intersection of horizontal and vertical lines.
The default is ‘+’.
The following are examples of invalid tables:
+-----+
+--+
+-++--+
|
|
| |
| || |
|
|
| |
| || |
+--+ |
+--+--+
+-++--+
| | |
| | |
+-++--+
| | |
| | |
| || |
+--+--+
+--+--+
+-++--+
a
b
c
From left to right:
a. Overlapped cells or non-rectangular cells are not allowed.
b. The border must be rectangular.

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c. Cells must have a minimum width/height of one character.
22.14.2 Creating a Table
To create a text-based table from scratch, type M-x table-insert. This command
prompts for the number of table columns, the number of table rows, cell width
and cell height. The cell width and cell height do not include the cell borders;
each can be specified as a single integer (which means each cell is given the same
width/height), or as a sequence of integers separated by spaces or commas (which
specify the width/height of the individual table columns/rows, counting from left
to right for table columns and from top to bottom for table rows). The specified
table is then inserted at point.
The table inserted by M-x table-insert contains special text properties, which
tell Emacs to treat it specially as a text-based table. If you save the buffer to a file
and visit it again later, those properties are lost, and the table appears to Emacs
as an ordinary piece of text. See the next section, for how to convert it back into a
table.
22.14.3 Table Recognition
Existing text-based tables in a buffer, which lack the special text properties applied by M-x table-insert, are not treated specially as tables. To apply those text
properties, type M-x table-recognize. This command scans the current buffer,
recognizes valid table cells, and applies the relevant text properties. Conversely,
type M-x table-unrecognize to unrecognize all tables in the current buffer, removing the special text properties and converting tables back to plain text.
You can also use the following commands to selectively recognize or unrecognize
tables:
M-x table-recognize-region
Recognize tables within the current region.
M-x table-unrecognize-region
Unrecognize tables within the current region.
M-x table-recognize-table
Recognize the table at point and activate it.
M-x table-unrecognize-table
Deactivate the table at point.
M-x table-recognize-cell
Recognize the cell at point and activate it.
M-x table-unrecognize-cell
Deactivate the cell at point.
See Section 22.14.7 [Table Conversion], page 245, for another way to recognize
a table.

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22.14.4 Commands for Table Cells
The commands M-x table-forward-cell and M-x table-backward-cell move
point from the current cell to an adjacent cell. The order is cyclic: when point
is in the last cell of a table, M-x table-forward-cell moves to the first cell. Likewise, when point is on the first cell, M-x table-backward-cell moves to the last
cell.
M-x table-span-cell prompts for a direction—right, left, above, or below—
and merges the current cell with the adjacent cell in that direction. This command
signals an error if the merge would result in an illegitimate cell layout.
M-x table-split-cell splits the current cell vertically or horizontally, prompting for the direction with the minibuffer. To split in a specific direction, use
M-x table-split-cell-vertically and M-x table-split-cell-horizontally.
When splitting vertically, the old cell contents are automatically split between the
two new cells. When splitting horizontally, you are prompted for how to divide the
cell contents, if the cell is non-empty; the options are ‘split’ (divide the contents at
point), ‘left’ (put all the contents in the left cell), and ‘right’ (put all the contents
in the right cell).
The following commands enlarge or shrink a cell. By default, they resize by one
row or column; if a numeric argument is supplied, that specifies the number of rows
or columns to resize by.
M-x table-heighten-cell
Enlarge the current cell vertically.
M-x table-shorten-cell
Shrink the current cell vertically.
M-x table-widen-cell
Enlarge the current cell horizontally.
M-x table-narrow-cell
Shrink the current cell horizontally.
22.14.5 Cell Justification
The command M-x table-justify imposes justification on one or more cells in a
text-based table. Justification determines how the text in the cell is aligned, relative
to the edges of the cell. Each cell in a table can be separately justified.
M-x table-justify first prompts for what to justify; the options are ‘cell’
(just the current cell), ‘column’ (all cells in the current table column) and ‘row’ (all
cells in the current table row). The command then prompts for the justification
style; the options are left, center, right, top, middle, bottom, or none (meaning
no vertical justification).
Horizontal and vertical justification styles are specified independently, and both
types can be in effect simultaneously; for instance, you can call M-x table-justify
twice, once to specify right justification and once to specify bottom justification,
to align the contents of a cell to the bottom right.

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The justification style is stored in the buffer as a text property, and is lost when
you kill the buffer or exit Emacs. However, the table recognition commands, such as
M-x table-recognize (see Section 22.14.3 [Table Recognition], page 243), attempt
to determine and re-apply each cell’s justification style, by examining its contents.
To disable this feature, change the variable table-detect-cell-alignment to nil.
22.14.6 Table Rows and Columns
M-x table-insert-row inserts a row of cells before the current table row. The
current row, together with point, is pushed down past the new row. To insert a row
after the last row at the bottom of a table, invoke this command with point below
the table, just below the bottom edge. You can insert more than one row at a time
by using a numeric prefix argument.
Similarly, M-x table-insert-column inserts a column of cells to the left of the
current table column. To insert a column to the right side of the rightmost column,
invoke this command with point to the right of the rightmost column, outside the
table. A numeric prefix argument specifies the number of columns to insert.
M-x table-delete-column deletes the column of cells at point. Similarly, M-x
table-delete-row deletes the row of cells at point. A numeric prefix argument to
either command specifies the number of columns or rows to delete.
22.14.7 Converting Between Plain Text and Tables
The command M-x table-capture captures plain text in a region and turns it into
a table. Unlike M-x table-recognize (see Section 22.14.3 [Table Recognition],
page 243), the original text does not need to have a table appearance; it only needs
to have a logical table-like structure.
For example, suppose we have the following numbers, which are divided into
three lines and separated horizontally by commas:
1, 2, 3, 4
5, 6, 7, 8
, 9, 10
Invoking M-x table-capture on that text produces this table:
+-----+-----+-----+-----+
|1
|2
|3
|4
|
+-----+-----+-----+-----+
|5
|6
|7
|8
|
+-----+-----+-----+-----+
|
|9
|10
|
|
+-----+-----+-----+-----+
M-x table-release does the opposite: it converts a table back to plain text,
removing its cell borders.
One application of this pair of commands is to edit a text in layout. Look at
the following three paragraphs (the latter two are indented with header lines):
table-capture is a powerful command.
Here are some things it can do:

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Using row and column delimiter regexps,
it parses the specified text area and
extracts cell items into a table.

Applying table-capture to a region containing the above text, with empty strings
for the column and row delimiter regexps, creates a table with a single cell like the
following one.
+----------------------------------------------------------+
|table-capture is a powerful command.
|
|Here are some things it can do:
|
|
|
|Parse Cell Items
Using row and column delimiter regexps,|
|
it parses the specified text area and |
|
extracts cell items into a table.
|
+----------------------------------------------------------+

We can then use the cell splitting commands (see Section 22.14.4 [Cell Commands],
page 244) to subdivide the table so that each paragraph occupies a cell:
+----------------------------------------------------------+
|table-capture is a powerful command.
|
|Here are some things it can do:
|
+-----------------+----------------------------------------+
|Parse Cell Items | Using row and column delimiter regexps,|
|
| it parses the specified text area and |
|
| extracts cell items into a table.
|
+-----------------+----------------------------------------+

Each cell can now be edited independently without affecting the layout of other
cells. When finished, we can invoke M-x table-release to convert the table back
to plain text.

22.14.8 Table Miscellany
The command table-query-dimension reports the layout of the table and table
cell at point. Here is an example of its output:
Cell: (21w, 6h), Table: (67w, 16h), Dim: (2c, 3r), Total Cells: 5

This indicates that the current cell is 21 characters wide and 6 lines high, the table
is 67 characters wide and 16 lines high with 2 columns and 3 rows, and a total of 5
cells.
M-x table-insert-sequence inserts a string into each cell. Each string is a
part of a sequence i.e. a series of increasing integer numbers.
M-x table-generate-source generates a table formatted for a specific markup
language. It asks for a language (which must be one of html, latex, or cals),
a destination buffer in which to put the result, and a table caption, and then
inserts the generated table into the specified buffer. The default destination buffer
is table.lang , where lang is the language you specified.

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22.15 Two-Column Editing
Two-column mode lets you conveniently edit two side-by-side columns of text. It
uses two side-by-side windows, each showing its own buffer. There are three ways
to enter two-column mode:
F2 2 or C-x 6 2
Enter two-column mode with the current buffer on the left, and on
the right, a buffer whose name is based on the current buffer’s name
(2C-two-columns). If the right-hand buffer doesn’t already exist, it
starts out empty; the current buffer’s contents are not changed.
This command is appropriate when the current buffer is empty or
contains just one column and you want to add another column.
F2 s or C-x 6 s
Split the current buffer, which contains two-column text, into two
buffers, and display them side by side (2C-split). The current buffer
becomes the left-hand buffer, but the text in the right-hand column
is moved into the right-hand buffer. The current column specifies the
split point. Splitting starts with the current line and continues to the
end of the buffer.
This command is appropriate when you have a buffer that already
contains two-column text, and you wish to separate the columns temporarily.
F2 b buffer RET
C-x 6 b buffer RET
Enter two-column mode using the current buffer as the lefthand buffer, and using buffer buffer as the right-hand buffer
(2C-associate-buffer).
F2 s or C-x 6 s looks for a column separator, which is a string that appears
on each line between the two columns. You can specify the width of the separator
with a numeric argument to F2 s; that many characters, before point, constitute
the separator string. By default, the width is 1, so the column separator is the
character before point.
When a line has the separator at the proper place, F2 s puts the text after the
separator into the right-hand buffer, and deletes the separator. Lines that don’t
have the column separator at the proper place remain unsplit; they stay in the
left-hand buffer, and the right-hand buffer gets an empty line to correspond. (This
is the way to write a line that “spans both columns while in two-column mode”:
write it in the left-hand buffer, and put an empty line in the right-hand buffer.)
The command C-x 6 RET or F2 RET (2C-newline) inserts a newline in each of
the two buffers at corresponding positions. This is the easiest way to add a new
line to the two-column text while editing it in split buffers.
When you have edited both buffers as you wish, merge them with F2 1 or C-x 6
1 (2C-merge). This copies the text from the right-hand buffer as a second column
in the other buffer. To go back to two-column editing, use F2 s.

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Use F2 d or C-x 6 d to dissociate the two buffers, leaving each as it stands (2Cdissociate). If the other buffer, the one not current when you type F2 d, is empty,
F2 d kills it.

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23 Editing Programs
This chapter describes Emacs features for facilitating editing programs. Some of
the things these features can do are:
• Find or move over top-level definitions (see Section 23.2 [Defuns], page 250).
• Apply the usual indentation conventions of the language (see Section 23.3
[Program Indent], page 252).
• Balance parentheses (see Section 23.4 [Parentheses], page 256).
• Insert, kill or align comments (see Section 23.5 [Comments], page 258).
• Highlight program syntax (see Section 11.12 [Font Lock], page 80).

23.1 Major Modes for Programming Languages
Emacs has specialized major modes (see Section 20.1 [Major Modes], page 204) for
many programming languages. A programming language mode typically specifies
the syntax of expressions, the customary rules for indentation, how to do syntax
highlighting for the language, and how to find the beginning or end of a function
definition. It often has features for compiling and debugging programs as well. The
major mode for each language is named after the language; for instance, the major
mode for the C programming language is c-mode.
Emacs has programming language modes for Lisp, Scheme, the Scheme-based
DSSSL expression language, Ada, ASM, AWK, C, C++, Delphi, Fortran, Icon,
IDL (CORBA), IDLWAVE, Java, Javascript, Metafont (TEX’s companion for font
creation), Modula2, Objective-C, Octave, Pascal, Perl, Pike, PostScript, Prolog,
Python, Ruby, Simula, Tcl, and VHDL. An alternative mode for Perl is called
CPerl mode. Modes are also available for the scripting languages of the common
GNU and Unix shells, VMS DCL, and MS-DOS/MS-Windows ‘BAT’ files, and for
makefiles, DNS master files, and various sorts of configuration files.
Ideally, Emacs should have a major mode for each programming language that
you might want to edit. If it doesn’t have a mode for your favorite language,
the mode might be implemented in a package not distributed with Emacs (see
Chapter 32 [Packages], page 430); or you can contribute one.
In most programming languages, indentation should vary from line to line to
illustrate the structure of the program. Therefore, in most programming language
modes, typing TAB updates the indentation of the current line (see Section 23.3
[Program Indent], page 252). Furthermore, DEL is usually bound to backwarddelete-char-untabify, which deletes backward treating each tab as if it were
the equivalent number of spaces, so that you can delete one column of indentation
without worrying whether the whitespace consists of spaces or tabs.
Entering a programming language mode runs the custom Lisp functions specified
in the hook variable prog-mode-hook, followed by those specified in the mode’s
own mode hook (see Section 20.1 [Major Modes], page 204). For instance, entering
C mode runs the hooks prog-mode-hook and c-mode-hook. See Section 33.2.2
[Hooks], page 445, for information about hooks.

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The Emacs distribution contains Info manuals for the major modes for Ada,
C/C++/Objective C/Java/Corba IDL/Pike/AWK, and IDLWAVE. For Fortran
mode, see Section “Fortran” in Specialized Emacs Features.

23.2 Top-Level Definitions, or Defuns
In Emacs, a major definition at the top level in the buffer, such as a function, is
called a defun. The name comes from Lisp, but in Emacs we use it for all languages.
23.2.1 Left Margin Convention
Many programming-language modes assume by default that any opening delimiter
found at the left margin is the start of a top-level definition, or defun. Therefore,
don’t put an opening delimiter at the left margin unless it should have that significance. For instance, never put an open-parenthesis at the left margin in a Lisp file
unless it is the start of a top-level list.
The convention speeds up many Emacs operations, which would otherwise have
to scan back to the beginning of the buffer to analyze the syntax of the code.
If you don’t follow this convention, not only will you have trouble when you
explicitly use the commands for motion by defuns; other features that use them will
also give you trouble. This includes the indentation commands (see Section 23.3
[Program Indent], page 252) and Font Lock mode (see Section 11.12 [Font Lock],
page 80).
The most likely problem case is when you want an opening delimiter at the start
of a line inside a string. To avoid trouble, put an escape character (‘\’, in C and
Emacs Lisp, ‘/’ in some other Lisp dialects) before the opening delimiter. This will
not affect the contents of the string, but will prevent that opening delimiter from
starting a defun. Here’s an example:
(insert "Foo:
\(bar)
")
To help you catch violations of this convention, Font Lock mode highlights
confusing opening delimiters (those that ought to be quoted) in bold red.
If you need to override this convention, you can do so by setting the variable
open-paren-in-column-0-is-defun-start. If this user option is set to t (the
default), opening parentheses or braces at column zero always start defuns. When
it is nil, defuns are found by searching for parens or braces at the outermost level.
Usually, you should leave this option at its default value of t. If your buffer
contains parentheses or braces in column zero which don’t start defuns, and it is
somehow impractical to remove these parentheses or braces, it might be helpful to
set the option to nil. Be aware that this might make scrolling and display in large
buffers quite sluggish. Furthermore, the parentheses and braces must be correctly
matched throughout the buffer for it to work properly.

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23.2.2 Moving by Defuns
These commands move point or set up the region based on top-level major definitions, also called defuns.
C-M-a

Move to beginning of current or preceding defun (beginning-ofdefun).

C-M-e

Move to end of current or following defun (end-of-defun).

C-M-h

Put region around whole current or following defun (mark-defun).

The commands to move to the beginning and end of the current defun are
C-M-a (beginning-of-defun) and C-M-e (end-of-defun). If you repeat one of
these commands, or use a positive numeric argument, each repetition moves to the
next defun in the direction of motion.
C-M-a with a negative argument −n moves forward n times to the next beginning of a defun. This is not exactly the same place that C-M-e with argument n
would move to; the end of this defun is not usually exactly the same place as the
beginning of the following defun. (Whitespace, comments, and perhaps declarations
can separate them.) Likewise, C-M-e with a negative argument moves back to an
end of a defun, which is not quite the same as C-M-a with a positive argument.
To operate on the current defun, use C-M-h (mark-defun), which sets the mark
at the end of the current defun and puts point at its beginning. See Section 8.2
[Marking Objects], page 49. This is the easiest way to get ready to kill the defun in
order to move it to a different place in the file. If you use the command while point
is between defuns, it uses the following defun. If you use the command while the
mark is already active, it sets the mark but does not move point; furthermore, each
successive use of C-M-h extends the end of the region to include one more defun.
In C mode, C-M-h runs the function c-mark-function, which is almost the same
as mark-defun; the difference is that it backs up over the argument declarations,
function name and returned data type so that the entire C function is inside the
region. This is an example of how major modes adjust the standard key bindings
so that they do their standard jobs in a way better fitting a particular language.
Other major modes may replace any or all of these key bindings for that purpose.
23.2.3 Imenu
The Imenu facility offers a way to find the major definitions in a file by name. It
is also useful in text formatter major modes, where it treats each chapter, section,
etc., as a definition. (See Section 25.3 [Tags], page 311, for a more powerful feature
that handles multiple files together.)
If you type M-x imenu, it reads the name of a definition using the minibuffer,
then moves point to that definition. You can use completion to specify the name;
the command always displays the whole list of valid names.
Alternatively, you can bind the command imenu to a mouse click. Then it
displays mouse menus for you to select a definition name. You can also add the
buffer’s index to the menu bar by calling imenu-add-menubar-index. If you want
to have this menu bar item available for all buffers in a certain major mode, you

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can do this by adding imenu-add-menubar-index to its mode hook. But if you
have done that, you will have to wait a little while each time you visit a file in that
mode, while Emacs finds all the definitions in that buffer.
When you change the contents of a buffer, if you add or delete definitions, you
can update the buffer’s index based on the new contents by invoking the ‘*Rescan*’
item in the menu. Rescanning happens automatically if you set imenu-auto-rescan
to a non-nil value. There is no need to rescan because of small changes in the text.
You can customize the way the menus are sorted by setting the variable imenusort-function. By default, names are ordered as they occur in the buffer; if you
want alphabetic sorting, use the symbol imenu--sort-by-name as the value. You
can also define your own comparison function by writing Lisp code.
Imenu provides the information to guide Which Function mode (see below). The
Speedbar can also use it (see Section 18.9 [Speedbar], page 174).
23.2.4 Which Function Mode
Which Function mode is a global minor mode (see Section 20.2 [Minor Modes],
page 205) which displays the current function name in the mode line, updating it
as you move around in a buffer.
To either enable or disable Which Function mode, use the command M-x
which-function-mode. Although Which Function mode is a global minor mode, it
takes effect only in certain major modes: those listed in the variable which-funcmodes. If the value of which-func-modes is t rather than a list of modes, then
Which Function mode applies to all major modes that know how to support it—in
other words, all the major modes that support Imenu.

23.3 Indentation for Programs
The best way to keep a program properly indented is to use Emacs to reindent it
as you change it. Emacs has commands to indent either a single line, a specified
number of lines, or all of the lines inside a single parenthetical grouping.
See Chapter 21 [Indentation], page 210, for general information about indentation. This section describes indentation features specific to programming language
modes.
Emacs also provides a Lisp pretty-printer in the pp package, which reformats
Lisp objects with nice-looking indentation.
23.3.1 Basic Program Indentation Commands
TAB

Adjust indentation of current line (indent-for-tab-command).

C-j

Insert a newline, then adjust indentation of following line (newlineand-indent).

The basic indentation command is TAB (indent-for-tab-command), which
was documented in Chapter 21 [Indentation], page 210. In programming language
modes, TAB indents the current line, based on the indentation and syntactic con-

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tent of the preceding lines; if the region is active, TAB indents each line within the
region, not just the current line.
The command C-j (newline-and-indent), which was documented in
Section 21.1 [Indentation Commands], page 210, does the same as RET followed
by TAB: it inserts a new line, then adjusts the line’s indentation.
When indenting a line that starts within a parenthetical grouping, Emacs usually
places the start of the line under the preceding line within the group, or under the
text after the parenthesis. If you manually give one of these lines a nonstandard
indentation (e.g. for aesthetic purposes), the lines below will follow it.
The indentation commands for most programming language modes assume that
a open-parenthesis, open-brace or other opening delimiter at the left margin is the
start of a function. If the code you are editing violates this assumption—even if the
delimiters occur in strings or comments—you must set open-paren-in-column-0is-defun-start to nil for indentation to work properly. See Section 23.2.1 [Left
Margin Paren], page 250.
23.3.2 Indenting Several Lines
Sometimes, you may want to reindent several lines of code at a time. One way to
do this is to use the mark; when the mark is active and the region is non-empty,
TAB indents every line in the region. Alternatively, the command C-M-\ (indentregion) indents every line in the region, whether or not the mark is active (see
Section 21.1 [Indentation Commands], page 210).
In addition, Emacs provides the following commands for indenting large chunks
of code:
C-M-q

Reindent all the lines within one parenthetical grouping.

C-u TAB

Shift an entire parenthetical grouping rigidly sideways so that its first
line is properly indented.

M-x indent-code-rigidly
Shift all the lines in the region rigidly sideways, but do not alter lines
that start inside comments and strings.
To reindent the contents of a single parenthetical grouping, position point before
the beginning of the grouping and type C-M-q. This changes the relative indentation
within the grouping, without affecting its overall indentation (i.e. the indentation
of the line where the grouping starts). The function that C-M-q runs depends on
the major mode; it is indent-pp-sexp in Lisp mode, c-indent-exp in C mode,
etc. To correct the overall indentation as well, type TAB first.
If you like the relative indentation within a grouping but not the indentation
of its first line, move point to that first line and type C-u TAB. In Lisp, C, and
some other major modes, TAB with a numeric argument reindents the current
line as usual, then reindents by the same amount all the lines in the parenthetical
grouping starting on the current line. It is clever, though, and does not alter lines
that start inside strings. Neither does it alter C preprocessor lines when in C mode,
but it does reindent any continuation lines that may be attached to them.

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The command M-x indent-code-rigidly rigidly shifts all the lines in the region
sideways, like indent-rigidly does (see Section 21.1 [Indentation Commands],
page 210). It doesn’t alter the indentation of lines that start inside a string, unless
the region also starts inside that string. The prefix arg specifies the number of
columns to indent.
23.3.3 Customizing Lisp Indentation
The indentation pattern for a Lisp expression can depend on the function called by
the expression. For each Lisp function, you can choose among several predefined
patterns of indentation, or define an arbitrary one with a Lisp program.
The standard pattern of indentation is as follows: the second line of the expression is indented under the first argument, if that is on the same line as the beginning
of the expression; otherwise, the second line is indented underneath the function
name. Each following line is indented under the previous line whose nesting depth
is the same.
If the variable lisp-indent-offset is non-nil, it overrides the usual indentation pattern for the second line of an expression, so that such lines are always
indented lisp-indent-offset more columns than the containing list.
Certain functions override the standard pattern. Functions whose names start
with def treat the second lines as the start of a body, by indenting the second line
lisp-body-indent additional columns beyond the open-parenthesis that starts the
expression.
You can override the standard pattern in various ways for individual functions,
according to the lisp-indent-function property of the function name. This is
normally done for macro definitions, using the declare construct. See Section
“Defining Macros” in the Emacs Lisp Reference Manual.
23.3.4 Commands for C Indentation
Here are special features for indentation in C mode and related modes:
C-c C-q

Reindent the current top-level function definition or aggregate type
declaration (c-indent-defun).

C-M-q

Reindent each line in the balanced expression that follows point (cindent-exp). A prefix argument inhibits warning messages about
invalid syntax.

TAB

Reindent the current line, and/or in some cases insert a tab character
(c-indent-command).
If c-tab-always-indent is t, this command always reindents the current line and does nothing else. This is the default.
If that variable is nil, this command reindents the current line only
if point is at the left margin or in the line’s indentation; otherwise, it
inserts a tab (or the equivalent number of spaces, if indent-tabs-mode
is nil).

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Any other value (not nil or t) means always reindent the line, and
also insert a tab if within a comment or a string.
To reindent the whole current buffer, type C-x h C-M-\. This first selects the
whole buffer as the region, then reindents that region.
To reindent the current block, use C-M-u C-M-q. This moves to the front of the
block and then reindents it all.
23.3.5 Customizing C Indentation
C mode and related modes use a flexible mechanism for customizing indentation.
C mode indents a source line in two steps: first it classifies the line syntactically
according to its contents and context; second, it determines the indentation offset
associated by your selected style with the syntactic construct and adds this onto
the indentation of the anchor statement.
C-c . RET style RET
Select a predefined style style (c-set-style).
A style is a named collection of customizations that can be used in C mode
and the related modes. Section “Styles” in The CC Mode Manual, for a complete
description. Emacs comes with several predefined styles, including gnu, k&r, bsd,
stroustrup, linux, python, java, whitesmith, ellemtel, and awk. Some of these
styles are primarily intended for one language, but any of them can be used with
any of the languages supported by these modes. To find out what a style looks like,
select it and reindent some code, e.g., by typing C-M-Q at the start of a function
definition.
To choose a style for the current buffer, use the command C-c .. Specify a style
name as an argument (case is not significant). This command affects the current
buffer only, and it affects only future invocations of the indentation commands; it
does not reindent the code already in the buffer. To reindent the whole buffer in
the new style, you can type C-x h C-M-\.
You can also set the variable c-default-style to specify the default style for
various major modes. Its value should be either the style’s name (a string) or an
alist, in which each element specifies one major mode and which indentation style
to use for it. For example,
(setq c-default-style
’((java-mode . "java")
(awk-mode . "awk")
(other . "gnu")))
specifies explicit choices for Java and AWK modes, and the default ‘gnu’ style for
the other C-like modes. (These settings are actually the defaults.) This variable
takes effect when you select one of the C-like major modes; thus, if you specify a
new default style for Java mode, you can make it take effect in an existing Java
mode buffer by typing M-x java-mode there.
The gnu style specifies the formatting recommended by the GNU Project for C;
it is the default, so as to encourage use of our recommended style.

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See Section “Indentation Engine Basics” in the CC Mode Manual, and Section
“Customizing Indentation” in the CC Mode Manual, for more information on customizing indentation for C and related modes, including how to override parts of
an existing style and how to define your own styles.
As an alternative to specifying a style, you can tell Emacs to guess a style by
typing M-x c-guess in a sample code buffer. You can then apply the guessed style
to other buffers with M-x c-guess-install. See Section “Guessing the Style” in
the CC Mode Manual, for details.

23.4 Commands for Editing with Parentheses
This section describes the commands and features that take advantage of the parenthesis structure in a program, or help you keep it balanced.
When talking about these facilities, the term “parenthesis” also includes braces,
brackets, or whatever delimiters are defined to match in pairs. The major mode controls which delimiters are significant, through the syntax table (see Section “Syntax
Tables” in The Emacs Lisp Reference Manual). In Lisp, only parentheses count; in
C, these commands apply to braces and brackets too.
You can use M-x check-parens to find any unbalanced parentheses and unbalanced string quotes in the buffer.
23.4.1 Expressions with Balanced Parentheses
Each programming language mode has its own definition of a balanced expression.
Balanced expressions typically include individual symbols, numbers, and string constants, as well as pieces of code enclosed in a matching pair of delimiters. The following commands deal with balanced expressions (in Emacs, such expressions are
referred to internally as sexps 1 ).
C-M-f

Move forward over a balanced expression (forward-sexp).

C-M-b

Move backward over a balanced expression (backward-sexp).

C-M-k

Kill balanced expression forward (kill-sexp).

C-M-t

Transpose expressions (transpose-sexps).

C-M-@
C-M-SPC

Put mark after following expression (mark-sexp).

To move forward over a balanced expression, use C-M-f (forward-sexp). If the
first significant character after point is an opening delimiter (e.g. ‘(’, ‘[’ or ‘{’ in C),
this command moves past the matching closing delimiter. If the character begins a
symbol, string, or number, the command moves over that.
The command C-M-b (backward-sexp) moves backward over a balanced
expression—like C-M-f, but in the reverse direction. If the expression is preceded
by any prefix characters (single-quote, backquote and comma, in Lisp), the
command moves back over them as well.
1

The word “sexp” is used to refer to an expression in Lisp.

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C-M-f or C-M-b with an argument repeats that operation the specified number of
times; with a negative argument means to move in the opposite direction. In most
modes, these two commands move across comments as if they were whitespace.
Note that their keys, C-M-f and C-M-b, are analogous to C-f and C-b, which move
by characters (see Section 4.2 [Moving Point], page 18), and M-f and M-b, which
move by words (see Section 22.1 [Words], page 214).
To kill a whole balanced expression, type C-M-k (kill-sexp). This kills the text
that C-M-f would move over.
C-M-t (transpose-sexps) switches the positions of the previous balanced expression and the next one. It is analogous to the C-t command, which transposes
characters (see Section 13.2 [Transpose], page 111). An argument to C-M-t serves
as a repeat count, moving the previous expression over that many following ones. A
negative argument moves the previous balanced expression backwards across those
before it. An argument of zero, rather than doing nothing, transposes the balanced
expressions ending at or after point and the mark.
To operate on balanced expressions with a command which acts on the region,
type C-M-SPC (mark-sexp). This sets the mark where C-M-f would move to. While
the mark is active, each successive call to this command extends the region by
shifting the mark by one expression. Positive or negative numeric arguments move
the mark forward or backward by the specified number of expressions. The alias
C-M-@ is equivalent to C-M-SPC. See Section 8.2 [Marking Objects], page 49, for
more information about this and related commands.
In languages that use infix operators, such as C, it is not possible to recognize all
balanced expressions because there can be multiple possibilities at a given position.
For example, C mode does not treat ‘foo + bar’ as a single expression, even though
it is one C expression; instead, it recognizes ‘foo’ as one expression and ‘bar’ as
another, with the ‘+’ as punctuation between them. However, C mode recognizes
‘(foo + bar)’ as a single expression, because of the parentheses.
23.4.2 Moving in the Parenthesis Structure
The following commands move over groupings delimited by parentheses (or whatever
else serves as delimiters in the language you are working with). They ignore strings
and comments, including any parentheses within them, and also ignore parentheses
that are “quoted” with an escape character. These commands are mainly intended
for editing programs, but can be useful for editing any text containing parentheses.
They are referred to internally as “list” commands because in Lisp these groupings
are lists.
These commands assume that the starting point is not inside a string or a
comment. If you invoke them from inside a string or comment, the results are
unreliable.
C-M-n

Move forward over a parenthetical group (forward-list).

C-M-p

Move backward over a parenthetical group (backward-list).

C-M-u

Move up in parenthesis structure (backward-up-list).

C-M-d

Move down in parenthesis structure (down-list).

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The “list” commands C-M-n (forward-list) and C-M-p (backward-list) move
forward or backward over one (or n) parenthetical groupings.
C-M-n and C-M-p try to stay at the same level in the parenthesis structure. To
move up one (or n) levels, use C-M-u (backward-up-list). C-M-u moves backward
up past one unmatched opening delimiter. A positive argument serves as a repeat
count; a negative argument reverses the direction of motion, so that the command
moves forward and up one or more levels.
To move down in the parenthesis structure, use C-M-d (down-list). In Lisp
mode, where ‘(’ is the only opening delimiter, this is nearly the same as searching
for a ‘(’. An argument specifies the number of levels to go down.
23.4.3 Matching Parentheses
Emacs has a number of parenthesis matching features, which make it easy to see
how and whether parentheses (or other delimiters) match up.
Whenever you type a self-inserting character that is a closing delimiter, the cursor moves momentarily to the location of the matching opening delimiter, provided
that is on the screen. If it is not on the screen, Emacs displays some of the text
near it in the echo area. Either way, you can tell which grouping you are closing off.
If the opening delimiter and closing delimiter are mismatched—such as in ‘[x)’—a
warning message is displayed in the echo area.
Three variables control the display of matching parentheses:
• blink-matching-paren turns the feature on or off: nil disables it, but the
default is t to enable it.
• blink-matching-delay says how many seconds to leave the cursor on the
matching opening delimiter, before bringing it back to the real location of
point. This may be an integer or floating-point number; the default is 1.
• blink-matching-paren-distance specifies how many characters back to
search to find the matching opening delimiter. If the match is not found
in that distance, Emacs stops scanning and nothing is displayed. The default
is 102400.
Show Paren mode, a global minor mode, provides a more powerful kind of automatic matching. Whenever point is before an opening delimiter or after a closing
delimiter, both that delimiter and its opposite delimiter are highlighted. To toggle
Show Paren mode, type M-x show-paren-mode.
Electric Pair mode, a global minor mode, provides a way to easily insert matching delimiters. Whenever you insert an opening delimiter, the matching closing
delimiter is automatically inserted as well, leaving point between the two. To toggle Electric Pair mode, type M-x electric-pair-mode.

23.5 Manipulating Comments
Because comments are such an important part of programming, Emacs provides
special commands for editing and inserting comments. It can also do spell checking
on comments with Flyspell Prog mode (see Section 13.4 [Spelling], page 112).

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Some major modes have special rules for indenting different kinds of comments.
For example, in Lisp code, comments starting with two semicolons are indented as
if they were lines of code, while those starting with three semicolons are supposed
to be aligned to the left margin and are often used for sectioning purposes. Emacs
understand these conventions; for instance, typing TAB on a comment line will
indent the comment to the appropriate position.
;; This function is just an example.
;;; Here either two or three semicolons are appropriate.
(defun foo (x)
;;; And now, the first part of the function:
;; The following line adds one.
(1+ x))
; This line adds one.
23.5.1 Comment Commands
The following commands operate on comments:
M-;

Insert or realign comment on current line; if the region is active, comment or uncomment the region instead (comment-dwim).

C-u M-;

Kill comment on current line (comment-kill).

C-x ;

Set comment column (comment-set-column).

C-M-j
M-j

Like RET followed by inserting and aligning a comment (commentindent-new-line).
See Section 23.5.2 [Multi-Line Comments],
page 260.

M-x comment-region
C-c C-c (in C-like modes)
Add comment delimiters to all the lines in the region.
The command to create or align a comment is M-; (comment-dwim). The word
“dwim” is an acronym for “Do What I Mean”; it indicates that this command can
be used for many different jobs relating to comments, depending on the situation
where you use it.
When a region is active (see Chapter 8 [Mark], page 47), M-; either adds comment delimiters to the region, or removes them. If every line in the region is already
a comment, it “uncomments” each of those lines by removing their comment delimiters. Otherwise, it adds comment delimiters to enclose the text in the region.
If you supply a prefix argument to M-; when a region is active, that specifies
the number of comment delimiters to add or delete. A positive argument n adds n
delimiters, while a negative argument -n removes n delimiters.
If the region is not active, and there is no existing comment on the current
line, M-; adds a new comment to the current line. If the line is blank (i.e. empty
or containing only whitespace characters), the comment is indented to the same
position where TAB would indent to (see Section 23.3.1 [Basic Indent], page 252). If
the line is non-blank, the comment is placed after the last non-whitespace character
on the line; normally, Emacs tries putting it at the column specified by the variable

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comment-column (see Section 23.5.3 [Options for Comments], page 261), but if
the line already extends past that column, it puts the comment at some suitable
position, usually separated from the non-comment text by at least one space. In
each case, Emacs places point after the comment’s starting delimiter, so that you
can start typing the comment text right away.
You can also use M-; to align an existing comment. If a line already contains
the comment-start string, M-; realigns it to the conventional alignment and moves
point after the comment’s starting delimiter. As an exception, comments starting
in column 0 are not moved. Even when an existing comment is properly aligned,
M-; is still useful for moving directly to the start of the comment text.
C-u M-; (comment-dwim with a prefix argument) kills any comment on the current line, along with the whitespace before it. Since the comment is saved to the
kill ring, you can reinsert it on another line by moving to the end of that line, doing
C-y, and then M-; to realign the comment. You can achieve the same effect as C-u
M-; by typing M-x comment-kill (comment-dwim actually calls comment-kill as a
subroutine when it is given a prefix argument).
The command M-x comment-region is equivalent to calling M-; on an active
region, except that it always acts on the region, even if the mark is inactive. In C
mode and related modes, this command is bound to C-c C-c. The command M-x
uncomment-region uncomments each line in the region; a numeric prefix argument
specifies the number of comment delimiters to remove (negative arguments specify
the number of comment to delimiters to add).
For C-like modes, you can configure the exact effect of M-; by setting the variables c-indent-comment-alist and c-indent-comments-syntactically-p. For
example, on a line ending in a closing brace, M-; puts the comment one space after
the brace rather than at comment-column. For full details see Section “Comment
Commands” in The CC Mode Manual.
23.5.2 Multiple Lines of Comments
If you are typing a comment and wish to continue it to another line, type M-j or
C-M-j (comment-indent-new-line). This breaks the current line, and inserts the
necessary comment delimiters and indentation to continue the comment.
For languages with closing comment delimiters (e.g. ‘*/’ in C), the exact behavior of M-j depends on the value of the variable comment-multi-line. If the value is
nil, the command closes the comment on the old line and starts a new comment on
the new line. Otherwise, it opens a new line within the current comment delimiters.
When Auto Fill mode is on, going past the fill column while typing a comment
also continues the comment, in the same way as an explicit invocation of M-j.
To turn existing lines into comment lines, use M-; with the region active, or use
M-x comment-region as described in the preceding section.
You can configure C Mode such that when you type a ‘/’ at the start of a line in
a multi-line block comment, this closes the comment. Enable the comment-closeslash clean-up for this. See Section “Clean-ups” in The CC Mode Manual.

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23.5.3 Options Controlling Comments
As mentioned in Section 23.5.1 [Comment Commands], page 259, when the M-j command adds a comment to a line, it tries to place the comment at the column specified
by the buffer-local variable comment-column. You can set either the local value or
the default value of this buffer-local variable in the usual way (see Section 33.2.3
[Locals], page 446). Alternatively, you can type C-x ; (comment-set-column) to
set the value of comment-column in the current buffer to the column where point is
currently located. C-u C-x ; sets the comment column to match the last comment
before point in the buffer, and then does a M-; to align the current line’s comment
under the previous one.
The comment commands recognize comments based on the regular expression
that is the value of the variable comment-start-skip. Make sure this regexp does
not match the null string. It may match more than the comment starting delimiter
in the strictest sense of the word; for example, in C mode the value of the variable
is "\\(//+\\|/\\*+\\)\\s *", which matches extra stars and spaces after the ‘/*’
itself, and accepts C++ style comments also. (Note that ‘\\’ is needed in Lisp
syntax to include a ‘\’ in the string, which is needed to deny the first star its special
meaning in regexp syntax. See Section 12.6 [Regexp Backslash], page 100.)
When a comment command makes a new comment, it inserts the value of
comment-start as an opening comment delimiter. It also inserts the value of
comment-end after point, as a closing comment delimiter. For example, in Lisp
mode, comment-start is ‘";"’ and comment-end is "" (the empty string). In C
mode, comment-start is "/* " and comment-end is " */".
The variable comment-padding specifies a string that the commenting commands should insert between the comment delimiter(s) and the comment text. The
default, ‘" "’, specifies a single space. Alternatively, the value can be a number,
which specifies that number of spaces, or nil, which means no spaces at all.
The variable comment-multi-line controls how M-j and Auto Fill mode continue comments over multiple lines. See Section 23.5.2 [Multi-Line Comments],
page 260.
The variable comment-indent-function should contain a function that will be
called to compute the alignment for a newly inserted comment or for aligning an
existing comment. It is set differently by various major modes. The function is
called with no arguments, but with point at the beginning of the comment, or at
the end of a line if a new comment is to be inserted. It should return the column
in which the comment ought to start. For example, in Lisp mode, the indent hook
function bases its decision on how many semicolons begin an existing comment, and
on the code in the preceding lines.

23.6 Documentation Lookup
Emacs provides several features you can use to look up the documentation of functions, variables and commands that you plan to use in your program.

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23.6.1 Info Documentation Lookup
For major modes that apply to languages which have documentation in Info, you
can use C-h S (info-lookup-symbol) to view the Info documentation for a symbol
used in the program. You specify the symbol with the minibuffer; the default is
the symbol appearing in the buffer at point. For example, in C mode this looks for
the symbol in the C Library Manual. The command only works if the appropriate
manual’s Info files are installed.
The major mode determines where to look for documentation for the symbol—
which Info files to look in, and which indices to search. You can also use M-x
info-lookup-file to look for documentation for a file name.
If you use C-h S in a major mode that does not support it, it asks you to specify
the “symbol help mode”. You should enter a command such as c-mode that would
select a major mode which C-h S does support.
23.6.2 Man Page Lookup
On Unix, the main form of on-line documentation was the manual page or man page.
In the GNU operating system, we aim to replace man pages with better-organized
manuals that you can browse with Info (see Section 7.7 [Misc Help], page 44). This
process is not finished, so it is still useful to read manual pages.
You can read the man page for an operating system command, library function,
or system call, with the M-x man command. This prompts for a topic, with completion (see Section 5.3 [Completion], page 29), and runs the man program to format
the corresponding man page. If the system permits, it runs man asynchronously, so
that you can keep on editing while the page is being formatted. The result goes in
a buffer named ‘*Man topic *’. These buffers use a special major mode, Man mode,
that facilitates scrolling and jumping to other manual pages. For details, type C-h
m while in a Man mode buffer.
Each man page belongs to one of ten or more sections, each named by a digit or
by a digit and a letter. Sometimes there are man pages with the same name in different sections. To read a man page from a specific section, type ‘topic (section )’
or ‘section topic ’ when M-x manual-entry prompts for the topic. For example,
the man page for the C library function chmod is in section 2, but there is a shell
command of the same name, whose man page is in section 1; to view the former,
type M-x manual-entry RET chmod(2) RET.
If you do not specify a section, M-x man normally displays only the first man
page found. On some systems, the man program accepts a ‘-a’ command-line option,
which tells it to display all the man pages for the specified topic. To make use of
this, change the value of the variable Man-switches to ‘"-a"’. Then, in the Man
mode buffer, you can type M-n and M-p to switch between man pages in different
sections. The mode line shows how many manual pages are available.
An alternative way of reading manual pages is the M-x woman command. Unlike
M-x man, it does not run any external programs to format and display the man pages;
the formatting is done by Emacs, so it works on systems such as MS-Windows where
the man program may be unavailable. It prompts for a man page, and displays it in
a buffer named ‘*WoMan section topic ’.

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M-x woman computes the completion list for manpages the first time you invoke
the command. With a numeric argument, it recomputes this list; this is useful if
you add or delete manual pages.
If you type a name of a manual page and M-x woman finds that several manual
pages by the same name exist in different sections, it pops up a window with possible
candidates asking you to choose one of them.
For more information about setting up and using M-x woman, see the WoMan
Info manual, which is distributed with Emacs.
23.6.3 Emacs Lisp Documentation Lookup
When editing Emacs Lisp code, you can use the commands C-h f (describefunction) and C-h v (describe-variable) to view the built-in documentation
for the Lisp functions and variables that you want to use. See Section 7.2 [Name
Help], page 40.
Eldoc is a buffer-local minor mode that helps with looking up Lisp documention.
When it is enabled, the echo area displays some useful information whenever there
is a Lisp function or variable at point; for a function, it shows the argument list,
and for a variable it shows the first line of the variable’s documentation string. To
toggle Eldoc mode, type M-x eldoc-mode. Eldoc mode can be used with the Emacs
Lisp and Lisp Interaction major modes.

23.7 Hideshow minor mode
Hideshow mode is a buffer-local minor mode that allows you to selectively display
portions of a program, which are referred to as blocks. Type M-x hs-minor-mode
to toggle this minor mode (see Section 20.2 [Minor Modes], page 205).
When you use Hideshow mode to hide a block, the block disappears from the
screen, to be replaced by an ellipsis (three periods in a row). Just what constitutes
a block depends on the major mode. In C mode and related modes, blocks are
delimited by braces, while in Lisp mode they are delimited by parentheses. Multiline comments also count as blocks.
Hideshow mode provides the following commands:
C-c @ C-h

Hide the current block (hs-hide-block).

C-c @ C-s

Show the current block (hs-show-block).

C-c @ C-c

Either hide or show the current block (hs-toggle-hiding).

S-Mouse-2

Toggle hiding for the block you click on (hs-mouse-toggle-hiding).

C-c @ C-M-h
Hide all top-level blocks (hs-hide-all).
C-c @ C-M-s
Show all blocks in the buffer (hs-show-all).
C-c @ C-l

Hide all blocks n levels below this block (hs-hide-level).

These variables can be used to customize Hideshow mode:

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hs-hide-comments-when-hiding-all
If non-nil, C-c @ C-M-h (hs-hide-all) hides comments too.
hs-isearch-open
This variable specifies the conditions under which incremental search
should unhide a hidden block when matching text occurs within the
block. Its value should be either code (unhide only code blocks),
comment (unhide only comments), t (unhide both code blocks and
comments), or nil (unhide neither code blocks nor comments). The
default value is code.

23.8 Completion for Symbol Names
Completion is normally done in the minibuffer (see Section 5.3 [Completion],
page 29), but you can also complete symbol names in ordinary Emacs buffers.
In programming language modes, type C-M-i or M-TAB to complete the partial
symbol before point. On graphical displays, the M-TAB key is usually reserved by
the window manager for switching graphical windows, so you should type C-M-i or
ESC TAB instead.
In most programming language modes, C-M-i (or M-TAB) invokes the command
completion-at-point, which generates its completion list in a flexible way. If
Semantic mode is enabled, it tries to use the Semantic parser data for completion
(see Section 23.10 [Semantic], page 265). If Semantic mode is not enabled or fails
at performing completion, it tries to complete using the selected tags table (see
Section 25.3 [Tags], page 311). If in Emacs Lisp mode, it performs completion using
the function, variable, or property names defined in the current Emacs session.
In all other respects, in-buffer symbol completion behaves like minibuffer completion. For instance, if Emacs cannot complete to a unique symbol, it displays
a list of completion alternatives in another window. See Section 5.3 [Completion],
page 29.
In Text mode and related modes, M-TAB completes words based on the spellchecker’s dictionary. See Section 13.4 [Spelling], page 112.

23.9 Glasses minor mode
Glasses mode is a buffer-local minor mode that makes it easier to read mixedcase (or “CamelCase”) symbols like ‘unReadableSymbol’, by altering how they are
displayed. By default, it displays extra underscores between each lower-case letter
and the following capital letter. This does not alter the buffer text, only how it is
displayed.
To toggle Glasses mode, type M-x glasses-mode (see Section 20.2 [Minor
Modes], page 205). When Glasses mode is enabled, the minor mode indicator ‘o^o’
appears in the mode line. For more information about Glasses mode, type C-h P
glasses RET.

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23.10 Semantic
Semantic is a package that provides language-aware editing commands based on
source code parsers. This section provides a brief description of Semantic; for
full details, see the Semantic Info manual, which is distributed with Emacs.
Most of the “language aware” features in Emacs, such as Font Lock mode (see
Section 11.12 [Font Lock], page 80), rely on “rules of thumb”2 that usually give good
results but are never completely exact. In contrast, the parsers used by Semantic
have an exact understanding of programming language syntax. This allows Semantic to provide search, navigation, and completion commands that are powerful and
precise.
To begin using Semantic, type M-x semantic-mode or click on the menu item
named ‘Source Code Parsers (Semantic)’ in the ‘Tools’ menu. This enables Semantic mode, a global minor mode.
When Semantic mode is enabled, Emacs automatically attempts to parses each
file you visit. Currently, Semantic understands C, C++, Scheme, Javascript, Java,
HTML, and Make. Within each parsed buffer, the following commands are available:
C-c , j

Prompt for the name of a function defined in the current file, and move
point there (semantic-complete-jump-local).

C-c , J

Prompt for the name of a function defined in any file Emacs has parsed,
and move point there (semantic-complete-jump).

C-c , SPC

Display a list of possible completions for the symbol at point
(semantic-complete-analyze-inline). This also activates a set
of special key bindings for choosing a completion: RET accepts the
current completion, M-n and M-p cycle through possible completions,
TAB completes as far as possible and then cycles, and C-g or any
other key aborts completion.

C-c , l

Display a list of the possible completions of the symbol at point, in
another window (semantic-analyze-possible-completions).

In addition to the above commands, the Semantic package provides a variety of
other ways to make use of parser information. For instance, you can use it to
display a list of completions when Emacs is idle.

23.11 Other Features Useful for Editing Programs
Some Emacs commands that aren’t designed specifically for editing programs are
useful for that nonetheless.
The Emacs commands that operate on words, sentences and paragraphs are useful for editing code. Most symbols names contain words (see Section 22.1 [Words],
page 214), while sentences can be found in strings and comments (see Section 22.2
[Sentences], page 215). As for paragraphs, they are defined in most programming
language modes to begin and end at blank lines (see Section 22.3 [Paragraphs],
2

Regular expressions and syntax tables.

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page 216). Therefore, judicious use of blank lines to make the program clearer will
also provide useful chunks of text for the paragraph commands to work on. Auto
Fill mode, if enabled in a programming language major mode, indents the new lines
which it creates.
Electric Layout mode (M-x electric-layout-mode) is a global minor mode that
automatically inserts newlines when you type certain characters; for example, ‘{’,
‘}’ and ‘;’ in Javascript mode.
Apart from Hideshow mode (see Section 23.7 [Hideshow], page 263), another
way to selectively display parts of a program is to use the selective display feature
(see Section 11.17 [Selective Display], page 85). Programming modes often also
support Outline minor mode (see Section 22.8 [Outline Mode], page 224), which
can be used with the Foldout package (see Section 22.8.5 [Foldout], page 228).

23.12 C and Related Modes
This section gives a brief description of the special features available in C, C++,
Objective-C, Java, CORBA IDL, Pike and AWK modes. (These are called “C
mode and related modes”.) For more details, see the CC mode Info manual, which
is distributed with Emacs.
23.12.1 C Mode Motion Commands
This section describes commands for moving point, in C mode and related modes.
C-M-a
C-M-e

C-c C-u

Move point to the beginning or end of the current function or top-level
definition. In languages with enclosing scopes (such as C++’s classes)
the current function is the immediate one, possibly inside a scope.
Otherwise it is the one defined by the least enclosing braces. (By
contrast, beginning-of-defun and end-of-defun search for braces
in column zero.) See Section 23.2.2 [Moving by Defuns], page 251.
Move point back to the containing preprocessor conditional, leaving
the mark behind. A prefix argument acts as a repeat count. With a
negative argument, move point forward to the end of the containing
preprocessor conditional.
‘#elif’ is equivalent to ‘#else’ followed by ‘#if’, so the function will
stop at a ‘#elif’ when going backward, but not when going forward.

C-c C-p

Move point back over a preprocessor conditional, leaving the mark
behind. A prefix argument acts as a repeat count. With a negative
argument, move forward.

C-c C-n

Move point forward across a preprocessor conditional, leaving the mark
behind. A prefix argument acts as a repeat count. With a negative
argument, move backward.

M-a

Move point to the beginning of the innermost C statement (cbeginning-of-statement). If point is already at the beginning of

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a statement, move to the beginning of the preceding statement. With
prefix argument n, move back n − 1 statements.
In comments or in strings which span more than one line, this command moves by sentences instead of statements.
M-e

Move point to the end of the innermost C statement or sentence;
like M-a except that it moves in the other direction (c-end-ofstatement).

23.12.2 Electric C Characters
In C mode and related modes, certain printing characters are electric—in addition
to inserting themselves, they also reindent the current line, and optionally also
insert newlines. The “electric” characters are {, }, :, #, ;, ,, <, >, /, *, (, and ).
You might find electric indentation inconvenient if you are editing chaotically
indented code. If you are new to CC Mode, you might find it disconcerting. You can
toggle electric action with the command C-c C-l; when it is enabled, ‘/l’ appears
in the mode line after the mode name:
C-c C-l

Toggle electric action (c-toggle-electric-state). With a positive
prefix argument, this command enables electric action, with a negative
one it disables it.

Electric characters insert newlines only when, in addition to the electric state,
the auto-newline feature is enabled (indicated by ‘/la’ in the mode line after the
mode name). You can turn this feature on or off with the command C-c C-a:
C-c C-a

Toggle the auto-newline feature (c-toggle-auto-newline). With a
prefix argument, this command turns the auto-newline feature on if
the argument is positive, and off if it is negative.

Usually the CC Mode style configures the exact circumstances in which Emacs
inserts auto-newlines. You can also configure this directly. See Section “Custom
Auto-newlines” in The CC Mode Manual.
23.12.3 Hungry Delete Feature in C
If you want to delete an entire block of whitespace at point, you can use hungry
deletion. This deletes all the contiguous whitespace either before point or after
point in a single operation. Whitespace here includes tabs and newlines, but not
comments or preprocessor commands.
C-c C-DEL
C-c DEL

Delete the entire block of whitespace preceding point (c-hungrydelete-backwards).

C-c C-d
C-c C-DELETE
C-c DELETE Delete the entire block of whitespace after point (c-hungry-deleteforward).

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As an alternative to the above commands, you can enable hungry delete mode.
When this feature is enabled (indicated by ‘/h’ in the mode line after the mode
name), a single DEL deletes all preceding whitespace, not just one space, and a
single C-c C-d (but not plain DELETE) deletes all following whitespace.
M-x c-toggle-hungry-state
Toggle the hungry-delete feature (c-toggle-hungry-state). With a
prefix argument, this command turns the hungry-delete feature on if
the argument is positive, and off if it is negative.
The variable c-hungry-delete-key controls whether the hungry-delete feature
is enabled.
23.12.4 Other Commands for C Mode
C-c C-w
M-x subword-mode
Enable (or disable) subword mode. In subword mode, Emacs’s word
commands recognize upper case letters in ‘StudlyCapsIdentifiers’
as word boundaries. This is indicated by the flag ‘/w’ on the mode
line after the mode name (e.g. ‘C/law’). You can even use M-x
subword-mode in non-CC Mode buffers.
In the GNU project, we recommend using underscores to separate
words within an identifier in C or C++, rather than using case distinctions.
M-x c-context-line-break
This command inserts a line break and indents the new line in a manner appropriate to the context. In normal code, it does the work of
C-j (newline-and-indent), in a C preprocessor line it additionally
inserts a ‘\’ at the line break, and within comments it’s like M-j (cindent-new-comment-line).
c-context-line-break isn’t bound to a key by default, but it needs
a binding to be useful. The following code will bind it to C-j. We
use c-initialization-hook here to make sure the keymap is loaded
before we try to change it.
(defun my-bind-clb ()
(define-key c-mode-base-map "\C-j"
’c-context-line-break))
(add-hook ’c-initialization-hook ’my-bind-clb)
C-M-h

Put mark at the end of a function definition, and put point at the
beginning (c-mark-function).

M-q

Fill a paragraph, handling C and C++ comments (c-fill-paragraph).
If any part of the current line is a comment or within a comment, this
command fills the comment or the paragraph of it that point is in,
preserving the comment indentation and comment delimiters.

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C-c C-e

Run the C preprocessor on the text in the region, and show the result,
which includes the expansion of all the macro calls (c-macro-expand).
The buffer text before the region is also included in preprocessing, for
the sake of macros defined there, but the output from this part isn’t
shown.
When you are debugging C code that uses macros, sometimes it is hard
to figure out precisely how the macros expand. With this command,
you don’t have to figure it out; you can see the expansions.

C-c C-\

Insert or align ‘\’ characters at the ends of the lines of the region (cbackslash-region). This is useful after writing or editing a C macro
definition.
If a line already ends in ‘\’, this command adjusts the amount of
whitespace before it. Otherwise, it inserts a new ‘\’. However, the
last line in the region is treated specially; no ‘\’ is inserted on that
line, and any ‘\’ there is deleted.

M-x cpp-highlight-buffer
Highlight parts of the text according to its preprocessor conditionals. This command displays another buffer named ‘*CPP Edit*’, which
serves as a graphic menu for selecting how to display particular kinds
of conditionals and their contents. After changing various settings,
click on ‘[A]pply these settings’ (or go to that buffer and type a)
to rehighlight the C mode buffer accordingly.
C-c C-s

Display the syntactic information about the current source line (cshow-syntactic-information). This information directs how the
line is indented.

M-x cwarn-mode
M-x global-cwarn-mode
CWarn minor mode highlights certain suspicious C and C++ constructions:
• Assignments inside expressions.
• Semicolon following immediately after ‘if’, ‘for’, and ‘while’
(except after a ‘do ... while’ statement);
• C++ functions with reference parameters.
You can enable the mode for one buffer with the command M-x
cwarn-mode, or for all suitable buffers with the command M-x
global-cwarn-mode or by customizing the variable globalcwarn-mode. You must also enable Font Lock mode to make it
work.
M-x hide-ifdef-mode
Hide-ifdef minor mode hides selected code within ‘#if’ and ‘#ifdef’
preprocessor blocks. If you change the variable hide-ifdef-shadow to
t, Hide-ifdef minor mode “shadows” preprocessor blocks by displaying

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them with a less prominent face, instead of hiding them entirely. See
the documentation string of hide-ifdef-mode for more information.
M-x ff-find-related-file
Find a file “related” in a special way to the file visited by the current
buffer. Typically this will be the header file corresponding to a C/C++
source file, or vice versa. The variable ff-related-file-alist specifies how to compute related file names.

23.13 Asm Mode
Asm mode is a major mode for editing files of assembler code. It defines these
commands:
TAB

tab-to-tab-stop.

C-j

Insert a newline and then indent using tab-to-tab-stop.

:

Insert a colon and then remove the indentation from before the label
preceding colon. Then do tab-to-tab-stop.

;

Insert or align a comment.

The variable asm-comment-char specifies which character starts comments in
assembler syntax.

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24 Compiling and Testing Programs
The previous chapter discusses the Emacs commands that are useful for making
changes in programs. This chapter deals with commands that assist in the process
of compiling and testing programs.

24.1 Running Compilations under Emacs
Emacs can run compilers for languages such as C and Fortran, feeding the compilation log into an Emacs buffer. It can also parse the error messages and show you
where the errors occurred.
M-x compile
Run a compiler asynchronously under Emacs, with error messages
going to the ‘*compilation*’ buffer.
M-x recompile
Invoke a compiler with the same command as in the last invocation of
M-x compile.
M-x kill-compilation
Kill the running compilation subprocess.
To run make or another compilation command, type M-x compile. This reads a
shell command line using the minibuffer, and then executes the command by running
a shell as a subprocess (or inferior process) of Emacs. The output is inserted in
a buffer named ‘*compilation*’. The current buffer’s default directory is used
as the working directory for the execution of the command; normally, therefore,
compilation takes place in this directory.
The default compilation command is ‘make -k’, which is usually correct for programs compiled using the make utility (the ‘-k’ flag tells make to continue compiling
as much as possible after an error). See Section “Make” in GNU Make Manual. If
you have done M-x compile before, the command that you specified is automatically
stored in the variable compile-command; this is used as the default the next time
you type M-x compile. A file can also specify a file-local value for compile-command
(see Section 33.2.4 [File Variables], page 447).
Starting a compilation displays the ‘*compilation*’ buffer in another window
but does not select it. While the compilation is running, the word ‘run’ is shown in
the major mode indicator for the ‘*compilation*’ buffer, and the word ‘Compiling’
appears in all mode lines. You do not have to keep the ‘*compilation*’ buffer
visible while compilation is running; it continues in any case. When the compilation
ends, for whatever reason, the mode line of the ‘*compilation*’ buffer changes to
say ‘exit’ (followed by the exit code: ‘[0]’ for a normal exit), or ‘signal’ (if a
signal terminated the process).
If you want to watch the compilation transcript as it appears, switch to the
‘*compilation*’ buffer and move point to the end of the buffer. When point is at
the end, new compilation output is inserted above point, which remains at the end.
Otherwise, point remains fixed while compilation output is added at the end of the
buffer.

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If you change the variable compilation-scroll-output to a non-nil value,
the ‘*compilation*’ buffer scrolls automatically to follow the output. If the value
is first-error, scrolling stops when the first error appears, leaving point at that
error. For any other non-nil value, scrolling continues until there is no more output.
To rerun the last compilation with the same command, type M-x recompile.
This reuses the compilation command from the last invocation of M-x compile. It
also reuses the ‘*compilation*’ buffer and starts the compilation in its default
directory, which is the directory in which the previous compilation was started.
Starting a new compilation also kills any compilation already running in
‘*compilation*’, as the buffer can only handle one compilation at any time. However, M-x compile asks for confirmation before actually killing a compilation that
is running. You can also kill the compilation process with M-x kill-compilation.
To run two compilations at once, start the first one, then rename the
‘*compilation*’ buffer (perhaps using rename-uniquely; see Section 16.3 [Misc
Buffer], page 152), then switch buffers and start the other compilation. This will
create a new ‘*compilation*’ buffer.
You can control the environment passed to the compilation command with the
variable compilation-environment. Its value is a list of environment variable
settings; each element should be a string of the form "envvarname =value ". These
environment variable settings override the usual ones.

24.2 Compilation Mode
The ‘*compilation*’ buffer uses a major mode called Compilation mode. Compilation mode turns each error message in the buffer into a hyperlink; you can move
point to it and type RET, or click on it with the mouse (see Section 18.3 [Mouse
References], page 167), to visit the locus of the error message in a separate window.
The locus is the specific position in a file where that error occurred.
If you change the variable compilation-auto-jump-to-first-error to a nonnil value, Emacs automatically visits the locus of the first error message that
appears in the ‘*compilation*’ buffer.
Compilation mode provides the following additional commands. These commands can also be used in ‘*grep*’ buffers, where the hyperlinks are search matches
rather than error messages (see Section 24.4 [Grep Searching], page 275).
M-g M-n
M-g n
C-x ‘
M-g M-p
M-g p

Visit the locus of the next error message or match (next-error).
Visit the locus of the previous error message or match (previouserror).

M-n

Move point to the next error message or match, without visiting its
locus (compilation-next-error).

M-p

Move point to the previous error message or match, without visiting
its locus (compilation-previous-error).

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M-}

Move point to the next error message or match occurring in a different
file (compilation-next-file).

M-{

Move point to the previous error message or match occurring in a
different file (compilation-previous-file).

C-c C-f

Toggle Next Error Follow minor mode, which makes cursor motion in
the compilation buffer produce automatic source display.

To visit errors sequentially, type C-x ‘ (next-error), or equivalently M-g M-n or
M-g n. This command can be invoked from any buffer, not just a Compilation mode
buffer. The first time you invoke it after a compilation, it visits the locus of the first
error message. Each subsequent C-x ‘ visits the next error, in a similar fashion. If
you visit a specific error with RET or a mouse click in the ‘*compilation*’ buffer,
subsequent C-x ‘ commands advance from there. When C-x ‘ finds no more error
messages to visit, it signals an error. C-u C-x ‘ starts again from the beginning of
the compilation buffer, and visits the first locus.
M-g M-p or M-g p (previous-error) iterates through errors in the opposite direction.
The next-error and previous-error commands don’t just act on the errors
or matches listed in ‘*compilation*’ and ‘*grep*’ buffers; they also know how to
iterate through error or match lists produced by other commands, such as M-x occur
(see Section 12.10 [Other Repeating Search], page 107). If you are already in a buffer
containing error messages or matches, those are the ones that are iterated through;
otherwise, Emacs looks for a buffer containing error messages or matches amongst
the windows of the selected frame, then for one that next-error or previouserror previously iterated through, and finally amongst all other buffers. If the
buffer chosen for iterating through is not currently displayed in a window, it will be
displayed.
By default, the next-error and previous-error commands skip less important
messages. The variable compilation-skip-threshold controls this. The default
value, 1, means to skip anything less important than a warning. A value of 2
means to skip anything less important than an error, while 0 means not to skip any
messages.
When Emacs visits the locus of an error message, it momentarily highlights the
relevant source line. The duration of this highlight is determined by the variable
next-error-highlight.
If the ‘*compilation*’ buffer is shown in a window with a left fringe (see
Section 11.14 [Fringes], page 83), the locus-visiting commands put an arrow in
the fringe, pointing to the current error message. If the window has no left fringe,
such as on a text terminal, these commands scroll the window so that the current
message is at the top of the window. If you change the variable compilationcontext-lines to an integer value n, these commands scroll the window so that
the current error message is n lines from the top, whether or not there is a fringe;
the default value, nil, gives the behavior described above.
To parse messages from the compiler, Compilation mode uses the variable
compilation-error-regexp-alist which lists various error message formats and

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tells Emacs how to extract the locus from each. A similar variable, grep-regexpalist, tells Emacs how to parse output from a grep command (see Section 24.4
[Grep Searching], page 275).
Compilation mode also defines the keys SPC and DEL to scroll by screenfuls;
M-n (compilation-next-error) and M-p (compilation-previous-error) to move
to the next or previous error message; and M-{ (compilation-next-file) and M-}
(compilation-previous-file) to move to the next or previous error message for
a different source file.
You can type C-c C-f to toggle Next Error Follow mode. In this minor mode,
ordinary cursor motion in the compilation buffer automatically updates the source
buffer, i.e. moving the cursor over an error message causes the locus of that error
to be displayed.
The features of Compilation mode are also available in a minor mode called
Compilation Minor mode. This lets you parse error messages in any buffer, not
just a normal compilation output buffer. Type M-x compilation-minor-mode to
enable the minor mode. For instance, in an Rlogin buffer (see Section 31.3.10
[Remote Host], page 411), Compilation minor mode automatically accesses remote
source files by FTP (see Section 15.1 [File Names], page 124).

24.3 Subshells for Compilation
The M-x compile command uses a shell to run the compilation command, but
specifies the option for a noninteractive shell. This means, in particular, that the
shell should start with no prompt. If you find your usual shell prompt making
an unsightly appearance in the ‘*compilation*’ buffer, it means you have made a
mistake in your shell’s init file by setting the prompt unconditionally. (This init file
may be named ‘.bashrc’, ‘.profile’, ‘.cshrc’, ‘.shrc’, etc., depending on what
shell you use.) The shell init file should set the prompt only if there already is a
prompt. Here’s how to do it in bash:
if [ "${PS1+set}" = set ]
then PS1=...
fi
And here’s how to do it in csh:
if ($?prompt) set prompt = ...
Emacs does not expect a compiler process to launch asynchronous subprocesses;
if it does, and they keep running after the main compiler process has terminated,
Emacs may kill them or their output may not arrive in Emacs. To avoid this
problem, make the main compilation process wait for its subprocesses to finish. In
a shell script, you can do this using ‘$!’ and ‘wait’, like this:
(sleep 10; echo 2nd)& pid=$! # Record pid of subprocess
echo first message
wait $pid
# Wait for subprocess
If the background process does not output to the compilation buffer, so you only
need to prevent it from being killed when the main compilation process terminates,
this is sufficient:

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nohup command ; sleep 1

24.4 Searching with Grep under Emacs
Just as you can run a compiler from Emacs and then visit the lines with compilation
errors, you can also run grep and then visit the lines on which matches were found.
This works by treating the matches reported by grep as if they were “errors”.
The output buffer uses Grep mode, which is a variant of Compilation mode (see
Section 24.2 [Compilation Mode], page 272).
M-x grep
M-x lgrep

Run grep asynchronously under Emacs, listing matching lines in the
buffer named ‘*grep*’.

M-x grep-find
M-x find-grep
M-x rgrep Run grep via find, and collect output in the ‘*grep*’ buffer.
M-x zrgrep Run zgrep and collect output in the ‘*grep*’ buffer.
M-x kill-grep
Kill the running grep subprocess.
To run grep, type M-x grep, then enter a command line that specifies how to
run grep. Use the same arguments you would give grep when running it normally:
a grep-style regexp (usually in single-quotes to quote the shell’s special characters)
followed by file names, which may use wildcards. If you specify a prefix argument
for M-x grep, it finds the tag (see Section 25.3 [Tags], page 311) in the buffer around
point, and puts that into the default grep command.
Your command need not simply run grep; you can use any shell command that
produces output in the same format. For instance, you can chain grep commands,
like this:
grep -nH -e foo *.el | grep bar | grep toto
The output from grep goes in the ‘*grep*’ buffer. You can find the corresponding lines in the original files using C-x ‘, RET, and so forth, just like compilation
errors.
Some grep programs accept a ‘--color’ option to output special markers around
matches for the purpose of highlighting. You can make use of this feature by setting
grep-highlight-matches to t. When displaying a match in the source buffer, the
exact match will be highlighted, instead of the entire source line.
The command M-x grep-find (also available as M-x find-grep) is similar to
M-x grep, but it supplies a different initial default for the command—one that runs
both find and grep, so as to search every file in a directory tree. See also the
find-grep-dired command, in Section 27.15 [Dired and Find], page 342.
The commands M-x lgrep (local grep) and M-x rgrep (recursive grep) are more
user-friendly versions of grep and grep-find, which prompt separately for the
regular expression to match, the files to search, and the base directory for the
search. Case sensitivity of the search is controlled by the current value of case-

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fold-search. The command M-x zrgrep is similar to M-x rgrep, but it calls zgrep
instead of grep to search the contents of gzipped files.
These commands build the shell commands based on the variables greptemplate (for lgrep) and grep-find-template (for rgrep). The files to search
can use aliases defined in the variable grep-files-aliases.
Directories listed in the variable grep-find-ignored-directories are automatically skipped by M-x rgrep. The default value includes the data directories
used by various version control systems.

24.5 Finding Syntax Errors On The Fly
Flymake mode is a minor mode that performs on-the-fly syntax checking for
many programming and markup languages, including C, C++, Perl, HTML, and
TEX/LaTEX. It is somewhat analogous to Flyspell mode, which performs spell
checking for ordinary human languages in a similar fashion (see Section 13.4 [Spelling], page 112). As you edit a file, Flymake mode runs an appropriate syntax
checking tool in the background, using a temporary copy of the buffer. It then
parses the error and warning messages, and highlights the erroneous lines in the
buffer. The syntax checking tool used depends on the language; for example, for
C/C++ files this is usually the C compiler. Flymake can also use build tools such
as make for checking complicated projects.
To enable Flymake mode, type M-x flymake-mode.
You can jump to
the errors that it finds by using M-x flymake-goto-next-error and M-x
flymake-goto-prev-error. To display any error messages associated with the
current line, type M-x flymake-display-err-menu-for-current-line.
For more details about using Flymake, see the Flymake Info manual, which is
distributed with Emacs.

24.6 Running Debuggers Under Emacs
The GUD (Grand Unified Debugger) library provides an Emacs interface to a wide
variety of symbolic debuggers. It can run the GNU Debugger (GDB), as well as
DBX, SDB, XDB, Perl’s debugging mode, the Python debugger PDB, and the Java
Debugger JDB.
Emacs provides a special interface to GDB, which uses extra Emacs windows
to display the state of the debugged program. See Section 24.6.5 [GDB Graphical
Interface], page 281.
Emacs also has a built-in debugger for Emacs Lisp programs. See Section “The
Lisp Debugger” in the Emacs Lisp Reference Manual.
24.6.1 Starting GUD
There are several commands for starting a debugger subprocess, each corresponding
to a particular debugger program.

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M-x gdb

277

Run GDB as a subprocess, and interact with it via an IDE-like Emacs
interface. See Section 24.6.5 [GDB Graphical Interface], page 281, for
more information about this command.

M-x gud-gdb
Run GDB, using a GUD interaction buffer for input and output to the
GDB subprocess (see Section 24.6.2 [Debugger Operation], page 277).
If such a buffer already exists, switch to it; otherwise, create the buffer
and switch to it.
The other commands in this list do the same, for other debugger programs.
M-x perldb Run the Perl interpreter in debug mode.
M-x jdb

Run the Java debugger.

M-x pdb

Run the Python debugger.

M-x dbx

Run the DBX debugger.

M-x xdb

Run the XDB debugger.

M-x sdb

Run the SDB debugger.

Each of these commands reads a command line to invoke the debugger, using
the minibuffer. The minibuffer’s initial contents contain the standard executable
name and options for the debugger, and sometimes also a guess for the name of the
executable file you want to debug. Shell wildcards and variables are not allowed in
this command line. Emacs assumes that the first command argument which does
not start with a ‘-’ is the executable file name.
Tramp provides a facility for remote debugging, whereby both the debugger and
the program being debugged are on the same remote host. See Section “Running
a debugger on a remote host” in The Tramp Manual, for details. This is separate
from GDB’s remote debugging feature, where the program and the debugger run
on different machines (see Section “Debugging Remote Programs” in The GNU
debugger).
24.6.2 Debugger Operation
The GUD interaction buffer is an Emacs buffer which is used to send text commands
to a debugger subprocess, and record its output. This is the basic interface for
interacting with a debugger, used by M-x gud-gdb and other commands listed in
the preceding section. The M-x gdb command extends this interface with additional
specialized buffers for controlling breakpoints, stack frames, and other aspects of
the debugger state (see Section 24.6.5 [GDB Graphical Interface], page 281).
The GUD interaction buffer uses a variant of Shell mode, so the Emacs
commands defined by Shell mode are available (see Section 31.3.3 [Shell Mode],
page 403). Completion is available for most debugger commands (see Section 5.3
[Completion], page 29), and you can use the usual Shell mode history commands
to repeat them. See the next section for special commands that can be used in the
GUD interaction buffer.

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As you debug a program, Emacs displays the relevant source files by visiting
them in Emacs buffers, with an arrow in the left fringe indicating the current execution line. (On a text terminal, the arrow appears as ‘=>’, overlaid on the first
two text columns.) Moving point in such a buffer does not move the arrow. You
are free to edit these source files, but note that inserting or deleting lines will throw
off the arrow’s positioning, as Emacs has no way to figure out which edited source
line corresponds to the line reported by the debugger subprocess. To update this
information, you typically have to recompile and restart the program.
GUD Tooltip mode is a global minor mode that adds tooltip support to GUD. To
toggle this mode, type M-x gud-tooltip-mode. It is disabled by default. If enabled,
you can move the mouse cursor over a variable to show its value in a tooltip (see
Section 18.17 [Tooltips], page 178); this takes effect in the GUD interaction buffer,
and in all source buffers with major modes listed in the variable gud-tooltipmodes. If the variable gud-tooltip-echo-area is non-nil, values are shown in the
echo area instead of a tooltip.
When using GUD Tooltip mode with M-x gud-gdb, you should note that displaying an expression’s value in GDB can sometimes expand a macro, potentially
causing side effects in the debugged program. If you use the M-x gdb interface, this
problem does not occur, as there is special code to avoid side-effects; furthermore,
you can display macro definitions associated with an identifier when the program
is not executing.
24.6.3 Commands of GUD
GUD provides commands for setting and clearing breakpoints, selecting stack
frames, and stepping through the program.
C-x SPC

Set a breakpoint on the source line that point is on.

C-x SPC (gud-break), when called in a source buffer, sets a debugger breakpoint
on the current source line. This command is available only after starting GUD. If
you call it in a buffer that is not associated with any debugger subprocess, it signals
a error.
The following commands are available both in the GUD interaction buffer and
globally, but with different key bindings. The keys starting with C-c are available
only in the GUD interaction buffer, while those starting with C-x C-a are available
globally. Some of these commands are also available via the tool bar; some are not
supported by certain debuggers.
C-c C-l
C-x C-a C-l
Display, in another window, the last source line referred to in the GUD
interaction buffer (gud-refresh).
C-c C-s
C-x C-a C-s
Execute the next single line of code (gud-step). If the line contains a
function call, execution stops after entering the called function.

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C-c C-n
C-x C-a C-n
Execute the next single line of code, stepping across function calls
without stopping inside the functions (gud-next).
C-c C-i
C-x C-a C-i
Execute a single machine instruction (gud-stepi).
C-c C-p
C-x C-a C-p
Evaluate the expression at point (gud-print). If Emacs does not print
the exact expression that you want, mark it as a region first.
C-c C-r
C-x C-a C-r
Continue execution without specifying any stopping point. The program will run until it hits a breakpoint, terminates, or gets a signal
that the debugger is checking for (gud-cont).
C-c C-d
C-x C-a C-d
Delete the breakpoint(s) on the current source line, if any (gudremove). If you use this command in the GUD interaction buffer,
it applies to the line where the program last stopped.
C-c C-t
C-x C-a C-t
Set a temporary breakpoint on the current source line, if any (gudtbreak). If you use this command in the GUD interaction buffer, it
applies to the line where the program last stopped.
C-c <
C-x C-a <
C-c >
C-x C-a >

Select the next enclosing stack frame (gud-up). This is equivalent to
the GDB command ‘up’.
Select the next inner stack frame (gud-down). This is equivalent to
the GDB command ‘down’.

C-c C-u
C-x C-a C-u
Continue execution to the current line (gud-until). The program will
run until it hits a breakpoint, terminates, gets a signal that the debugger is checking for, or reaches the line on which the cursor currently
sits.
C-c C-f
C-x C-a C-f
Run the program until the selected stack frame returns or stops for
some other reason (gud-finish).

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If you are using GDB, these additional key bindings are available:
C-x C-a C-j
Only useful in a source buffer, gud-jump transfers the program’s execution point to the current line. In other words, the next line that
the program executes will be the one where you gave the command.
If the new execution line is in a different function from the previously
one, GDB prompts for confirmation since the results may be bizarre.
See the GDB manual entry regarding jump for details.
TAB

With GDB, complete a symbol name (gud-gdb-complete-command).
This key is available only in the GUD interaction buffer.

These commands interpret a numeric argument as a repeat count, when that
makes sense.
Because TAB serves as a completion command, you can’t use it to enter a tab
as input to the program you are debugging with GDB. Instead, type C-q TAB to
enter a tab.
24.6.4 GUD Customization
On startup, GUD runs one of the following hooks: gdb-mode-hook, if you are using GDB; dbx-mode-hook, if you are using DBX; sdb-mode-hook, if you are using
SDB; xdb-mode-hook, if you are using XDB; perldb-mode-hook, for Perl debugging mode; pdb-mode-hook, for PDB; jdb-mode-hook, for JDB. See Section 33.2.2
[Hooks], page 445.
The gud-def Lisp macro (see Section “Defining Macros” in the Emacs Lisp
Reference Manual) provides a convenient way to define an Emacs command that
sends a particular command string to the debugger, and set up a key binding for in
the GUD interaction buffer:
(gud-def function cmdstring binding docstring )
This defines a command named function which sends cmdstring to the debugger process, and gives it the documentation string docstring. You can then use
the command function in any buffer. If binding is non-nil, gud-def also binds
the command to C-c binding in the GUD buffer’s mode and to C-x C-a binding
generally.
The command string cmdstring may contain certain ‘%’-sequences that stand for
data to be filled in at the time function is called:
‘%f’

The name of the current source file. If the current buffer is the GUD
buffer, then the “current source file” is the file that the program
stopped in.

‘%l’

The number of the current source line. If the current buffer is the
GUD buffer, then the “current source line” is the line that the program
stopped in.

‘%e’

In transient-mark-mode the text in the region, if it is active. Otherwise
the text of the C lvalue or function-call expression at or adjacent to
point.

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‘%a’

The text of the hexadecimal address at or adjacent to point.

‘%p’

The numeric argument of the called function, as a decimal number. If
the command is used without a numeric argument, ‘%p’ stands for the
empty string.
If you don’t use ‘%p’ in the command string, the command you define
ignores any numeric argument.

‘%d’

The name of the directory of the current source file.

‘%c’

Fully qualified class name derived from the expression surrounding
point (jdb only).

24.6.5 GDB Graphical Interface
The command M-x gdb starts GDB in an IDE-like interface, with specialized buffers
for controlling breakpoints, stack frames, and other aspects of the debugger state.
It also provides additional ways to control the debugging session with the mouse,
such as clicking in the fringe of a source buffer to set a breakpoint there.
To run GDB using just the GUD interaction buffer interface, without these
additional features, use M-x gud-gdb (see Section 24.6.1 [Starting GUD], page 276).
You must use this if you want to debug multiple programs within one Emacs session,
as that is currently unsupported by M-x gdb.
Internally, M-x gdb informs GDB that its “screen size” is unlimited; for correct
operation, you must not change GDB’s screen height and width values during the
debugging session.
24.6.5.1 GDB User Interface Layout
If the variable gdb-many-windows is nil (the default), M-x gdb normally displays
only the GUD interaction buffer. However, if the variable gdb-show-main is also
non-nil, it starts with two windows: one displaying the GUD interaction buffer,
and the other showing the source for the main function of the program you are
debugging.
If gdb-many-windows is non-nil, then M-x gdb displays the following frame
layout:
+--------------------------------+--------------------------------+
|
GUD interaction buffer
|
Locals/Registers buffer
|
|--------------------------------+--------------------------------+
|
Primary Source buffer
|
I/O buffer for debugged pgm |
|--------------------------------+--------------------------------+
|
Stack buffer
|
Breakpoints/Threads buffer
|
+--------------------------------+--------------------------------+

However, if gdb-use-separate-io-buffer is nil, the I/O buffer does not appear and the primary source buffer occupies the full width of the frame.
If you ever change the window layout, you can restore the “many windows”
layout by typing M-x gdb-restore-windows. To toggle between the many windows
layout and a simple layout with just the GUD interaction buffer and a source file,
type M-x gdb-many-windows.

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You may also specify additional GDB-related buffers to display, either in
the same frame or a different one. Select the buffers you want by typing M-x
gdb-display-buffertype -buffer or M-x gdb-frame-buffertype -buffer, where
buffertype is the relevant buffer type, such as ‘breakpoints’. You can do the same
with the menu bar, with the ‘GDB-Windows’ and ‘GDB-Frames’ sub-menus of the
‘GUD’ menu.
When you finish debugging, kill the GUD interaction buffer with C-x k, which
will also kill all the buffers associated with the session. However you need not do
this if, after editing and re-compiling your source code within Emacs, you wish
to continue debugging. When you restart execution, GDB automatically finds the
new executable. Keeping the GUD interaction buffer has the advantage of keeping
the shell history as well as GDB’s breakpoints. You do need to check that the
breakpoints in recently edited source files are still in the right places.
24.6.5.2 Source Buffers
Mouse-1 (in fringe)
Set or clear a breakpoint on that line.
C-Mouse-1 (in fringe)
Enable or disable a breakpoint on that line.
Mouse-3 (in fringe)
Continue execution to that line.
C-Mouse-3 (in fringe)
Jump to that line.
On a graphical display, you can click Mouse-1 in the fringe of a source buffer,
to set a breakpoint on that line (see Section 11.14 [Fringes], page 83). A red dot
appears in the fringe, where you clicked. If a breakpoint already exists there, the
click removes it. A C-Mouse-1 click enables or disables an existing breakpoint; a
breakpoint that is disabled, but not unset, is indicated by a gray dot.
On a text terminal, or when fringes are disabled, enabled breakpoints are indicated with a ‘B’ character in the left margin of the window. Disabled breakpoints
are indicated with ‘b’. (The margin is only displayed if a breakpoint is present.)
A solid arrow in the left fringe of a source buffer indicates the line of the innermost frame where the debugged program has stopped. A hollow arrow indicates
the current execution line of a higher-level frame. If you drag the arrow in the
fringe with Mouse-1, that causes execution to advance to the line where you release
the button. Alternatively, you can click Mouse-3 in the fringe to advance to that
line. You can click C-Mouse-3 in the fringe to jump to that line without executing
the intermediate lines. This command allows you to go backwards, which can be
useful for running through code that has already executed, in order to examine its
execution in more detail.
24.6.5.3 Breakpoints Buffer
The GDB Breakpoints buffer shows the breakpoints, watchpoints and catchpoints
in the debugger session. See Section “Breakpoints” in The GNU debugger. It

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provides the following commands, which mostly apply to the current breakpoint
(the breakpoint which point is on):
SPC

Enable/disable current breakpoint (gdb-toggle-breakpoint). On a
graphical display, this changes the color of the dot in the fringe of
the source buffer at that line. The dot is red when the breakpoint is
enabled, and gray when it is disabled.

D

Delete the current breakpoint (gdb-delete-breakpoint).

RET

Visit the source line for the current breakpoint (gdb-gotobreakpoint).

Mouse-2

Visit the source line for the breakpoint you click on.

When gdb-many-windows is non-nil, the GDB Breakpoints buffer shares its
window with the GDB Threads buffer. To switch from one to the other click
with Mouse-1 on the relevant button in the header line. If gdb-show-threads-bydefault is non-nil, the GDB Threads buffer is the one shown by default.
24.6.5.4 Threads Buffer
The GDB Threads buffer displays a summary of the threads in the debugged program. See Section “Debugging programs with multiple threads” in The GNU debugger. To select a thread, move point there and type RET (gdb-select-thread),
or click on it with Mouse-2. This also displays the associated source buffer, and
updates the contents of the other GDB buffers.
You can customize variables under gdb-buffers group to select fields included
in GDB Threads buffer.
gdb-thread-buffer-verbose-names
Show long thread names like ‘Thread 0x4e2ab70 (LWP 1983)’.
gdb-thread-buffer-arguments
Show arguments of thread top frames.
gdb-thread-buffer-locations
Show file information or library names.
gdb-thread-buffer-addresses
Show addresses for thread frames in threads buffer.
To view information for several threads simultaneously, use the following commands from the GDB Threads buffer.
d

Display disassembly buffer for the thread
(gdb-display-disassembly-for-thread).

at

current

line

f

Display the GDB Stack buffer for the thread at current line (gdbdisplay-stack-for-thread).

l

Display the GDB Locals buffer for the thread at current line (gdbdisplay-locals-for-thread).

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Display the GDB Registers buffer for the thread at current line (gdbdisplay-registers-for-thread).

Their upper-case counterparts, D, F ,L and R, display the corresponding buffer in a
new frame.
When you create a buffer showing information about some specific thread, it
becomes bound to that thread and keeps showing actual information while you
debug your program. The mode indicator for each GDB buffer shows the number
of thread it is showing information about. The thread number is also included in
the buffer name of bound buffers.
Further commands are available in the GDB Threads buffer which depend on
the mode of GDB that is used for controlling execution of your program. See
Section 24.6.5.8 [Multithreaded Debugging], page 286.
24.6.5.5 Stack Buffer
The GDB Stack buffer displays a call stack, with one line for each of the nested
subroutine calls (stack frames) in the debugger session. See Section “Backtraces”
in The GNU debugger.
On graphical displays, the selected stack frame is indicated by an arrow in the
fringe. On text terminals, or when fringes are disabled, the selected stack frame is
displayed in reverse contrast. To select a stack frame, move point in its line and
type RET (gdb-frames-select), or click Mouse-2 on it. Doing so also updates the
Locals buffer (described in the next section).
24.6.5.6 Other GDB Buffers
Locals Buffer
This buffer displays the values of local variables of the current frame
for simple data types (see Section “Information on a frame” in The
GNU debugger). Press RET or click Mouse-2 on the value if you want
to edit it.
Arrays and structures display their type only. With GDB 6.4 or later,
you can examine the value of the local variable at point by typing
RET, or with a Mouse-2 click. With earlier versions of GDB, use RET
or Mouse-2 on the type description (‘[struct/union]’ or ‘[array]’).
See Section 24.6.5.7 [Watch Expressions], page 285.
Registers Buffer
This buffer displays the values held by the registers (see Section “Registers” in The GNU debugger). Press RET or click Mouse-2 on a
register if you want to edit its value. With GDB 6.4 or later, recently
changed register values display with font-lock-warning-face.
Assembler Buffer
The assembler buffer displays the current frame as machine code. An
arrow points to the current instruction, and you can set and remove
breakpoints as in a source buffer. Breakpoint icons also appear in the
fringe or margin.

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Memory Buffer
The memory buffer lets you examine sections of program memory (see
Section “Examining memory” in The GNU debugger). Click Mouse-1
on the appropriate part of the header line to change the starting address or number of data items that the buffer displays. Alternatively,
use S or N respectively. Click Mouse-3 on the header line to select the
display format or unit size for these data items.
When gdb-many-windows is non-nil, the locals buffer shares its window with
the registers buffer, just like breakpoints and threads buffers. To switch from one
to the other, click with Mouse-1 on the relevant button in the header line.
24.6.5.7 Watch Expressions
If you want to see how a variable changes each time your program stops, move point
into the variable name and click on the watch icon in the tool bar (gud-watch) or
type C-x C-a C-w. If you specify a prefix argument, you can enter the variable name
in the minibuffer.
Each watch expression is displayed in the speedbar (see Section 18.9 [Speedbar], page 174). Complex data types, such as arrays, structures and unions are
represented in a tree format. Leaves and simple data types show the name of the
expression and its value and, when the speedbar frame is selected, display the type
as a tooltip. Higher levels show the name, type and address value for pointers and
just the name and type otherwise. Root expressions also display the frame address
as a tooltip to help identify the frame in which they were defined.
To expand or contract a complex data type, click Mouse-2 or press SPC on the
tag to the left of the expression. Emacs asks for confirmation before expanding
the expression if its number of immediate children exceeds the value of the variable
gdb-max-children.
To delete a complex watch expression, move point to the root expression in the
speedbar and type D (gdb-var-delete).
To edit a variable with a simple data type, or a simple element of a complex
data type, move point there in the speedbar and type RET (gdb-edit-value). Or
you can click Mouse-2 on a value to edit it. Either way, this reads the new value
using the minibuffer.
If you set the variable gdb-show-changed-values to non-nil (the default
value), Emacs uses font-lock-warning-face to highlight values that have recently
changed and shadow face to make variables which have gone out of scope less noticeable. When a variable goes out of scope you can’t edit its value.
If the variable gdb-delete-out-of-scope is non-nil (the default value), Emacs
automatically deletes watch expressions which go out of scope. Sometimes, when
re-entering the same function, it may be useful to set this value to nil so that you
don’t need to recreate the watch expression.
If the variable gdb-use-colon-colon-notation is non-nil, Emacs uses the
‘function ::variable ’ format. This allows the user to display watch expressions
which share the same variable name. The default value is nil.

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To automatically raise the speedbar every time the display of watch expressions
updates, set gdb-speedbar-auto-raise to non-nil. This can be useful if you are
debugging with a full screen Emacs frame.
24.6.5.8 Multithreaded Debugging
In GDB’s all-stop mode, whenever your program stops, all execution threads stop.
Likewise, whenever you restart the program, all threads start executing. See Section
“All-Stop Mode” in The GNU debugger. For some multi-threaded targets, GDB
supports a further mode of operation, called non-stop mode, in which you can
examine stopped program threads in the debugger while other threads continue to
execute freely. See Section “Non-Stop Mode” in The GNU debugger. Versions of
GDB prior to 7.0 do not support non-stop mode, and it does not work on all targets.
The variable gdb-non-stop-setting determines whether Emacs runs GDB in
all-stop mode or non-stop mode. The default is t, which means it tries to use nonstop mode if that is available. If you change the value to nil, or if non-stop mode
is unavailable, Emacs runs GDB in all-stop mode. The variable takes effect when
Emacs begins a debugging session; if you change its value, you should restart any
active debugging session.
When a thread stops in non-stop mode, Emacs usually switches to that thread.
If you don’t want Emacs to do this switch if another stopped thread is already
selected, change the variable gdb-switch-when-another-stopped to nil.
Emacs can decide whether or not to switch to the stopped thread depending on
the reason which caused the stop. Customize the variable gdb-switch-reasons to
select the stop reasons which will cause a thread switch.
The variable gdb-stopped-hooks allows you to execute your functions whenever
some thread stops.
In non-stop mode, you can switch between different modes for GUD execution
control commands.
Non-stop/A
When gdb-gud-control-all-threads is t (the default value), interruption and continuation commands apply to all threads, so you can
halt or continue all your threads with one command using gud-stopsubjob and gud-cont, respectively. The ‘Go’ button is shown on the
toolbar when at least one thread is stopped, whereas ‘Stop’ button is
shown when at least one thread is running.
Non-stop/T
When gdb-gud-control-all-threads is nil, only the current thread
is stopped/continued. ‘Go’ and ‘Stop’ buttons on the GUD toolbar are
shown depending on the state of current thread.
You can change the current value of gdb-gud-control-all-threads from the
tool bar or from ‘GUD->GDB-MI’ menu.
Stepping commands always apply to the current thread.

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In non-stop mode, you can interrupt/continue your threads without selecting
them. Hitting i in threads buffer interrupts thread under point, c continues it, s
steps through. More such commands may be added in the future.
Note that when you interrupt a thread, it stops with the ‘signal received’
reason. If that reason is included in your gdb-switch-reasons (it is by default),
Emacs will switch to that thread.

24.7 Executing Lisp Expressions
Emacs has major modes for several variants of Lisp. They use the same editing commands as other programming language modes (see Chapter 23 [Programs],
page 249). In addition, they provide special commands for executing Lisp expressions.
Emacs Lisp mode
The mode for editing Emacs Lisp source files. It defines C-M-x to
evaluate the current top-level Lisp expression. See Section 24.9 [Lisp
Eval], page 288.
Lisp Interaction mode
The mode for an interactive Emacs Lisp session. It defines C-j to
evaluate the expression before point and insert its value in the buffer.
See Section 24.10 [Lisp Interaction], page 290.
Lisp mode

The mode for editing source files of programs that run in Lisps other
than Emacs Lisp. It defines C-M-x to evaluate the current top-level
expression in an external Lisp. See Section 24.11 [External Lisp],
page 290.

Inferior Lisp mode
The mode for an interactive session with an external Lisp which is
being run as a subprocess (or inferior process) of Emacs.
Scheme mode
Like Lisp mode, but for Scheme programs.
Inferior Scheme mode
Like Inferior Lisp mode, but for Scheme.

24.8 Libraries of Lisp Code for Emacs
Emacs Lisp code is stored in files whose names conventionally end in ‘.el’. Such
files are automatically visited in Emacs Lisp mode.
Emacs Lisp code can be compiled into byte-code, which loads faster, takes up
less space, and executes faster. By convention, compiled Emacs Lisp code goes in
a separate file whose name ends in ‘.elc’. For example, the compiled code for
‘foo.el’ goes in ‘foo.elc’. See Section “Byte Compilation” in the Emacs Lisp
Reference Manual.
To load an Emacs Lisp file, type M-x load-file. This command reads a file
name using the minibuffer, and executes the contents of that file as Emacs Lisp

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code. It is not necessary to visit the file first; this command reads the file directly
from disk, not from an existing Emacs buffer.
If an Emacs Lisp file is installed in the Emacs Lisp load path (defined below),
you can load it by typing M-x load-library, instead of using M-x load-file. The
M-x load-library command prompts for a library name rather than a file name;
it searches through each directory in the Emacs Lisp load path, trying to find a
file matching that library name. If the library name is ‘foo ’, it tries looking for
files named ‘foo.elc’, ‘foo.el’, and lastly just ‘foo ’; the first one found is loaded.
This command prefers ‘.elc’ files over ‘.el’ files because compiled files load and
run faster. If it finds that ‘lib.el’ is newer than ‘lib.elc’, it issues a warning, in
case someone made changes to the ‘.el’ file and forgot to recompile it, but loads the
‘.elc’ file anyway. (Due to this behavior, you can save unfinished edits to Emacs
Lisp source files, and not recompile until your changes are ready for use.)
Emacs Lisp programs usually load Emacs Lisp files using the load function. This
is similar to load-library, but is lower-level and accepts additional arguments. See
Section “How Programs Do Loading” in the Emacs Lisp Reference Manual.
The Emacs Lisp load path is specified by the variable load-path. Its value
should be a list of directory names (strings). These directories are searched, in the
specified order, by the M-x load-library command, the lower-level load function,
and other Emacs functions that find Emacs Lisp libraries. A list entry in load-path
can also have the special value nil, which stands for the current default directory,
but it is almost always a bad idea to use this. (If you find yourself wishing that nil
were in the list, most likely what you really want is to use M-x load-file.)
The default value of load-path is a list of directories where the Lisp code for
Emacs itself is stored. If you have libraries of your own in another directory, you can
add that directory to the load path. Unlike most other variables described in this
manual, load-path cannot be changed via the Customize interface (see Section 33.1
[Easy Customization], page 434), but you can add a directory to it by putting a
line like this in your init file (see Section 33.4 [Init File], page 461):
(add-to-list ’load-path "/path/to/my/lisp/library")
Some commands are autoloaded: when you run them, Emacs automatically
loads the associated library first. For instance, the M-x compile command (see
Section 24.1 [Compilation], page 271) is autoloaded; if you call it, Emacs automatically loads the compile library first. In contrast, the command M-x recompile is
not autoloaded, so it is unavailable until you load the compile library.
By default, Emacs refuses to load compiled Lisp files which were compiled with
XEmacs, a modified versions of Emacs—they can cause Emacs to crash. Set the
variable load-dangerous-libraries to t if you want to try loading them.

24.9 Evaluating Emacs Lisp Expressions
Emacs Lisp mode is the major mode for editing Emacs Lisp. Its mode command is
M-x emacs-lisp-mode.
Emacs provides several commands for evaluating Emacs Lisp expressions. You
can use these commands in Emacs Lisp mode, to test your Emacs Lisp code as

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it is being written. For example, after re-writing a function, you can evaluate
the function definition to make it take effect for subsequent function calls. These
commands are also available globally, and can be used outside Emacs Lisp mode.
M-:

Read a single Emacs Lisp expression in the minibuffer, evaluate it,
and print the value in the echo area (eval-expression).

C-x C-e

Evaluate the Emacs Lisp expression before point, and print the value
in the echo area (eval-last-sexp).

C-M-x (in Emacs Lisp mode)
M-x eval-defun
Evaluate the defun containing or after point, and print the value in
the echo area (eval-defun).
M-x eval-region
Evaluate all the Emacs Lisp expressions in the region.
M-x eval-buffer
Evaluate all the Emacs Lisp expressions in the buffer.
M-: (eval-expression) reads an expression using the minibuffer, and evaluates
it. (Before evaluating the expression, the current buffer switches back to the buffer
that was current when you typed M-:, not the minibuffer into which you typed the
expression.)
The command C-x C-e (eval-last-sexp) evaluates the Emacs Lisp expression
preceding point in the buffer, and displays the value in the echo area. When the
result of an evaluation is an integer, you can type C-x C-e a second time to display the value of the integer result in additional formats (octal, hexadecimal, and
character).
If M-: or C-x C-e is given a prefix argument, it inserts the value into the current
buffer at point, rather than displaying it in the echo area. The argument’s value
does not matter.
The eval-defun command is bound to C-M-x in Emacs Lisp mode. It evaluates
the top-level Lisp expression containing or following point, and prints the value in
the echo area. In this context, a top-level expression is referred to as a “defun”, but
it need not be an actual defun (function definition). In particular, this command
treats defvar expressions specially. Normally, evaluating a defvar expression does
nothing if the variable it defines already has a value. But this command unconditionally resets the variable to the initial value specified by the defvar; this is
convenient for debugging Emacs Lisp programs. defcustom and defface expressions are treated similarly. Note that the other commands documented in this
section do not have this special feature.
With a prefix argument, C-M-x instruments the function definition for Edebug,
the Emacs Lisp Debugger. See Section “Instrumenting” in the Emacs Lisp Reference
Manual.
The command M-x eval-region parses the text of the region as one or more
Lisp expressions, evaluating them one by one. M-x eval-buffer is similar but
evaluates the entire buffer.

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The options eval-expression-print-level and eval-expression-printlength control the maximum depth and length of lists to print in the result of
the evaluation commands before abbreviating them. eval-expression-debug-onerror controls whether evaluation errors invoke the debugger when these commands
are used; its default is t.

24.10 Lisp Interaction Buffers
When Emacs starts up, it contains a buffer named ‘*scratch*’, which is provided for evaluating Emacs Lisp expressions interactively. Its major mode is
Lisp Interaction mode. You can also enable Lisp Interaction mode by typing M-x
lisp-interaction-mode.
In the ‘*scratch*’ buffer, and other Lisp Interaction mode buffers, C-j (evalprint-last-sexp) evaluates the Lisp expression before point, and inserts the value
at point. Thus, as you type expressions into the buffer followed by C-j after each
expression, the buffer records a transcript of the evaluated expressions and their
values. All other commands in Lisp Interaction mode are the same as in Emacs
Lisp mode.
At startup, the ‘*scratch*’ buffer contains a short message, in the form of a Lisp
comment, that explains what it is for. This message is controlled by the variable
initial-scratch-message, which should be either a string, or nil (which means
to suppress the message).
An alternative way of evaluating Emacs Lisp expressions interactively is to use
Inferior Emacs Lisp mode, which provides an interface rather like Shell mode (see
Section 31.3.3 [Shell Mode], page 403) for evaluating Emacs Lisp expressions. Type
M-x ielm to create an ‘*ielm*’ buffer which uses this mode. For more information,
see that command’s documentation.

24.11 Running an External Lisp
Lisp mode is the major mode for editing programs written in general-purpose Lisp
dialects, such as Common Lisp. Its mode command is M-x lisp-mode. Emacs uses
Lisp mode automatically for files whose names end in ‘.l’, ‘.lsp’, or ‘.lisp’.
You can run an external Lisp session as a subprocess or inferior process of
Emacs, and pass expressions to it to be evaluated. To begin an external Lisp
session, type M-x run-lisp. This runs the program named lisp, and sets it up so
that both input and output go through an Emacs buffer named ‘*inferior-lisp*’.
To change the name of the Lisp program run by M-x run-lisp, change the variable
inferior-lisp-program.
The major mode for the ‘*lisp*’ buffer is Inferior Lisp mode, which combines
the characteristics of Lisp mode and Shell mode (see Section 31.3.3 [Shell Mode],
page 403). To send input to the Lisp session, go to the end of the ‘*lisp*’ buffer
and type the input, followed by RET. Terminal output from the Lisp session is
automatically inserted in the buffer.
When you edit a Lisp program in Lisp mode, you can type C-M-x (lisp-evaldefun) to send an expression from the Lisp mode buffer to a Lisp session that you

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had started with M-x run-lisp. The expression sent is the top-level Lisp expression
at or following point. The resulting value goes as usual into the ‘*inferior-lisp*’
buffer. Note that the effect of C-M-x in Lisp mode is thus very similar to its effect in
Emacs Lisp mode (see Section 24.9 [Lisp Eval], page 288), except that the expression
is sent to a different Lisp environment instead of being evaluated in Emacs.
The facilities for editing Scheme code, and for sending expressions to a Scheme
subprocess, are very similar. Scheme source files are edited in Scheme mode, which
can be explicitly enabled with M-x scheme-mode. You can initiate a Scheme session by typing M-x run-scheme (the buffer for interacting with Scheme is named
‘*scheme*’), and send expressions to it by typing C-M-x.

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25 Maintaining Large Programs
This chapter describes Emacs features for maintaining large programs. If you are
maintaining a large Lisp program, then in addition to the features described here,
you may find the ‘ERT’ (“Emacs Lisp Regression Testing”) library useful (see Section
“ERT” in Emacs Lisp Regression Testing).

25.1 Version Control
A version control system is a program that can record multiple versions of a source
file, storing information such as the creation time of each version, who made it, and
a description of what was changed.
The Emacs version control interface is called VC. VC commands work with
several different version control systems; currently, it supports GNU Arch, Bazaar,
CVS, Git, Mercurial, Monotone, RCS, SCCS/CSSC, and Subversion. Of these, the
GNU project distributes CVS, Arch, RCS, and Bazaar.
VC is enabled automatically whenever you visit a file governed by a version
control system. To disable VC entirely, set the customizable variable vc-handledbackends to nil (see Section “Customizing VC” in Specialized Emacs Features).
25.1.1 Introduction to Version Control
VC allows you to use a version control system from within Emacs, integrating the
version control operations smoothly with editing. It provides a uniform interface
for common operations in many version control operations.
Some uncommon or intricate version control operations, such as altering repository settings, are not supported in VC. You should perform such tasks outside
Emacs, e.g. via the command line.
This section provides a general overview of version control, and describes the
version control systems that VC supports. You can skip this section if you are
already familiar with the version control system you want to use.
25.1.1.1 Understanding the problems it addresses
Version control systems provide you with three important capabilities:
• Reversibility: the ability to back up to a previous state if you discover that
some modification you did was a mistake or a bad idea.
• Concurrency: the ability to have many people modifying the same collection
of files knowing that conflicting modifications can be detected and resolved.
• History: the ability to attach historical data to your data, such as explanatory
comments about the intention behind each change to it. Even for a programmer
working solo, change histories are an important aid to memory; for a multiperson project, they are a vitally important form of communication among
developers.

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25.1.1.2 Supported Version Control Systems
VC currently works with many different version control systems, which it refers to
as back ends:
• SCCS was the first version control system ever built, and was long ago superseded by more advanced ones. VC compensates for certain features missing
in SCCS (e.g. tag names for releases) by implementing them itself. Other VC
features, such as multiple branches, are simply unavailable. Since SCCS is
non-free, we recommend avoiding it.
• CSSC is a free replacement for SCCS. You should use CSSC only if, for some
reason, you cannot use a more recent and better-designed version control system.
• RCS is the free version control system around which VC was initially built. It
is relatively primitive: it cannot be used over the network, and works at the
level of individual files. Almost everything you can do with RCS can be done
through VC.
• CVS is the free version control system that was, until recently (circa 2008),
used by the majority of free software projects. Nowadays, it is slowly being
superseded by newer systems. CVS allows concurrent multi-user development
either locally or over the network. Unlike newer systems, it lacks support
for atomic commits and file moving/renaming. VC supports all basic editing
operations under CVS.
• Subversion (svn) is a free version control system designed to be similar to
CVS but without its problems (e.g., it supports atomic commits of filesets,
and versioning of directories, symbolic links, meta-data, renames, copies, and
deletes).
• GNU Arch is one of the earliest decentralized version control systems (the
other being Monotone). See Section 25.1.1.3 [VCS Concepts], page 293, for
a description of decentralized version control systems. It is no longer under
active development, and has been deprecated in favor of Bazaar.
• Git is a decentralized version control system originally invented by Linus Torvalds to support development of Linux (his kernel). VC supports many common Git operations, but others, such as repository syncing, must be done from
the command line.
• Mercurial (hg) is a decentralized version control system broadly resembling
Git. VC supports most Mercurial commands, with the exception of repository
sync operations.
• Bazaar (bzr) is a decentralized version control system that supports both
repository-based and decentralized versioning. VC supports most basic editing
operations under Bazaar.
25.1.1.3 Concepts of Version Control
When a file is under version control, we say that it is registered in the version control
system. The system has a repository which stores both the file’s present state and

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its change history—enough to reconstruct the current version or any earlier version.
The repository also contains other information, such as log entries that describe the
changes made to each file.
The copy of a version-controlled file that you actually edit is called the work file.
You can change each work file as you would an ordinary file. After you are done
with a set of changes, you may commit (or check in) the changes; this records the
changes in the repository, along with a descriptive log entry.
A directory tree of work files is called a working tree.
Each commit creates a new revision in the repository. The version control system
keeps track of all past revisions and the changes that were made in each revision.
Each revision is named by a revision ID, whose format depends on the version
control system; in the simplest case, it is just an integer.
To go beyond these basic concepts, you will need to understand three aspects in
which version control systems differ. As explained in the next three sections, they
can be lock-based or merge-based; file-based or changeset-based; and centralized
or decentralized. VC handles all these modes of operation, but it cannot hide the
differences.
25.1.1.4 Merge-based vs lock-based Version Control
A version control system typically has some mechanism to coordinate between users
who want to change the same file. There are two ways to do this: merging and
locking.
In a version control system that uses merging, each user may modify a work file
at any time. The system lets you merge your work file, which may contain changes
that have not been committed, with the latest changes that others have committed.
Older version control systems use a locking scheme instead. Here, work files are
normally read-only. To edit a file, you ask the version control system to make it
writable for you by locking it; only one user can lock a given file at any given time.
This procedure is analogous to, but different from, the locking that Emacs uses
to detect simultaneous editing of ordinary files (see Section 15.3.4 [Interlocking],
page 133). When you commit your changes, that unlocks the file, and the work
file becomes read-only again. Other users may then lock the file to make their own
changes.
Both locking and merging systems can have problems when multiple users try to
modify the same file at the same time. Locking systems have lock conflicts; a user
may try to check a file out and be unable to because it is locked. In merging systems,
merge conflicts happen when you commit a change to a file that conflicts with a
change committed by someone else after your checkout. Both kinds of conflict have
to be resolved by human judgment and communication. Experience has shown that
merging is superior to locking, both in convenience to developers and in minimizing
the number and severity of conflicts that actually occur.
SCCS always uses locking. RCS is lock-based by default but can be told to
operate in a merging style. CVS and Subversion are merge-based by default but
can be told to operate in a locking mode. Decentralized version control systems,
such as GNU Arch, Git, and Mercurial, are exclusively merging-based.

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VC mode supports both locking and merging version control. The terms “commit” and “update” are used in newer version control systems; older lock-based systems use the terms “check in” and “check out”. VC hides the differences between
them as much as possible.
25.1.1.5 Changeset-based vs File-based Version Control
On SCCS, RCS, CVS, and other early version control systems, version control
operations are file-based: each file has its own comment and revision history separate from that of all other files. Newer systems, beginning with Subversion, are
changeset-based: a commit may include changes to several files, and the entire set
of changes is handled as a unit. Any comment associated with the change does not
belong to a single file, but to the changeset itself.
Changeset-based version control is more flexible and powerful than file-based
version control; usually, when a change to multiple files has to be reversed, it’s
good to be able to easily identify and remove all of it.
25.1.1.6 Decentralized vs Centralized Repositories
Early version control systems were designed around a centralized model in which
each project has only one repository used by all developers. SCCS, RCS, CVS, and
Subversion share this kind of model. One of its drawbacks is that the repository is
a choke point for reliability and efficiency.
GNU Arch pioneered the concept of distributed or decentralized version control,
later implemented in Git, Mercurial, and Bazaar. A project may have several different repositories, and these systems support a sort of super-merge between repositories that tries to reconcile their change histories. In effect, there is one repository
for each developer, and repository merges take the place of commit operations.
VC helps you manage the traffic between your personal workfiles and a repository. Whether the repository is a single master, or one of a network of peer repositories, is not something VC has to care about.
25.1.1.7 Types of Log File
Projects that use a version control system can have two types of log for changes.
One is the log maintained by the version control system: each time you commit
a change, you fill out a log entry for the change (see Section 25.1.4 [Log Buffer],
page 299). This is called the version control log.
The other kind of log is the file ‘ChangeLog’ (see Section 25.2 [Change Log],
page 309). It provides a chronological record of all changes to a large portion of
a program—typically one directory and its subdirectories. A small program would
use one ‘ChangeLog’ file; a large program may have a ‘ChangeLog’ file in each major
directory. See Section 25.2 [Change Log], page 309. Programmers have used change
logs since long before version control systems.
Changeset-based version systems typically maintain a changeset-based modification log for the entire system, which makes change log files somewhat redundant.
One advantage that they retain is that it is sometimes useful to be able to view the
transaction history of a single directory separately from those of other directories.

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A project maintained with version control can use just the version control log,
or it can use both kinds of logs. It can handle some files one way and some files the
other way. Each project has its policy, which you should follow.
When the policy is to use both, you typically want to write an entry for each
change just once, then put it into both logs. You can write the entry in ‘ChangeLog’,
then copy it to the log buffer with C-c C-a when committing the change (see
Section 25.1.4 [Log Buffer], page 299). Or you can write the entry in the log buffer
while committing the change, and later use the C-x v a command to copy it to
‘ChangeLog’ (see Section “Change Logs and VC” in Specialized Emacs Features).
25.1.2 Version Control and the Mode Line
When you visit a file that is under version control, Emacs indicates this on the
mode line. For example, ‘Bzr-1223’ says that Bazaar is used for that file, and the
current revision ID is 1223.
The character between the back-end name and the revision ID indicates the
version control status of the work file. In a merge-based version control system,
a ‘-’ character indicates that the work file is unmodified, and ‘:’ indicates that it
has been modified. ‘!’ indicates that the file contains conflicts as result of a recent
merge operation (see Section 25.1.10.3 [Merging], page 308), or that the file was
removed from the version control. Finally, ‘?’ means that the file is under version
control, but is missing from the working tree.
In a lock-based system, ‘-’ indicates an unlocked file, and ‘:’ a locked file; if the
file is locked by another user (for instance, ‘jim’), that is displayed as ‘RCS:jim:1.3’.
‘@’ means that the file was locally added, but not yet committed to the master
repository.
On a graphical display, you can move the mouse over this mode line indicator to
pop up a “tool-tip”, which displays a more verbose description of the version control
status. Pressing Mouse-1 over the indicator pops up a menu of VC commands,
identical to ‘Tools / Version Control’ on the menu bar.
When Auto Revert mode (see Section 15.4 [Reverting], page 135) reverts a buffer
that is under version control, it updates the version control information in the mode
line. However, Auto Revert mode may not properly update this information if the
version control status changes without changes to the work file, from outside the
current Emacs session. If you set auto-revert-check-vc-info to t, Auto Revert
mode updates the version control status information every auto-revert-interval
seconds, even if the work file itself is unchanged. The resulting CPU usage depends
on the version control system, but is usually not excessive.
25.1.3 Basic Editing under Version Control
Most VC commands operate on VC filesets. A VC fileset is a collection of one or
more files that a VC operation acts on. When you type VC commands in a buffer
visiting a version-controlled file, the VC fileset is simply that one file. When you
type them in a VC Directory buffer, and some files in it are marked, the VC fileset
consists of the marked files (see Section 25.1.9 [VC Directory Mode], page 304).

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On modern changeset-based version control systems (see Section 25.1.1.5 [VCS
Changesets], page 295), VC commands handle multi-file VC filesets as a group. For
example, committing a multi-file VC fileset generates a single revision, containing
the changes to all those files. On older file-based version control systems like CVS,
each file in a multi-file VC fileset is handled individually; for example, a commit
generates one revision for each changed file.
C-x v v

Perform the next appropriate version control operation on the current
VC fileset.

The principal VC command is a multi-purpose command, C-x v v (vc-nextaction), which performs the “most appropriate” action on the current VC fileset:
either registering it with a version control system, or committing it, or unlocking
it, or merging changes into it. The precise actions are described in detail in the
following subsections. You can use C-x v v either in a file-visiting buffer or in a VC
Directory buffer.
Note that VC filesets are distinct from the “named filesets” used for viewing and
visiting files in functional groups (see Section 15.17 [Filesets], page 148). Unlike
named filesets, VC filesets are not named and don’t persist across sessions.
25.1.3.1 Basic Version Control with Merging
On a merging-based version control system (i.e. most modern ones; see
Section 25.1.1.4 [VCS Merging], page 294), C-x v v does the following:
• If there is more than one file in the VC fileset and the files have inconsistent version control statuses, signal an error. (Note, however, that a fileset is allowed
to include both “newly-added” files and “modified” files; see Section 25.1.5
[Registering], page 300.)
• If none of the files in the VC fileset are registered with a version control system,
register the VC fileset, i.e. place it under version control. See Section 25.1.5
[Registering], page 300. If Emacs cannot find a system to register under, it
prompts for a repository type, creates a new repository, and registers the VC
fileset with it.
• If every work file in the VC fileset is unchanged, do nothing.
• If every work file in the VC fileset has been modified, commit the changes. To
do this, Emacs pops up a ‘*vc-log*’ buffer; type the desired log entry for the
new revision, followed by C-c C-c to commit. See Section 25.1.4 [Log Buffer],
page 299.
If committing to a shared repository, the commit may fail if the repository that
has been changed since your last update. In that case, you must perform an
update before trying again. On a decentralized version control system, use C-x
v + (see Section 25.1.10.2 [VC Pull], page 308) or C-x v m (see Section 25.1.10.3
[Merging], page 308). On a centralized version control system, type C-x v v
again to merge in the repository changes.
• Finally, if you are using a centralized version control system, check if each
work file in the VC fileset is up-to-date. If any file has been changed in the
repository, offer to update it.

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These rules also apply when you use RCS in its “non-locking” mode, except that
changes are not automatically merged from the repository. Nothing informs you if
another user has committed changes in the same file since you began editing it; when
you commit your revision, his changes are removed (however, they remain in the
repository and are thus not irrevocably lost). Therefore, you must verify that the
current revision is unchanged before committing your changes. In addition, locking
is possible with RCS even in this mode: C-x v v with an unmodified file locks the
file, just as it does with RCS in its normal locking mode (see Section 25.1.3.2 [VC
With A Locking VCS], page 298).
25.1.3.2 Basic Version Control with Locking
On a locking-based version control system (such as SCCS, and RCS in its default
mode), C-x v v does the following:
• If there is more than one file in the VC fileset and the files have inconsistent
version control statuses, signal an error.
• If each file in the VC fileset is not registered with a version control system,
register the VC fileset. See Section 25.1.5 [Registering], page 300. If Emacs
cannot find a system to register under, it prompts for a repository type, creates
a new repository, and registers the VC fileset with it.
• If each file is registered and unlocked, lock it and make it writable, so that you
can begin to edit it.
• If each file is locked by you and contains changes, commit the changes. To do
this, Emacs pops up a ‘*vc-log*’ buffer; type the desired log entry for the
new revision, followed by C-c C-c to commit (see Section 25.1.4 [Log Buffer],
page 299).
• If each file is locked by you, but you have not changed it, release the lock and
make the file read-only again.
• If each file is locked by another user, ask whether you want to “steal the lock”.
If you say yes, the file becomes locked by you, and a warning message is sent
to the user who had formerly locked the file.
These rules also apply when you use CVS in locking mode, except that CVS
does not support stealing locks.
25.1.3.3 Advanced Control in C-x v v
When you give a prefix argument to vc-next-action (C-u C-x v v), it still performs the next logical version control operation, but accepts additional arguments
to specify precisely how to do the operation.
• You can specify the name of a version control system. This is useful if the
fileset can be managed by more than one version control system, and Emacs
fails to detect the correct one.
• Otherwise, if using CVS or RCS, you can specify a revision ID.
If the fileset is modified (or locked), this makes Emacs commit with that revision ID. You can create a new branch by supplying an appropriate revision ID
(see Section 25.1.10 [Branches], page 307).

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If the fileset is unmodified (and unlocked), this checks the specified revision
into the working tree. You can also specify a revision on another branch by
giving its revision or branch ID (see Section 25.1.10.1 [Switching Branches],
page 307). An empty argument (i.e. C-u C-x v v RET) checks out the latest
(“head”) revision on the current branch.
This signals an error on a decentralized version control system. Those systems
do not let you specify your own revision IDs, nor do they use the concept of
“checking out” individual files.
25.1.4 Features of the Log Entry Buffer
When you tell VC to commit a change, it pops up a buffer named ‘*vc-log*’. In
this buffer, you should write a log entry describing the changes you have made (see
Section 25.1.1.1 [Why Version Control?], page 292). After you are done, type C-c
C-c (log-edit-done) to exit the buffer and commit the change, together with your
log entry.
The major mode for the ‘*vc-log*’ buffer is Log Edit mode, a variant of Text
mode (see Section 22.7 [Text Mode], page 223). On entering Log Edit mode, Emacs
runs the hooks text-mode-hook and vc-log-mode-hook (see Section 33.2.2 [Hooks],
page 445).
In the ‘*vc-log*’ buffer, you can write one or more header lines, specifying
additional information to be supplied to the version control system. Each header
line must occupy a single line at the top of the buffer; the first line that is not
a header line is treated as the start of the log entry. For example, the following
header line states that the present change was not written by you, but by another
developer:
Author: J. R. Hacker 

Apart from the ‘Author’ header, Emacs recognizes the headers ‘Date’ (a manuallyspecified commit time) and ‘Fixes’ (a reference to a bug fixed by the change).
Not all version control systems recognize all headers: Bazaar recognizes all three
headers, while Git, Mercurial, and Monotone recognize only ‘Author’ and ‘Date’.
If you specify a header for a system that does not support it, the header is treated
as part of the log entry.
While in the ‘*vc-log*’ buffer, the “current VC fileset” is considered to be the
fileset that will be committed if you type C-c C-c. To view a list of the files in the
VC fileset, type C-c C-f (log-edit-show-files). To view a diff of changes between
the VC fileset and the version from which you started editing (see Section 25.1.6
[Old Revisions], page 300), type C-c C-d (log-edit-show-diff).
If the VC fileset includes one or more ‘ChangeLog’ files (see Section 25.2 [Change
Log], page 309), type C-c C-a (log-edit-insert-changelog) to pull the relevant
entries into the ‘*vc-log*’ buffer. If the topmost item in each ‘ChangeLog’ was
made under your user name on the current date, this command searches that item
for entries matching the file(s) to be committed, and inserts them.
To abort a commit, just don’t type C-c C-c in that buffer. You can switch
buffers and do other editing. As long as you don’t try to make another commit,

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the entry you were editing remains in the ‘*vc-log*’ buffer, and you can go back
to that buffer at any time to complete the commit.
You can also browse the history of previous log entries to duplicate a commit
comment. This can be useful when you want to make several commits with similar
comments. The commands M-n, M-p, M-s and M-r for doing this work just like the
minibuffer history commands (see Section 5.4 [Minibuffer History], page 34), except
that they are used outside the minibuffer.
25.1.5 Registering a File for Version Control
C-x v i

Register the visited file for version control.

The command C-x v i (vc-register) registers each file in the current VC fileset, placing it under version control. This is essentially equivalent to the action
of C-x v v on an unregistered VC fileset (see Section 25.1.3 [Basic VC Editing],
page 296), except that if the VC fileset is already registered, C-x v i signals an
error whereas C-x v v performs some other action.
To register a file, Emacs must choose a version control system. For a multi-file
VC fileset, the VC Directory buffer specifies the system to use (see Section 25.1.9
[VC Directory Mode], page 304). For a single-file VC fileset, if the file’s directory
already contains files registered in a version control system, or if the directory is
part of a directory tree controlled by a version control system, Emacs chooses that
system. In the event that more than one version control system is applicable,
Emacs uses the one that appears first in the variable vc-handled-backends. If
Emacs cannot find a version control system to register the file under, it prompts for
a repository type, creates a new repository, and registers the file into that repository.
On most version control systems, registering a file with C-x v i or C-x v v adds
it to the “working tree” but not to the repository. Such files are labeled as ‘added’
in the VC Directory buffer, and show a revision ID of ‘@@’ in the mode line. To
make the registration take effect in the repository, you must perform a commit (see
Section 25.1.3 [Basic VC Editing], page 296). Note that a single commit can include
both file additions and edits to existing files.
On a locking-based version control system (see Section 25.1.1.4 [VCS Merging],
page 294), registering a file leaves it unlocked and read-only. Type C-x v v to start
editing it.
25.1.6 Examining And Comparing Old Revisions
C-x v =

Compare the work files in the current VC fileset with the versions
you started from (vc-diff). With a prefix argument, prompt for two
revisions of the current VC fileset and compare them. You can also call
this command from a Dired buffer (see Chapter 27 [Dired], page 329).

C-x v D

Compare the entire working tree to the revision you started from (vcroot-diff). With a prefix argument, prompt for two revisions and
compare their trees.

C-x v ~

Prompt for a revision of the current file, and visit it in a separate
buffer (vc-revision-other-window).

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Display an annotated version of the current file: for each line, show
the latest revision in which it was modified (vc-annotate).

C-x v = (vc-diff) displays a diff which compares each work file in the current
VC fileset to the version(s) from which you started editing. The diff is displayed
in another window, in a Diff mode buffer (see Section 15.9 [Diff Mode], page 141)
named ‘*vc-diff*’. The usual Diff mode commands are available in this buffer.
In particular, the g (revert-buffer) command performs the file comparison again,
generating a new diff.
To compare two arbitrary revisions of the current VC fileset, call vc-diff
with a prefix argument: C-u C-x v =. This prompts for two revision IDs (see
Section 25.1.1.3 [VCS Concepts], page 293), and displays a diff between those versions of the fileset. This will not work reliably for multi-file VC filesets, if the
version control system is file-based rather than changeset-based (e.g. CVS), since
then revision IDs for different files would not be related in any meaningful way.
Instead of the revision ID, some version control systems let you specify revisions
in other formats. For instance, under Bazaar you can enter ‘date:yesterday’ for
the argument to C-u C-x v = (and related commands) to specify the first revision
committed after yesterday. See the documentation of the version control system for
details.
If you invoke C-x v = or C-u C-x v = from a Dired buffer (see Chapter 27 [Dired],
page 329), the file listed on the current line is treated as the current VC fileset.
C-x v D (vc-root-diff) is similar to C-x v =, but it displays the changes in the
entire current working tree (i.e. the working tree containing the current VC fileset).
If you invoke this command from a Dired buffer, it applies to the working tree
containing the directory.
You can customize the diff options that C-x v = and C-x v D use for generating
diffs. The options used are taken from the first non-nil value amongst the variables vc-backend -diff-switches, vc-diff-switches, and diff-switches (see
Section 15.8 [Comparing Files], page 140), in that order. Here, backend stands for
the relevant version control system, e.g. bzr for Bazaar. Since nil means to check
the next variable in the sequence, either of the first two may use the value t to
mean no switches at all. Most of the vc-backend -diff-switches variables default
to nil, but some default to t; these are for version control systems whose diff
implementations do not accept common diff options, such as Subversion.
To directly examine an older version of a file, visit the work file and type C-x
v ~ revision RET (vc-revision-other-window). This retrieves the file version
corresponding to revision, saves it to ‘filename.~revision ~’, and visits it in a
separate window.
Many version control systems allow you to view files annotated with per-line
revision information, by typing C-x v g (vc-annotate). This creates a new buffer
(the “annotate buffer”) displaying the file’s text, with each line colored to show how
old it is. Red text is new, blue is old, and intermediate colors indicate intermediate
ages. By default, the color is scaled over the full range of ages, such that the oldest
changes are blue, and the newest changes are red.

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When you give a prefix argument to this command, Emacs reads two arguments
using the minibuffer: the revision to display and annotate (instead of the current
file contents), and the time span in days the color range should cover.
From the annotate buffer, these and other color scaling options are available
from the ‘VC-Annotate’ menu. In this buffer, you can also use the following keys
to browse the annotations of past revisions, view diffs, or view log entries:
p

Annotate the previous revision, i.e. the revision before the one currently annotated. A numeric prefix argument is a repeat count, so
C-u 10 p would take you back 10 revisions.

n

Annotate the next revision, i.e. the revision after the one currently
annotated. A numeric prefix argument is a repeat count.

j

Annotate the revision indicated by the current line.

a

Annotate the revision before the one indicated by the current line.
This is useful to see the state the file was in before the change on the
current line was made.

f

Show in a buffer the file revision indicated by the current line.

d

Display the diff between the current line’s revision and the previous
revision. This is useful to see what the current line’s revision actually
changed in the file.

D

Display the diff between the current line’s revision and the previous
revision for all files in the changeset (for VC systems that support
changesets). This is useful to see what the current line’s revision actually changed in the tree.

l

Show the log of the current line’s revision. This is useful to see the
author’s description of the changes in the revision on the current line.

w

Annotate the working revision–the one you are editing. If you used
p and n to browse to other revisions, use this key to return to your
working revision.

v

Toggle the annotation visibility. This is useful for looking just at the
file contents without distraction from the annotations.

25.1.7 VC Change Log
C-x v l

Display the change history for the current fileset (vc-print-log).

C-x v L

Display the change history for the current repository (vc-print-rootlog).

C-x v I

Display the changes that a pull operation will retrieve (vc-logincoming).

C-x v O

Display the changes that will be sent by the next push operation (vclog-outgoing).

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C-x v l (vc-print-log) displays a buffer named ‘*vc-change-log*’, showing
the history of changes made to the current file, including who made the changes,
the dates, and the log entry for each change (these are the same log entries you
would enter via the ‘*vc-log*’ buffer; see Section 25.1.4 [Log Buffer], page 299).
Point is centered at the revision of the file currently being visited. With a prefix
argument, the command prompts for the revision to center on, and the maximum
number of revisions to display.
If you call C-x v l from a VC Directory buffer (see Section 25.1.9 [VC Directory
Mode], page 304) or a Dired buffer (see Chapter 27 [Dired], page 329), it applies to
the file listed on the current line.
C-x v L (vc-print-root-log) displays a ‘*vc-change-log*’ buffer showing the
history of the entire version-controlled directory tree (RCS, SCCS, and CVS do
not support this feature). With a prefix argument, the command prompts for the
maximum number of revisions to display.
The C-x v L history is shown in a compact form, usually showing only the first
line of each log entry. However, you can type RET (log-view-toggle-entrydisplay) in the ‘*vc-change-log*’ buffer to reveal the entire log entry for the
revision at point. A second RET hides it again.
On a decentralized version control system, the C-x v I (vc-log-incoming) command displays a log buffer showing the changes that will be applied, the next time
you run the version control system’s “pull” command to get new revisions from
another repository (see Section 25.1.10.2 [VC Pull], page 308). This other repository is the default one from which changes are pulled, as defined by the version
control system; with a prefix argument, vc-log-incoming prompts for a specific
repository. Similarly, C-x v O (vc-log-outgoing) shows the changes that will be
sent to another repository, the next time you run the “push” command; with a
prefix argument, it prompts for a specific destination repository.
In the ‘*vc-change-log*’ buffer, you can use the following keys to move between
the logs of revisions and of files, and to examine and compare past revisions (see
Section 25.1.6 [Old Revisions], page 300):
p

Move to the previous revision entry. (Revision entries in the log buffer
are usually in reverse-chronological order, so the previous revision-item
usually corresponds to a newer revision.) A numeric prefix argument
is a repeat count.

n

Move to the next revision entry. A numeric prefix argument is a repeat
count.

P

Move to the log of the previous file, if showing logs for a multi-file VC
fileset. Otherwise, just move to the beginning of the log. A numeric
prefix argument is a repeat count.

N

Move to the log of the next file, if showing logs for a multi-file VC
fileset. A numeric prefix argument is a repeat count.

a

Annotate the revision on the current line (see Section 25.1.6 [Old Revisions], page 300).

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e

Modify the change comment displayed at point. Note that not all VC
systems support modifying change comments.

f

Visit the revision indicated at the current line.

d

Display a diff between the revision at point and the next earlier revision, for the specific file.

D

Display the changeset diff between the revision at point and the next
earlier revision. This shows the changes to all files made in that revision.

RET

In a compact-style log buffer (e.g. the one created by C-x v L), toggle
between showing and hiding the full log entry for the revision at point.

Because fetching many log entries can be slow, the ‘*vc-change-log*’ buffer
displays no more than 2000 revisions by default. The variable vc-log-show-limit
specifies this limit; if you set the value to zero, that removes the limit. You can also
increase the number of revisions shown in an existing ‘*vc-change-log*’ buffer by
clicking on the ‘Show 2X entries’ or ‘Show unlimited entries’ buttons at the end
of the buffer. However, RCS, SCCS, and CVS do not support this feature.
25.1.8 Undoing Version Control Actions
C-x v u

Revert the work file(s) in the current VC fileset to the last revision
(vc-revert).

If you want to discard all the changes you have made to the current VC fileset,
type C-x v u (vc-revert-buffer). This shows you a diff between the work file(s)
and the revision from which you started editing, and asks for confirmation for
discarding the changes. If you agree, the fileset is reverted. If you don’t want C-x v
u to show a diff, set the variable vc-revert-show-diff to nil (you can still view
the diff directly with C-x v =; see Section 25.1.6 [Old Revisions], page 300). Note
that C-x v u cannot be reversed with the usual undo commands (see Section 13.1
[Undo], page 110), so use it with care.
On locking-based version control systems, C-x v u leaves files unlocked; you must
lock again to resume editing. You can also use C-x v u to unlock a file if you lock
it and then decide not to change it.
25.1.9 VC Directory Mode
The VC Directory buffer is a specialized buffer for viewing the version control
statuses of the files in a directory tree, and performing version control operations
on those files. In particular, it is used to specify multi-file VC filesets for commands
like C-x v v to act on (see Section 25.1.9.2 [VC Directory Commands], page 305).
To use the VC Directory buffer, type C-x v d (vc-dir). This reads a directory
name using the minibuffer, and switches to a VC Directory buffer for that directory.
By default, the buffer is named ‘*vc-dir*’. Its contents are described below.
The vc-dir command automatically detects the version control system to be
used in the specified directory. In the event that more than one system is being

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used in the directory, you should invoke the command with a prefix argument, C-u
C-x v d; this prompts for the version control system which the VC Directory buffer
should use.
25.1.9.1 The VC Directory Buffer
The VC Directory buffer contains a list of version-controlled files and their version
control statuses. It lists files in the current directory (the one specified when you
called C-x v d) and its subdirectories, but only those with a “noteworthy” status.
Files that are up-to-date (i.e. the same as in the repository) are omitted. If all the
files in a subdirectory are up-to-date, the subdirectory is not listed either. As an
exception, if a file has become up-to-date as a direct result of a VC command, it is
listed.
Here is an example of a VC Directory buffer listing:

*

edited
added
unregistered

*

edited

./
configure.ac
README
temp.txt
src/
src/main.c

Two work files have been modified but not committed: ‘configure.ac’ in the
current directory, and ‘foo.c’ in the ‘src/’ subdirectory. The file named ‘README’
has been added but is not yet committed, while ‘temp.txt’ is not under version
control (see Section 25.1.5 [Registering], page 300).
The ‘*’ characters next to the entries for ‘README’ and ‘src/main.c’ indicate
that the user has marked out these files as the current VC fileset (see below).
The above example is typical for a decentralized version control system like
Bazaar, Git, or Mercurial. Other systems can show other statuses. For instance,
CVS shows the ‘needs-update’ status if the repository has changes that have not
been applied to the work file. RCS and SCCS show the name of the user locking a
file as its status.
The VC Directory buffer omits subdirectories listed in the variable vcdirectory-exclusion-list. Its default value contains directories that are used
internally by version control systems.
25.1.9.2 VC Directory Commands
Emacs provides several commands for navigating the VC Directory buffer, and for
“marking” files as belonging to the current VC fileset.
n
SPC

Move point to the next entry (vc-dir-next-line).

p

Move point to the previous entry (vc-dir-previous-line).

TAB

Move to the next directory entry (vc-dir-next-directory).

S-TAB

Move to the previous directory entry (vc-dir-previous-directory).

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RET
f

306

Visit the file or directory listed on the current line (vc-dir-findfile).

o

Visit the file or directory on the current line, in a separate window
(vc-dir-find-file-other-window).

m

Mark the file or directory on the current line (vc-dir-mark), putting
it in the current VC fileset. If the region is active, mark all files in the
region.
A file cannot be marked with this command if it is already in a marked
directory, or one of its subdirectories. Similarly, a directory cannot be
marked with this command if any file in its tree is marked.

M

If point is on a file entry, mark all files with the same status; if point
is on a directory entry, mark all files in that directory tree (vc-dirmark-all-files). With a prefix argument, mark all listed files and
directories.

q

Bury the VC Directory buffer, and delete its window if the window
was created just for that buffer.

u

Unmark the file or directory on the current line. If the region is active,
unmark all the files in the region (vc-dir-unmark).

U

If point is on a file entry, unmark all files with the same status; if
point is on a directory entry, unmark all files in that directory tree
(vc-dir-unmark-all-files). With a prefix argument, unmark all
files and directories.

x

Hide files with ‘up-to-date’ status (vc-dir-hide-up-to-date).

q

Quit the VC Directory buffer, and bury it (quit-window).

While in the VC Directory buffer, all the files that you mark with m (vc-dirmark) or M (vc-dir-mark) are in the current VC fileset. If you mark a directory
entry with m, all the listed files in that directory tree are in the current VC fileset.
The files and directories that belong to the current VC fileset are indicated with
a ‘*’ character in the VC Directory buffer, next to their VC status. In this way,
you can set up a multi-file VC fileset to be acted on by VC commands like C-x v v
(see Section 25.1.3 [Basic VC Editing], page 296), C-x v = (see Section 25.1.6 [Old
Revisions], page 300), and C-x v u (see Section 25.1.8 [VC Undo], page 304).
The VC Directory buffer also defines some single-key shortcuts for VC commands
with the C-x v prefix: =, +, l, i, and v.
For example, you can commit a set of edited files by opening a VC Directory
buffer, where the files are listed with the ‘edited’ status; marking the files; and
typing v or C-x v v (vc-next-action). If the version control system is changesetbased, Emacs will commit the files in a single revision.
While in the VC Directory buffer, you can also perform search and replace on
the current VC fileset, with the following commands:

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S

Search the fileset (vc-dir-search).

Q

Do a regular expression query replace on the fileset (vc-dir-queryreplace-regexp).

M-s a C-s

Do an incremental search on the fileset (vc-dir-isearch).

M-s a C-M-s
Do an incremental regular expression search on the fileset (vc-dirisearch-regexp).
Apart from acting on multiple files, these commands behave much like their singlebuffer counterparts (see Chapter 12 [Search], page 91).
The above commands are also available via the menu bar, and via a context menu
invoked by Mouse-2. Furthermore, some VC backends use the menu to provide extra
backend-specific commands. For example, Git and Bazaar allow you to manipulate
stashes and shelves (where are a way to temporarily put aside uncommitted changes,
and bring them back at a later time).
25.1.10 Version Control Branches
One use of version control is to support multiple independent lines of development,
which are called branches. Branches are used for maintaining separate “stable”
and “development” versions of a program, and for developing unrelated features in
isolation from one another.
VC’s support for branch operations is currently fairly limited. For decentralized
version control systems, it provides commands for updating one branch with the
contents of another, and for merging the changes made to two different branches
(see Section 25.1.10.3 [Merging], page 308). For centralized version control systems,
it supports checking out different branches and committing into new or different
branches.
25.1.10.1 Switching between Branches
The various version control systems differ in how branches are implemented, and
these differences cannot be entirely concealed by VC.
On some decentralized version control systems, including Bazaar and Mercurial
in its normal mode of operation, each branch has its own working directory tree,
so switching between branches just involves switching directories. On Git, switching between branches is done using the git branch command, which changes the
contents of the working tree itself.
On centralized version control systems, you can switch between branches by
typing C-u C-x v v in an up-to-date work file (see Section 25.1.3.3 [Advanced C-x
v v], page 298), and entering the revision ID for a revision on another branch. On
CVS, for instance, revisions on the trunk (the main line of development) normally
have IDs of the form 1.1, 1.2, 1.3, . . . , while the first branch created from (say)
revision 1.2 has revision IDs 1.2.1.1, 1.2.1.2, . . . , the second branch created from
revision 1.2 has revision IDs 1.2.2.1, 1.2.2.2, . . . , and so forth. You can also specify
the branch ID, which is a branch revision ID omitting its final component (e.g.
1.2.1), to switch to the latest revision on that branch.

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On a locking-based system, switching to a different branch also unlocks (writeprotects) the working tree.
Once you have switched to a branch, VC commands will apply to that branch
until you switch away; for instance, any VC filesets that you commit will be committed to that specific branch.
25.1.10.2 Pulling Changes into a Branch
C-x v +

On a decentralized version control system, update the current branch
by “pulling in” changes from another location.
On a centralized version control system, update the current VC fileset.

On a decentralized version control system, the command C-x v + (vc-pull)
updates the current branch and working tree. It is typically used to update a copy
of a remote branch. If you supply a prefix argument, the command prompts for the
exact version control command to use, which lets you specify where to pull changes
from. Otherwise, it pulls from a default location determined by the version control
system.
Amongst decentralized version control systems, C-x v + is currently supported
only by Bazaar, Git, and Mercurial. On Bazaar, it calls bzr pull for ordinary
branches (to pull from a master branch into a mirroring branch), and bzr update
for a bound branch (to pull from a central repository). On Git, it calls git pull to
fetch changes from a remote repository and merge it into the current branch. On
Mercurial, it calls hg pull -u to fetch changesets from the default remote repository
and update the working directory.
Prior to pulling, you can use C-x v I (vc-log-incoming) to view a log buffer
of the changes to be applied. See Section 25.1.7 [VC Change Log], page 302.
On a centralized version control system like CVS, C-x v + updates the current
VC fileset from the repository.
25.1.10.3 Merging Branches
C-x v m

On a decentralized version control system, merge changes from another
branch into the current one.
On a centralized version control system, merge changes from another
branch into the current VC fileset.

While developing a branch, you may sometimes need to merge in changes that
have already been made in another branch. This is not a trivial operation, as
overlapping changes may have been made to the two branches.
On a decentralized version control system, merging is done with the command
C-x v m (vc-merge). On Bazaar, this prompts for the exact arguments to pass to
bzr merge, offering a sensible default if possible. On Git, this prompts for the name
of a branch to merge from, with completion (based on the branch names known to
the current repository). The output from running the merge command is shown in
a separate buffer.

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On a centralized version control system like CVS, C-x v m prompts for a branch
ID, or a pair of revision IDs (see Section 25.1.10.1 [Switching Branches], page 307);
then it finds the changes from that branch, or the changes between the two revisions
you specified, and merges those changes into the current VC fileset. If you just type
RET, Emacs simply merges any changes that were made on the same branch since
you checked the file out.
Immediately after performing a merge, only the working tree is modified, and
you can review the changes produced by the merge with C-x v D and related commands (see Section 25.1.6 [Old Revisions], page 300). If the two branches contained
overlapping changes, merging produces a conflict; a warning appears in the output
of the merge command, and conflict markers are inserted into each affected work
file, surrounding the two sets of conflicting changes. You must then resolve the
conflict by editing the conflicted files. Once you are done, the modified files must
be committed in the usual way for the merge to take effect (see Section 25.1.3 [Basic
VC Editing], page 296).
25.1.10.4 Creating New Branches
On centralized version control systems like CVS, Emacs supports creating new
branches as part of a commit operation. When committing a modified VC fileset,
type C-u C-x v v (vc-next-action with a prefix argument; see Section 25.1.3.3
[Advanced C-x v v], page 298). Then Emacs prompts for a revision ID for the
new revision. You should specify a suitable branch ID for a branch starting at the
current revision. For example, if the current revision is 2.5, the branch ID should
be 2.5.1, 2.5.2, and so on, depending on the number of existing branches at that
point.
To create a new branch at an older revision (one that is no longer the head
of a branch), first select that revision (see Section 25.1.10.1 [Switching Branches],
page 307). Your procedure will then differ depending on whether you are using a
locking or merging-based VCS.
On a locking VCS, you will need to lock the old revision branch with C-x v v.
You’ll be asked to confirm, when you lock the old revision, that you really mean
to create a new branch—if you say no, you’ll be offered a chance to lock the latest
revision instead. On a merging-based VCS you will skip this step.
Then make your changes and type C-x v v again to commit a new revision. This
creates a new branch starting from the selected revision.
After the branch is created, subsequent commits create new revisions on that
branch. To leave the branch, you must explicitly select a different revision with C-u
C-x v v.

25.2 Change Logs
Many software projects keep a change log. This is a file, normally named
‘ChangeLog’, containing a chronological record of when and how the program was
changed. Sometimes, there are several change log files, each recording the changes
in one directory or directory tree.

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25.2.1 Change Log Commands
The Emacs command C-x 4 a adds a new entry to the change log file for the file
you are editing (add-change-log-entry-other-window). If that file is actually a
backup file, it makes an entry appropriate for the file’s parent—that is useful for
making log entries for functions that have been deleted in the current version.
C-x 4 a visits the change log file and creates a new entry unless the most recent
entry is for today’s date and your name. It also creates a new item for the current
file. For many languages, it can even guess the name of the function or other object
that was changed.
When the variable add-log-keep-changes-together is non-nil, C-x 4 a adds
to any existing item for the file rather than starting a new item.
You can combine multiple changes of the same nature. If you don’t enter any
text after the initial C-x 4 a, any subsequent C-x 4 a adds another symbol to the
change log entry.
If add-log-always-start-new-record is non-nil, C-x 4 a always makes a new
entry, even if the last entry was made by you and on the same date.
If the value of the variable change-log-version-info-enabled is non-nil,
C-x 4 a adds the file’s version number to the change log entry. It finds the version
number by searching the first ten percent of the file, using regular expressions from
the variable change-log-version-number-regexp-list.
The change log file is visited in Change Log mode. In this major mode, each
bunch of grouped items counts as one paragraph, and each entry is considered a
page. This facilitates editing the entries. C-j and auto-fill indent each new line like
the previous line; this is convenient for entering the contents of an entry.
You can use the next-error command (by default bound to C-x ‘) to move
between entries in the Change Log, when Change Log mode is on. You will jump to
the actual site in the file that was changed, not just to the next Change Log entry.
You can also use previous-error to move back in the same list.
You can use the command M-x change-log-merge to merge other log files into
a buffer in Change Log Mode, preserving the date ordering of entries.
Version control systems are another way to keep track of changes in your program
and keep a change log. In the VC log buffer, typing C-c C-a (log-edit-insertchangelog) inserts the relevant Change Log entry, if one exists. See Section 25.1.4
[Log Buffer], page 299.
25.2.2 Format of ChangeLog
A change log entry starts with a header line that contains the current date, your
name (taken from the variable add-log-full-name), and your email address (taken
from the variable add-log-mailing-address). Aside from these header lines, every
line in the change log starts with a space or a tab. The bulk of the entry consists
of items, each of which starts with a line starting with whitespace and a star. Here
are two entries, both dated in May 1993, with two items and one item respectively.
1993-05-25

Richard Stallman



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* man.el: Rename symbols ‘man-*’ to ‘Man-*’.
(manual-entry): Make prompt string clearer.
* simple.el (blink-matching-paren-distance):
Change default to 12,000.
1993-05-24

Richard Stallman



* vc.el (minor-mode-map-alist): Don’t use it if it’s void.
(vc-cancel-version): Doc fix.

One entry can describe several changes; each change should have its own item,
or its own line in an item. Normally there should be a blank line between items.
When items are related (parts of the same change, in different places), group them
by leaving no blank line between them.
You should put a copyright notice and permission notice at the end of the change
log file. Here is an example:
Copyright 1997, 1998 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification, are
permitted provided the copyright notice and this notice are preserved.

Of course, you should substitute the proper years and copyright holder.

25.3 Tags Tables
A tag is a reference to a subunit in a program or in a document. In source code,
tags reference syntactic elements of the program: functions, subroutines, data types,
macros, etc. In a document, tags reference chapters, sections, appendices, etc. Each
tag specifies the name of the file where the corresponding subunit is defined, and
the position of the subunit’s definition in that file.
A tags table records the tags extracted by scanning the source code of a certain
program or a certain document. Tags extracted from generated files reference the
original files, rather than the generated files that were scanned during tag extraction.
Examples of generated files include C files generated from Cweb source files, from a
Yacc parser, or from Lex scanner definitions; ‘.i’ preprocessed C files; and Fortran
files produced by preprocessing ‘.fpp’ source files.
To produce a tags table, you run the etags shell command on a document or
the source code file. The ‘etags’ program writes the tags to a tags table file, or
tags file in short. The conventional name for a tags file is ‘TAGS’. See Section 25.3.2
[Create Tags Table], page 314.
Emacs provides many commands for searching and replacing using the information recorded in tags tables. For instance, the M-. (find-tag) jumps to the location
of a specified function definition in its source file. See Section 25.3.5 [Find Tag],
page 317.
The Ebrowse facility is similar to etags but specifically tailored for C++. See
Section “Ebrowse” in Ebrowse User’s Manual. The Semantic package provides
another way to generate and use tags, separate from the etags facility. See
Section 23.10 [Semantic], page 265.

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25.3.1 Source File Tag Syntax
Here is how tag syntax is defined for the most popular languages:
• In C code, any C function or typedef is a tag, and so are definitions of struct,
union and enum. #define macro definitions, #undef and enum constants are
also tags, unless you specify ‘--no-defines’ when making the tags table. Similarly, global variables are tags, unless you specify ‘--no-globals’, and so are
struct members, unless you specify ‘--no-members’. Use of ‘--no-globals’,
‘--no-defines’ and ‘--no-members’ can make the tags table file much smaller.
You can tag function declarations and external variables in addition to function
definitions by giving the ‘--declarations’ option to etags.
• In C++ code, in addition to all the tag constructs of C code, member functions
are also recognized; member variables are also recognized, unless you use the
‘--no-members’ option. Tags for variables and functions in classes are named
‘class ::variable ’ and ‘class ::function ’. operator definitions have tag
names like ‘operator+’.
• In Java code, tags include all the constructs recognized in C++, plus the
interface, extends and implements constructs. Tags for variables and functions in classes are named ‘class.variable ’ and ‘class.function ’.
• In LaTEX documents, the arguments for \chapter, \section, \subsection,
\subsubsection, \eqno, \label, \ref, \cite, \bibitem, \part, \appendix,
\entry, \index, \def, \newcommand, \renewcommand, \newenvironment and
\renewenvironment are tags.
Other commands can make tags as well, if you specify them in the environment variable TEXTAGS before invoking etags. The value of this environment
variable should be a colon-separated list of command names. For example,
TEXTAGS="mycommand:myothercommand"
export TEXTAGS
specifies (using Bourne shell syntax) that the commands ‘\mycommand’ and
‘\myothercommand’ also define tags.
• In Lisp code, any function defined with defun, any variable defined with
defvar or defconst, and in general the first argument of any expression that
starts with ‘(def’ in column zero is a tag.
• In Scheme code, tags include anything defined with def or with a construct
whose name starts with ‘def’. They also include variables set with set! at
top level in the file.
Several other languages are also supported:
• In Ada code, functions, procedures, packages, tasks and types are tags. Use
the ‘--packages-only’ option to create tags for packages only.
In Ada, the same name can be used for different kinds of entity (e.g., for
a procedure and for a function). Also, for things like packages, procedures
and functions, there is the spec (i.e. the interface) and the body (i.e. the
implementation). To make it easier to pick the definition you want, Ada tag
name have suffixes indicating the type of entity:

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‘/b’

package body.

‘/f’

function.

‘/k’

task.

‘/p’

procedure.

‘/s’

package spec.

‘/t’

type.

313

Thus, M-x find-tag RET bidule/b RET will go directly to the body of the
package bidule, while M-x find-tag RET bidule RET will just search for any
tag bidule.
• In assembler code, labels appearing at the start of a line, followed by a colon,
are tags.
• In Bison or Yacc input files, each rule defines as a tag the nonterminal it
constructs. The portions of the file that contain C code are parsed as C code.
• In Cobol code, tags are paragraph names; that is, any word starting in column
8 and followed by a period.
• In Erlang code, the tags are the functions, records and macros defined in the
file.
• In Fortran code, functions, subroutines and block data are tags.
• In HTML input files, the tags are the title and the h1, h2, h3 headers. Also,
tags are name= in anchors and all occurrences of id=.
• In Lua input files, all functions are tags.
• In makefiles, targets are tags; additionally, variables are tags unless you specify
‘--no-globals’.
• In Objective C code, tags include Objective C definitions for classes, class
categories, methods and protocols. Tags for variables and functions in classes
are named ‘class ::variable ’ and ‘class ::function ’.
• In Pascal code, the tags are the functions and procedures defined in the file.
• In Perl code, the tags are the packages, subroutines and variables defined by
the package, sub, my and local keywords. Use ‘--globals’ if you want to tag
global variables. Tags for subroutines are named ‘package ::sub ’. The name
for subroutines defined in the default package is ‘main::sub ’.
• In PHP code, tags are functions, classes and defines. Vars are tags too, unless
you use the ‘--no-members’ option.
• In PostScript code, the tags are the functions.
• In Prolog code, tags are predicates and rules at the beginning of line.
• In Python code, def or class at the beginning of a line generate a tag.
You can also generate tags based on regexp matching (see Section 25.3.3 [Etags
Regexps], page 315) to handle other formats and languages.

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25.3.2 Creating Tags Tables
The etags program is used to create a tags table file. It knows the syntax of several
languages, as described in the previous section. Here is how to run etags:
etags inputfiles ...
The etags program reads the specified files, and writes a tags table named ‘TAGS’
in the current working directory. You can optionally specify a different file name
for the tags table by using the ‘--output=file ’ option; specifying ‘-’ as a file name
prints the tags table to standard output.
If the specified files don’t exist, etags looks for compressed versions of them and
uncompresses them to read them. Under MS-DOS, etags also looks for file names
like ‘mycode.cgz’ if it is given ‘mycode.c’ on the command line and ‘mycode.c’
does not exist.
If the tags table becomes outdated due to changes in the files described in it,
you can update it by running the etags program again. If the tags table does not
record a tag, or records it for the wrong file, then Emacs will not be able to find
that definition until you update the tags table. But if the position recorded in the
tags table becomes a little bit wrong (due to other editing), Emacs will still be able
to find the right position, with a slight delay.
Thus, there is no need to update the tags table after each edit. You should
update a tags table when you define new tags that you want to have listed, or
when you move tag definitions from one file to another, or when changes become
substantial.
You can make a tags table include another tags table, by passing the
‘--include=file ’ option to etags. It then covers all the files covered by the
included tags file, as well as its own.
If you specify the source files with relative file names when you run etags, the
tags file will contain file names relative to the directory where the tags file was
initially written. This way, you can move an entire directory tree containing both
the tags file and the source files, and the tags file will still refer correctly to the source
files. If the tags file is ‘-’ or is in the ‘/dev’ directory, however, the file names are
made relative to the current working directory. This is useful, for example, when
writing the tags to ‘/dev/stdout’.
When using a relative file name, it should not be a symbolic link pointing to a
tags file in a different directory, because this would generally render the file names
invalid.
If you specify absolute file names as arguments to etags, then the tags file will
contain absolute file names. This way, the tags file will still refer to the same files
even if you move it, as long as the source files remain in the same place. Absolute
file names start with ‘/’, or with ‘device :/’ on MS-DOS and MS-Windows.
When you want to make a tags table from a great number of files, you may have
problems listing them on the command line, because some systems have a limit on
its length. You can circumvent this limit by telling etags to read the file names
from its standard input, by typing a dash in place of the file names, like this:
find . -name "*.[chCH]" -print | etags -

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etags recognizes the language used in an input file based on its file name and
contents. You can specify the language explicitly with the ‘--language=name ’
option. You can intermix these options with file names; each one applies to the file
names that follow it. Specify ‘--language=auto’ to tell etags to resume guessing
the language from the file names and file contents. Specify ‘--language=none’ to
turn off language-specific processing entirely; then etags recognizes tags by regexp
matching alone (see Section 25.3.3 [Etags Regexps], page 315).
The option ‘--parse-stdin=file ’ is mostly useful when calling etags from
programs. It can be used (only once) in place of a file name on the command line.
etags will read from standard input and mark the produced tags as belonging to
the file file.
‘etags --help’ outputs the list of the languages etags knows, and the file name
rules for guessing the language. It also prints a list of all the available etags options,
together with a short explanation. If followed by one or more ‘--language=lang ’
options, it outputs detailed information about how tags are generated for lang.
25.3.3 Etags Regexps
The ‘--regex’ option to etags allows tags to be recognized by regular expression
matching. You can intermix this option with file names; each one applies to the
source files that follow it. If you specify multiple ‘--regex’ options, all of them are
used in parallel. The syntax is:
--regex=[{language}]/tagregexp /[nameregexp /]modifiers

The essential part of the option value is tagregexp, the regexp for matching tags. It
is always used anchored, that is, it only matches at the beginning of a line. If you
want to allow indented tags, use a regexp that matches initial whitespace; start it
with ‘[ \t]*’.
In these regular expressions, ‘\’ quotes the next character, and all the GCC
character escape sequences are supported (‘\a’ for bell, ‘\b’ for back space, ‘\d’ for
delete, ‘\e’ for escape, ‘\f’ for formfeed, ‘\n’ for newline, ‘\r’ for carriage return,
‘\t’ for tab, and ‘\v’ for vertical tab).
Ideally, tagregexp should not match more characters than are needed to recognize what you want to tag. If the syntax requires you to write tagregexp so it
matches more characters beyond the tag itself, you should add a nameregexp, to
pick out just the tag. This will enable Emacs to find tags more accurately and to
do completion on tag names more reliably. You can find some examples below.
The modifiers are a sequence of zero or more characters that modify the way
etags does the matching. A regexp with no modifiers is applied sequentially to
each line of the input file, in a case-sensitive way. The modifiers and their meanings
are:
‘i’

Ignore case when matching this regexp.

‘m’

Match this regular expression against the whole file, so that multi-line
matches are possible.

‘s’

Match this regular expression against the whole file, and allow ‘.’ in
tagregexp to match newlines.

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The ‘-R’ option cancels all the regexps defined by preceding ‘--regex’ options.
It too applies to the file names following it. Here’s an example:
etags --regex=/reg1 /i voo.doo --regex=/reg2 /m \
bar.ber -R --lang=lisp los.er

Here etags chooses the parsing language for ‘voo.doo’ and ‘bar.ber’ according
to their contents. etags also uses reg1 to recognize additional tags in ‘voo.doo’,
and both reg1 and reg2 to recognize additional tags in ‘bar.ber’. reg1 is checked
against each line of ‘voo.doo’ and ‘bar.ber’, in a case-insensitive way, while reg2 is
checked against the whole ‘bar.ber’ file, permitting multi-line matches, in a casesensitive way. etags uses only the Lisp tags rules, with no user-specified regexp
matching, to recognize tags in ‘los.er’.
You can restrict a ‘--regex’ option to match only files of a given language by
using the optional prefix {language}. (‘etags --help’ prints the list of languages
recognized by etags.) This is particularly useful when storing many predefined
regular expressions for etags in a file. The following example tags the DEFVAR
macros in the Emacs source files, for the C language only:
--regex=’{c}/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/’

When you have complex regular expressions, you can store the list of them in a file.
The following option syntax instructs etags to read two files of regular expressions.
The regular expressions contained in the second file are matched without regard to
case.
--regex=@case-sensitive-file --ignore-case-regex=@ignore-case-file

A regex file for etags contains one regular expression per line. Empty lines, and
lines beginning with space or tab are ignored. When the first character in a line is
‘@’, etags assumes that the rest of the line is the name of another file of regular
expressions; thus, one such file can include another file. All the other lines are taken
to be regular expressions. If the first non-whitespace text on the line is ‘--’, that
line is a comment.
For example, we can create a file called ‘emacs.tags’ with the following contents:
-- This is for GNU Emacs C source files
{c}/[ \t]*DEFVAR_[A-Z_ \t(]+"\([^"]+\)"/\1/

and then use it like this:
etags --regex=@emacs.tags *.[ch] */*.[ch]

Here are some more examples. The regexps are quoted to protect them from
shell interpretation.
• Tag Octave files:
etags --language=none \
--regex=’/[ \t]*function.*=[ \t]*\([^ \t]*\)[ \t]*(/\1/’ \
--regex=’/###key \(.*\)/\1/’ \
--regex=’/[ \t]*global[ \t].*/’ \
*.m

Note that tags are not generated for scripts, so that you have to add a line by
yourself of the form ‘###key scriptname ’ if you want to jump to it.
• Tag Tcl files:
etags --language=none --regex=’/proc[ \t]+\([^ \t]+\)/\1/’ *.tcl

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• Tag VHDL files:
etags --language=none \
--regex=’/[ \t]*\(ARCHITECTURE\|CONFIGURATION\) +[^ ]* +OF/’ \
--regex=’/[ \t]*\(ATTRIBUTE\|ENTITY\|FUNCTION\|PACKAGE\
\( BODY\)?\|PROCEDURE\|PROCESS\|TYPE\)[ \t]+\([^ \t(]+\)/\3/’

25.3.4 Selecting a Tags Table
Emacs has at any time one selected tags table. All the commands for working with
tags tables use the selected one. To select a tags table, type M-x visit-tags-table,
which reads the tags table file name as an argument, with ‘TAGS’ in the default
directory as the default.
Emacs does not actually read in the tags table contents until you try to use
them; all visit-tags-table does is store the file name in the variable tags-filename, and setting the variable yourself is just as good. The variable’s initial value is
nil; that value tells all the commands for working with tags tables that they must
ask for a tags table file name to use.
Using visit-tags-table when a tags table is already loaded gives you a choice:
you can add the new tags table to the current list of tags tables, or start a new list.
The tags commands use all the tags tables in the current list. If you start a new
list, the new tags table is used instead of others. If you add the new table to the
current list, it is used as well as the others.
You can specify a precise list of tags tables by setting the variable tags-tablelist to a list of strings, like this:
(setq tags-table-list
’("~/emacs" "/usr/local/lib/emacs/src"))
This tells the tags commands to look at the ‘TAGS’ files in your ‘~/emacs’ directory
and in the ‘/usr/local/lib/emacs/src’ directory. The order depends on which
file you are in and which tags table mentions that file, as explained above.
Do not set both tags-file-name and tags-table-list.
25.3.5 Finding a Tag
The most important thing that a tags table enables you to do is to find the definition
of a specific tag.
M-. tag RET
Find first definition of tag (find-tag).
C-u M-.

Find next alternate definition of last tag specified.

C-u - M-.

Go back to previous tag found.

C-M-. pattern RET
Find a tag whose name matches pattern (find-tag-regexp).
C-u C-M-.

Find the next tag whose name matches the last pattern used.

C-x 4 . tag RET
Find first definition of tag, but display it in another window (findtag-other-window).

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C-x 5 . tag RET
Find first definition of tag, and create a new frame to select the buffer
(find-tag-other-frame).
M-*

Pop back to where you previously invoked M-. and friends.

M-. (find-tag) prompts for a tag name and jumps to its source definition.
It works by searching through the tags table for that tag’s file and approximate
character position, visiting that file, and searching for the tag definition at everincreasing distances away from the recorded approximate position.
When entering the tag argument to M-., the usual minibuffer completion commands can be used (see Section 5.3 [Completion], page 29), with the tag names in
the selected tags table as completion candidates. If you specify an empty argument,
the balanced expression in the buffer before or around point is the default argument.
See Section 23.4.1 [Expressions], page 256.
You don’t need to give M-. the full name of the tag; a part will do. M-. finds
tags which contain that argument as a substring. However, it prefers an exact
match to a substring match. To find other tags that match the same substring, give
find-tag a numeric argument, as in C-u M-. or M-0 M-.; this does not read a tag
name, but continues searching the tags table’s text for another tag containing the
same substring last used.
Like most commands that can switch buffers, find-tag has a variant that displays the new buffer in another window, and one that makes a new frame for it.
The former is C-x 4 . (find-tag-other-window), and the latter is C-x 5 . (findtag-other-frame).
To move back to previous tag definitions, use C-u - M-.; more generally, M-.
with a negative numeric argument. Similarly, C-x 4 . with a negative argument
finds the previous tag location in another window.
As well as going back to places you’ve found tags recently, you can go back to
places from where you found them, using M-* (pop-tag-mark). Thus you can find
and examine the definition of something with M-. and then return to where you
were with M-*.
Both C-u - M-. and M-* allow you to retrace your steps to a depth determined
by the variable find-tag-marker-ring-length.
The command C-M-. (find-tag-regexp) visits the tags that match a specified
regular expression. It is just like M-. except that it does regexp matching instead
of substring matching.
25.3.6 Searching and Replacing with Tags Tables
The commands in this section visit and search all the files listed in the selected
tags table, one by one. For these commands, the tags table serves only to specify
a sequence of files to search. These commands scan the list of tags tables starting
with the first tags table (if any) that describes the current file, proceed from there
to the end of the list, and then scan from the beginning of the list until they have
covered all the tables in the list.

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M-x tags-search RET regexp RET
Search for regexp through the files in the selected tags table.
M-x tags-query-replace RET regexp RET replacement RET
Perform a query-replace-regexp on each file in the selected tags
table.
M-,

Restart one of the commands above, from the current location of point
(tags-loop-continue).

M-x tags-search reads a regexp using the minibuffer, then searches for matches
in all the files in the selected tags table, one file at a time. It displays the name
of the file being searched so you can follow its progress. As soon as it finds an
occurrence, tags-search returns.
Having found one match, you probably want to find all the rest. Type M-,
(tags-loop-continue) to resume the tags-search, finding one more match. This
searches the rest of the current buffer, followed by the remaining files of the tags
table.
M-x tags-query-replace performs a single query-replace-regexp through all
the files in the tags table. It reads a regexp to search for and a string to replace
with, just like ordinary M-x query-replace-regexp. It searches much like M-x
tags-search, but repeatedly, processing matches according to your input. See
Section 12.9 [Replace], page 103, for more information on query replace.
You can control the case-sensitivity of tags search commands by customizing
the value of the variable tags-case-fold-search. The default is to use the same
setting as the value of case-fold-search (see Section 12.8 [Search Case], page 103).
It is possible to get through all the files in the tags table with a single invocation
of M-x tags-query-replace. But often it is useful to exit temporarily, which you
can do with any input event that has no special query replace meaning. You can
resume the query replace subsequently by typing M-,; this command resumes the
last tags search or replace command that you did. For instance, to skip the rest of
the current file, you can type M-> M-,.
The commands in this section carry out much broader searches than the findtag family. The find-tag commands search only for definitions of tags that match
your substring or regexp. The commands tags-search and tags-query-replace
find every occurrence of the regexp, as ordinary search commands and replace commands do in the current buffer.
These commands create buffers only temporarily for the files that they have to
search (those which are not already visited in Emacs buffers). Buffers in which no
match is found are quickly killed; the others continue to exist.
As an alternative to tags-search, you can run grep as a subprocess and have
Emacs show you the matching lines one by one. See Section 24.4 [Grep Searching],
page 275.
25.3.7 Tags Table Inquiries

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C-M-i
M-TAB

320

Perform completion on the text around point, using the selected tags
table if one is loaded (completion-at-point).

M-x list-tags RET file RET
Display a list of the tags defined in the program file file.
M-x tags-apropos RET regexp RET
Display a list of all tags matching regexp.
In most programming language modes, you can type C-M-i or M-TAB
(completion-at-point) to complete the symbol at point. If there is a selected
tags table, this command can use it to generate completion candidates. See
Section 23.8 [Symbol Completion], page 264.
M-x list-tags reads the name of one of the files covered by the selected tags
table, and displays a list of tags defined in that file. Do not include a directory
as part of the file name unless the file name recorded in the tags table includes a
directory.
M-x tags-apropos is like apropos for tags (see Section 7.3 [Apropos], page 41).
It displays a list of tags in the selected tags table whose entries match regexp.
If the variable tags-apropos-verbose is non-nil, it displays the names of the
tags files together with the tag names. You can customize the appearance of the
output by setting the variable tags-tag-face to a face. You can display additional
output by customizing the variable tags-apropos-additional-actions; see its
documentation for details.
M-x next-file visits files covered by the selected tags table. The first time it
is called, it visits the first file covered by the table. Each subsequent call visits the
next covered file, unless a prefix argument is supplied, in which case it returns to
the first file.

25.4 Emacs Development Environment
EDE (Emacs Development Environment) is a package that simplifies the task of
creating, building, and debugging large programs with Emacs. It provides some of
the features of an IDE, or Integrated Development Environment, in Emacs.
This section provides a brief description of EDE usage. For full details on Ede,
type C-h i and then select the EDE manual.
EDE is implemented as a global minor mode (see Section 20.2 [Minor Modes],
page 205). To enable it, type M-x global-ede-mode or click on the ‘Project
Support (EDE)’ item in the ‘Tools’ menu. You can also enable EDE each time
you start Emacs, by adding the following line to your initialization file:
(global-ede-mode t)

Activating EDE adds a menu named ‘Development’ to the menu bar. Many EDE
commands, including the ones described below, can be invoked from this menu.
EDE organizes files into projects, which correspond to directory trees. The
project root is the topmost directory of a project. To define a new project, visit a
file in the desired project root and type M-x ede-new. This command prompts for

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a project type, which refers to the underlying method that EDE will use to manage
the project (see Section “Creating a Project” in Emacs Development Environment).
The most common project types are ‘Make’, which uses Makefiles, and ‘Automake’,
which uses GNU Automake (see Section “Top” in Automake). In both cases, EDE
also creates a file named ‘Project.ede’, which stores information about the project.
A project may contain one or more targets. A target can be an object file,
executable program, or some other type of file, which is “built” from one or more
of the files in the project.
To add a new target to a project, type C-c . t (M-x ede-new-target). This
command also asks if you wish to “add” the current file to that target, which means
that the target is to be built from that file. After you have defined a target, you
can add more files to it by typing C-c . a (ede-add-file).
To build a target, type C-c . c (ede-compile-target). To build all the targets
in the project, type C-c . C (ede-compile-project). EDE uses the file types to
guess how the target should be built.

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26 Abbrevs
A defined abbrev is a word which expands, if you insert it, into some different text.
Abbrevs are defined by the user to expand in specific ways. For example, you might
define ‘foo’ as an abbrev expanding to ‘find outer otter’. Then you could insert
‘find outer otter ’ into the buffer by typing f o o SPC.
A second kind of abbreviation facility is called dynamic abbrev expansion. You
use dynamic abbrev expansion with an explicit command to expand the letters in
the buffer before point by looking for other words in the buffer that start with those
letters. See Section 26.6 [Dynamic Abbrevs], page 326.
“Hippie” expansion generalizes abbreviation expansion. See Section “Hippie
Expansion” in Features for Automatic Typing.

26.1 Abbrev Concepts
An abbrev is a word that has been defined to expand into a specified expansion.
When you insert a word-separator character following the abbrev, that expands the
abbrev—replacing the abbrev with its expansion. For example, if ‘foo’ is defined as
an abbrev expanding to ‘find outer otter’, then typing f o o . will insert ‘find
outer otter.’.
Abbrevs expand only when Abbrev mode, a buffer-local minor mode, is enabled.
Disabling Abbrev mode does not cause abbrev definitions to be forgotten, but they
do not expand until Abbrev mode is enabled again. The command M-x abbrev-mode
toggles Abbrev mode; with a numeric argument, it turns Abbrev mode on if the
argument is positive, off otherwise. See Section 20.2 [Minor Modes], page 205.
Abbrevs can have mode-specific definitions, active only in one major mode. Abbrevs can also have global definitions that are active in all major modes. The same
abbrev can have a global definition and various mode-specific definitions for different major modes. A mode-specific definition for the current major mode overrides
a global definition.
You can define abbrevs interactively during the editing session, irrespective of
whether Abbrev mode is enabled. You can also save lists of abbrev definitions in
files, which you can the reload for use in later sessions.

26.2 Defining Abbrevs
C-x a g

Define an abbrev, using one or more words before point as its expansion (add-global-abbrev).

C-x a l

Similar, but define an abbrev specific to the current major mode (addmode-abbrev).

C-x a i g

Define a word in the buffer as an abbrev (inverse-add-globalabbrev).

C-x a i l

Define a word in the buffer as a mode-specific abbrev (inverse-addmode-abbrev).

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M-x define-global-abbrev RET abbrev RET exp RET
Define abbrev as an abbrev expanding into exp.
M-x define-mode-abbrev RET abbrev RET exp RET
Define abbrev as a mode-specific abbrev expanding into exp.
M-x kill-all-abbrevs
Discard all abbrev definitions, leaving a blank slate.
The usual way to define an abbrev is to enter the text you want the abbrev to
expand to, position point after it, and type C-x a g (add-global-abbrev). This
reads the abbrev itself using the minibuffer, and then defines it as an abbrev for
one or more words before point. Use a numeric argument to say how many words
before point should be taken as the expansion. For example, to define the abbrev
‘foo’ as mentioned above, insert the text ‘find outer otter’ and then type C-u 3
C-x a g f o o RET.
An argument of zero to C-x a g means to use the contents of the region as the
expansion of the abbrev being defined.
The command C-x a l (add-mode-abbrev) is similar, but defines a mode-specific
abbrev for the current major mode. The arguments work the same as for C-x a g.
C-x a i g (inverse-add-global-abbrev) and C-x a i l (inverse-add-modeabbrev) perform the opposite task: if the abbrev text is already in the buffer,
you use these commands to define an abbrev by specifying the expansion in the
minibuffer. These commands will expand the abbrev text used for the definition.
You can define an abbrev without inserting either the abbrev or its expansion in
the buffer using the command define-global-abbrev. It reads two arguments—
the abbrev, and its expansion. The command define-mode-abbrev does likewise
for a mode-specific abbrev.
To change the definition of an abbrev, just make a new definition. When an
abbrev has a prior definition, the abbrev definition commands ask for confirmation
before replacing it.
To remove an abbrev definition, give a negative argument to the abbrev definition command: C-u - C-x a g or C-u - C-x a l. The former removes a global definition, while the latter removes a mode-specific definition. M-x kill-all-abbrevs
removes all abbrev definitions, both global and local.

26.3 Controlling Abbrev Expansion
When Abbrev mode is enabled, an abbrev expands whenever it is present in the
buffer just before point and you type a self-inserting whitespace or punctuation
character (SPC, comma, etc.). More precisely, any character that is not a word
constituent expands an abbrev, and any word-constituent character can be part of
an abbrev. The most common way to use an abbrev is to insert it and then insert
a punctuation or whitespace character to expand it.
Abbrev expansion preserves case: ‘foo’ expands to ‘find outer otter’, and
‘Foo’ to ‘Find outer otter’. ‘FOO’ expands to ‘Find Outer Otter’ by default, but
if you change the variable abbrev-all-caps to a non-nil value, it expands to ‘FIND
OUTER OTTER’.

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These commands are used to control abbrev expansion:
M-’

Separate a prefix from a following abbrev to be expanded (abbrevprefix-mark).

C-x a e

Expand the abbrev before point (expand-abbrev). This is effective
even when Abbrev mode is not enabled.

M-x expand-region-abbrevs
Expand some or all abbrevs found in the region.
You may wish to expand an abbrev and attach a prefix to the expansion; for
example, if ‘cnst’ expands into ‘construction’, you might want to use it to enter
‘reconstruction’. It does not work to type recnst, because that is not necessarily
a defined abbrev. What you can do is use the command M-’ (abbrev-prefix-mark)
in between the prefix ‘re’ and the abbrev ‘cnst’. First, insert ‘re’. Then type M-’;
this inserts a hyphen in the buffer to indicate that it has done its work. Then
insert the abbrev ‘cnst’; the buffer now contains ‘re-cnst’. Now insert a non-word
character to expand the abbrev ‘cnst’ into ‘construction’. This expansion step
also deletes the hyphen that indicated M-’ had been used. The result is the desired
‘reconstruction’.
If you actually want the text of the abbrev in the buffer, rather than its expansion, you can accomplish this by inserting the following punctuation with C-q.
Thus, foo C-q , leaves ‘foo,’ in the buffer, not expanding it.
If you expand an abbrev by mistake, you can undo the expansion by typing
C-/ (undo). See Section 13.1 [Undo], page 110. This undoes the insertion of the
abbrev expansion and brings back the abbrev text. If the result you want is the
terminating non-word character plus the unexpanded abbrev, you must reinsert the
terminating character, quoting it with C-q. You can also use the command M-x
unexpand-abbrev to cancel the last expansion without deleting the terminating
character.
M-x expand-region-abbrevs searches through the region for defined abbrevs,
and for each one found offers to replace it with its expansion. This command is
useful if you have typed in text using abbrevs but forgot to turn on Abbrev mode
first. It may also be useful together with a special set of abbrev definitions for
making several global replacements at once. This command is effective even if
Abbrev mode is not enabled.
Expanding any abbrev runs abbrev-expand-functions, a special hook. Functions in this special hook can make arbitrary changes to the abbrev expansion. See
Section “Abbrev Expansion” in The Emacs Lisp Reference Manual.

26.4 Examining and Editing Abbrevs
M-x list-abbrevs
Display a list of all abbrev definitions. With a numeric argument, list
only local abbrevs.
M-x edit-abbrevs
Edit a list of abbrevs; you can add, alter or remove definitions.

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The output from M-x list-abbrevs looks like this:
various other tables...
(lisp-mode-abbrev-table)
"dk"
0
"define-key"
(global-abbrev-table)
"dfn"
0
"definition"
(Some blank lines of no semantic significance, and some other abbrev tables, have
been omitted.)
A line containing a name in parentheses is the header for abbrevs in a particular
abbrev table; global-abbrev-table contains all the global abbrevs, and the other
abbrev tables that are named after major modes contain the mode-specific abbrevs.
Within each abbrev table, each nonblank line defines one abbrev. The word at
the beginning of the line is the abbrev. The number that follows is the number of
times the abbrev has been expanded. Emacs keeps track of this to help you see
which abbrevs you actually use, so that you can eliminate those that you don’t use
often. The string at the end of the line is the expansion.
Some abbrevs are marked with ‘(sys)’. These “system” abbrevs (see Section
“Abbrevs” in The Emacs Lisp Reference Manual) are pre-defined by various modes,
and are not saved to your abbrev file. To disable a “system” abbrev, define an
abbrev of the same name that expands to itself, and save it to your abbrev file.
M-x edit-abbrevs allows you to add, change or kill abbrev definitions by editing
a list of them in an Emacs buffer. The list has the same format described above.
The buffer of abbrevs is called ‘*Abbrevs*’, and is in Edit-Abbrevs mode. Type C-c
C-c in this buffer to install the abbrev definitions as specified in the buffer—and
delete any abbrev definitions not listed.
The command edit-abbrevs is actually the same as list-abbrevs except that
it selects the buffer ‘*Abbrevs*’ whereas list-abbrevs merely displays it in another
window.

26.5 Saving Abbrevs
These commands allow you to keep abbrev definitions between editing sessions.
M-x write-abbrev-file RET file RET
Write a file file describing all defined abbrevs.
M-x read-abbrev-file RET file RET
Read the file file and define abbrevs as specified therein.
M-x define-abbrevs
Define abbrevs from definitions in current buffer.
M-x insert-abbrevs
Insert all abbrevs and their expansions into current buffer.
M-x write-abbrev-file reads a file name using the minibuffer and then writes
a description of all current abbrev definitions into that file. This is used to save
abbrev definitions for use in a later session. The text stored in the file is a series of

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Lisp expressions that, when executed, define the same abbrevs that you currently
have.
M-x read-abbrev-file reads a file name using the minibuffer and then reads the
file, defining abbrevs according to the contents of the file. The function quietlyread-abbrev-file is similar except that it does not display a message in the echo
area; you cannot invoke it interactively, and it is used primarily in your init file (see
Section 33.4 [Init File], page 461). If either of these functions is called with nil
as the argument, it uses the file given by the variable abbrev-file-name, which
is ‘~/.emacs.d/abbrev_defs’ by default. This is your standard abbrev definition
file, and Emacs loads abbrevs from it automatically when it starts up. (As an
exception, Emacs does not load the abbrev file when it is started in batch mode.
See Section C.2 [Initial Options], page 507, for a description of batch mode.)
Emacs will offer to save abbrevs automatically if you have changed any of them,
whenever it offers to save all files (for C-x s or C-x C-c). It saves them in the
file specified by abbrev-file-name. This feature can be inhibited by setting the
variable save-abbrevs to nil.
The commands M-x insert-abbrevs and M-x define-abbrevs are similar to
the previous commands but work on text in an Emacs buffer. M-x insert-abbrevs
inserts text into the current buffer after point, describing all current abbrev definitions; M-x define-abbrevs parses the entire current buffer and defines abbrevs
accordingly.

26.6 Dynamic Abbrev Expansion
The abbrev facility described above operates automatically as you insert text, but
all abbrevs must be defined explicitly. By contrast, dynamic abbrevs allow the
meanings of abbreviations to be determined automatically from the contents of the
buffer, but dynamic abbrev expansion happens only when you request it explicitly.
M-/

Expand the word in the buffer before point as a dynamic abbrev,
by searching in the buffer for words starting with that abbreviation
(dabbrev-expand).

C-M-/

Complete the word before point as a dynamic abbrev (dabbrevcompletion).

For example, if the buffer contains ‘does this follow ’ and you type f o M-/,
the effect is to insert ‘follow’ because that is the last word in the buffer that
starts with ‘fo’. A numeric argument to M-/ says to take the second, third, etc.
distinct expansion found looking backward from point. Repeating M-/ searches for
an alternative expansion by looking farther back. After scanning all the text before
point, it searches the text after point. The variable dabbrev-limit, if non-nil,
specifies how far away in the buffer to search for an expansion.
After scanning the current buffer, M-/ normally searches other buffers, unless
you have set dabbrev-check-all-buffers to nil.
For finer control over which buffers to scan, customize the variable dabbrevignored-buffer-regexps. Its value is a list of regular expressions. If a buffer’s

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name matches any of these regular expressions, dynamic abbrev expansion skips
that buffer.
A negative argument to M-/, as in C-u - M-/, says to search first for expansions
after point, then other buffers, and consider expansions before point only as a last
resort. If you repeat the M-/ to look for another expansion, do not specify an
argument. Repeating M-/ cycles through all the expansions after point and then
the expansions before point.
After you have expanded a dynamic abbrev, you can copy additional words that
follow the expansion in its original context. Simply type SPC M-/ for each additional
word you want to copy. The spacing and punctuation between words is copied along
with the words.
The command C-M-/ (dabbrev-completion) performs completion of a dynamic
abbrev. Instead of trying the possible expansions one by one, it finds all of them,
then inserts the text that they have in common. If they have nothing in common,
C-M-/ displays a list of completions, from which you can select a choice in the usual
manner. See Section 5.3 [Completion], page 29.
Dynamic abbrev expansion is completely independent of Abbrev mode; the expansion of a word with M-/ is completely independent of whether it has a definition
as an ordinary abbrev.

26.7 Customizing Dynamic Abbreviation
Normally, dynamic abbrev expansion ignores case when searching for expansions.
That is, the expansion need not agree in case with the word you are expanding.
This feature is controlled by the variable dabbrev-case-fold-search. If it is
t, case is ignored in this search; if it is nil, the word and the expansion must
match in case. If the value is case-fold-search (the default), then the variable
case-fold-search controls whether to ignore case while searching for expansions
(see Section 12.8 [Search Case], page 103).
Normally, dynamic abbrev expansion preserves the case pattern of the dynamic
abbrev you are expanding, by converting the expansion to that case pattern.
The variable dabbrev-case-replace controls whether to preserve the case pattern of the dynamic abbrev. If it is t, the dynamic abbrev’s case pattern is preserved
in most cases; if it is nil, the expansion is always copied verbatim. If the value is
case-replace (the default), then the variable case-replace controls whether to
copy the expansion verbatim (see Section 12.9.3 [Replacement and Case], page 105).
However, if the expansion contains a complex mixed case pattern, and the dynamic abbrev matches this pattern as far as it goes, then the expansion is always
copied verbatim, regardless of those variables. Thus, for example, if the buffer
contains variableWithSillyCasePattern, and you type v a M-/, it copies the expansion verbatim including its case pattern.
The variable dabbrev-abbrev-char-regexp, if non-nil, controls which characters are considered part of a word, for dynamic expansion purposes. The regular
expression must match just one character, never two or more. The same regular
expression also determines which characters are part of an expansion. The value

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nil has a special meaning: dynamic abbrevs are made of word characters, but
expansions are made of word and symbol characters.
In shell scripts and makefiles, a variable name is sometimes prefixed with ‘$’ and
sometimes not. Major modes for this kind of text can customize dynamic abbrev
expansion to handle optional prefixes by setting the variable dabbrev-abbrevskip-leading-regexp. Its value should be a regular expression that matches the
optional prefix that dynamic abbrev expression should ignore.

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27 Dired, the Directory Editor
Dired makes an Emacs buffer containing a listing of a directory, and optionally some
of its subdirectories as well. You can use the normal Emacs commands to move
around in this buffer, and special Dired commands to operate on the listed files.
The Dired buffer is “read-only”, and inserting text in it is not allowed. Ordinary
printing characters such as d and x are redefined for special Dired commands. Some
Dired commands mark or flag the current file (that is, the file on the current line);
other commands operate on the marked files or on the flagged files. You first mark
certain files in order to operate on all of them with one command.
The Dired-X package provides various extra features for Dired mode. See Section
“Top” in Dired Extra User’s Manual.
You can also view a list of files in a directory with C-x C-d (list-directory).
Unlike Dired, this command does not allow you to operate on the listed files. See
Section 15.7 [Directories], page 139.

27.1 Entering Dired
To invoke Dired, type C-x d (dired). This reads a directory name using the minibuffer, and opens a Dired buffer listing the files in that directory. You can also
supply a wildcard file name pattern as the minibuffer argument, in which case the
Dired buffer lists all files matching that pattern. The usual history and completion
commands can be used in the minibuffer; in particular, M-n puts the name of the
visited file (if any) in the minibuffer (see Section 5.4 [Minibuffer History], page 34).
You can also invoke Dired by giving C-x C-f (find-file) a directory name.
The variable dired-listing-switches specifies the options to give to ls for
listing the directory; this string must contain ‘-l’. If you use a prefix argument with
the dired command, you can specify the ls switches with the minibuffer before you
enter the directory specification. No matter how they are specified, the ls switches
can include short options (that is, single characters) requiring no arguments, and
long options (starting with ‘--’) whose arguments are specified with ‘=’.
If your ls program supports the ‘--dired’ option, Dired automatically passes it
that option; this causes ls to emit special escape sequences for certain unusual file
names, without which Dired will not be able to parse those names. The first time
you run Dired in an Emacs session, it checks whether ls supports the ‘--dired’
option by calling it once with that option. If the exit code is 0, Dired will subsequently use the ‘--dired’ option; otherwise it will not. You can inhibit this check
by customizing the variable dired-use-ls-dired. The value unspecified (the
default) means to perform the check; any other non-nil value means to use the
‘--dired’ option; and nil means not to use the ‘--dired’ option.
On MS-Windows and MS-DOS systems, Emacs emulates ls. See Section G.4
[ls in Lisp], page 538, for options and peculiarities of this emulation.
To display the Dired buffer in another window, use C-x 4 d (dired-otherwindow). C-x 5 d (dired-other-frame) displays the Dired buffer in a separate
frame.

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Typing q (quit-window) buries the Dired buffer, and deletes its window if the
window was created just for that buffer.

27.2 Navigation in the Dired Buffer
All the usual Emacs cursor motion commands are available in Dired buffers. The
keys C-n and C-p are redefined to put the cursor at the beginning of the file name
on the line, rather than at the beginning of the line.
For extra convenience, SPC and n in Dired are equivalent to C-n. p is equivalent
to C-p. (Moving by lines is so common in Dired that it deserves to be easy to type.)
DEL (move up and unflag) is also often useful simply for moving up (see Section 27.3
[Dired Deletion], page 330).
j (dired-goto-file) prompts for a file name using the minibuffer, and moves
point to the line in the Dired buffer describing that file.
M-s f C-s (dired-isearch-filenames) performs a forward incremental search
in the Dired buffer, looking for matches only amongst the file names and ignoring
the rest of the text in the buffer. M-s f M-C-s (dired-isearch-filenames-regexp)
does the same, using a regular expression search. If you change the variable diredisearch-filenames to t, then the usual search commands also limit themselves to
the file names; for instance, C-s behaves like M-s f C-s. If the value is dwim, then
search commands match the file names only when point was on a file name initially.
See Chapter 12 [Search], page 91, for information about incremental search.
Some additional navigation commands are available when the Dired buffer includes several directories. See Section 27.12 [Subdirectory Motion], page 340.

27.3 Deleting Files with Dired
One of the most frequent uses of Dired is to first flag files for deletion, then delete
the files that were flagged.
d

Flag this file for deletion.

u

Remove deletion flag on this line.

DEL

Move point to previous line and remove the deletion flag on that line.

x

Delete the files that are flagged for deletion.

You can flag a file for deletion by moving to the line describing the file and
typing d (dired-flag-file-deletion). The deletion flag is visible as a ‘D’ at the
beginning of the line. This command moves point to the next line, so that repeated
d commands flag successive files. A numeric argument serves as a repeat count.
The reason for flagging files for deletion, rather than deleting files immediately,
is to reduce the danger of deleting a file accidentally. Until you direct Dired to
delete the flagged files, you can remove deletion flags using the commands u and
DEL. u (dired-unmark) works just like d, but removes flags rather than making
flags. DEL (dired-unmark-backward) moves upward, removing flags; it is like u
with argument −1.

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To delete the flagged files, type x (dired-do-flagged-delete). This command
first displays a list of all the file names flagged for deletion, and requests confirmation
with yes. If you confirm, Dired deletes the flagged files, then deletes their lines from
the text of the Dired buffer. The Dired buffer, with somewhat fewer lines, remains
selected.
If you answer no or quit with C-g when asked to confirm, you return immediately
to Dired, with the deletion flags still present in the buffer, and no files actually
deleted.
You can delete empty directories just like other files, but normally Dired cannot
delete directories that are nonempty. If the variable dired-recursive-deletes is
non-nil, then Dired can delete nonempty directories including all their contents.
That can be somewhat risky.
If you change the variable delete-by-moving-to-trash to t, the above deletion commands will move the affected files or directories into the operating system’s Trash, instead of deleting them outright. See Section 15.10 [Misc File Ops],
page 143.

27.4 Flagging Many Files at Once
The #, ~, ., % &, and % d commands flag many files for deletion, based on their file
names:
#

Flag all auto-save files (files whose names start and end with ‘#’) for
deletion (see Section 15.5 [Auto Save], page 136).

~

Flag all backup files (files whose names end with ‘~’) for deletion (see
Section 15.3.2 [Backup], page 130).

. (Period)

Flag excess numeric backup files for deletion. The oldest and newest
few backup files of any one file are exempt; the middle ones are flagged.

%&

Flag for deletion all files with certain kinds of names which suggest
you could easily create those files again.

% d regexp RET
Flag for deletion all files whose names match the regular expression
regexp.
# (dired-flag-auto-save-files) flags all files whose names look like autosave files—that is, files whose names begin and end with ‘#’. See Section 15.5 [Auto
Save], page 136.
~ (dired-flag-backup-files) flags all files whose names say they are backup
files—that is, files whose names end in ‘~’. See Section 15.3.2 [Backup], page 130.
. (period, dired-clean-directory) flags just some of the backup files for deletion: all but the oldest few and newest few backups of any one file. Normally, the
number of newest versions kept for each file is given by the variable dired-keptversions (not kept-new-versions; that applies only when saving). The number
of oldest versions to keep is given by the variable kept-old-versions.

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Period with a positive numeric argument, as in C-u 3 ., specifies the number
of newest versions to keep, overriding dired-kept-versions. A negative numeric
argument overrides kept-old-versions, using minus the value of the argument to
specify the number of oldest versions of each file to keep.
% & (dired-flag-garbage-files) flags files whose names match the regular
expression specified by the variable dired-garbage-files-regexp. By default,
this matches certain files produced by TEX, ‘.bak’ files, and the ‘.orig’ and ‘.rej’
files produced by patch.
% d flags all files whose names match a specified regular expression (dired-flagfiles-regexp). Only the non-directory part of the file name is used in matching.
You can use ‘^’ and ‘$’ to anchor matches. You can exclude certain subdirectories from marking by hiding them while you use % d. See Section 27.13 [Hiding
Subdirectories], page 340.

27.5 Visiting Files in Dired
There are several Dired commands for visiting or examining the files listed in the
Dired buffer. All of them apply to the current line’s file; if that file is really a
directory, these commands invoke Dired on that subdirectory (making a separate
Dired buffer).
f

RET
e

Visit the file described on the current line, like typing C-x C-f and supplying that file name (dired-find-file). See Section 15.2 [Visiting],
page 125.
Equivalent to f.

o

Like f, but uses another window to display the file’s buffer (diredfind-file-other-window). The Dired buffer remains visible in the
first window. This is like using C-x 4 C-f to visit the file. See
Chapter 17 [Windows], page 159.

C-o

Visit the file described on the current line, and display the buffer
in another window, but do not select that window (dired-displayfile).

Mouse-1
Mouse-2

Visit the file whose name you clicked on (dired-mouse-find-fileother-window). This uses another window to display the file, like the
o command.

v

View the file described on the current line, with View mode (diredview-file). View mode provides convenient commands to navigate
the buffer but forbids changing it; See Section 11.6 [View Mode],
page 75.

^

Visit the parent directory of the current directory (dired-updirectory). This is equivalent to moving to the line for ‘..’ and
typing f there.

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27.6 Dired Marks vs. Flags
Instead of flagging a file with ‘D’, you can mark the file with some other character
(usually ‘*’). Most Dired commands to operate on files use the files marked with
‘*’. The only command that operates on flagged files is x, which deletes them.
Here are some commands for marking with ‘*’, for unmarking, and for operating
on marks. (See Section 27.3 [Dired Deletion], page 330, for commands to flag and
unflag files.)
m
*m

Mark the current file with ‘*’ (dired-mark). With a numeric argument
n, mark the next n files starting with the current file. (If n is negative,
mark the previous −n files.)

**

Mark all executable files with ‘*’ (dired-mark-executables). With
a numeric argument, unmark all those files.

*@

Mark all symbolic links with ‘*’ (dired-mark-symlinks). With a
numeric argument, unmark all those files.

*/

Mark with ‘*’ all files which are directories, except for ‘.’ and ‘..’
(dired-mark-directories). With a numeric argument, unmark all
those files.

*s

Mark all the files in the current subdirectory, aside from ‘.’ and ‘..’
(dired-mark-subdir-files).

u
*u
DEL
* DEL
*!
U

Remove any mark on this line (dired-unmark).
Move point to previous line and remove any mark on that line (diredunmark-backward).
Remove all marks from all the files in this Dired buffer (dired-unmarkall-marks).

* ? markchar
M-DEL
Remove all marks that use the character markchar (dired-unmarkall-files). The argument is a single character—do not use RET to
terminate it. See the description of the * c command below, which
lets you replace one mark character with another.
With a numeric argument, this command queries about each marked
file, asking whether to remove its mark. You can answer y meaning
yes, n meaning no, or ! to remove the marks from the remaining files
without asking about them.
* C-n
M-}

Move down to the next marked file (dired-next-marked-file) A file
is “marked” if it has any kind of mark.

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* C-p
M-{
t
*t

334

Move up to the previous marked file (dired-prev-marked-file)
Toggle all marks (dired-toggle-marks): files marked with ‘*’ become
unmarked, and unmarked files are marked with ‘*’. Files marked in
any other way are not affected.

* c old-markchar new-markchar
Replace all marks that use the character old-markchar with marks that
use the character new-markchar (dired-change-marks). This command is the primary way to create or use marks other than ‘*’ or ‘D’.
The arguments are single characters—do not use RET to terminate
them.
You can use almost any character as a mark character by means of
this command, to distinguish various classes of files. If old-markchar
is a space (‘ ’), then the command operates on all unmarked files; if
new-markchar is a space, then the command unmarks the files it acts
on.
To illustrate the power of this command, here is how to put ‘D’ flags on
all the files that have no marks, while unflagging all those that already
have ‘D’ flags:
* c D t * c SPC D * c t SPC
This assumes that no files were already marked with ‘t’.
% m regexp RET
* % regexp RET
Mark (with ‘*’) all files whose names match the regular expression regexp (dired-mark-files-regexp). This command is like % d, except
that it marks files with ‘*’ instead of flagging with ‘D’.
Only the non-directory part of the file name is used in matching. Use
‘^’ and ‘$’ to anchor matches. You can exclude subdirectories by
temporarily hiding them (see Section 27.13 [Hiding Subdirectories],
page 340).
% g regexp RET
Mark (with ‘*’) all files whose contents contain a match for the regular
expression regexp (dired-mark-files-containing-regexp). This
command is like % m, except that it searches the file contents instead
of the file name.
C-/
C-x u
C-_

Undo changes in the Dired buffer, such as adding or removing marks
(dired-undo). This command does not revert the actual file operations, nor recover lost files! It just undoes changes in the buffer itself.
In some cases, using this after commands that operate on files can
cause trouble. For example, after renaming one or more files, dired-

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undo restores the original names in the Dired buffer, which gets the
Dired buffer out of sync with the actual contents of the directory.

27.7 Operating on Files
This section describes the basic Dired commands to operate on one file or several
files. All of these commands are capital letters; all of them use the minibuffer, either
to read an argument or to ask for confirmation, before they act. All of them let you
specify the files to manipulate in these ways:
• If you give the command a numeric prefix argument n, it operates on the next
n files, starting with the current file. (If n is negative, the command operates
on the −n files preceding the current line.)
• Otherwise, if some files are marked with ‘*’, the command operates on all those
files.
• Otherwise, the command operates on the current file only.
Certain other Dired commands, such as ! and the ‘%’ commands, use the same
conventions to decide which files to work on.
Commands which ask for a destination directory, such as those which copy and
rename files or create links for them, try to guess the default target directory for
the operation. Normally, they suggest the Dired buffer’s default directory, but if
the variable dired-dwim-target is non-nil, and if there is another Dired buffer
displayed in the next window, that other buffer’s directory is suggested instead.
Here are the file-manipulating Dired commands that operate on files.
C new RET

Copy the specified files (dired-do-copy). The argument new is the
directory to copy into, or (if copying a single file) the new name. This
is like the shell command cp.
If dired-copy-preserve-time is non-nil, then copying with this
command preserves the modification time of the old file in the copy,
like ‘cp -p’.
The variable dired-recursive-copies controls whether to copy directories recursively (like ‘cp -r’). The default is top, which means to
ask before recursively copying a directory.

D

Delete the specified files (dired-do-delete). This is like the shell
command rm.
Like the other commands in this section, this command operates on the
marked files, or the next n files. By contrast, x (dired-do-flaggeddelete) deletes all flagged files.

R new RET

Rename the specified files (dired-do-rename). If you rename a single
file, the argument new is the new name of the file. If you rename
several files, the argument new is the directory into which to move the
files (this is like the shell command mv).
Dired automatically changes the visited file name of buffers associated
with renamed files so that they refer to the new names.

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H new RET

Make hard links to the specified files (dired-do-hardlink). This is
like the shell command ln. The argument new is the directory to make
the links in, or (if making just one link) the name to give the link.

S new RET

Make symbolic links to the specified files (dired-do-symlink). This
is like ‘ln -s’. The argument new is the directory to make the links
in, or (if making just one link) the name to give the link.

M modespec RET
Change the mode (also called permission bits) of the specified files
(dired-do-chmod). modespec can be in octal or symbolic notation,
like arguments handled by the chmod program.
G newgroup RET
Change the group of the specified files to newgroup (dired-do-chgrp).
O newowner RET
Change the owner of the specified files to newowner (dired-dochown). (On most systems, only the superuser can do this.)
The variable dired-chown-program specifies the name of the program
to use to do the work (different systems put chown in different places).
T timestamp RET
Touch the specified files (dired-do-touch). This means updating
their modification times to the present time. This is like the shell
command touch.
P command RET
Print the specified files (dired-do-print). You must specify the command to print them with, but the minibuffer starts out with a suitable guess made using the variables lpr-command and lpr-switches
(the same variables that lpr-buffer uses; see Section 31.5 [Printing],
page 417).
Z

Compress the specified files (dired-do-compress). If the file appears
to be a compressed file already, uncompress it instead.

:d

Decrypt the specified files (epa-dired-do-decrypt). See Section
“Dired integration” in EasyPG Assistant User’s Manual.

:v

Verify digital signatures on the specified files (epa-dired-do-verify).
See Section “Dired integration” in EasyPG Assistant User’s Manual.

:s

Digitally sign the specified files (epa-dired-do-sign). See Section
“Dired integration” in EasyPG Assistant User’s Manual.

:e

Encrypt the specified files (epa-dired-do-encrypt). See Section
“Dired integration” in EasyPG Assistant User’s Manual.

L

Load the specified Emacs Lisp files (dired-do-load). See Section 24.8
[Lisp Libraries], page 287.

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B

337

Byte compile the specified Emacs Lisp files (dired-do-bytecompile). See Section “Byte Compilation” in The Emacs Lisp
Reference Manual.

A regexp RET
Search all the specified files for the regular expression regexp (direddo-search).
This command is a variant of tags-search. The search stops at the
first match it finds; use M-, to resume the search and find the next
match. See Section 25.3.6 [Tags Search], page 318.
Q regexp RET to RET
Perform query-replace-regexp on each of the specified files, replacing matches for regexp with the string to (dired-do-query-replaceregexp).
This command is a variant of tags-query-replace. If you exit the
query replace loop, you can use M-, to resume the scan and replace
more matches. See Section 25.3.6 [Tags Search], page 318.

27.8 Shell Commands in Dired
The Dired command ! (dired-do-shell-command) reads a shell command string in
the minibuffer and runs that shell command on one or more files. The files that the
shell command operates on are determined in the usual way for Dired commands
(see Section 27.7 [Operating on Files], page 335). The command X is a synonym for
!.
The command & (dired-do-async-shell-command) does the same, except that
it runs the shell command asynchronously. You can also do this with !, by appending a ‘&’ character to the end of the shell command.
For both ! and &, the working directory for the shell command is the top-level
directory of the Dired buffer.
If you tell ! or & to operate on more than one file, the shell command string
determines how those files are passed to the shell command:
• If you use ‘*’ surrounded by whitespace in the command string, then the
command runs just once, with the list of file names substituted for the ‘*’.
The order of file names is the order of appearance in the Dired buffer.
Thus, ! tar cf foo.tar * RET runs tar on the entire list of file names, putting
them into one tar file ‘foo.tar’.
If you want to use ‘*’ as a shell wildcard with whitespace around it, write
‘*""’. In the shell, this is equivalent to ‘*’; but since the ‘*’ is not surrounded
by whitespace, Dired does not treat it specially.
• Otherwise, if the command string contains ‘?’ surrounded by whitespace,
Emacs runs the shell command once for each file, substituting the current
file name for ‘?’ each time. You can use ‘?’ more than once in the command;
the same file name replaces each occurrence.

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• If the command string contains neither ‘*’ nor ‘?’, Emacs runs the shell command once for each file, adding the file name at the end. For example, !
uudecode RET runs uudecode on each file.
To iterate over the file names in a more complicated fashion, use an explicit shell
loop. For example, here is how to uuencode each file, making the output file name
by appending ‘.uu’ to the input file name:
for file in * ; do uuencode "$file" "$file" >"$file".uu; done
The ! and & commands do not attempt to update the Dired buffer to show new
or modified files, because they don’t know what files will be changed. Use the g
command to update the Dired buffer (see Section 27.14 [Dired Updating], page 341).
See Section 31.3.1 [Single Shell], page 402, for information about running shell
commands outside Dired.

27.9 Transforming File Names in Dired
This section describes Dired commands which alter file names in a systematic way.
Each command operates on some or all of the marked files, using a new name made
by transforming the existing name.
Like the basic Dired file-manipulation commands (see Section 27.7 [Operating
on Files], page 335), the commands described here operate either on the next n
files, or on all files marked with ‘*’, or on the current file. (To mark files, use the
commands described in Section 27.6 [Marks vs Flags], page 333.)
All of the commands described in this section work interactively: they ask you
to confirm the operation for each candidate file. Thus, you can select more files
than you actually need to operate on (e.g., with a regexp that matches many files),
and then filter the selected names by typing y or n when the command prompts for
confirmation.
%u

Rename each of the selected files to an upper-case name (diredupcase). If the old file names are ‘Foo’ and ‘bar’, the new names
are ‘FOO’ and ‘BAR’.

%l

Rename each of the selected files to a lower-case name (direddowncase). If the old file names are ‘Foo’ and ‘bar’, the new names
are ‘foo’ and ‘bar’.

%
%
%
%

R
C
H
S

from
from
from
from

RET to RET
RET to RET
RET to RET
RET to RET
These four commands rename, copy, make hard links and make soft
links, in each case computing the new name by regular-expression
substitution from the name of the old file.

The four regular-expression substitution commands effectively perform a searchand-replace on the selected file names. They read two arguments: a regular expression from, and a substitution pattern to; they match each “old” file name against
from, and then replace the matching part with to. You can use ‘\&’ and ‘\digit ’

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in to to refer to all or part of what the pattern matched in the old file name, as
in replace-regexp (see Section 12.9.2 [Regexp Replace], page 104). If the regular
expression matches more than once in a file name, only the first match is replaced.
For example, % R ^.*$ RET x-\& RET renames each selected file by prepending
‘x-’ to its name. The inverse of this, removing ‘x-’ from the front of each file name,
is also possible: one method is % R ^x-\(.*\)$ RET \1 RET; another is % R ^x- RET
RET. (Use ‘^’ and ‘$’ to anchor matches that should span the whole file name.)
Normally, the replacement process does not consider the files’ directory names;
it operates on the file name within the directory. If you specify a numeric argument
of zero, then replacement affects the entire absolute file name including directory
name. (A non-zero argument specifies the number of files to operate on.)
You may want to select the set of files to operate on using the same regexp
from that you will use to operate on them. To do this, mark those files with % m
from RET, then use the same regular expression in the command to operate on the
files. To make this more convenient, the % commands to operate on files use the
last regular expression specified in any % command as a default.

27.10 File Comparison with Dired
Here are two Dired commands that compare specified files using diff. They show
the output in a buffer using Diff mode (see Section 15.8 [Comparing Files], page 140).
=

Compare the current file (the file at point) with another file (the file
at the mark) using the diff program (dired-diff). The file at the
mark is the first argument of diff, and the file at point is the second
argument. This refers to the ordinary Emacs mark, not Dired marks;
use C-SPC (set-mark-command) to set the mark at the first file’s line
(see Section 8.1 [Setting Mark], page 47).

M-=

Compare the current file with its latest backup file (dired-backupdiff). If the current file is itself a backup, compare it with the file it
is a backup of; this way, you can compare a file with any one of its
backups.
The backup file is the first file given to diff.

27.11 Subdirectories in Dired
A Dired buffer usually displays just one directory, but you can optionally include
its subdirectories as well.
The simplest way to include multiple directories in one Dired buffer is to specify
the options ‘-lR’ for running ls. (If you give a numeric argument when you run
Dired, then you can specify these options in the minibuffer.) That produces a
recursive directory listing showing all subdirectories at all levels.
More often, you will want to show only specific subdirectories. You can do this
with i (dired-maybe-insert-subdir):
i

Insert the contents of a subdirectory later in the buffer.

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If you use this command on a line that describes a file which is a directory, it inserts
the contents of that directory into the same Dired buffer, and moves there. Inserted
subdirectory contents follow the top-level directory of the Dired buffer, just as they
do in ‘ls -lR’ output.
If the subdirectory’s contents are already present in the buffer, the i command
just moves to it.
In either case, i sets the Emacs mark before moving, so C-u C-SPC returns to
your previous position in the Dired buffer (see Section 8.1 [Setting Mark], page 47).
You can also use ‘^’ to return to the parent directory in the same Dired buffer (see
Section 27.5 [Dired Visiting], page 332).
Use the l command (dired-do-redisplay) to update the subdirectory’s contents, and use C-u k on the subdirectory header line to remove the subdirectory
listing (see Section 27.14 [Dired Updating], page 341). You can also hide and show
inserted subdirectories (see Section 27.13 [Hiding Subdirectories], page 340).

27.12 Moving Over Subdirectories
When a Dired buffer lists subdirectories, you can use the page motion commands
C-x [ and C-x ] to move by entire directories (see Section 22.4 [Pages], page 217).
The following commands move across, up and down in the tree of directories
within one Dired buffer. They move to directory header lines, which are the lines
that give a directory’s name, at the beginning of the directory’s contents.
C-M-n

Go to next subdirectory header line, regardless of level (dired-nextsubdir).

C-M-p

Go to previous subdirectory header line, regardless of level (diredprev-subdir).

C-M-u

Go up to the parent directory’s header line (dired-tree-up).

C-M-d

Go down in the directory tree, to the first subdirectory’s header line
(dired-tree-down).

<

Move up to the previous directory-file line (dired-prev-dirline).
These lines are the ones that describe a directory as a file in its parent
directory.

>

Move down to the next directory-file line (dired-prev-dirline).

27.13 Hiding Subdirectories
Hiding a subdirectory means to make it invisible, except for its header line.
$

Hide or show the subdirectory that point is in, and move point to the
next subdirectory (dired-hide-subdir). This is a toggle. A numeric
argument serves as a repeat count.

M-$

Hide all subdirectories in this Dired buffer, leaving only their header
lines (dired-hide-all). Or, if any subdirectory is currently hidden,

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make all subdirectories visible again. You can use this command to
get an overview in very deep directory trees or to move quickly to
subdirectories far away.
Ordinary Dired commands never consider files inside a hidden subdirectory. For
example, the commands to operate on marked files ignore files in hidden directories
even if they are marked. Thus you can use hiding to temporarily exclude subdirectories from operations without having to remove the Dired marks on files in those
subdirectories.
See Section 27.14 [Dired Updating], page 341, for how to insert or delete a
subdirectory listing.

27.14 Updating the Dired Buffer
This section describes commands to update the Dired buffer to reflect outside (nonDired) changes in the directories and files, and to delete part of the Dired buffer.
g

Update the entire contents of the Dired buffer (revert-buffer).

l

Update the specified files (dired-do-redisplay). You specify the files
for l in the same way as for file operations.

k

Delete the specified file lines—not the files, just the lines (dired-dokill-lines).

s

Toggle between alphabetical order and date/time order (dired-sorttoggle-or-edit).

C-u s switches RET
Refresh the Dired buffer using switches as dired-listing-switches.
Type g (revert-buffer) to update the contents of the Dired buffer, based on
changes in the files and directories listed. This preserves all marks except for those
on files that have vanished. Hidden subdirectories are updated but remain hidden.
To update only some of the files, type l (dired-do-redisplay). Like the Dired
file-operating commands, this command operates on the next n files (or previous −n
files), or on the marked files if any, or on the current file. Updating the files means
reading their current status, then updating their lines in the buffer to indicate that
status.
If you use l on a subdirectory header line, it updates the contents of the corresponding subdirectory.
If you use C-x d or some other Dired command to visit a directory that is already
being shown in a Dired buffer, Dired switches to that buffer but does not update
it. If the buffer is not up-to-date, Dired displays a warning telling you to type G to
update it. You can also tell Emacs to revert each Dired buffer automatically when
you revisit it, by setting the variable dired-auto-revert-buffer to a non-nil
value.
To delete the specified file lines from the buffer—not delete the files—type k
(dired-do-kill-lines). Like the file-operating commands, this command oper-

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ates on the next n files, or on the marked files if any; but it does not operate on the
current file as a last resort.
If you use k with a numeric prefix argument to kill the line for a file that is a
directory, which you have inserted in the Dired buffer as a subdirectory, it removed
that subdirectory line from the buffer as well. Typing C-u k on the header line for
a subdirectory also removes the subdirectory line from the Dired buffer.
The g command brings back any individual lines that you have killed in this
way, but not subdirectories—you must use i to reinsert a subdirectory.
The files in a Dired buffers are normally listed in alphabetical order by file
names. Alternatively Dired can sort them by date/time. The Dired command s
(dired-sort-toggle-or-edit) switches between these two sorting modes. The
mode line in a Dired buffer indicates which way it is currently sorted—by name, or
by date.
C-u s switches RET lets you specify a new value for dired-listing-switches.

27.15 Dired and find
You can select a set of files for display in a Dired buffer more flexibly by using the
find utility to choose the files.
To search for files with names matching a wildcard pattern use M-x
find-name-dired. It reads arguments directory and pattern, and chooses all the
files in directory or its subdirectories whose individual names match pattern.
The files thus chosen are displayed in a Dired buffer, in which the ordinary Dired
commands are available.
If you want to test the contents of files, rather than their names, use M-x
find-grep-dired. This command reads two minibuffer arguments, directory and
regexp; it chooses all the files in directory or its subdirectories that contain a
match for regexp. It works by running the programs find and grep. See also M-x
grep-find, in Section 24.4 [Grep Searching], page 275. Remember to write the
regular expression for grep, not for Emacs. (An alternative method of showing files
whose contents match a given regexp is the % g regexp command, see Section 27.6
[Marks vs Flags], page 333.)
The most general command in this series is M-x find-dired, which lets you
specify any condition that find can test. It takes two minibuffer arguments, directory and find-args; it runs find in directory, passing find-args to tell find what
condition to test. To use this command, you need to know how to use find.
The format of listing produced by these commands is controlled by the variable
find-ls-option. This is a pair of options; the first specifying how to call find to
produce the file listing, and the second telling Dired to parse the output.
The command M-x locate provides a similar interface to the locate program.
M-x locate-with-filter is similar, but keeps only files whose names match a given
regular expression.
These buffers don’t work entirely like ordinary Dired buffers: file operations
work, but do not always automatically update the buffer. Reverting the buffer with
g deletes all inserted subdirectories, and erases all flags and marks.

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27.16 Editing the Dired Buffer
Wdired is a special mode that allows you to perform file operations by editing
the Dired buffer directly (the “W” in “Wdired” stands for “writable”.) To enter
Wdired mode, type C-x C-q (dired-toggle-read-only) while in a Dired buffer.
Alternatively, use the ‘Immediate / Edit File Names’ menu item.
While in Wdired mode, you can rename files by editing the file names displayed
in the Dired buffer. All the ordinary Emacs editing commands, including rectangle
operations and query-replace, are available for this. Once you are done editing,
type C-c C-c (wdired-finish-edit). This applies your changes and switches back
to ordinary Dired mode.
Apart from simply renaming files, you can move a file to another directory by
typing in the new file name (either absolute or relative). To mark a file for deletion,
delete the entire file name. To change the target of a symbolic link, edit the link
target name which appears next to the link name.
The rest of the text in the buffer, such as the file sizes and modification dates,
is marked read-only, so you can’t edit it. However, if you set wdired-allow-tochange-permissions to t, you can edit the file permissions. For example, you can
change ‘-rw-r--r--’ to ‘-rw-rw-rw-’ to make a file world-writable. These changes
also take effect when you type C-c C-c.

27.17 Viewing Image Thumbnails in Dired
Image-Dired is a facility for browsing image files. It provides viewing the images
either as thumbnails or in full size, either inside Emacs or through an external
viewer.
To enter Image-Dired, mark the image files you want to look at in the Dired
buffer, using m as usual. Then type C-t d (image-dired-display-thumbs). This
creates and switches to a buffer containing image-dired, corresponding to the marked
files.
You can also enter Image-Dired directly by typing M-x image-dired. This
prompts for a directory; specify one that has image files. This creates thumbnails for all the images in that directory, and displays them all in the “thumbnail
buffer”. This takes a long time if the directory contains many image files, and it
asks for confirmation if the number of image files exceeds image-dired-show-allfrom-dir-max-files.
With point in the thumbnail buffer, you can type RET (image-dired-displaythumbnail-original-image) to display a sized version of it in another window.
This sizes the image to fit the window. Use the arrow keys to move around in
the buffer. For easy browsing, use SPC (image-dired-display-next-thumbnailoriginal) to advance and display the next image. Typing DEL (image-direddisplay-previous-thumbnail-original) backs up to the previous thumbnail and
displays that instead.
To view and the image in its original size, either provide a prefix argument (C-u)
before pressing RET, or type C-RET (image-dired-thumbnail-display-external)

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to display the image in an external viewer. You must first configure image-diredexternal-viewer.
You can delete images through Image-Dired also. Type d (image-dired-flagthumb-original-file) to flag the image file for deletion in the Dired buffer. You
can also delete the thumbnail image from the thumbnail buffer with C-d (imagedired-delete-char).
More advanced features include image tags, which are metadata used to categorize image files. The tags are stored in a plain text file configured by image-direddb-file.
To tag image files, mark them in the dired buffer (you can also mark files in Dired
from the thumbnail buffer by typing m) and type C-t t (image-dired-tag-files).
This reads the tag name in the minibuffer. To mark files having a certain tag,
type C-t f (image-dired-mark-tagged-files). After marking image files with a
certain tag, you can use C-t d to view them.
You can also tag a file directly from the thumbnail buffer by typing t t and you
can remove a tag by typing t r. There is also a special “tag” called “comment”
for each file (it is not a tag in the exact same sense as the other tags, it is handled
slightly different). That is used to enter a comment or description about the image.
You comment a file from the thumbnail buffer by typing c. You will be prompted
for a comment. Type C-t c to add a comment from Dired (image-dired-diredcomment-files).
Image-Dired also provides simple image manipulation. In the thumbnail buffer,
type L to rotate the original image 90 degrees anti clockwise, and R to rotate it
90 degrees clockwise. This rotation is lossless, and uses an external utility called
JpegTRAN.

27.18 Other Dired Features
The command + (dired-create-directory) reads a directory name, and creates
that directory. It signals an error if the directory already exists.
The command M-s a C-s (dired-do-isearch) begins a “multi-file” incremental
search on the marked files. If a search fails at the end of a file, typing C-s advances
to the next marked file and repeats the search; at the end of the last marked
file, the search wraps around to the first marked file. The command M-s a M-C-s
(dired-do-isearch-regexp) does the same with a regular expression search. See
Section 12.1.2 [Repeat Isearch], page 92, for information about search repetition.
The command w (dired-copy-filename-as-kill) puts the names of the
marked (or next n) files into the kill ring, as if you had killed them with C-w.
The names are separated by a space.
With a zero prefix argument, this uses the absolute file name of each marked
file. With just C-u as the prefix argument, it uses file names relative to the Dired
buffer’s default directory. (This can still contain slashes if in a subdirectory.) As a
special case, if point is on a directory headerline, w gives you the absolute name of
that directory. Any prefix argument or marked files are ignored in this case.

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The main purpose of this command is so that you can yank the file names into
arguments for other Emacs commands. It also displays what it added to the kill
ring, so you can use it to display the list of currently marked files in the echo area.
If the directory you are visiting is under version control (see Section 25.1 [Version
Control], page 292), then the normal VC diff and log commands will operate on the
selected files.
The command M-x dired-compare-directories is used to compare the current Dired buffer with another directory. It marks all the files that are “different”
between the two directories. It puts these marks in all Dired buffers where these
files are listed, which of course includes the current buffer.
The default comparison method (used if you type RET at the prompt) is to
compare just the file names—each file name that does not appear in the other
directory is “different”. You can specify more stringent comparisons by entering a
Lisp expression, which can refer to the variables size1 and size2, the respective
file sizes; mtime1 and mtime2, the last modification times in seconds, as floating
point numbers; and fa1 and fa2, the respective file attribute lists (as returned
by the function file-attributes). This expression is evaluated for each pair of
like-named files, and if the expression’s value is non-nil, those files are considered
“different”.
For instance, the sequence M-x dired-compare-directories RET (> mtime1
mtime2) RET marks files newer in this directory than in the other, and marks files
older in the other directory than in this one. It also marks files with no counterpart,
in both directories, as always.
On the X Window System, Emacs supports the “drag and drop” protocol. You
can drag a file object from another program, and drop it onto a Dired buffer; this
either moves, copies, or creates a link to the file in that directory. Precisely which
action is taken is determined by the originating program. Dragging files out of a
Dired buffer is currently not supported.

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28 The Calendar and the Diary
Emacs provides the functions of a desk calendar, with a diary of planned or past
events. It also has facilities for managing your appointments, and keeping track of
how much time you spend working on certain projects.
To enter the calendar, type M-x calendar; this displays a three-month calendar
centered on the current month, with point on the current date. With a numeric
argument, as in C-u M-x calendar, it prompts you for the month and year to be
the center of the three-month calendar. The calendar uses its own buffer, whose
major mode is Calendar mode.
Mouse-3 in the calendar brings up a menu of operations on a particular date;
Mouse-2 brings up a menu of commonly used calendar features that are independent
of any particular date. To exit the calendar, type q.
This chapter describes the basic calendar features. For more advanced topics,
see Section “Advanced Calendar/Diary Usage” in Specialized Emacs Features.

28.1 Movement in the Calendar
Calendar mode provides commands to move through the calendar in logical units of
time such as days, weeks, months, and years. If you move outside the three months
originally displayed, the calendar display “scrolls” automatically through time to
make the selected date visible. Moving to a date lets you view its holidays or diary
entries, or convert it to other calendars; moving by long time periods is also useful
simply to scroll the calendar.
28.1.1 Motion by Standard Lengths of Time
The commands for movement in the calendar buffer parallel the commands for
movement in text. You can move forward and backward by days, weeks, months,
and years.
C-f

Move point one day forward (calendar-forward-day).

C-b

Move point one day backward (calendar-backward-day).

C-n

Move point one week forward (calendar-forward-week).

C-p

Move point one week backward (calendar-backward-week).

M-}

Move point one month forward (calendar-forward-month).

M-{

Move point one month backward (calendar-backward-month).

C-x ]

Move point one year forward (calendar-forward-year).

C-x [

Move point one year backward (calendar-backward-year).

The day and week commands are natural analogues of the usual Emacs commands for moving by characters and by lines. Just as C-n usually moves to the
same column in the following line, in Calendar mode it moves to the same day in
the following week. And C-p moves to the same day in the previous week.

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The arrow keys are equivalent to C-f, C-b, C-n and C-p, just as they normally
are in other modes.
The commands for motion by months and years work like those for weeks, but
move a larger distance. The month commands M-} and M-{ move forward or backward by an entire month. The year commands C-x ] and C-x [ move forward or
backward a whole year.
The easiest way to remember these commands is to consider months and years
analogous to paragraphs and pages of text, respectively. But the commands themselves are not quite analogous. The ordinary Emacs paragraph commands move
to the beginning or end of a paragraph, whereas these month and year commands
move by an entire month or an entire year, keeping the same date within the month
or year.
All these commands accept a numeric argument as a repeat count. For convenience, the digit keys and the minus sign specify numeric arguments in Calendar
mode even without the Meta modifier. For example, 100 C-f moves point 100 days
forward from its present location.
28.1.2 Beginning or End of Week, Month or Year
A week (or month, or year) is not just a quantity of days; we think of weeks (months,
years) as starting on particular dates. So Calendar mode provides commands to
move to the start or end of a week, month or year:
C-a

Move point to start of week (calendar-beginning-of-week).

C-e

Move point to end of week (calendar-end-of-week).

M-a

Move point to start of month (calendar-beginning-of-month).

M-e

Move point to end of month (calendar-end-of-month).

M-<

Move point to start of year (calendar-beginning-of-year).

M->

Move point to end of year (calendar-end-of-year).

These commands also take numeric arguments as repeat counts, with the repeat
count indicating how many weeks, months, or years to move backward or forward.
By default, weeks begin on Sunday. To make them begin on Monday instead,
set the variable calendar-week-start-day to 1.
28.1.3 Specified Dates
Calendar mode provides commands for moving to a particular date specified in
various ways.
gd

Move point to specified date (calendar-goto-date).

gD

Move point to specified day of year (calendar-goto-day-of-year).

gw

Move point to specified week of year (calendar-iso-goto-week).

o

Center calendar around specified month (calendar-other-month).

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Move point to today’s date (calendar-goto-today).

g d (calendar-goto-date) prompts for a year, a month, and a day of the month,
and then moves to that date. Because the calendar includes all dates from the
beginning of the current era, you must type the year in its entirety; that is, type
‘1990’, not ‘90’.
g D (calendar-goto-day-of-year) prompts for a year and day number, and
moves to that date. Negative day numbers count backward from the end of the
year. g w (calendar-iso-goto-week) prompts for a year and week number, and
moves to that week.
o (calendar-other-month) prompts for a month and year, then centers the
three-month calendar around that month.
You can return to today’s date with . (calendar-goto-today).

28.2 Scrolling in the Calendar
The calendar display scrolls automatically through time when you move out of the
visible portion. You can also scroll it manually. Imagine that the calendar window
contains a long strip of paper with the months on it. Scrolling the calendar means
moving the strip horizontally, so that new months become visible in the window.
>

Scroll calendar one month forward (calendar-scroll-left).

<

Scroll calendar one month backward (calendar-scroll-right).

C-v
NEXT
M-v
PRIOR

Scroll forward by three months (calendar-scroll-left-threemonths).
Scroll backward by three months (calendar-scroll-right-threemonths).

The most basic calendar scroll commands scroll by one month at a time. This
means that there are two months of overlap between the display before the command
and the display after. > scrolls the calendar contents one month forward in time. <
scrolls the contents one month backwards in time.
The commands C-v and M-v scroll the calendar by an entire “screenful”—three
months—in analogy with the usual meaning of these commands. C-v makes later
dates visible and M-v makes earlier dates visible. These commands take a numeric
argument as a repeat count; in particular, since C-u multiplies the next command
by four, typing C-u C-v scrolls the calendar forward by a year and typing C-u M-v
scrolls the calendar backward by a year.
The function keys NEXT and PRIOR are equivalent to C-v and M-v, just as
they are in other modes.

28.3 Counting Days
M-=

Display the number of days in the current region (calendar-countdays-region).

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To determine the number of days in a range, set the mark on one date using
C-SPC, move point to another date, and type M-= (calendar-count-days-region).
The numbers of days shown is inclusive; that is, it includes the days specified by
mark and point.

28.4 Miscellaneous Calendar Commands
pd

Display day-in-year (calendar-print-day-of-year).

C-c C-l

Regenerate the calendar window (calendar-redraw).

SPC

Scroll the next window up (scroll-other-window).

DEL

Scroll the next window down (scroll-other-window-down).

q

Exit from calendar (calendar-exit).

To display the number of days elapsed since the start of the year, or the number
of days remaining in the year, type the p d command (calendar-print-day-ofyear). This displays both of those numbers in the echo area. The count of days
elapsed includes the selected date. The count of days remaining does not include
that date.
If the calendar window text gets corrupted, type C-c C-l (calendar-redraw) to
redraw it. (This can only happen if you use non-Calendar-mode editing commands.)
In Calendar mode, you can use SPC (scroll-other-window) and DEL (scrollother-window-down) to scroll the other window (if there is one) up or down, respectively. This is handy when you display a list of holidays or diary entries in
another window.
To exit from the calendar, type q (calendar-exit). This buries all buffers
related to the calendar, selecting other buffers. (If a frame contains a dedicated
calendar window, exiting from the calendar deletes or iconifies that frame depending
on the value of calendar-remove-frame-by-deleting.)

28.5 Writing Calendar Files
You can write calendars and diary entries to HTML and LaTEX files.
The Calendar HTML commands produce files of HTML code that contain calendar and diary entries. Each file applies to one month, and has a name of the
format ‘yyyy-mm.html’, where yyyy and mm are the four-digit year and two-digit
month, respectively. The variable cal-html-directory specifies the default output
directory for the HTML files.
Diary entries enclosed by < and > are interpreted as HTML tags (for example:
this is a diary entry with some red text). You can change
the overall appearance of the displayed HTML pages (for example, the color of
various page elements, header styles) via a stylesheet ‘cal.css’ in the directory
containing the HTML files (see the value of the variable cal-html-css-default
for relevant style settings).
Hm

Generate a one-month calendar (cal-html-cursor-month).

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Generate a calendar file for each month of a year, as well as an index
page (cal-html-cursor-year). By default, this command writes files
to a yyyy subdirectory - if this is altered some hyperlinks between
years will not work.

If the variable cal-html-print-day-number-flag is non-nil, then the monthly
calendars show the day-of-the-year number. The variable cal-html-year-indexcols specifies the number of columns in the yearly index page.
The Calendar LaTEX commands produce a buffer of LaTEX code that prints as
a calendar. Depending on the command you use, the printed calendar covers the
day, week, month or year that point is in.
tm

Generate a one-month calendar (cal-tex-cursor-month).

tM

Generate a sideways-printing one-month calendar (cal-tex-cursormonth-landscape).

td

Generate a one-day calendar (cal-tex-cursor-day).

tw1

Generate a one-page calendar for one week (cal-tex-cursor-week).

tw2

Generate a two-page calendar for one week (cal-tex-cursor-week2).

tw3

Generate an ISO-style calendar for one week (cal-tex-cursor-weekiso).

tw4

Generate a calendar for one Monday-starting week (cal-tex-cursorweek-monday).

tfw

Generate a Filofax-style two-weeks-at-a-glance calendar (cal-texcursor-filofax-2week).

tfW

Generate a Filofax-style one-week-at-a-glance calendar (cal-texcursor-filofax-week).

ty

Generate a calendar for one year (cal-tex-cursor-year).

tY

Generate a sideways-printing calendar for one year (cal-tex-cursoryear-landscape).

tfy

Generate a Filofax-style calendar for one year (cal-tex-cursorfilofax-year).

Some of these commands print the calendar sideways (in “landscape mode”),
so it can be wider than it is long. Some of them use Filofax paper size (3.75in x
6.75in). All of these commands accept a prefix argument, which specifies how many
days, weeks, months or years to print (starting always with the selected one).
If the variable cal-tex-holidays is non-nil (the default), then the printed
calendars show the holidays in calendar-holidays. If the variable cal-tex-diary
is non-nil (the default is nil), diary entries are included also (in monthly, filofax,
and iso-week calendars only). If the variable cal-tex-rules is non-nil (the default
is nil), the calendar displays ruled pages in styles that have sufficient room. Consult
the documentation of the individual cal-tex functions to see which calendars support
which features.

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You can use the variable cal-tex-preamble-extra to insert extra LaTEX commands in the preamble of the generated document if you need to.

28.6 Holidays
The Emacs calendar knows about many major and minor holidays, and can display
them. You can add your own holidays to the default list.
Mouse-3 Holidays
h
Display holidays for the selected date (calendar-cursor-holidays).
x

Mark holidays in the calendar window (calendar-mark-holidays).

u

Unmark calendar window (calendar-unmark).

a

List all holidays for the displayed three months in another window
(calendar-list-holidays).

M-x holidays
List all holidays for three months around today’s date in another window.
M-x list-holidays
List holidays in another window for a specified range of years.
To see if any holidays fall on a given date, position point on that date in the
calendar window and use the h command. Alternatively, click on that date with
Mouse-3 and then choose Holidays from the menu that appears. Either way, this
displays the holidays for that date, in the echo area if they fit there, otherwise in a
separate window.
To view the distribution of holidays for all the dates shown in the calendar,
use the x command. This displays the dates that are holidays in a different face.
See Section “Calendar Customizing” in Specialized Emacs Features. The command
applies both to the currently visible months and to other months that subsequently
become visible by scrolling. To turn marking off and erase the current marks,
type u, which also erases any diary marks (see Section 28.10 [Diary], page 358). If
the variable calendar-mark-holidays-flag is non-nil, creating or updating the
calendar marks holidays automatically.
To get even more detailed information, use the a command, which displays a
separate buffer containing a list of all holidays in the current three-month range.
You can use SPC and DEL in the calendar window to scroll that list up and down,
respectively.
The command M-x holidays displays the list of holidays for the current month
and the preceding and succeeding months; this works even if you don’t have a
calendar window. If the variable calendar-view-holidays-initially-flag is
non-nil, creating the calendar displays holidays in this way. If you want the list of
holidays centered around a different month, use C-u M-x holidays, which prompts
for the month and year.

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The holidays known to Emacs include United States holidays and the major
Bahá’ı́, Chinese, Christian, Islamic, and Jewish holidays; also the solstices and
equinoxes.
The command M-x holiday-list displays the list of holidays for a range of
years. This function asks you for the starting and stopping years, and allows you
to choose all the holidays or one of several categories of holidays. You can use this
command even if you don’t have a calendar window.
The dates used by Emacs for holidays are based on current practice, not historical fact. For example Veteran’s Day began in 1919, but is shown in earlier
years.

28.7 Times of Sunrise and Sunset
Special calendar commands can tell you, to within a minute or two, the times of
sunrise and sunset for any date.
Mouse-3 Sunrise/sunset
S
Display times of sunrise and sunset for the selected date (calendarsunrise-sunset).
M-x sunrise-sunset
Display times of sunrise and sunset for today’s date.
C-u M-x sunrise-sunset
Display times of sunrise and sunset for a specified date.
M-x calendar-sunrise-sunset-month
Display times of sunrise and sunset for the selected month.
Within the calendar, to display the local times of sunrise and sunset in the echo
area, move point to the date you want, and type S. Alternatively, click Mouse-3 on
the date, then choose ‘Sunrise/sunset’ from the menu that appears. The command
M-x sunrise-sunset is available outside the calendar to display this information
for today’s date or a specified date. To specify a date other than today, use C-u
M-x sunrise-sunset, which prompts for the year, month, and day.
You can display the times of sunrise and sunset for any location and any date
with C-u C-u M-x sunrise-sunset. This asks you for a longitude, latitude, number
of minutes difference from Coordinated Universal Time, and date, and then tells
you the times of sunrise and sunset for that location on that date.
Because the times of sunrise and sunset depend on the location on earth, you
need to tell Emacs your latitude, longitude, and location name before using these
commands. Here is an example of what to set:
(setq calendar-latitude 40.1)
(setq calendar-longitude -88.2)
(setq calendar-location-name "Urbana, IL")
Use one decimal place in the values of calendar-latitude and calendarlongitude.
Your time zone also affects the local time of sunrise and sunset. Emacs usually
gets time zone information from the operating system, but if these values are not

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what you want (or if the operating system does not supply them), you must set
them yourself. Here is an example:
(setq calendar-time-zone -360)
(setq calendar-standard-time-zone-name "CST")
(setq calendar-daylight-time-zone-name "CDT")
The value of calendar-time-zone is the number of minutes difference between
your local standard time and Coordinated Universal Time (Greenwich time). The
values of calendar-standard-time-zone-name and calendar-daylight-timezone-name are the abbreviations used in your time zone. Emacs displays the times
of sunrise and sunset corrected for daylight saving time. See Section 28.13 [Daylight
Saving], page 365, for how daylight saving time is determined.
As a user, you might find it convenient to set the calendar location variables for
your usual physical location in your ‘.emacs’ file. If you are a system administrator, you may want to set these variables for all users in a ‘default.el’ file. See
Section 33.4 [Init File], page 461.

28.8 Phases of the Moon
These calendar commands display the dates and times of the phases of the moon
(new moon, first quarter, full moon, last quarter). This feature is useful for debugging problems that “depend on the phase of the moon”.
M

Display the dates and times for all the quarters of the moon for the
three-month period shown (calendar-lunar-phases).

M-x lunar-phases
Display dates and times of the quarters of the moon for three months
around today’s date.
Within the calendar, use the M command to display a separate buffer of the
phases of the moon for the current three-month range. The dates and times listed
are accurate to within a few minutes.
Outside the calendar, use the command M-x lunar-phases to display the list
of the phases of the moon for the current month and the preceding and succeeding months. For information about a different month, use C-u M-x lunar-phases,
which prompts for the month and year.
The dates and times given for the phases of the moon are given in local time
(corrected for daylight saving, when appropriate). See the discussion in the previous
section. See Section 28.7 [Sunrise/Sunset], page 352.

28.9 Conversion To and From Other Calendars
The Emacs calendar displayed is always the Gregorian calendar, sometimes called
the “new style” calendar, which is used in most of the world today. However,
this calendar did not exist before the sixteenth century and was not widely used
before the eighteenth century; it did not fully displace the Julian calendar and
gain universal acceptance until the early twentieth century. The Emacs calendar
can display any month since January, year 1 of the current era, but the calendar

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displayed is always the Gregorian, even for a date at which the Gregorian calendar
did not exist.
While Emacs cannot display other calendars, it can convert dates to and from
several other calendars.
28.9.1 Supported Calendar Systems
The ISO commercial calendar is often used in business.
The Julian calendar, named after Julius Caesar, was the one used in Europe
throughout medieval times, and in many countries up until the nineteenth century.
Astronomers use a simple counting of days elapsed since noon, Monday, January
1, 4713 B.C. on the Julian calendar. The number of days elapsed is called the Julian
day number or the Astronomical day number.
The Hebrew calendar is used by tradition in the Jewish religion. The Emacs calendar program uses the Hebrew calendar to determine the dates of Jewish holidays.
Hebrew calendar dates begin and end at sunset.
The Islamic calendar is used in many predominantly Islamic countries. Emacs
uses it to determine the dates of Islamic holidays. There is no universal agreement
in the Islamic world about the calendar; Emacs uses a widely accepted version,
but the precise dates of Islamic holidays often depend on proclamation by religious
authorities, not on calculations. As a consequence, the actual dates of observance
can vary slightly from the dates computed by Emacs. Islamic calendar dates begin
and end at sunset.
The French Revolutionary calendar was created by the Jacobins after the 1789
revolution, to represent a more secular and nature-based view of the annual cycle,
and to install a 10-day week in a rationalization measure similar to the metric
system. The French government officially abandoned this calendar at the end of
1805.
The Maya of Central America used three separate, overlapping calendar systems, the long count, the tzolkin, and the haab. Emacs knows about all three of
these calendars. Experts dispute the exact correlation between the Mayan calendar
and our calendar; Emacs uses the Goodman-Martinez-Thompson correlation in its
calculations.
The Copts use a calendar based on the ancient Egyptian solar calendar. Their
calendar consists of twelve 30-day months followed by an extra five-day period.
Once every fourth year they add a leap day to this extra period to make it six days.
The Ethiopic calendar is identical in structure, but has different year numbers and
month names.
The Persians use a solar calendar based on a design of Omar Khayyam. Their
calendar consists of twelve months of which the first six have 31 days, the next five
have 30 days, and the last has 29 in ordinary years and 30 in leap years. Leap years
occur in a complicated pattern every four or five years. The calendar implemented
here is the arithmetical Persian calendar championed by Birashk, based on a 2,820year cycle. It differs from the astronomical Persian calendar, which is based on
astronomical events. As of this writing the first future discrepancy is projected to

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occur on March 20, 2025. It is currently not clear what the official calendar of Iran
will be at that time.
The Chinese calendar is a complicated system of lunar months arranged into
solar years. The years go in cycles of sixty, each year containing either twelve
months in an ordinary year or thirteen months in a leap year; each month has
either 29 or 30 days. Years, ordinary months, and days are named by combining
one of ten “celestial stems” with one of twelve “terrestrial branches” for a total of
sixty names that are repeated in a cycle of sixty.
The Bahá’ı́ calendar system is based on a solar cycle of 19 months with 19 days
each. The four remaining “intercalary” days are placed between the 18th and 19th
months.
28.9.2 Converting To Other Calendars
The following commands describe the selected date (the date at point) in various
other calendar systems:
Mouse-3 Other calendars
po
Display the selected date in various other calendars.
print-other-dates).

(calendar-

pc

Display ISO commercial calendar equivalent for selected day
(calendar-iso-print-date).

pj

Display Julian date for selected day (calendar-julian-print-date).

pa

Display astronomical (Julian) day number for selected day (calendarastro-print-day-number).

ph

Display Hebrew date for selected day (calendar-hebrew-printdate).

pi

Display Islamic date for selected day (calendar-islamic-printdate).

pf

Display French Revolutionary date for selected day (calendarfrench-print-date).

pb

Display Bahá’ı́ date for selected day (calendar-bahai-print-date).

pC

Display Chinese date for selected day (calendar-chinese-printdate).

pk

Display Coptic date for selected day (calendar-coptic-print-date).

pe

Display Ethiopic date for selected day (calendar-ethiopic-printdate).

pp

Display Persian date for selected day (calendar-persian-printdate).

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356

Display Mayan date for selected day (calendar-mayan-print-date).

Otherwise, move point to the date you want to convert, then type the appropriate command starting with p from the table above. The prefix p is a mnemonic for
“print”, since Emacs “prints” the equivalent date in the echo area. p o displays the
date in all forms known to Emacs. You can also use Mouse-3 and then choose Other
calendars from the menu that appears. This displays the equivalent forms of the
date in all the calendars Emacs understands, in the form of a menu. (Choosing an
alternative from this menu doesn’t actually do anything—the menu is used only for
display.)
28.9.3 Converting From Other Calendars
You can use the other supported calendars to specify a date to move to. This section
describes the commands for doing this using calendars other than Mayan; for the
Mayan calendar, see the following section.
gc

Move to a date specified in the ISO commercial calendar (calendariso-goto-date).

gw

Move to a week specified in the ISO commercial calendar (calendariso-goto-week).

gj

Move to a date specified in the Julian calendar (calendar-juliangoto-date).

ga

Move to a date specified with an astronomical (Julian) day number
(calendar-astro-goto-day-number).

gb

Move to a date specified in the Bahá’ı́ calendar (calendar-bahaigoto-date).

gh

Move to a date specified in the Hebrew calendar (calendar-hebrewgoto-date).

gi

Move to a date specified in the Islamic calendar (calendar-islamicgoto-date).

gf

Move to a date specified in the French Revolutionary calendar
(calendar-french-goto-date).

gC

Move to a date specified in the Chinese calendar (calendar-chinesegoto-date).

gp

Move to a date specified in the Persian calendar (calendar-persiangoto-date).

gk

Move to a date specified in the Coptic calendar (calendar-copticgoto-date).

ge

Move to a date specified in the Ethiopic calendar (calendarethiopic-goto-date).

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These commands ask you for a date on the other calendar, move point to the
Gregorian calendar date equivalent to that date, and display the other calendar’s
date in the echo area. Emacs uses strict completion (see Section 5.3.3 [Completion
Exit], page 31) whenever it asks you to type a month name, so you don’t have to
worry about the spelling of Hebrew, Islamic, or French names.
One common issue concerning the Hebrew calendar is the computation of the
anniversary of a date of death, called a “yahrzeit”. The Emacs calendar includes
a facility for such calculations. If you are in the calendar, the command M-x
calendar-hebrew-list-yahrzeits asks you for a range of years and then displays a list of the yahrzeit dates for those years for the date given by point. If you
are not in the calendar, this command first asks you for the date of death and the
range of years, and then displays the list of yahrzeit dates.
28.9.4 Converting from the Mayan Calendar
Here are the commands to select dates based on the Mayan calendar:
gml

Move to a date specified by the long count calendar (calendar-mayangoto-long-count-date).

gmnt

Move to the next occurrence of a place in the tzolkin calendar
(calendar-mayan-next-tzolkin-date).

gmpt

Move to the previous occurrence of a place in the tzolkin calendar
(calendar-mayan-previous-tzolkin-date).

gmnh

Move to the next occurrence of a place in the haab calendar
(calendar-mayan-next-haab-date).

gmph

Move to the previous occurrence of a place in the haab calendar
(calendar-mayan-previous-haab-date).

gmnc

Move to the next occurrence of a place in the calendar round
(calendar-mayan-next-calendar-round-date).

gmpc

Move to the previous occurrence of a place in the calendar round
(calendar-mayan-previous-calendar-round-date).

To understand these commands, you need to understand the Mayan calendars.
The long count is a counting of days with these units:
1 kin = 1 day 1 uinal = 20 kin 1 tun = 18 uinal
1 katun = 20 tun 1 baktun = 20 katun
Thus, the long count date 12.16.11.16.6 means 12 baktun, 16 katun, 11 tun, 16
uinal, and 6 kin. The Emacs calendar can handle Mayan long count dates as early
as 7.17.18.13.3, but no earlier. When you use the g m l command, type the Mayan
long count date with the baktun, katun, tun, uinal, and kin separated by periods.
The Mayan tzolkin calendar is a cycle of 260 days formed by a pair of independent cycles of 13 and 20 days. Since this cycle repeats endlessly, Emacs provides
commands to move backward and forward to the previous or next point in the cycle.
Type g m p t to go to the previous tzolkin date; Emacs asks you for a tzolkin date

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and moves point to the previous occurrence of that date. Similarly, type g m n t to
go to the next occurrence of a tzolkin date.
The Mayan haab calendar is a cycle of 365 days arranged as 18 months of 20
days each, followed by a 5-day monthless period. Like the tzolkin cycle, this cycle
repeats endlessly, and there are commands to move backward and forward to the
previous or next point in the cycle. Type g m p h to go to the previous haab date;
Emacs asks you for a haab date and moves point to the previous occurrence of that
date. Similarly, type g m n h to go to the next occurrence of a haab date.
The Maya also used the combination of the tzolkin date and the haab date. This
combination is a cycle of about 52 years called a calendar round. If you type g m
p c, Emacs asks you for both a haab and a tzolkin date and then moves point to
the previous occurrence of that combination. Use g m n c to move point to the next
occurrence of a combination. These commands signal an error if the haab/tzolkin
date combination you have typed is impossible.
Emacs uses strict completion (see Section 5.3.3 [Completion Exit], page 31)
whenever it asks you to type a Mayan name, so you don’t have to worry about
spelling.

28.10 The Diary
The Emacs diary keeps track of appointments or other events on a daily basis, in
conjunction with the calendar. To use the diary feature, you must first create a
diary file containing a list of events and their dates. Then Emacs can automatically
pick out and display the events for today, for the immediate future, or for any
specified date.
The name of the diary file is specified by the variable diary-file; ‘~/diary’ is
the default. Here’s an example showing what that file looks like:
12/22/2012 Twentieth wedding anniversary!!
&1/1.
Happy New Year!
10/22
Ruth’s birthday.
* 21, *:
Payday
Tuesday--weekly meeting with grad students at 10am
Supowit, Shen, Bitner, and Kapoor to attend.
1/13/89
Friday the thirteenth!!
&thu 4pm
squash game with Lloyd.
mar 16
Dad’s birthday
April 15, 2013 Income tax due.
&* 15
time cards due.
This format is essentially the same as the one used by the separate calendar utility
that is present on some Unix systems. This example uses extra spaces to align the
event descriptions of most of the entries. Such formatting is purely a matter of
taste.
Although you probably will start by creating a diary manually, Emacs provides
a number of commands to let you view, add, and change diary entries.

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28.10.1 Displaying the Diary
Once you have created a diary file, you can use the calendar to view it. You can
also view today’s events outside of Calendar mode. In the following, key bindings
refer to the Calendar buffer.
Mouse-3 Diary
d
Display all diary entries for the selected date (diary-view-entries).
s

Display the entire diary file (diary-show-all-entries).

m

Mark all visible dates that have diary entries (diary-mark-entries).

u

Unmark the calendar window (calendar-unmark).

M-x diary-print-entries
Print hard copy of the diary display as it appears.
M-x diary

Display all diary entries for today’s date.

M-x diary-mail-entries
Mail yourself email reminders about upcoming diary entries.
Displaying the diary entries with d shows in a separate window the diary entries
for the selected date in the calendar. The mode line of the new window shows the
date of the diary entries. Holidays are shown either in the buffer or in the mode
line, depending on the display method you choose (see Section “Diary Display” in
Specialized Emacs Features). If you specify a numeric argument with d, it shows all
the diary entries for that many successive days. Thus, 2 d displays all the entries
for the selected date and for the following day.
Another way to display the diary entries for a date is to click Mouse-3 on the
date, and then choose Diary entries from the menu that appears. If the variable
calendar-view-diary-initially-flag is non-nil, creating the calendar lists the
diary entries for the current date (provided the current date is visible).
To get a broader view of which days are mentioned in the diary, use the m
command. This marks the dates that have diary entries in a different face. See
Section “Calendar Customizing” in Specialized Emacs Features.
This command applies both to the months that are currently visible and to
those that subsequently become visible after scrolling. To turn marking off and
erase the current marks, type u, which also turns off holiday marks (see Section 28.6
[Holidays], page 351). If the variable calendar-mark-diary-entries-flag is nonnil, creating or updating the calendar marks diary dates automatically.
To see the full diary file, rather than just some of the entries, use the s command.
The command M-x diary displays the diary entries for the current date, independently of the calendar display, and optionally for the next few days as well;
the variable diary-number-of-entries specifies how many days to include. See
Section “Diary Customizing” in Specialized Emacs Features.
If you put (diary) in your ‘.emacs’ file, this automatically displays a window
with the day’s diary entries when you start Emacs.

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Some people like to receive email notifications of events in their diary. To send
such mail to yourself, use the command M-x diary-mail-entries. A prefix argument specifies how many days (starting with today) to check; otherwise, the variable
diary-mail-days says how many days.
28.10.2 The Diary File
Your diary file is a file that records events associated with particular dates. The
name of the diary file is specified by the variable diary-file; ‘~/diary’ is the
default. The calendar utility program supports a subset of the format allowed by
the Emacs diary facilities, so you can use that utility to view the diary file, with
reasonable results aside from the entries it cannot understand.
Each entry in the diary file describes one event and consists of one or more lines.
An entry always begins with a date specification at the left margin. The rest of
the entry is simply text to describe the event. If the entry has more than one line,
then the lines after the first must begin with whitespace to indicate they continue
a previous entry. Lines that do not begin with valid dates and do not continue a
preceding entry are ignored.
You can also use a format where the first line of a diary entry consists only of
the date or day name (with no following blanks or punctuation). For example:
02/11/2012
Bill B. visits Princeton today
2pm Cognitive Studies Committee meeting
2:30-5:30 Liz at Lawrenceville
4:00pm Dentist appt
7:30pm Dinner at George’s
8:00-10:00pm concert
This entry will have a different appearance if you use the simple diary display (see
Section “Diary Display” in Specialized Emacs Features). The simple diary display
omits the date line at the beginning; only the continuation lines appear. This style
of entry looks neater when you display just a single day’s entries, but can cause
confusion if you ask for more than one day’s entries.
You can inhibit the marking of certain diary entries in the calendar window; to
do this, insert the string that diary-nonmarking-symbol specifies (default ‘&’) at
the beginning of the entry, before the date. This has no effect on display of the
entry in the diary window; it only affects marks on dates in the calendar window.
Nonmarking entries are especially useful for generic entries that would otherwise
mark many different dates.
28.10.3 Date Formats
Here are some sample diary entries, illustrating different ways of formatting a date.
The examples all show dates in American order (month, day, year), but Calendar
mode supports European order (day, month, year) and ISO order (year, month,
day) as options.
4/20/12 Switch-over to new tabulation system
apr. 25 Start tabulating annual results

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4/30 Results for April are due
*/25 Monthly cycle finishes
Friday Don’t leave without backing up files
The first entry appears only once, on April 20, 2012. The second and third
appear every year on the specified dates, and the fourth uses a wildcard (asterisk)
for the month, so it appears on the 25th of every month. The final entry appears
every week on Friday.
You can use just numbers to express a date, as in ‘month /day ’ or
‘month /day /year ’. This must be followed by a nondigit. In the date itself, month
and day are numbers of one or two digits. The optional year is also a number, and
may be abbreviated to the last two digits; that is, you can use ‘11/12/2012’ or
‘11/12/12’.
Dates can also have the form ‘monthname day ’ or ‘monthname day, year ’, where
the month’s name can be spelled in full or abbreviated (with or without a period).
The preferred abbreviations for month and day names can be set using the variables calendar-abbrev-length, calendar-month-abbrev-array, and calendarday-abbrev-array. The default is to use the first three letters of a name as its
abbreviation. Case is not significant.
A date may be generic; that is, partially unspecified. Then the entry applies
to all dates that match the specification. If the date does not contain a year, it is
generic and applies to any year. Alternatively, month, day, or year can be ‘*’; this
matches any month, day, or year, respectively. Thus, a diary entry ‘3/*/*’ matches
any day in March of any year; so does ‘march *’.
If you prefer the European style of writing dates (in which the day comes before the month), or the ISO style (in which the order is year, month, day), type
M-x calendar-set-date-style while in the calendar, or customize the variable
calendar-date-style. This affects how diary dates are interpreted, date display,
and the order in which some commands expect their arguments to be given.
You can use the name of a day of the week as a generic date which applies to
any date falling on that day of the week. You can abbreviate the day of the week
as described above, or spell it in full; case is not significant.
28.10.4 Commands to Add to the Diary
While in the calendar, there are several commands to create diary entries. The basic
commands are listed here; more sophisticated commands are in the next section
(see Section 28.10.5 [Special Diary Entries], page 362). Entries can also be based on
non-Gregorian calendars. See Section “Non-Gregorian Diary” in Specialized Emacs
Features.
id

Add a diary entry for the selected date (diary-insert-entry).

iw

Add a diary entry for the selected day of the week (diary-insertweekly-entry).

im

Add a diary entry for the selected day of the month (diary-insertmonthly-entry).

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Add a diary entry for the selected day of the year (diary-insertyearly-entry).

You can make a diary entry for a specific date by selecting that date in the
calendar window and typing the i d command. This command displays the end of
your diary file in another window and inserts the date; you can then type the rest
of the diary entry.
If you want to make a diary entry that applies to a specific day of the week,
select that day of the week (any occurrence will do) and type i w. This inserts the
day-of-week as a generic date; you can then type the rest of the diary entry. You
can make a monthly diary entry in the same fashion: select the day of the month,
use the i m command, and type the rest of the entry. Similarly, you can insert a
yearly diary entry with the i y command.
All of the above commands make marking diary entries by default. To make a
nonmarking diary entry, give a prefix argument to the command. For example, C-u
i w makes a nonmarking weekly diary entry.
When you modify the diary file, be sure to save the file before exiting Emacs.
Saving the diary file after using any of the above insertion commands will automatically update the diary marks in the calendar window, if appropriate. You can use
the command calendar-redraw to force an update at any time.
28.10.5 Special Diary Entries
In addition to entries based on calendar dates, the diary file can contain sexp entries
for regular events such as anniversaries. These entries are based on Lisp expressions
(sexps) that Emacs evaluates as it scans the diary file. Instead of a date, a sexp
entry contains ‘%%’ followed by a Lisp expression which must begin and end with
parentheses. The Lisp expression determines which dates the entry applies to.
Calendar mode provides commands to insert certain commonly used sexp entries:
ia

Add an anniversary diary entry for the selected date (diary-insertanniversary-entry).

ib

Add a block diary entry for the current region (diary-insert-blockentry).

ic

Add a cyclic diary entry starting at the date (diary-insert-cyclicentry).

If you want to make a diary entry that applies to the anniversary of a specific
date, move point to that date and use the i a command. This displays the end of
your diary file in another window and inserts the anniversary description; you can
then type the rest of the diary entry. The entry looks like this:
%%(diary-anniversary 10 31 1948) Arthur’s birthday
This entry applies to October 31 in any year after 1948; ‘10 31 1948’ specifies the
date. (If you are using the European or ISO calendar style, the input order of
month, day and year is different.) The reason this expression requires a beginning
year is that advanced diary functions can use it to calculate the number of elapsed
years.

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A block diary entry applies to a specified range of consecutive dates. Here is
a block diary entry that applies to all dates from June 24, 2012 through July 10,
2012:
%%(diary-block 6 24 2012 7 10 2012) Vacation
The ‘6 24 2012’ indicates the starting date and the ‘7 10 2012’ indicates the stopping date. (Again, if you are using the European or ISO calendar style, the input
order of month, day and year is different.)
To insert a block entry, place point and the mark on the two dates that begin
and end the range, and type i b. This command displays the end of your diary file
in another window and inserts the block description; you can then type the diary
entry.
Cyclic diary entries repeat after a fixed interval of days. To create one, select
the starting date and use the i c command. The command prompts for the length
of interval, then inserts the entry, which looks like this:
%%(diary-cyclic 50 3 1 2012) Renew medication
This entry applies to March 1, 2012 and every 50th day following; ‘3 1 2012’ specifies
the starting date. (If you are using the European or ISO calendar style, the input
order of month, day and year is different.)
All three of these commands make marking diary entries. To insert a nonmarking
entry, give a prefix argument to the command. For example, C-u i a makes a
nonmarking anniversary diary entry.
Marking sexp diary entries in the calendar can be time-consuming, since every
date visible in the calendar window must be individually checked. So it’s a good
idea to make sexp diary entries nonmarking (with ‘&’) when possible.
Another sophisticated kind of sexp entry, a floating diary entry, specifies a regularly occurring event by offsets specified in days, weeks, and months. It is comparable to a crontab entry interpreted by the cron utility. Here is a nonmarking,
floating diary entry that applies to the fourth Thursday in November:
&%%(diary-float 11 4 4) American Thanksgiving
The 11 specifies November (the eleventh month), the 4 specifies Thursday (the
fourth day of the week, where Sunday is numbered zero), and the second 4 specifies
the fourth Thursday (1 would mean “first”, 2 would mean “second”, −2 would mean
“second-to-last”, and so on). The month can be a single month or a list of months.
Thus you could change the 11 above to ‘’(1 2 3)’ and have the entry apply to the
last Thursday of January, February, and March. If the month is t, the entry applies
to all months of the year.
Each of the standard sexp diary entries takes an optional parameter specifying
the name of a face or a single-character string to use when marking the entry in the
calendar. Most generally, sexp diary entries can perform arbitrary computations to
determine when they apply. See Section “Sexp Diary Entries” in Specialized Emacs
Features.

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28.11 Appointments
If you have a diary entry for an appointment, and that diary entry begins with a
recognizable time of day, Emacs can warn you in advance that an appointment is
pending. Emacs alerts you to the appointment by displaying a message in your
chosen format, as specified by the variable appt-display-format. If the value of
appt-audible is non-nil, the warning includes an audible reminder. In addition,
if appt-display-mode-line is non-nil, Emacs displays the number of minutes to
the appointment on the mode line.
If appt-display-format has the value window, then the variable apptdisplay-duration controls how long the reminder window is visible for; and the
variables appt-disp-window-function and appt-delete-window-function give
the names of functions used to create and destroy the window, respectively.
To enable appointment notification, type M-x appt-activate. With a positive
argument, it enables notification; with a negative argument, it disables notification;
with no argument, it toggles. Enabling notification also sets up an appointment list
for today from the diary file, giving all diary entries found with recognizable times
of day, and reminds you just before each of them.
For example, suppose the diary file contains these lines:
Monday
9:30am Coffee break
12:00pm Lunch
Then on Mondays, you will be reminded at around 9:20am about your coffee break
and at around 11:50am about lunch. The variable appt-message-warning-time
specifies how many minutes (default 12) in advance to warn you. This is a default
warning time. Each appointment can specify a different warning time by adding a
piece matching appt-warning-time-regexp (see that variable’s documentation for
details).
You can write times in am/pm style (with ‘12:00am’ standing for midnight and
‘12:00pm’ standing for noon), or 24-hour European/military style. You need not
be consistent; your diary file can have a mixture of the two styles. Times must be
at the beginning of diary entries if they are to be recognized.
Emacs updates the appointments list from the diary file automatically just after midnight. You can force an update at any time by re-enabling appointment
notification. Both these actions also display the day’s diary buffer, unless you set
appt-display-diary to nil. The appointments list is also updated whenever the
diary file (or a file it includes; see Section “Fancy Diary Display” in Specialized
Emacs Features) is saved.
You can also use the appointment notification facility like an alarm clock. The
command M-x appt-add adds entries to the appointment list without affecting your
diary file. You delete entries from the appointment list with M-x appt-delete.

28.12 Importing and Exporting Diary Entries
You can transfer diary entries between Emacs diary files and a variety of other
formats.

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You can import diary entries from Outlook-generated appointment messages.
While viewing such a message in Rmail or Gnus, do M-x diary-from-outlook to
import the entry. You can make this command recognize additional appointment
message formats by customizing the variable diary-outlook-formats.
The icalendar package allows you to transfer data between your Emacs diary
file and iCalendar files, which are defined in “RFC 2445—Internet Calendaring and
Scheduling Core Object Specification (iCalendar)” (as well as the earlier vCalendar
format).
The command icalendar-import-buffer extracts iCalendar data from the current buffer and adds it to your diary file. This function is also suitable for automatic
extraction of iCalendar data; for example with the Rmail mail client one could use:
(add-hook ’rmail-show-message-hook ’icalendar-import-buffer)
The command icalendar-import-file imports an iCalendar file and adds the
results to an Emacs diary file. For example:
(icalendar-import-file "/here/is/calendar.ics"
"/there/goes/ical-diary")
You can use an #include directive to add the import file contents to the main diary
file, if these are different files. See Section “Fancy Diary Display” in Specialized
Emacs Features.
Use icalendar-export-file to interactively export an entire Emacs diary file
to iCalendar format. To export only a part of a diary file, mark the relevant area,
and call icalendar-export-region. In both cases, Emacs appends the result to
the target file.

28.13 Daylight Saving Time
Emacs understands the difference between standard time and daylight saving time—
the times given for sunrise, sunset, solstices, equinoxes, and the phases of the moon
take that into account. The rules for daylight saving time vary from place to place
and have also varied historically from year to year. To do the job properly, Emacs
needs to know which rules to use.
Some operating systems keep track of the rules that apply to the place where
you are; on these systems, Emacs gets the information it needs from the system
automatically. If some or all of this information is missing, Emacs fills in the gaps
with the rules currently used in Cambridge, Massachusetts. If the resulting rules are
not what you want, you can tell Emacs the rules to use by setting certain variables:
calendar-daylight-savings-starts and calendar-daylight-savings-ends.
These values should be Lisp expressions that refer to the variable year, and
evaluate to the Gregorian date on which daylight saving time starts or (respectively)
ends, in the form of a list (month day year ). The values should be nil if your
area does not use daylight saving time.
Emacs uses these expressions to determine the starting date of daylight saving
time for the holiday list and for correcting times of day in the solar and lunar
calculations.
The values for Cambridge, Massachusetts are as follows:

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(calendar-nth-named-day 2 0 3 year)
(calendar-nth-named-day 1 0 11 year)
That is, the second 0th day (Sunday) of the third month (March) in the year
specified by year, and the first Sunday of the eleventh month (November) of that
year. If daylight saving time were changed to start on October 1, you would set
calendar-daylight-savings-starts to this:
(list 10 1 year)
If there is no daylight saving time at your location, or if you want all
times in standard time, set calendar-daylight-savings-starts and calendardaylight-savings-ends to nil.
The variable calendar-daylight-time-offset specifies the difference between
daylight saving time and standard time, measured in minutes. The value for Cambridge, Massachusetts is 60.
Finally, the two variables calendar-daylight-savings-starts-time and
calendar-daylight-savings-ends-time specify the number of minutes after
midnight local time when the transition to and from daylight saving time should
occur. For Cambridge, Massachusetts both variables’ values are 120.

28.14 Summing Time Intervals
The timeclock package adds up time intervals, so you can (for instance) keep track
of how much time you spend working on particular projects.
Use the M-x timeclock-in command when you start working on a project, and
M-x timeclock-out command when you’re done. Each time you do this, it adds
one time interval to the record of the project. You can change to working on a
different project with M-x timeclock-change.
Once you’ve collected data from a number of time intervals, you can use M-x
timeclock-workday-remaining to see how much time is left to work today (assuming a typical average of 8 hours a day), and M-x timeclock-when-to-leave
which will calculate when you’re “done”.
If you want Emacs to display the amount of time “left” of your workday in the
mode line, either customize the timeclock-modeline-display variable and set its
value to t, or invoke the M-x timeclock-modeline-display command.
Terminating the current Emacs session might or might not mean that you have
stopped working on the project and, by default, Emacs asks you. You can, however,
customize the value of the variable timeclock-ask-before-exiting to nil to avoid
the question; then, only an explicit M-x timeclock-out or M-x timeclock-change
will tell Emacs that the current interval is over.
The timeclock functions work by accumulating the data in a file called
‘.timelog’ in your home directory. You can specify a different name for this file by
customizing the variable timeclock-file. If you edit the timeclock file manually,
or if you change the value of any of timeclock’s customizable variables, you should
run the command M-x timeclock-reread-log to update the data in Emacs from
the file.

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29 Sending Mail
To send an email message from Emacs, type C-x m. This switches to a buffer named
‘*unsent mail*’, where you can edit the text and headers of the message. When
done, type C-c C-s or C-c C-c to send it.
C-x m

Begin composing mail (compose-mail).

C-x 4 m

Likewise, in another window (compose-mail-other-window).

C-x 5 m

Likewise, but in a new frame (compose-mail-other-frame).

C-c C-s

In the mail buffer, send the message (message-send).

C-c C-c

In the mail buffer, send the message and bury the buffer (messagesend-and-exit).

The mail buffer is an ordinary Emacs buffer, so you can switch to other buffers
while composing the mail. If you want to send another mail before finishing the
current one, type C-x m again to open a new mail buffer whose name has a different
numeric suffix (see Section 16.3 [Misc Buffer], page 152). If you invoke the command
with a prefix argument, C-u C-x m, Emacs switches back to the last mail buffer, and
asks if you want to erase the message in that buffer; if you answer no, this lets you
pick up editing the message where you left off.
The command C-x 4 m (compose-mail-other-window) does the same as C-x m,
except it displays the mail buffer in a different window. The command C-x 5 m
(compose-mail-other-frame) does it in a new frame.
When you type C-c C-c or C-c C-s to send the mail, Emacs may ask you how
it should deliver the mail—either directly via SMTP, or using some other method.
See Section 29.4.1 [Mail Sending], page 370, for details.

29.1 The Format of the Mail Buffer
Here is an example of the contents of a mail buffer:
To: subotai@example.org
CC: mongol.soldier@example.net, rms@gnu.org
Subject: Re: What is best in life?
From: conan@example.org
--text follows this line-To crush your enemies, see them driven before you, and to
hear the lamentation of their women.
At the top of the mail buffer is a set of header fields, which are used for specifying
information about the email’s recipient(s), subject, and so on. The above buffer
contains header fields for ‘To’, ‘Cc’, ‘Subject’, and ‘From’. Some header fields are
automatically pre-initialized in the mail buffer, when appropriate.
The line that says ‘--text follows this line--’ separates the header fields
from the body (or text) of the message. Everything above that line is treated as
part of the headers; everything below it is treated as the body. The delimiter line
itself does not appear in the message actually sent.

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You can insert and edit header fields using ordinary editing commands. See
Section 29.4.2 [Header Editing], page 372, for commands specific to editing header
fields. Certain headers, such as ‘Date’ and ‘Message-Id’, are normally omitted from
the mail buffer and are created automatically when the message is sent.

29.2 Mail Header Fields
A header field in the mail buffer starts with a field name at the beginning of a line,
terminated by a colon. Upper and lower case are equivalent in field names. After
the colon and optional whitespace comes the contents of the field.
You can use any name you like for a header field, but normally people use only
standard field names with accepted meanings.
The ‘From’ header field identifies the person sending the email (i.e. you). This
should be a valid mailing address, as replies are normally sent there. The default contents of this header field are computed from the variables user-full-name
(which specifies your full name) and user-mail-address (your email address). On
some operating systems, Emacs initializes these two variables using environment
variables (see Section C.4.1 [General Variables], page 510). If this information is
unavailable or wrong, you should customize the variables yourself (see Section 33.1
[Easy Customization], page 434).
The value of the variable mail-from-style specifies how to format the contents
of the ‘From’ field:
nil

Use just the address, as in ‘king@grassland.com’.

parens

Use both address and full name, as in:
‘king@grassland.com (Elvis Parsley)’.

angles

Use both address and full name, as in:
‘Elvis Parsley ’.

any other value
Use angles normally. But if the address must be “quoted” to remain
syntactically valid under the angles format but not under the parens
format, use parens instead. This is the default.
Apart from ‘From’, here is a table of commonly-used fields:
‘To’

The mailing address(es) to which the message is addressed. To list
more than one address, use commas to separate them.

‘Subject’

The subject of the message.

‘CC’

Additional mailing address(es) to send the message to. This is like ‘To’,
except that these readers should not regard the message as directed
at them.

‘BCC’

Additional mailing address(es) to send the message to, which should
not appear in the header of the message actually sent. “BCC” stands
for blind carbon copies.

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‘FCC’

The name of a file, to which a copy of the sent message should be
appended. Emacs writes the message in mbox format, unless the file is
in Babyl format (used by Rmail before Emacs 23), in which case Emacs
writes in Babyl format. If an Rmail buffer is visiting the file, Emacs
updates it accordingly. To specify more than one file, use several ‘FCC’
fields, with one file name in each field.

‘Reply-to’

An address to which replies should be sent, instead of ‘From’. This is
used if, for some reason, your ‘From’ address cannot receive replies.

‘Mail-reply-to’
This field takes precedence over ‘Reply-to’. It is used because some
mailing lists set the ‘Reply-to’ field for their own purposes (a somewhat controversial practice).
‘Mail-followup-to’
One of more address(es) to use as default recipient(s) for follow-up
messages. This is typically used when you reply to a message from a
mailing list that you are subscribed to, and want replies to go to the
list without sending an extra copy to you.
‘In-reply-to’
An identifier for the message you are replying to. Most mail readers
use this information to group related messages together. Normally,
this header is filled in automatically when you reply to a message in
any mail program built into Emacs.
‘References’
Identifiers for previous related messages. Like ‘In-reply-to’, this is
normally filled in automatically for you.
The ‘To’, ‘CC’, and ‘BCC’ fields can appear any number of times, and each such
header field can contain multiple addresses, separated by commas. This way, you
can specify any number of places to send the message. These fields can also have
continuation lines: one or more lines starting with whitespace, following the starting
line of the field, are considered part of the field. Here’s an example of a ‘To’ field
with a continuation line:
To: foo@example.net, this@example.net,
bob@example.com
You can direct Emacs to insert certain default headers into the mail buffer by
setting the variable mail-default-headers to a string. Then C-x m inserts this
string into the message headers. For example, here is how to add a ‘Reply-to’ and
‘FCC’ header to each message:
(setq mail-default-headers
"Reply-to: foo@example.com\nFCC: ~/Mail/sent")

If the default header fields are not appropriate for a particular message, edit them
as necessary before sending the message.

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29.3 Mail Aliases
You can define mail aliases, which are short mnemonic names that stand for one or
more mailing addresses. By default, mail aliases are defined in the file ‘~/.mailrc’.
You can specify a different file name to use, by setting the variable mail-personalalias-file.
To define an alias in ‘.mailrc’, write a line like this:
alias nick fulladdresses
This means that nick should expand into fulladdresses, where fulladdresses can be
either a single address, or multiple addresses separated with spaces. For instance,
to make maingnu stand for gnu@gnu.org plus a local address of your own, put in
this line:
alias maingnu gnu@gnu.org local-gnu
If an address contains a space, quote the whole address with a pair of double quotes,
like this:
alias jsmith "John Q. Smith "
Note that you need not include double quotes around individual parts of the address,
such as the person’s full name. Emacs puts them in if they are needed. For instance,
it inserts the above address as ‘"John Q. Smith" ’.
Emacs also recognizes “include” commands in ‘.mailrc’. They look like this:
source filename
The ‘.mailrc’ file is not unique to Emacs; many other mail-reading programs use
it for mail aliases, and it can contain various other commands. However, Emacs
ignores everything except alias definitions and include commands.
Mail aliases expand as abbrevs—that is to say, as soon as you type a wordseparator character after an alias (see Chapter 26 [Abbrevs], page 322). This expansion takes place only within the ‘To’, ‘From’, ‘CC’, ‘BCC’, and ‘Reply-to’ header
fields (plus their ‘Resent-’ variants); it does not take place in other header fields,
such as ‘Subject’.
You can also insert an aliased address directly, using the command M-x
mail-abbrev-insert-alias. This reads an alias name, with completion, and inserts its definition at point.

29.4 Mail Commands
The default major mode for the ‘*mail*’ buffer is called Message mode. It behaves
like Text mode in many ways, but provides several additional commands on the C-c
prefix, which make editing a message more convenient.
In this section, we will describe some of the most commonly-used commands
available in Message mode.
29.4.1 Mail Sending
C-c C-c

Send the message, and bury the mail buffer (message-send-andexit).

C-c C-s

Send the message, and leave the mail buffer selected (message-send).

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The usual command to send a message is C-c C-c (mail-send-and-exit). This
sends the message and then “buries” the mail buffer, putting it at the lowest priority
for reselection. If you want it to kill the mail buffer instead, change the variable
message-kill-buffer-on-exit to t.
The command C-c C-s (message-send) sends the message and leaves the buffer
selected. Use this command if you want to modify the message (perhaps with new
recipients) and send it again.
Sending a message runs the hook message-send-hook. It also marks the mail
buffer as unmodified, except if the mail buffer is also a file-visiting buffer (in that
case, only saving the file does that, and you don’t get a warning if you try to send
the same message twice).
The variable send-mail-function controls how the message is delivered. Its
value should be one of the following functions:
sendmail-query-once
Query for a delivery method (one of the other entries in this list),
and use that method for this message; then save the method to sendmail-function, so that it is used for future deliveries. This is the
default, unless you have already set the variables for sending mail via
smtpmail-send-it (see below).
smtpmail-send-it
Send mail using the through an external mail host, such as your Internet service provider’s outgoing SMTP mail server. If you have not told
Emacs how to contact the SMTP server, it prompts for this information, which is saved in the smtpmail-smtp-server variable and the
file ‘~/.authinfo’. See Section “Emacs SMTP Library” in Sending
mail via SMTP.
sendmail-send-it
Send mail using the system’s default sendmail program, or equivalent.
This requires the system to be set up for delivering mail directly via
SMTP.
mailclient-send-it
Pass the mail buffer on to the system’s designated mail client. See the
commentary section in the file ‘mailclient.el’ for details.
feedmail-send-it
This is similar to sendmail-send-it, but allows you to queue messages for later sending. See the commentary section in the file
‘feedmail.el’ for details.
When you send a message containing non-ASCII characters, they need to be encoded with a coding system (see Section 19.6 [Coding Systems], page 188). Usually
the coding system is specified automatically by your chosen language environment
(see Section 19.3 [Language Environments], page 183). You can explicitly specify
the coding system for outgoing mail by setting the variable sendmail-codingsystem (see Section 19.7 [Recognize Coding], page 190). If the coding system thus

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determined does not handle the characters in a particular message, Emacs asks you
to select the coding system to use, showing a list of possible coding systems.
29.4.2 Mail Header Editing
Message mode provides the following special commands to move to particular header
fields and to complete addresses in headers.
C-c C-f C-t
Move to the ‘To’ header (message-goto-to).
C-c C-f C-s
Move to the ‘Subject’ header (message-goto-subject).
C-c C-f C-c
Move to the ‘CC’ header (message-goto-cc).
C-c C-f C-b
Move to the ‘BCC’ header (message-goto-bcc).
C-c C-f C-r
Move to the ‘Reply-To’ header (message-goto-reply-to).
C-c C-f C-f
Move to the ‘Mail-Followup-To’ header field (message-gotofollowup-to).
C-c C-f C-w
Add a new ‘FCC’ header field, with file-name completion (messagegoto-fcc).
C-c C-b

Move to the start of the message body (message-goto-body).

TAB

Complete a mailing address (message-tab).

The commands to move point to particular header fields are all based on the
prefix C-c C-f (‘C-f’ is for “field”). If the field in question does not exist, the
command creates one (the exception is mail-fcc, which creates a new field each
time).
The command C-c C-b (message-goto-body) moves point to just after the
header separator line—that is, to the beginning of the body.
While editing a header field that contains addresses, such as ‘To:’, ‘CC:’ and
‘BCC:’, you can complete an address by typing TAB (message-tab). This attempts
to insert the full name corresponding to the address based on a couple of methods,
including EUDC, a library that recognizes a number of directory server protocols
(see Section “EUDC” in The Emacs Unified Directory Client). Failing that, it
attempts to expand the address as a mail alias (see Section 29.3 [Mail Aliases],
page 370). If point is on a header field that does not take addresses, or if it is in
the message body, then TAB just inserts a tab character.

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29.4.3 Citing Mail
C-c C-y

Yank the selected message from the mail reader, as a citation
(message-yank-original).

C-c C-q

Fill each paragraph cited from another message (message-fillyanked-message).

You can use the command C-c C-y (message-yank-original) to cite a message
that you are replying to. This inserts the text of that message into the mail buffer.
This command works only if the mail buffer is invoked from a mail reader running
in Emacs, such as Rmail.
By default, Emacs inserts the string ‘>’ in front of each line of the cited text;
this prefix string is specified by the variable message-yank-prefix. If you call
message-yank-original with a prefix argument, the citation prefix is not inserted.
After using C-c C-y, you can type C-c C-q (message-fill-yanked-message) to
fill the paragraphs of the cited message. One use of C-c C-q fills all such paragraphs,
each one individually. To fill a single paragraph of the quoted message, use M-q. If
filling does not automatically handle the type of citation prefix you use, try setting
the fill prefix explicitly. See Section 22.5 [Filling], page 218.
You can customize mail citation through the hook mail-citation-hook. For
example, you can use the Supercite package, which provides more flexible citation
(see Section “Introduction” in Supercite).
29.4.4 Mail Miscellany
You can attach a file to an outgoing message by typing C-c C-a (mml-attachfile) in the mail buffer. Attaching is done using the Multipurpose Internet Mail
Extensions (MIME) standard.
The mml-attach-file command prompts for the name of the file, and for the
attachment’s content type, description, and disposition. The content type is normally detected automatically; just type RET to accept the default. The description
is a single line of text that the recipient will see next to the attachment; you may
also choose to leave this empty. The disposition is either ‘inline’ (the default),
which means the recipient will see a link to the attachment within the message
body, or ‘attachment’, which means the link will be separate from the body.
The mml-attach-file command is specific to Message mode; in Mail mode use
mail-add-attachment instead. It will prompt only for the name of the file, and
will determine the content type and the disposition automatically. If you want to
include some description of the attached file, type that in the message body.
The actual contents of the attached file are not inserted into the mail buffer.
Instead, some placeholder text is inserted into the mail buffer, like this:
<#part type="text/plain" filename="~/foo.txt" disposition=inline>
<#/part>

When you type C-c C-c or C-c C-s to send the message, the attached file will be
delivered with it.
While composing a message, you can do spelling correction on the message text
by typing M-x ispell-message. If you have yanked an incoming message into the

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outgoing draft, this command skips what was yanked, but it checks the text that
you yourself inserted (it looks for indentation or mail-yank-prefix to distinguish
the cited lines from your input). See Section 13.4 [Spelling], page 112.
Turning on Message mode (which C-x m does automatically) runs the normal
hooks text-mode-hook and message-mode-hook. Initializing a new outgoing message runs the normal hook message-setup-hook; you can use this hook if you want
to make changes to the appearance of the mail buffer. See Section 33.2.2 [Hooks],
page 445.
The main difference between these hooks is just when they are invoked. Whenever you type C-x m, message-mode-hook runs as soon as the mail buffer is created.
Then the message-setup function inserts the default contents of the buffer. After
these default contents are inserted, message-setup-hook runs.
If you use C-x m to continue an existing composition, message-mode-hook runs
immediately after switching to the mail buffer. If the buffer is unmodified, or if
you decide to erase it and start again, message-setup-hook runs after the default
contents are inserted.

29.5 Mail Signature
You can add a standard piece of text—your mail signature—to the end of every
message. This signature may contain information such as your telephone number
or your physical location. The variable mail-signature determines how Emacs
handles the mail signature.
The default value of mail-signature is t; this means to look for your mail
signature in the file ‘~/.signature’. If this file exists, its contents are automatically
inserted into the end of the mail buffer. You can change the signature file via the
variable mail-signature-file.
If you change mail-signature to a string, that specifies the text of the signature
directly.
If you change mail-signature to nil, Emacs will not insert your mail signature
automatically. You can insert your mail signature by typing C-c C-w (messageinsert-signature) in the mail buffer. Emacs will look for your signature in the
signature file.
By convention, a mail signature should be marked by a line whose contents are
‘-- ’. If your signature lacks this prefix, it is added for you. The remainder of your
signature should be no more than four lines.

29.6 Mail Amusements
M-x spook adds a line of randomly chosen keywords to an outgoing mail message.
The keywords are chosen from a list of words that suggest you are discussing something subversive.
The idea behind this feature is the suspicion that the NSA1 and other intelligence
agencies snoop on all electronic mail messages that contain keywords suggesting
1

The US National Security Agency.

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they might find them interesting. (The agencies say that they don’t, but that’s
what they would say.) The idea is that if lots of people add suspicious words to
their messages, the agencies will get so busy with spurious input that they will have
to give up reading it all. Whether or not this is true, it at least amuses some people.
You can use the fortune program to put a “fortune cookie” message into outgoing mail. To do this, add fortune-to-signature to mail-setup-hook:
(add-hook ’mail-setup-hook ’fortune-to-signature)
You will probably need to set the variable fortune-file before using this.

29.7 Mail-Composition Methods
In this chapter we have described the usual Emacs mode for editing and sending
mail—Message mode. This is only one of several available modes. Prior to Emacs
23.2, the default mode was Mail mode, which is similar to Message mode in many
respects but lacks features such as MIME support. Another available mode is MH-E
(see Section “MH-E” in The Emacs Interface to MH ).
You can choose any of these mail user agents as your preferred method for editing
and sending mail. The commands C-x m, C-x 4 m and C-x 5 m use whichever agent
you have specified; so do various other parts of Emacs that send mail, such as the bug
reporter (see Section 34.3 [Bugs], page 473). To specify a mail user agent, customize
the variable mail-user-agent. Currently, legitimate values include message-useragent (Message mode) sendmail-user-agent (Mail mode), gnus-user-agent, and
mh-e-user-agent.
If you select a different mail-composition method, the information in this chapter
about the mail buffer and Message mode does not apply; the other methods use a
different format of text in a different buffer, and their commands are different as
well.
Similarly, to specify your preferred method for reading mail, customize the variable read-mail-command. The default is rmail (see Chapter 30 [Rmail], page 376).

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30 Reading Mail with Rmail
Rmail is an Emacs subsystem for reading and disposing of mail that you receive.
Rmail stores mail messages in files called Rmail files. Reading the messages in an
Rmail file is done in a special major mode, Rmail mode, which redefines most letters
to run commands for managing mail.

30.1 Basic Concepts of Rmail
Using Rmail in the simplest fashion, you have one Rmail file ‘~/RMAIL’ in which
all of your mail is saved. It is called your primary Rmail file. The command M-x
rmail reads your primary Rmail file, merges new mail in from your inboxes, displays
the first message you haven’t read yet, and lets you begin reading. The variable
rmail-file-name specifies the name of the primary Rmail file.
Rmail displays only one message in the Rmail file at a time. The message that
is shown is called the current message. Rmail mode’s special commands can do
such things as delete the current message, copy it into another file, send a reply, or
move to another message. You can also create multiple Rmail files and use Rmail
to move messages between them.
Within the Rmail file, messages are normally arranged sequentially in order of
receipt; you can specify other ways to sort them (see Section 30.12 [Rmail Sorting],
page 390). Messages are identified by consecutive integers which are their message
numbers. The number of the current message is displayed in Rmail’s mode line,
followed by the total number of messages in the file. You can move to a message
by specifying its message number with the j key (see Section 30.3 [Rmail Motion],
page 377).
Following the usual conventions of Emacs, changes in an Rmail file become
permanent only when you save the file. You can save it with s (rmail-expungeand-save), which also expunges deleted messages from the file first (see Section 30.4
[Rmail Deletion], page 378). To save the file without expunging, use C-x C-s. Rmail
also saves the Rmail file after merging new mail from an inbox file (see Section 30.5
[Rmail Inbox], page 379).
You can exit Rmail with q (rmail-quit); this expunges and saves the Rmail
file, then buries the Rmail buffer as well as its summary buffer, if present (see
Section 30.11 [Rmail Summary], page 386). But there is no need to “exit” formally.
If you switch from Rmail to editing in other buffers, and never switch back, you have
exited. Just make sure to save the Rmail file eventually (like any other file you have
changed). C-x s is a suitable way to do this (see Section 15.3.1 [Save Commands],
page 128). The Rmail command b, rmail-bury, buries the Rmail buffer and its
summary without expunging and saving the Rmail file.

30.2 Scrolling Within a Message
When Rmail displays a message that does not fit on the screen, you must scroll
through it to read the rest. You could do this with C-v, M-v and M-<, but in Rmail
scrolling is so frequent that it deserves to be easier.

Chapter 30: Reading Mail with Rmail
SPC

Scroll forward (scroll-up-command).

DEL

Scroll backward (scroll-down-command).

.

Scroll to start of message (rmail-beginning-of-message).

/

Scroll to end of message (rmail-end-of-message).

377

Since the most common thing to do while reading a message is to scroll through it
by screenfuls, Rmail makes SPC and DEL do the same as C-v (scroll-up-command)
and M-v (scroll-down-command) respectively.
The command . (rmail-beginning-of-message) scrolls back to the beginning
of the selected message. This is not quite the same as M-<: for one thing, it does
not set the mark; for another, it resets the buffer boundaries of the current message
if you have changed them. Similarly, the command / (rmail-end-of-message)
scrolls forward to the end of the selected message.

30.3 Moving Among Messages
The most basic thing to do with a message is to read it. The way to do this in Rmail
is to make the message current. The usual practice is to move sequentially through
the file, since this is the order of receipt of messages. When you enter Rmail, you are
positioned at the first message that you have not yet made current (that is, the first
one that has the ‘unseen’ attribute; see Section 30.9 [Rmail Attributes], page 384).
Move forward to see the other new messages; move backward to re-examine old
messages.
n

Move to the next nondeleted message, skipping any intervening deleted
messages (rmail-next-undeleted-message).

p

Move to the previous nondeleted message (rmail-previousundeleted-message).

M-n

Move to the next message, including deleted messages (rmail-nextmessage).

M-p

Move to the previous message, including deleted messages (rmailprevious-message).

C-c C-n

Move to the next message with the same subject as the current one
(rmail-next-same-subject).

C-c C-p

Move to the previous message with the same subject as the current
one (rmail-previous-same-subject).

j

Move to the first message. With argument n, move to message number
n (rmail-show-message).

>

Move to the last message (rmail-last-message).

<

Move to the first message (rmail-first-message).

M-s regexp RET
Move to the next message containing a match for regexp (rmailsearch).

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- M-s regexp RET
Move to the previous message containing a match for regexp.
n and p are the usual way of moving among messages in Rmail. They move
through the messages sequentially, but skip over deleted messages, which is usually what you want to do. Their command definitions are named rmail-nextundeleted-message and rmail-previous-undeleted-message. If you do not
want to skip deleted messages—for example, if you want to move to a message
to undelete it—use the variants M-n and M-p (rmail-next-message and rmailprevious-message). A numeric argument to any of these commands serves as a
repeat count.
In Rmail, you can specify a numeric argument by typing just the digits. You
don’t need to type C-u first.
The M-s (rmail-search) command is Rmail’s version of search. The usual
incremental search command C-s works in Rmail, but it searches only within the
current message. The purpose of M-s is to search for another message. It reads
a regular expression (see Section 12.5 [Regexps], page 97) nonincrementally, then
searches starting at the beginning of the following message for a match. It then
selects that message. If regexp is empty, M-s reuses the regexp used the previous
time.
To search backward in the file for another message, give M-s a negative argument.
In Rmail you can do this with - M-s. This begins searching from the end of the
previous message.
It is also possible to search for a message based on labels. See Section 30.8
[Rmail Labels], page 383.
The C-c C-n (rmail-next-same-subject) command moves to the next message with the same subject as the current one. A prefix argument serves as a
repeat count. With a negative argument, this command moves backward, acting
like C-c C-p (rmail-previous-same-subject). When comparing subjects, these
commands ignore the prefixes typically added to the subjects of replies.
To move to a message specified by absolute message number, use j (rmail-showmessage) with the message number as argument. With no argument, j selects the
first message. < (rmail-first-message) also selects the first message. > (rmaillast-message) selects the last message.

30.4 Deleting Messages
When you no longer need to keep a message, you can delete it. This flags it as
ignorable, and some Rmail commands pretend it is no longer present; but it still
has its place in the Rmail file, and still has its message number.
Expunging the Rmail file actually removes the deleted messages. The remaining
messages are renumbered consecutively.
d

Delete the current message, and move to the next nondeleted message
(rmail-delete-forward).

C-d

Delete the current message, and move to the previous nondeleted message (rmail-delete-backward).

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u

Undelete the current message, or move back to the previous deleted
message and undelete it (rmail-undelete-previous-message).

x

Expunge the Rmail file (rmail-expunge).

There are two Rmail commands for deleting messages. Both delete the current
message and select another. d (rmail-delete-forward) moves to the following
message, skipping messages already deleted, while C-d (rmail-delete-backward)
moves to the previous nondeleted message. If there is no nondeleted message to
move to in the specified direction, the message that was just deleted remains current.
d with a prefix argument is equivalent to C-d. Note that the Rmail summary
versions of these commands behave slightly differently (see Section 30.11.2 [Rmail
Summary Edit], page 388).
Whenever Rmail deletes a message, it runs the hook rmail-delete-messagehook. When the hook functions are invoked, the message has been marked deleted,
but it is still the current message in the Rmail buffer.
To make all the deleted messages finally vanish from the Rmail file, type x
(rmail-expunge). Until you do this, you can still undelete the deleted messages.
The undeletion command, u (rmail-undelete-previous-message), is designed to
cancel the effect of a d command in most cases. It undeletes the current message if
the current message is deleted. Otherwise it moves backward to previous messages
until a deleted message is found, and undeletes that message.
You can usually undo a d with a u because the u moves back to and undeletes
the message that the d deleted. But this does not work when the d skips a few
already-deleted messages that follow the message being deleted; then the u command undeletes the last of the messages that were skipped. There is no clean way to
avoid this problem. However, by repeating the u command, you can eventually get
back to the message that you intend to undelete. You can also select a particular
deleted message with the M-p command, then type u to undelete it.
A deleted message has the ‘deleted’ attribute, and as a result ‘deleted’ appears
in the mode line when the current message is deleted. In fact, deleting or undeleting
a message is nothing more than adding or removing this attribute. See Section 30.9
[Rmail Attributes], page 384.

30.5 Rmail Files and Inboxes
When you receive mail locally, the operating system places incoming mail for you
in a file that we call your inbox. When you start up Rmail, it runs a C program
called movemail to copy the new messages from your local inbox into your primary
Rmail file, which also contains other messages saved from previous Rmail sessions.
It is in this file that you actually read the mail with Rmail. This operation is called
getting new mail. You can get new mail at any time in Rmail by typing g.
The variable rmail-primary-inbox-list contains a list of the files that are
inboxes for your primary Rmail file. If you don’t set this variable explicitly,
Rmail uses the MAIL environment variable, or, as a last resort, a default inbox
based on rmail-spool-directory. The default inbox file depends on your oper-

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ating system; often it is ‘/var/mail/username ’, ‘/var/spool/mail/username ’, or
‘/usr/spool/mail/username ’.
You can specify the inbox file(s) for any Rmail file for the current session with
the command set-rmail-inbox-list; see Section 30.6 [Rmail Files], page 380.
There are two reasons for having separate Rmail files and inboxes.
1. The inbox file format varies between operating systems and according to the
other mail software in use. Only one part of Rmail needs to know about the
alternatives, and it need only understand how to convert all of them to Rmail’s
own format.
2. It is very cumbersome to access an inbox file without danger of losing mail,
because it is necessary to interlock with mail delivery. Moreover, different
operating systems use different interlocking techniques. The strategy of moving
mail out of the inbox once and for all into a separate Rmail file avoids the need
for interlocking in all the rest of Rmail, since only Rmail operates on the Rmail
file.
Rmail was originally written to use the Babyl format as its internal format.
Since then, we have recognized that the usual inbox format (‘mbox’) on Unix and
GNU systems is adequate for the job, and so since Emacs 23 Rmail uses that as
its internal format. The Rmail file is still separate from the inbox file, even though
their format is the same.
When getting new mail, Rmail first copies the new mail from the inbox file to
the Rmail file; then it saves the Rmail file; then it clears out the inbox file. This way,
a system crash may cause duplication of mail between the inbox and the Rmail file,
but cannot lose mail. If rmail-preserve-inbox is non-nil, then Rmail does not
clear out the inbox file when it gets new mail. You may wish to set this, for example,
on a portable computer you use to check your mail via POP while traveling, so that
your mail will remain on the server and you can save it later on your workstation.
In some cases, Rmail copies the new mail from the inbox file indirectly. First it
runs the movemail program to move the mail from the inbox to an intermediate file
called ‘.newmail-inboxname ’, in the same directory as the Rmail file. Then Rmail
merges the new mail from that file, saves the Rmail file, and only then deletes the
intermediate file. If there is a crash at the wrong time, this file continues to exist,
and Rmail will use it again the next time it gets new mail from that inbox.
If Rmail is unable to convert the data in ‘.newmail-inboxname ’ into mbox
format, it renames the file to ‘RMAILOSE.n ’ (n is an integer chosen to make the
name unique) so that Rmail will not have trouble with the data again. You should
look at the file, find whatever message confuses Rmail (probably one that includes
the control-underscore character, octal code 037), and delete it. Then you can use
1 g to get new mail from the corrected file.

30.6 Multiple Rmail Files
Rmail operates by default on your primary Rmail file, which is named ‘~/RMAIL’ and
receives your incoming mail from your system inbox file. But you can also have other
Rmail files and edit them with Rmail. These files can receive mail through their

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own inboxes, or you can move messages into them with explicit Rmail commands
(see Section 30.7 [Rmail Output], page 381).
i file RET Read file into Emacs and run Rmail on it (rmail-input).
M-x set-rmail-inbox-list RET files RET
Specify inbox file names for current Rmail file to get mail from.
g

Merge new mail from current Rmail file’s inboxes (rmail-get-newmail).

C-u g file RET
Merge new mail from inbox file file.
To run Rmail on a file other than your primary Rmail file, you can use the i
(rmail-input) command in Rmail. This visits the file in Rmail mode. You can use
M-x rmail-input even when not in Rmail, but it is easier to type C-u M-x rmail,
which does the same thing.
The file you read with i should normally be a valid mbox file. If it is not, Rmail
tries to convert its text to mbox format, and visits the converted text in the buffer.
If you save the buffer, that converts the file.
If you specify a file name that doesn’t exist, i initializes a new buffer for creating
a new Rmail file.
You can also select an Rmail file from a menu. In the Classify menu, choose
the Input Rmail File item; then choose the Rmail file you want. The variables
rmail-secondary-file-directory and rmail-secondary-file-regexp specify
which files to offer in the menu: the first variable says which directory to find
them in; the second says which files in that directory to offer (all those that match
the regular expression). If no files match, you cannot select this menu item. These
variables also apply to choosing a file for output (see Section 30.7 [Rmail Output],
page 381).
The inbox files to use are specified by the variable rmail-inbox-list, which is
buffer-local in Rmail mode. As a special exception, if you have specified no inbox
files for your primary Rmail file, it uses the MAIL environment variable, or your
standard system inbox.
The g command (rmail-get-new-mail) merges mail into the current Rmail file
from its inboxes. If the Rmail file has no inboxes, g does nothing. The command
M-x rmail also merges new mail into your primary Rmail file.
To merge mail from a file that is not the usual inbox, give the g key a numeric
argument, as in C-u g. Then it reads a file name and merges mail from that file.
The inbox file is not deleted or changed in any way when g with an argument is
used. This is, therefore, a general way of merging one file of messages into another.

30.7 Copying Messages Out to Files
These commands copy messages from an Rmail file into another file.
o file RET Append a full copy of the current message to the file file (rmailoutput).

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C-o file RET
Append a copy of the current message, as displayed, to the file file
(rmail-output-as-seen).
w file RET Output just the message body to the file file, taking the default file
name from the message ‘Subject’ header.
The commands o and C-o copy the current message into a specified file, adding
it at the end. The two commands differ mainly in how much to copy: o copies
the full message headers, even if they are not all visible, while C-o copies exactly
the headers currently displayed and no more. See Section 30.13 [Rmail Display],
page 391. In addition, o converts the message to Babyl format (used by Rmail in
Emacs version 22 and before) if the file is in Babyl format; C-o cannot output to
Babyl files at all.
If the output file is currently visited in an Emacs buffer, the output commands
append the message to that buffer. It is up to you to save the buffer eventually in
its file.
Sometimes you may receive a message whose body holds the contents of a file.
You can save the body to a file (excluding the message header) with the w command
(rmail-output-body-to-file). Often these messages contain the intended file
name in the ‘Subject’ field, so the w command uses the ‘Subject’ field as the default
for the output file name. However, the file name is read using the minibuffer, so
you can specify a different name if you wish.
You can also output a message to an Rmail file chosen with a menu. In the
Classify menu, choose the Output Rmail File menu item; then choose the Rmail file
you want. This outputs the current message to that file, like the o command. The
variables rmail-secondary-file-directory and rmail-secondary-file-regexp
specify which files to offer in the menu: the first variable says which directory to
find them in; the second says which files in that directory to offer (all those that
match the regular expression). If no files match, you cannot select this menu item.
Copying a message with o or C-o gives the original copy of the message the
‘filed’ attribute, so that ‘filed’ appears in the mode line when such a message is
current.
If you like to keep just a single copy of every mail message, set the variable
rmail-delete-after-output to t; then the o, C-o and w commands delete the
original message after copying it. (You can undelete it afterward if you wish.)
The variable rmail-output-file-alist lets you specify intelligent defaults for
the output file, based on the contents of the current message. The value should be
a list whose elements have this form:
(regexp . name-exp )
If there’s a match for regexp in the current message, then the default file name for
output is name-exp. If multiple elements match the message, the first matching
element decides the default file name. The subexpression name-exp may be a string
constant giving the file name to use, or more generally it may be any Lisp expression
that returns a file name as a string. rmail-output-file-alist applies to both o
and C-o.

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Rmail can automatically save messages from your primary Rmail file (the one
that rmail-file-name specifies) to other files, based on the value of the variable rmail-automatic-folder-directives. This variable is a list of elements
(‘directives’) that say which messages to save where. Each directive is a list
consisting of an output file, followed by one or more pairs of a header name and
a regular expression. If a message has a header matching the specified regular expression, that message is saved to the given file. If the directive has more than
one header entry, all must match. Rmail checks directives when it shows a message
from the file rmail-file-name, and applies the first that matches (if any). If the
output file is nil, the message is deleted, not saved. For example, you can use this
feature to save messages from a particular address, or with a particular subject, to
a dedicated file.

30.8 Labels
Each message can have various labels assigned to it as a means of classification.
Each label has a name; different names are different labels. Any given label is
either present or absent on a particular message. A few label names have standard
meanings and are given to messages automatically by Rmail when appropriate; these
special labels are called attributes. All other labels are assigned only by users.
a label RET
Assign the label label to the current message (rmail-add-label).
k label RET
Remove the label label from the current message (rmail-kill-label).
C-M-n labels RET
Move to the next message that has one of the labels labels (rmailnext-labeled-message).
C-M-p labels RET
Move to the previous message that has one of the labels labels (rmailprevious-labeled-message).
l labels RET
C-M-l labels RET
Make a summary of all messages containing any of the labels labels
(rmail-summary-by-labels).
The a (rmail-add-label) and k (rmail-kill-label) commands allow you to
assign or remove any label on the current message. If the label argument is empty,
it means to assign or remove the same label most recently assigned or removed.
Once you have given messages labels to classify them as you wish, there are
three ways to use the labels: in moving, in summaries, and in sorting.
C-M-n labels RET (rmail-next-labeled-message) moves to the next message
that has one of the labels labels. The argument labels specifies one or more label names, separated by commas. C-M-p (rmail-previous-labeled-message) is
similar, but moves backwards to previous messages. A numeric argument to either
command serves as a repeat count.

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The command C-M-l labels RET (rmail-summary-by-labels) displays a summary containing only the messages that have at least one of a specified set of labels. The argument labels is one or more label names, separated by commas. See
Section 30.11 [Rmail Summary], page 386, for information on summaries.
If the labels argument to C-M-n, C-M-p or C-M-l is empty, it means to use the
last set of labels specified for any of these commands.
See Section 30.12 [Rmail Sorting], page 390, for information on sorting messages
with labels.

30.9 Rmail Attributes
Some labels such as ‘deleted’ and ‘filed’ have built-in meanings, and Rmail assigns them to messages automatically at appropriate times; these labels are called
attributes. Here is a list of Rmail attributes:
‘unseen’

Means the message has never been current. Assigned to messages when
they come from an inbox file, and removed when a message is made
current. When you start Rmail, it initially shows the first message
that has this attribute.

‘deleted’

Means the message is deleted. Assigned by deletion commands and
removed by undeletion commands (see Section 30.4 [Rmail Deletion],
page 378).

‘filed’

Means the message has been copied to some other file. Assigned by
the o and C-o file output commands (see Section 30.7 [Rmail Output],
page 381).

‘answered’

Means you have mailed an answer to the message. Assigned by the r
command (rmail-reply). See Section 30.10 [Rmail Reply], page 385.

‘forwarded’
Means you have forwarded the message. Assigned by the f command
(rmail-forward). See Section 30.10 [Rmail Reply], page 385.
‘edited’

Means you have edited the text of the message within Rmail. See
Section 30.15 [Rmail Editing], page 392.

‘resent’

Means you have resent the message. Assigned by the command M-x
rmail-resend. See Section 30.10 [Rmail Reply], page 385.

‘retried’

Means you have retried a failed outgoing message. Assigned by the
command M-x rmail-retry-failure. See Section 30.10 [Rmail Reply], page 385.

All other labels are assigned or removed only by users, and have no standard
meaning.

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30.10 Sending Replies
Rmail has several commands to send outgoing mail. See Chapter 29 [Sending Mail],
page 367, for information on using Message mode, including certain features meant
to work with Rmail. What this section documents are the special commands of
Rmail for entering the mail buffer. Note that the usual keys for sending mail—C-x
m, C-x 4 m, and C-x 5 m—also work normally in Rmail mode.
m

Send a message (rmail-mail).

c

Continue editing the already started outgoing message (rmailcontinue).

r

Send a reply to the current Rmail message (rmail-reply).

f

Forward the current message to other users (rmail-forward).

C-u f

Resend the current message to other users (rmail-resend).

M-m

Try sending a bounced message a second time (rmail-retryfailure).

The most common reason to send a message while in Rmail is to reply to the
message you are reading. To do this, type r (rmail-reply). This displays a mail
composition buffer in another window, much like C-x 4 m, but preinitializes the
‘Subject’, ‘To’, ‘CC’, ‘In-reply-to’ and ‘References’ header fields based on the
message you are replying to. The ‘To’ field starts out as the address of the person
who sent the message you received, and the ‘CC’ field starts out with all the other
recipients of that message.
You can exclude certain recipients from being included automatically in replies,
using the variable mail-dont-reply-to-names. Its value should be a regular expression; any recipients that match are excluded from the ‘CC’ field. They are also
excluded from the ‘To’ field, unless this would leave the field empty. If this variable
is nil, then the first time you compose a reply it is initialized to a default value that
matches your own address.
To omit the ‘CC’ field completely for a particular reply, enter the reply command
with a numeric argument: C-u r or 1 r. This means to reply only to the sender of
the original message.
Once the mail composition buffer has been initialized, editing and sending the
mail goes as usual (see Chapter 29 [Sending Mail], page 367). You can edit the
presupplied header fields if they are not what you want. You can also use commands such as C-c C-y, which yanks in the message that you are replying to (see
Section 29.4 [Mail Commands], page 370). You can also switch to the Rmail buffer,
select a different message there, switch back, and yank the new current message.
Sometimes a message does not reach its destination. Mailers usually send the
failed message back to you, enclosed in a failure message. The Rmail command M-m
(rmail-retry-failure) prepares to send the same message a second time: it sets
up a mail composition buffer with the same text and header fields as before. If you
type C-c C-c right away, you send the message again exactly the same as the first
time. Alternatively, you can edit the text or headers and then send it. The variable

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rmail-retry-ignored-headers, in the same format as rmail-ignored-headers
(see Section 30.13 [Rmail Display], page 391), controls which headers are stripped
from the failed message when retrying it.
Another frequent reason to send mail in Rmail is to forward the current message
to other users. f (rmail-forward) makes this easy by preinitializing the mail
composition buffer with the current message as the text, and a subject of the form
[from : subject ], where from and subject are the sender and subject of the original
message. All you have to do is fill in the recipients and send. When you forward a
message, recipients get a message which is “from” you, and which has the original
message in its contents.
Rmail offers two formats for forwarded messages. The default is to use MIME
(see Section 30.13 [Rmail Display], page 391) format. This includes the original
message as a separate part. You can use a simpler format if you prefer, by setting the
variable rmail-enable-mime-composing to nil. In this case, Rmail just includes
the original message enclosed between two delimiter lines. It also modifies every
line that starts with a dash, by inserting ‘- ’ at the start of the line. When you
receive a forwarded message in this format, if it contains something besides ordinary
text—for example, program source code—you might find it useful to undo that
transformation. You can do this by selecting the forwarded message and typing
M-x unforward-rmail-message. This command extracts the original forwarded
message, deleting the inserted ‘- ’ strings, and inserts it into the Rmail file as a
separate message immediately following the current one.
Resending is an alternative similar to forwarding; the difference is that resending
sends a message that is “from” the original sender, just as it reached you—with a
few added header fields (‘Resent-From’ and ‘Resent-To’) to indicate that it came
via you. To resend a message in Rmail, use C-u f. (f runs rmail-forward, which
invokes rmail-resend if you provide a numeric argument.)
Use the m (rmail-mail) command to start editing an outgoing message that is
not a reply. It leaves the header fields empty. Its only difference from C-x 4 m is
that it makes the Rmail buffer accessible for C-c C-y, just as r does.
The c (rmail-continue) command resumes editing the mail composition buffer,
to finish editing an outgoing message you were already composing, or to alter a
message you have sent.
If you set the variable rmail-mail-new-frame to a non-nil value, then all the
Rmail commands to start sending a message create a new frame to edit it in. This
frame is deleted when you send the message.
All the Rmail commands to send a message use the mail-composition method
that you have chosen (see Section 29.7 [Mail Methods], page 375).

30.11 Summaries
A summary is a buffer containing one line per message to give you an overview of
the mail in an Rmail file. Each line shows the message number and date, the sender,
the line count, the labels, and the subject. Moving point in the summary buffer
selects messages as you move to their summary lines. Almost all Rmail commands

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are valid in the summary buffer also; when used there, they apply to the message
described by the current line of the summary.
A summary buffer applies to a single Rmail file only; if you are editing multiple
Rmail files, each one can have its own summary buffer. The summary buffer name
is made by appending ‘-summary’ to the Rmail buffer’s name. Normally only one
summary buffer is displayed at a time.
30.11.1 Making Summaries
Here are the commands to create a summary for the current Rmail buffer. Once
the Rmail buffer has a summary, changes in the Rmail buffer (such as deleting or
expunging messages, and getting new mail) automatically update the summary.
h
C-M-h

Summarize all messages (rmail-summary).

l labels RET
C-M-l labels RET
Summarize messages that have one or more of the specified labels
(rmail-summary-by-labels).
C-M-r rcpts RET
Summarize messages that match the specified recipients (rmailsummary-by-recipients).
C-M-t topic RET
Summarize messages that have a match for the specified regexp topic
in their subjects (rmail-summary-by-topic).
C-M-s regexp RET
Summarize messages whose headers match the specified regular expression regexp (rmail-summary-by-regexp).
C-M-f senders RET
Summarize messages that match the specified senders.
summary-by-senders).

(rmail-

The h or C-M-h (rmail-summary) command fills the summary buffer for the
current Rmail buffer with a summary of all the messages in the buffer. It then
displays and selects the summary buffer in another window.
C-M-l labels RET (rmail-summary-by-labels) makes a partial summary mentioning only the messages that have one or more of the labels labels. labels should
contain label names separated by commas.
C-M-r rcpts RET (rmail-summary-by-recipients) makes a partial summary
mentioning only the messages that have one or more recipients matching the regular expression rcpts. You can use commas to separate multiple regular expressions.
These are matched against the ‘To’, ‘From’, and ‘CC’ headers (supply a prefix argument to exclude this header).
C-M-t topic RET (rmail-summary-by-topic) makes a partial summary mentioning only the messages whose subjects have a match for the regular expression

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topic. You can use commas to separate multiple regular expressions. With a prefix
argument, the match is against the whole message, not just the subject.
C-M-s regexp RET (rmail-summary-by-regexp) makes a partial summary that
mentions only the messages whose headers (including the date and the subject lines)
match the regular expression regexp.
C-M-f senders RET (rmail-summary-by-senders) makes a partial summary
that mentions only the messages whose ‘From’ fields match the regular expression
senders. You can use commas to separate multiple regular expressions.
Note that there is only one summary buffer for any Rmail buffer; making any
kind of summary discards any previous summary.
The variable rmail-summary-window-size says how many lines to use for
the summary window. The variable rmail-summary-line-count-flag controls
whether the summary line for a message should include the line count of the message. Setting this option to nil might speed up the generation of summaries.
30.11.2 Editing in Summaries
You can use the Rmail summary buffer to do almost anything you can do in the
Rmail buffer itself. In fact, once you have a summary buffer, there’s no need to
switch back to the Rmail buffer.
You can select and display various messages in the Rmail buffer, from the summary buffer, just by moving point in the summary buffer to different lines. It doesn’t
matter what Emacs command you use to move point; whichever line point is on at
the end of the command, that message is selected in the Rmail buffer.
Almost all Rmail commands work in the summary buffer as well as in the Rmail
buffer. Thus, d in the summary buffer deletes the current message, u undeletes,
and x expunges. (However, in the summary buffer, a numeric argument to d, C-d
and u serves as a repeat count. A negative argument reverses the meaning of d and
C-d. Also, if there are no more undeleted messages in the relevant direction, the
delete commands go to the first or last message, rather than staying on the current
message.) o and C-o output the current message to a FILE; r starts a reply to
it; etc. You can scroll the current message while remaining in the summary buffer
using SPC and DEL.
M-u (rmail-summary-undelete-many) undeletes all deleted messages in the
summary. A prefix argument means to undelete that many of the previous deleted
messages.
The Rmail commands to move between messages also work in the summary
buffer, but with a twist: they move through the set of messages included in the
summary. They also ensure the Rmail buffer appears on the screen (unlike cursor
motion commands, which update the contents of the Rmail buffer but don’t display
it in a window unless it already appears). Here is a list of these commands:
n

Move to next line, skipping lines saying ‘deleted’, and select its message
(rmail-summary-next-msg).

p

Move to previous line, skipping lines saying ‘deleted’, and select its
message (rmail-summary-previous-msg).

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M-n

Move to next line and select its message (rmail-summary-next-all).

M-p

Move to previous line and select its message (rmail-summaryprevious-all).

>

Move to the last line, and select its message (rmail-summary-lastmessage).

<

Move to the first line, and select its message (rmail-summary-firstmessage).

j
RET

Select the message on the current line (ensuring that the Rmail buffer
appears on the screen; rmail-summary-goto-msg). With argument n,
select message number n and move to its line in the summary buffer;
this signals an error if the message is not listed in the summary buffer.

M-s pattern RET
Search through messages for pattern starting with the current message; select the message found, and move point in the summary buffer
to that message’s line (rmail-summary-search). A prefix argument
acts as a repeat count; a negative argument means search backward
(equivalent to rmail-summary-search-backward.)
C-M-n labels RET
Move to the next message with at least one of the specified labels (rmail-summary-next-labeled-message). labels is a commaseparated list of labels. A prefix argument acts as a repeat count.
C-M-p labels RET
Move to the previous message with at least one of the specified labels
(rmail-summary-previous-labeled-message).
C-c C-n RET
Move to the next message with the same subject as the current message
(rmail-summary-next-same-subject). A prefix argument acts as a
repeat count.
C-c C-p RET
Move to the previous message with the same subject as the current
message (rmail-summary-previous-same-subject).
Deletion, undeletion, and getting new mail, and even selection of a different
message all update the summary buffer when you do them in the Rmail buffer.
If the variable rmail-redisplay-summary is non-nil, these actions also bring the
summary buffer back onto the screen.
When you are finished using the summary, type Q (rmail-summary-wipe) to
delete the summary buffer’s window. You can also exit Rmail while in the summary:
q (rmail-summary-quit) deletes the summary window, then exits from Rmail by
saving the Rmail file and switching to another buffer. Alternatively, b (rmailsummary-bury) simply buries the Rmail summary and buffer.

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30.12 Sorting the Rmail File
C-c C-s C-d
M-x rmail-sort-by-date
Sort messages of current Rmail buffer by date.
C-c C-s C-s
M-x rmail-sort-by-subject
Sort messages of current Rmail buffer by subject.
C-c C-s C-a
M-x rmail-sort-by-author
Sort messages of current Rmail buffer by author’s name.
C-c C-s C-r
M-x rmail-sort-by-recipient
Sort messages of current Rmail buffer by recipient’s names.
C-c C-s C-c
M-x rmail-sort-by-correspondent
Sort messages of current Rmail buffer by the name of the other correspondent.
C-c C-s C-l
M-x rmail-sort-by-lines
Sort messages of current Rmail buffer by number of lines.
C-c C-s C-k RET labels RET
M-x rmail-sort-by-labels RET labels RET
Sort messages of current Rmail buffer by labels. The argument labels
should be a comma-separated list of labels. The order of these labels
specifies the order of messages; messages with the first label come first,
messages with the second label come second, and so on. Messages that
have none of these labels come last.
The Rmail sort commands perform a stable sort: if there is no reason to prefer
either one of two messages, their order remains unchanged. You can use this to sort
by more than one criterion. For example, if you use rmail-sort-by-date and then
rmail-sort-by-author, messages from the same author appear in order by date.
With a prefix argument, all these commands reverse the order of comparison.
This means they sort messages from newest to oldest, from biggest to smallest, or
in reverse alphabetical order.
The same keys in the summary buffer run similar functions; for example, C-c C-s
C-l runs rmail-summary-sort-by-lines. Note that these commands always sort
the whole Rmail buffer, even if the summary is only showing a subset of messages.
Note that you cannot undo a sort, so you may wish to save the Rmail buffer
before sorting it.

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30.13 Display of Messages
This section describes how Rmail displays mail headers, MIME sections and attachments, URLs, and encrypted messages.
t

Toggle display of complete header (rmail-toggle-header).

Before displaying each message for the first time, Rmail reformats its header,
hiding uninteresting header fields to reduce clutter. The t (rmail-toggle-header)
command toggles this, switching between showing the reformatted header fields
and showing the complete, original header. With a positive prefix argument, the
command shows the reformatted header; with a zero or negative prefix argument,
it shows the full header. Selecting the message again also reformats it if necessary.
The variable rmail-ignored-headers holds a regular expression specifying the
header fields to hide; any matching header line will be hidden. The variable rmailnonignored-headers overrides this: any header field matching that regular expression is shown even if it matches rmail-ignored-headers too. The variable
rmail-displayed-headers is an alternative to these two variables; if non-nil, this
should be a regular expression specifying which headers to display (the default is
nil).
Rmail highlights certain header fields that are especially interesting—by default,
the ‘From’ and ‘Subject’ fields. This highlighting uses the rmail-highlight face.
The variable rmail-highlighted-headers holds a regular expression specifying the
header fields to highlight; if it matches the beginning of a header field, that whole
field is highlighted. To disable this feature, set rmail-highlighted-headers to
nil.
If a message is in MIME (Multipurpose Internet Mail Extensions) format and
contains multiple parts (MIME entities), Rmail displays each part with a tagline.
The tagline summarizes the part’s index, size, and content type. Depending on the
content type, it may also contain one or more buttons; these perform actions such
as saving the part into a file.
RET

Hide or show the MIME part at point (rmail-mime-toggle-hidden).

TAB

Move point to the next MIME tagline button. (rmail-mime-nextitem).

S-TAB

Move point to the previous MIME part (rmail-mime-previous-item).

v

Toggle between MIME display and raw message (rmail-mime).

Each plain-text MIME part is initially displayed immediately after its tagline,
as part of the Rmail buffer, while MIME parts of other types are represented only
by their taglines, with their actual contents hidden. In either case, you can toggle a
MIME part between its “displayed” and “hidden” states by typing RET anywhere
in the part—or anywhere in its tagline (except for buttons for other actions, if there
are any). Type RET (or click with the mouse) to activate a tagline button, and
TAB to cycle point between tagline buttons.
The v (rmail-mime) command toggles between the default MIME display described above, and a “raw” display showing the undecoded MIME data. With a
prefix argument, this command toggles the display of only an entity at point.

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To prevent Rmail from handling MIME decoded messages, change the variable
rmail-enable-mime to nil. When this is the case, the v (rmail-mime) command
instead creates a temporary buffer to display the current MIME message.
If the current message is an encrypted one, use the command M-x
rmail-epa-decrypt to decrypt it, using the EasyPG library (see Section
“EasyPG” in EasyPG Assistant User’s Manual).
You can highlight and activate URLs in the Rmail buffer using Goto Address
mode:
(add-hook ’rmail-show-message-hook ’goto-address-mode)
Then you can browse these URLs by clicking on them with Mouse-2 (or Mouse-1
quickly) or by moving to one and typing C-c RET. See Section 31.11.2 [Activating
URLs], page 426.

30.14 Rmail and Coding Systems
Rmail automatically decodes messages which contain non-ASCII characters, just as
Emacs does with files you visit and with subprocess output. Rmail uses the standard
‘charset=charset ’ header in the message, if any, to determine how the message was
encoded by the sender. It maps charset into the corresponding Emacs coding system
(see Section 19.6 [Coding Systems], page 188), and uses that coding system to
decode message text. If the message header doesn’t have the ‘charset’ specification,
or if charset is not recognized, Rmail chooses the coding system with the usual
Emacs heuristics and defaults (see Section 19.7 [Recognize Coding], page 190).
Occasionally, a message is decoded incorrectly, either because Emacs guessed
the wrong coding system in the absence of the ‘charset’ specification, or because
the specification was inaccurate. For example, a misconfigured mailer could send a
message with a ‘charset=iso-8859-1’ header when the message is actually encoded
in koi8-r. When you see the message text garbled, or some of its characters
displayed as hex codes or empty boxes, this may have happened.
You can correct the problem by decoding the message again using the right
coding system, if you can figure out or guess which one is right. To do this, invoke
the M-x rmail-redecode-body command. It reads the name of a coding system,
and then redecodes the message using the coding system you specified. If you
specified the right coding system, the result should be readable.

30.15 Editing Within a Message
Most of the usual Emacs key bindings are available in Rmail mode, though a few,
such as C-M-n and C-M-h, are redefined by Rmail for other purposes. However, the
Rmail buffer is normally read only, and most of the letters are redefined as Rmail
commands. If you want to edit the text of a message, you must use the Rmail
command e.
e

Edit the current message as ordinary text.

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The e command (rmail-edit-current-message) switches from Rmail mode
into Rmail Edit mode, another major mode which is nearly the same as Text mode.
The mode line indicates this change.
In Rmail Edit mode, letters insert themselves as usual and the Rmail commands
are not available. You can edit the message body and header fields. When you are
finished editing the message, type C-c C-c to switch back to Rmail mode. Alternatively, you can return to Rmail mode but cancel any editing that you have done,
by typing C-c C-].
Entering Rmail Edit mode runs the hook text-mode-hook; then it runs the
hook rmail-edit-mode-hook (see Section 33.2.2 [Hooks], page 445). Returning to
ordinary Rmail mode adds the attribute ‘edited’ to the message, if you have made
any changes in it.

30.16 Digest Messages
A digest message is a message which exists to contain and carry several other
messages. Digests are used on some mailing lists; all the messages that arrive for
the list during a period of time such as one day are put inside a single digest which
is then sent to the subscribers. Transmitting the single digest uses less computer
time than transmitting the individual messages even though the total size is the
same, because of the per-message overhead in network mail transmission.
When you receive a digest message, the most convenient way to read it is to
undigestify it: to turn it back into many individual messages. Then you can read
and delete the individual messages as it suits you. To do this, select the digest
message and type the command M-x undigestify-rmail-message. This extracts
the submessages as separate Rmail messages, and inserts them following the digest.
The digest message itself is flagged as deleted.

30.17 Reading Rot13 Messages
Mailing list messages that might offend or annoy some readers are sometimes encoded in a simple code called rot13—so named because it rotates the alphabet by
13 letters. This code is not for secrecy, as it provides none; rather, it enables those
who wish to to avoid seeing the real text of the message. For example, a review of
a film might use rot13 to hide important plot points.
To view a buffer that uses the rot13 code, use the command M-x
rot13-other-window. This displays the current buffer in another window which
applies the code when displaying the text.

30.18 movemail program
Rmail uses the movemail program to move mail from your inbox to your Rmail file
(see Section 30.5 [Rmail Inbox], page 379). When loaded for the first time, Rmail
attempts to locate the movemail program and determine its version. There are two
versions of the movemail program: the native one, shipped with GNU Emacs (the
“emacs version”) and the one included in GNU mailutils (the “mailutils version”,

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see Section “movemail” in GNU mailutils). They support the same command line
syntax and the same basic subset of options. However, the Mailutils version offers
additional features.
The Emacs version of movemail is able to retrieve mail from the usual Unix
mailbox formats and from remote mailboxes using the POP3 protocol.
The Mailutils version is able to handle a wide set of mailbox formats, such as
plain Unix mailboxes, maildir and MH mailboxes, etc. It is able to access remote
mailboxes using the POP3 or IMAP4 protocol, and can retrieve mail from them
using a TLS encrypted channel. It also accepts mailbox arguments in URL form.
The detailed description of mailbox URLs can be found in Section “URL” in Mailbox
URL Formats. In short, a URL is:
proto ://[user [:password ]@]host-or-file-name

where square brackets denote optional elements.
proto

Specifies the mailbox protocol, or format to use. The exact semantics
of the rest of URL elements depends on the actual value of proto (see
below).

user

User name to access the remote mailbox.

password

User password to access the remote mailbox.

host-or-file-name
Hostname of the remote server for remote mailboxes or file name of a
local mailbox.
Proto can be one of:
mbox

Usual Unix mailbox format. In this case, neither user nor pass are
used, and host-or-file-name denotes the file name of the mailbox file,
e.g., mbox://var/spool/mail/smith.

mh

A local mailbox in the MH format. User and pass are not used. Hostor-file-name denotes the name of MH folder, e.g., mh://Mail/inbox.

maildir

A local mailbox in the maildir format. User and pass are not used,
and host-or-file-name denotes the name of maildir mailbox, e.g.,
maildir://mail/inbox.

file

Any local mailbox format. Its actual format is detected automatically
by movemail.

pop

A remote mailbox to be accessed via POP3 protocol.
specifies the remote user name to use, pass may be
to specify the user password, host-or-file-name is the
or IP address of the remote mail server to connect to;
pop://smith:guessme@remote.server.net.

User
used
name
e.g.,

imap

A remote mailbox to be accessed via IMAP4 protocol.
specifies the remote user name to use, pass may be
to specify the user password, host-or-file-name is the
or IP address of the remote mail server to connect to;
imap://smith:guessme@remote.server.net.

User
used
name
e.g.,

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Alternatively, you can specify the file name of the mailbox to use. This is
equivalent to specifying the ‘file’ protocol:
/var/spool/mail/user ≡ file://var/spool/mail/user

The variable rmail-movemail-program controls which version of movemail to
use. If that is a string, it specifies the absolute file name of the movemail executable.
If it is nil, Rmail searches for movemail in the directories listed in rmail-movemailsearch-path, then in exec-path (see Section 31.3 [Shell], page 401), then in execdirectory.

30.19 Retrieving Mail from Remote Mailboxes
Some sites use a method called POP for accessing users’ inbox data instead of
storing the data in inbox files. By default, the Emacs movemail can work with POP
(unless the Emacs configure script was run with the option ‘--without-pop’).
Similarly, the Mailutils movemail by default supports POP, unless it was configured with the ‘--disable-pop’ option.
Both versions of movemail only work with POP3, not with older versions of
POP.
No matter which flavor of movemail you use, you can specify a POP inbox
by using a POP URL (see Section 30.18 [Movemail], page 393). A POP URL is
a “file name” of the form ‘pop://username @hostname ’, where hostname is the
host name or IP address of the remote mail server and username is the user name
on that server. Additionally, you may specify the password in the mailbox URL:
‘pop://username :password @hostname ’. In this case, password takes preference
over the one set by rmail-remote-password (see below). This is especially useful
if you have several remote mailboxes with different passwords.
For backward compatibility, Rmail also supports an alternative way of
specifying remote POP mailboxes. Specifying an inbox name in the form
‘po:username :hostname ’ is equivalent to ‘pop://username @hostname ’. If you
omit the :hostname part, the MAILHOST environment variable specifies the machine
on which to look for the POP server.
Another method for accessing remote mailboxes is IMAP. This method is supported only by the Mailutils movemail. To specify an IMAP mailbox in the inbox
list, use the following mailbox URL: ‘imap://username [:password ]@hostname ’.
The password part is optional, as described above.
Accessing a remote mailbox may require a password. Rmail uses the following
algorithm to retrieve it:
1. If a password is present in the mailbox URL (see above), it is used.
2. If the variable rmail-remote-password-required is nil, Rmail assumes no
password is required.
3. If the variable rmail-remote-password is non-nil, its value is used.
4. Otherwise, Rmail will ask you for the password to use.
If you need to pass additional command-line flags to movemail, set the variable
rmail-movemail-flags a list of the flags you wish to use. Do not use this variable

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to pass the ‘-p’ flag to preserve your inbox contents; use rmail-preserve-inbox
instead.
The movemail program installed at your site may support Kerberos authentication (the Emacs movemail does so if Emacs was configured with the option
--with-kerberos or --with-kerberos5). If it is supported, it is used by default
whenever you attempt to retrieve POP mail when rmail-remote-password and
rmail-remote-password-required are unset.
Some POP servers store messages in reverse order. If your server does this, and
you would rather read your mail in the order in which it was received, you can tell
movemail to reverse the order of downloaded messages by adding the ‘-r’ flag to
rmail-movemail-flags.
Mailutils movemail supports TLS encryption. If you wish to use it, add the
‘--tls’ flag to rmail-movemail-flags.

30.20 Retrieving Mail from Local Mailboxes in Various
Formats
If your incoming mail is stored on a local machine in a format other than Unix mailbox, you will need the Mailutils movemail to retrieve it. See Section 30.18 [Movemail], page 393, for the detailed description of movemail versions. For example, to
access mail from a inbox in maildir format located in ‘/var/spool/mail/in’, you
would include the following in the Rmail inbox list:
maildir://var/spool/mail/in

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31 Miscellaneous Commands
This chapter contains several brief topics that do not fit anywhere else: viewing
“document files”, reading Usenet news, running shell commands and shell subprocesses, using a single shared Emacs for utilities that expect to run an editor
as a subprocess, printing hardcopy, sorting text, narrowing display to part of the
buffer, editing binary files, saving an Emacs session for later resumption, following
hyperlinks, browsing images, emulating other editors, and various diversions and
amusements.

31.1 Gnus
Gnus is an Emacs package primarily designed for reading and posting Usenet news.
It can also be used to read and respond to messages from a number of other sources—
email, remote directories, digests, and so on. Here we introduce Gnus and describe
several basic features. For full details on Gnus, type C-h i and then select the Gnus
manual.
31.1.1 Gnus Buffers
Gnus uses several buffers to display information and to receive commands. The
three most commonly-used Gnus buffers are the group buffer, the summary buffer
and the article buffer.
The group buffer contains a list of article sources (e.g. newsgroups and email
inboxes), which are collectively referred to as groups. This is the first buffer Gnus
displays when it starts up. It normally displays only the groups to which you
subscribe and that contain unread articles. From this buffer, you can select a group
to read.
The summary buffer lists the articles in a single group, showing one article per
line. By default, it displays each article’s author, subject, and line number. The
summary buffer is created when you select a group in the group buffer, and is killed
when you exit the group.
From the summary buffer, you can choose an article to view. The article is
displayed in the article buffer. In normal Gnus usage, you view this buffer but do
not select it—all useful Gnus commands can be invoked from the summary buffer.
But you can select the article buffer, and execute Gnus commands from it, if you
wish.
31.1.2 When Gnus Starts Up
If your system has been set up for reading Usenet news, getting started with Gnus
is easy—just type M-x gnus.
On starting up, Gnus reads your news initialization file: a file named ‘.newsrc’
in your home directory which lists your Usenet newsgroups and subscriptions (this
file is not unique to Gnus; it is used by many other newsreader programs). It then
tries to contact the system’s default news server, which is typically specified by the
NNTPSERVER environment variable.

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If your system does not have a default news server, or if you wish to use Gnus
for reading email, then before invoking M-x gnus you need to tell Gnus where to
get news and/or mail. To do this, customize the variables gnus-select-method
and/or gnus-secondary-select-methods. See the Gnus manual for details.
Once Gnus has started up, it displays the group buffer. By default, the
group buffer shows only a small number of subscribed groups. Groups with other
statuses—unsubscribed, killed, or zombie—are hidden. The first time you start
Gnus, any group to which you are not subscribed is made into a killed group; any
group that subsequently appears on the news server becomes a zombie group.
To proceed, you must select a group in the group buffer to open the summary
buffer for that group; then, select an article in the summary buffer to view its article
buffer in a separate window. The following sections explain how to use the group
and summary buffers to do this.
To quit Gnus, type q in the group buffer. This automatically records your
group statuses in the files ‘.newsrc’ and ‘.newsrc.eld’, so that they take effect in
subsequent Gnus sessions.
31.1.3 Using the Gnus Group Buffer
The following commands are available in the Gnus group buffer:
SPC
l
As
L
Au

Switch to the summary buffer for the group on the current line.
In the group buffer, list only the groups to which you subscribe and
which contain unread articles (this is the default listing).
List all subscribed and unsubscribed groups, but not killed or zombie
groups.

Ak

List killed groups.

Az

List zombie groups.

u

Toggle the subscription status of the group on the current line (i.e.
turn a subscribed group into an unsubscribed group, or vice versa).
Invoking this on a killed or zombie group turns it into an unsubscribed
group.

C-k

Kill the group on the current line. Killed groups are not recorded in
the ‘.newsrc’ file, and they are not shown in the l or L listings.

DEL

Move point to the previous group containing unread articles.

n

Move point to the next unread group.

p

Move point to the previous unread group.

q

Update your Gnus settings, and quit Gnus.

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31.1.4 Using the Gnus Summary Buffer
The following commands are available in the Gnus summary buffer:
SPC

If there is no article selected, select the article on the current line and
display its article buffer. Otherwise, try scrolling the selected article
buffer in its window; on reaching the end of the buffer, select the next
unread article.
Thus, you can read through all articles by repeatedly typing SPC.

DEL

Scroll the text of the article backwards.

n

Select the next unread article.

p

Select the previous unread article.

s

Do an incremental search on the selected article buffer, as if you
switched to the buffer and typed C-s (see Section 12.1 [Incremental
Search], page 91).

M-s regexp RET
Search forward for articles containing a match for regexp.
Exit the summary buffer and return to the group buffer.

q

31.2 Document Viewing
DocView mode is a major mode for viewing DVI, PostScript (PS), PDF, OpenDocument, and Microsoft Office documents. It provides features such as slicing,
zooming, and searching inside documents. It works by converting the document to
a set of images using the gs (GhostScript) command and other external tools1 , and
displaying those images.
When you visit a document file that can be displayed with DocView mode,
Emacs automatically uses DocView mode2 . As an exception, when you visit a
PostScript file, Emacs switches to PS mode, a major mode for editing PostScript
files as text; however, it also enables DocView minor mode, so you can type C-c C-c
to view the document with DocView. In either DocView mode or DocView minor
mode, repeating C-c C-c (doc-view-toggle-display) toggles between DocView
and the underlying file contents.
You can explicitly enable DocView mode with the command M-x doc-viewmode. You can toggle DocView minor mode with M-x doc-view-minor-mode.
When DocView mode starts, it displays a welcome screen and begins formatting
the file, page by page. It displays the first page once that has been formatted.
To kill the DocView buffer, type k (doc-view-kill-proc-and-buffer). To
bury it, type q (quit-window).
1
2

gs is a hard requirement. For DVI files, dvipdf or dvipdfm is needed. For OpenDocument and Microsoft Office documents, the unoconv tool is needed.
The needed external tools for the document type must be available, and Emacs must be
running in a graphical frame and have PNG image support. If any of these requirements
is not fulfilled, Emacs falls back to another major mode.

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31.2.1 DocView Navigation
In DocView mode, you can scroll the current page using the usual Emacs movement
keys: C-p, C-n, C-b, C-f, and the arrow keys.
By default, the line-motion keys C-p and C-n stop scrolling at the beginning
and end of the current page, respectively. However, if you change the variable docview-continuous to a non-nil value, then C-p displays the previous page if you
are already at the beginning of the current page, and C-n displays the next page if
you are at the end of the current page.
You can also display the next page by typing n, NEXT or C-x ] (doc-viewnext-page). To display the previous page, type p, PRIOR or C-x [ (doc-viewprevious-page).
SPC (doc-view-scroll-up-or-next-page) is a convenient way to advance
through the document. It scrolls within the current page or advances to the next.
DEL moves backwards in a similar way (doc-view-scroll-down-or-previouspage).
To go to the first page, type M-< (doc-view-first-page); to go to the last one,
type M-> (doc-view-last-page). To jump to a page by its number, type M-g M-g
or M-g g (doc-view-goto-page).
You can enlarge or shrink the document with + (doc-view-enlarge) and (doc-view-shrink). These commands work by reconverting the document at the
new size. To specify the default size for DocView, customize the variable doc-viewresolution.
31.2.2 DocView Searching
In DocView mode, you can search the file’s text for a regular expression (see
Section 12.5 [Regexps], page 97). The interface for searching is inspired by isearch
(see Section 12.1 [Incremental Search], page 91).
To begin a search, type C-s (doc-view-search) or C-r (doc-view-searchbackward). This reads a regular expression using a minibuffer, then echoes the
number of matches found within the document. You can move forward and back
among the matches by typing C-s and C-r. DocView mode has no way to show the
match inside the page image; instead, it displays a tooltip (at the mouse position)
listing all matching lines in the current page. To force display of this tooltip, type
C-t (doc-view-show-tooltip).
To start a new search, use the search command with a prefix argument; i.e., C-u
C-s for a forward search or C-u C-r for a backward search.
31.2.3 DocView Slicing
Documents often have wide margins for printing. They are annoying when reading the document on the screen, because they use up screen space and can cause
inconvenient scrolling.
With DocView you can hide these margins by selecting a slice of pages to display.
A slice is a rectangle within the page area; once you specify a slice in DocView, it
applies to whichever page you look at.

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To specify the slice numerically, type s s (doc-view-set-slice); then enter the
top left pixel position and the slice’s width and height.
A more convenient graphical way to specify the slice is with s m (doc-viewset-slice-using-mouse), where you use the mouse to select the slice.
To cancel the selected slice, type s r (doc-view-reset-slice). Then DocView
shows the entire page including its entire margins.
31.2.4 DocView Conversion
For efficiency, DocView caches the images produced by gs. The name of this directory is given by the variable doc-view-cache-directory. You can clear the cache
directory by typing M-x doc-view-clear-cache.
To force reconversion of the currently viewed document, type r or g (revertbuffer). To kill the converter process associated with the current buffer, type K
(doc-view-kill-proc). The command k (doc-view-kill-proc-and-buffer) kills
the converter process and the DocView buffer.

31.3 Running Shell Commands from Emacs
Emacs has commands for passing single command lines to shell subprocesses, and
for running a shell interactively with input and output to an Emacs buffer, and for
running a shell in a terminal emulator window.
M-! cmd RET
Run the shell command cmd and display the output (shell-command).
M-| cmd RET
Run the shell command cmd with region contents as input; optionally
replace the region with the output (shell-command-on-region).
M-& cmd RET
Run the shell command cmd asynchronously, and display the output
(async-shell-command).
M-x shell

Run a subshell with input and output through an Emacs buffer. You
can then give commands interactively.

M-x term

Run a subshell with input and output through an Emacs buffer. You
can then give commands interactively. Full terminal emulation is available.

Whenever you specify a relative file name for an executable program (either
in the cmd argument to one of the above commands, or in other contexts), Emacs
searches for the program in the directories specified by the variable exec-path. The
value of this variable must be a list of directory names; the default value is initialized from the environment variable PATH when Emacs is started (see Section C.4.1
[General Variables], page 510).
M-x eshell invokes a shell implemented entirely in Emacs. It is documented in
its own manual. See the Eshell Info manual, which is distributed with Emacs.

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31.3.1 Single Shell Commands
M-! (shell-command) reads a line of text using the minibuffer and executes it as a
shell command, in a subshell made just for that command. Standard input for the
command comes from the null device. If the shell command produces any output,
the output appears either in the echo area (if it is short), or in an Emacs buffer
named ‘*Shell Command Output*’, displayed in another window (if the output is
long).
For instance, one way to decompress a file named ‘foo.gz’ is to type M-! gunzip
foo.gz RET. That shell command normally creates the file ‘foo’ and produces no
terminal output.
A numeric argument to shell-command, e.g. M-1 M-!, causes it to insert terminal
output into the current buffer instead of a separate buffer. It puts point before the
output, and sets the mark after the output. For instance, M-1 M-! gunzip < foo.gz
RET would insert the uncompressed form of the file ‘foo.gz’ into the current buffer.
Provided the specified shell command does not end with ‘&’, it runs synchronously, and you must wait for it to exit before continuing to use Emacs. To
stop waiting, type C-g to quit; this sends a SIGINT signal to terminate the shell
command (this is the same signal that C-c normally generates in the shell). Emacs
then waits until the command actually terminates. If the shell command doesn’t
stop (because it ignores the SIGINT signal), type C-g again; this sends the command
a SIGKILL signal, which is impossible to ignore.
A shell command that ends in ‘&’ is executed asynchronously, and you can
continue to use Emacs as it runs. You can also type M-& (async-shell-command)
to execute a shell command asynchronously; this is exactly like calling M-! with a
trailing ‘&’, except that you do not need the ‘&’. The output buffer for asynchronous
shell commands is named ‘*Async Shell Command*’. Emacs inserts the output into
this buffer as it comes in, whether or not the buffer is visible in a window.
M-| (shell-command-on-region) is like M-!, but passes the contents of the
region as the standard input to the shell command, instead of no input. With a
numeric argument, it deletes the old region and replaces it with the output from
the shell command.
For example, you can use M-| with the gpg program to see what keys are in
the buffer. If the buffer contains a GnuPG key, type C-x h M-| gpg RET to feed
the entire buffer contents to gpg. This will output the list of keys to the ‘*Shell
Command Output*’ buffer.
The above commands use the shell specified by the variable shell-file-name.
Its default value is determined by the SHELL environment variable when Emacs is
started. If the file name is relative, Emacs searches the directories listed in execpath (see Section 31.3 [Shell], page 401).
To specify a coding system for M-! or M-|, use the command C-x RET c immediately beforehand. See Section 19.11 [Communication Coding], page 194.
By default, error output is intermixed with the regular output in the output
buffer. But if you change the value of the variable shell-command-default-errorbuffer to a string, error output is inserted into a buffer of that name.

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31.3.2 Interactive Subshell
To run a subshell interactively, type M-x shell. This creates (or reuses) a buffer
named ‘*shell*’, and runs a shell subprocess with input coming from and output
going to that buffer. That is to say, any terminal output from the subshell goes into
the buffer, advancing point, and any terminal input for the subshell comes from
text in the buffer. To give input to the subshell, go to the end of the buffer and
type the input, terminated by RET.
While the subshell is waiting or running a command, you can switch windows
or buffers and perform other editing in Emacs. Emacs inserts the output from the
subshell into the Shell buffer whenever it has time to process it (e.g. while waiting
for keyboard input).
In the Shell buffer, prompts are displayed with the face comint-highlightprompt, and submitted input lines are displayed with the face comint-highlightinput. This makes it easier to distinguish input lines from the shell output. See
Section 11.8 [Faces], page 75.
To make multiple subshells, invoke M-x shell with a prefix argument (e.g. C-u
M-x shell). Then the command will read a buffer name, and create (or reuse)
a subshell in that buffer. You can also rename the ‘*shell*’ buffer using M-x
rename-uniquely, then create a new ‘*shell*’ buffer using plain M-x shell. Subshells in different buffers run independently and in parallel.
To specify the shell file name used by M-x shell, customize the variable
explicit-shell-file-name. If this is nil (the default), Emacs uses the environment variable ESHELL if it exists. Otherwise, it usually uses the variable shellfile-name (see Section 31.3.1 [Single Shell], page 402); but if the default directory
is remote (see Section 15.13 [Remote Files], page 145), it prompts you for the shell
file name.
Emacs sends the new shell the contents of the file ‘~/.emacs_shellname ’ as
input, if it exists, where shellname is the name of the file that the shell was loaded
from. For example, if you use bash, the file sent to it is ‘~/.emacs_bash’. If this
file is not found, Emacs tries with ‘~/.emacs.d/init_shellname.sh’.
To specify a coding system for the shell, you can use the command C-x RET c
immediately before M-x shell. You can also change the coding system for a running
subshell by typing C-x RET p in the shell buffer. See Section 19.11 [Communication
Coding], page 194.
Emacs sets the environment variable INSIDE_EMACS in the subshell to
‘version,comint’, where version is the Emacs version (e.g. ‘24.1’). Programs
can check this variable to determine whether they are running inside an Emacs
subshell. (It also sets the EMACS environment variable to t, if that environment
variable is not already defined. However, this environment variable is deprecated;
programs that use it should switch to using INSIDE_EMACS instead.)
31.3.3 Shell Mode
The major mode for Shell buffers is Shell mode. Many of its special commands are
bound to the C-c prefix, and resemble the usual editing and job control characters

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present in ordinary shells, except that you must type C-c first. Here is a list of
Shell mode commands:
RET

Send the current line as input to the subshell (comint-send-input).
Any shell prompt at the beginning of the line is omitted (see
Section 31.3.4 [Shell Prompts], page 406). If point is at the end
of buffer, this is like submitting the command line in an ordinary
interactive shell. However, you can also invoke RET elsewhere in the
shell buffer to submit the current line as input.

TAB

Complete the command name or file name before point in the shell
buffer (completion-at-point). This uses the usual Emacs completion
rules (see Section 5.3 [Completion], page 29), with the completion
alternatives being file names, environment variable names, the shell
command history, and history references (see Section 31.3.5.3 [History
References], page 408).
The variable shell-completion-fignore specifies a list of file name
extensions to ignore in Shell mode completion. The default setting is
nil, but some users prefer ("~" "#" "%") to ignore file names ending
in ‘~’, ‘#’ or ‘%’. Other related Comint modes use the variable comintcompletion-fignore instead.

M-?

Display temporarily a list of the possible completions of the file name
before point (comint-dynamic-list-filename-completions).

C-d

Either delete a character or send EOF (comint-delchar-or-maybeeof). Typed at the end of the shell buffer, this sends EOF to the
subshell. Typed at any other position in the buffer, this deletes a
character as usual.

C-c C-a

Move to the beginning of the line, but after the prompt if any (comintbol-or-process-mark). If you repeat this command twice in a row,
the second time it moves back to the process mark, which is the beginning of the input that you have not yet sent to the subshell. (Normally
that is the same place—the end of the prompt on this line—but after
C-c SPC the process mark may be in a previous line.)

C-c SPC

Accumulate multiple lines of input, then send them together. This
command inserts a newline before point, but does not send the preceding text as input to the subshell—at least, not yet. Both lines, the
one before this newline and the one after, will be sent together (along
with the newline that separates them), when you type RET.

C-c C-u

Kill all text pending at end of buffer to be sent as input (comintkill-input). If point is not at end of buffer, this only kills the part
of this text that precedes point.

C-c C-w

Kill a word before point (backward-kill-word).

C-c C-c

Interrupt the shell or its current subjob if any (comint-interruptsubjob). This command also kills any shell input pending in the shell
buffer and not yet sent.

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C-c C-z

Stop the shell or its current subjob if any (comint-stop-subjob).
This command also kills any shell input pending in the shell buffer
and not yet sent.

C-c C-\

Send quit signal to the shell or its current subjob if any (comintquit-subjob). This command also kills any shell input pending in
the shell buffer and not yet sent.

C-c C-o

Delete the last batch of output from a shell command (comintdelete-output). This is useful if a shell command spews out lots
of output that just gets in the way.

C-c C-s

Write the last batch of output from a shell command to a file (comintwrite-output). With a prefix argument, the file is appended to instead. Any prompt at the end of the output is not written.

C-c C-r
C-M-l

Scroll to display the beginning of the last batch of output at the top
of the window; also move the cursor there (comint-show-output).

C-c C-e

Scroll to put the end of the buffer at the bottom of the window
(comint-show-maximum-output).

C-c C-f

Move forward across one shell command, but not beyond the current
line (shell-forward-command). The variable shell-command-regexp
specifies how to recognize the end of a command.

C-c C-b

Move backward across one shell command, but not beyond the current
line (shell-backward-command).

M-x dirs

Ask the shell for its working directory, and update the Shell buffer’s
default directory. See Section 31.3.6 [Directory Tracking], page 409.

M-x send-invisible RET text RET
Send text as input to the shell, after reading it without echoing. This is
useful when a shell command runs a program that asks for a password.
Please note that Emacs will not echo passwords by default. If you
really want them to be echoed, evaluate the following Lisp expression:
(remove-hook ’comint-output-filter-functions
’comint-watch-for-password-prompt)
M-x comint-continue-subjob
Continue the shell process. This is useful if you accidentally suspend
the shell process.3
M-x comint-strip-ctrl-m
Discard all control-M characters from the current group of shell output. The most convenient way to use this command is to make it run
3

You should not suspend the shell process. Suspending a subjob of the shell is a completely different matter—that is normal practice, but you must use the shell to continue
the subjob; this command won’t do it.

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automatically when you get output from the subshell. To do that,
evaluate this Lisp expression:
(add-hook ’comint-output-filter-functions
’comint-strip-ctrl-m)
M-x comint-truncate-buffer
This command truncates the shell buffer to a certain maximum number of lines, specified by the variable comint-buffer-maximum-size.
Here’s how to do this automatically each time you get output from
the subshell:
(add-hook ’comint-output-filter-functions
’comint-truncate-buffer)
Shell mode is a derivative of Comint mode, a general-purpose mode for communicating with interactive subprocesses. Most of the features of Shell mode actually
come from Comint mode, as you can see from the command names listed above.
The special features of Shell mode include the directory tracking feature, and a few
user commands.
Other Emacs features that use variants of Comint mode include GUD (see
Section 24.6 [Debuggers], page 276) and M-x run-lisp (see Section 24.11 [External
Lisp], page 290).
You can use M-x comint-run to execute any program of your choice in a subprocess using unmodified Comint mode—without the specializations of Shell mode.
31.3.4 Shell Prompts
A prompt is text output by a program to show that it is ready to accept new user
input. Normally, Comint mode (and thus Shell mode) automatically figures out
part of the buffer is a prompt, based on the output of the subprocess. (Specifically,
it assumes that any received output line which doesn’t end with a newline is a
prompt.)
Comint mode divides the buffer into two types of fields: input fields (where user
input is typed) and output fields (everywhere else). Prompts are part of the output
fields. Most Emacs motion commands do not cross field boundaries, unless they
move over multiple lines. For instance, when point is in the input field on a shell
command line, C-a puts point at the beginning of the input field, after the prompt.
Internally, the fields are implemented using the field text property (see Section
“Text Properties” in the Emacs Lisp Reference Manual).
If you change the variable comint-use-prompt-regexp to a non-nil value, then
Comint mode recognize prompts using a regular expression (see Section 12.5 [Regexps], page 97). In Shell mode, the regular expression is specified by the variable
shell-prompt-pattern. The default value of comint-use-prompt-regexp is nil,
because this method for recognizing prompts is unreliable, but you may want to set
it to a non-nil value in unusual circumstances. In that case, Emacs does not divide the Comint buffer into fields, so the general motion commands behave as they
normally do in buffers without special text properties. However, you can use the
paragraph motion commands to conveniently navigate the buffer (see Section 22.3

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[Paragraphs], page 216); in Shell mode, Emacs uses shell-prompt-pattern as
paragraph boundaries.
31.3.5 Shell Command History
Shell buffers support three ways of repeating earlier commands. You can use keys
like those used for the minibuffer history; these work much as they do in the minibuffer, inserting text from prior commands while point remains always at the end
of the buffer. You can move through the buffer to previous inputs in their original
place, then resubmit them or copy them to the end. Or you can use a ‘!’-style
history reference.
31.3.5.1 Shell History Ring
M-p
C-UP

Fetch the next earlier old shell command.

M-n
C-DOWN

Fetch the next later old shell command.

M-r

Begin an incremental regexp search of old shell commands.

C-c C-x

Fetch the next subsequent command from the history.

C-c .

Fetch one argument from an old shell command.

C-c C-l

Display the buffer’s history of shell commands in another window
(comint-dynamic-list-input-ring).

Shell buffers provide a history of previously entered shell commands. To reuse
shell commands from the history, use the editing commands M-p, M-n, M-r and M-s.
These work just like the minibuffer history commands (see Section 5.4 [Minibuffer
History], page 34), except that they operate within the Shell buffer rather than the
minibuffer.
M-p fetches an earlier shell command to the end of the shell buffer. Successive
use of M-p fetches successively earlier shell commands, each replacing any text that
was already present as potential shell input. M-n does likewise except that it finds
successively more recent shell commands from the buffer. C-UP works like M-p, and
C-DOWN like M-n.
The history search command M-r begins an incremental regular expression search
of previous shell commands. After typing M-r, start typing the desired string or
regular expression; the last matching shell command will be displayed in the current
line. Incremental search commands have their usual effects—for instance, C-s and
C-r search forward and backward for the next match (see Section 12.1 [Incremental
Search], page 91). When you find the desired input, type RET to terminate the
search. This puts the input in the command line. Any partial input you were
composing before navigating the history list is restored when you go to the beginning
or end of the history ring.
Often it is useful to reexecute several successive shell commands that were previously executed in sequence. To do this, first find and reexecute the first command

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of the sequence. Then type C-c C-x; that will fetch the following command—the
one that follows the command you just repeated. Then type RET to reexecute this
command. You can reexecute several successive commands by typing C-c C-x RET
over and over.
The command C-c . (comint-input-previous-argument) copies an individual
argument from a previous command, like ESC . in Bash. The simplest use copies
the last argument from the previous shell command. With a prefix argument n,
it copies the nth argument instead. Repeating C-c . copies from an earlier shell
command instead, always using the same value of n (don’t give a prefix argument
when you repeat the C-c . command).
These commands get the text of previous shell commands from a special history
list, not from the shell buffer itself. Thus, editing the shell buffer, or even killing
large parts of it, does not affect the history that these commands access.
Some shells store their command histories in files so that you can refer to
commands from previous shell sessions. Emacs reads the command history file
for your chosen shell, to initialize its own command history. The file name is
‘~/.bash_history’ for bash, ‘~/.sh_history’ for ksh, and ‘~/.history’ for other
shells.
31.3.5.2 Shell History Copying
C-c C-p

Move point to the previous prompt (comint-previous-prompt).

C-c C-n

Move point to the following prompt (comint-next-prompt).

C-c RET

Copy the input command at point, inserting the copy at the end of
the buffer (comint-copy-old-input). This is useful if you move point
back to a previous command. After you copy the command, you can
submit the copy as input with RET. If you wish, you can edit the
copy before resubmitting it. If you use this command on an output
line, it copies that line to the end of the buffer.

Mouse-2

If comint-use-prompt-regexp is nil (the default), copy the old input
command that you click on, inserting the copy at the end of the buffer
(comint-insert-input). If comint-use-prompt-regexp is non-nil,
or if the click is not over old input, just yank as usual.

Moving to a previous input and then copying it with C-c RET or Mouse-2 produces the same results—the same buffer contents—that you would get by using M-p
enough times to fetch that previous input from the history list. However, C-c RET
copies the text from the buffer, which can be different from what is in the history
list if you edit the input text in the buffer after it has been sent.
31.3.5.3 Shell History References
Various shells including csh and bash support history references that begin with
‘!’ and ‘^’. Shell mode recognizes these constructs, and can perform the history
substitution for you.

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If you insert a history reference and type TAB, this searches the input history
for a matching command, performs substitution if necessary, and places the result
in the buffer in place of the history reference. For example, you can fetch the most
recent command beginning with ‘mv’ with ! m v TAB. You can edit the command if
you wish, and then resubmit the command to the shell by typing RET.
Shell mode can optionally expand history references in the buffer when you send
them to the shell. To request this, set the variable comint-input-autoexpand to
input. You can make SPC perform history expansion by binding SPC to the
command comint-magic-space.
Shell mode recognizes history references when they follow a prompt. See
Section 31.3.4 [Shell Prompts], page 406, for how Shell mode recognizes prompts.
31.3.6 Directory Tracking
Shell mode keeps track of ‘cd’, ‘pushd’ and ‘popd’ commands given to the subshell,
in order to keep the Shell buffer’s default directory (see Section 15.1 [File Names],
page 124) the same as the shell’s working directory. It recognizes these commands
by examining lines of input that you send.
If you use aliases for these commands, you can tell Emacs to recognize them also,
by setting the variables shell-pushd-regexp, shell-popd-regexp, and shell-cdregexp to the appropriate regular expressions (see Section 12.5 [Regexps], page 97).
For example, if shell-pushd-regexp matches the beginning of a shell command
line, that line is regarded as a pushd command. These commands are recognized
only at the beginning of a shell command line.
If Emacs gets confused about changes in the working directory of the subshell,
type M-x dirs. This command asks the shell for its working directory and updates
the default directory accordingly. It works for shells that support the most common
command syntax, but may not work for unusual shells.
You can also use Dirtrack mode, a buffer-local minor mode that implements an
alternative method of tracking the shell’s working directory. To use this method,
your shell prompt must contain the working directory at all times, and you must
supply a regular expression for recognizing which part of the prompt contains the
working directory; see the documentation of the variable dirtrack-list for details. To use Dirtrack mode, type M-x dirtrack-mode in the Shell buffer, or add
dirtrack-mode to shell-mode-hook (see Section 33.2.2 [Hooks], page 445).
31.3.7 Shell Mode Options
If the variable comint-scroll-to-bottom-on-input is non-nil, insertion and yank
commands scroll the selected window to the bottom before inserting. The default
is nil.
If comint-scroll-show-maximum-output is non-nil, then arrival of output
when point is at the end tries to scroll the last line of text to the bottom line
of the window, showing as much useful text as possible. (This mimics the scrolling
behavior of most terminals.) The default is t.
By setting comint-move-point-for-output, you can opt for having point jump
to the end of the buffer whenever output arrives—no matter where in the buffer

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point was before. If the value is this, point jumps in the selected window. If the
value is all, point jumps in each window that shows the Comint buffer. If the value
is other, point jumps in all nonselected windows that show the current buffer. The
default value is nil, which means point does not jump to the end.
If you set comint-prompt-read-only, the prompts in the Comint buffer are
read-only.
The variable comint-input-ignoredups controls whether successive identical
inputs are stored in the input history. A non-nil value means to omit an input
that is the same as the previous input. The default is nil, which means to store
each input even if it is equal to the previous input.
Three variables customize file name completion.
The variable comintcompletion-addsuffix controls whether completion inserts a space or a slash to
indicate a fully completed file or directory name (non-nil means do insert a space
or slash). comint-completion-recexact, if non-nil, directs TAB to choose the
shortest possible completion if the usual Emacs completion algorithm cannot add
even a single character. comint-completion-autolist, if non-nil, says to list all
the possible completions whenever completion is not exact.
Command completion normally considers only executable files. If you set shellcompletion-execonly to nil, it considers nonexecutable files as well.
You can configure the behavior of ‘pushd’. Variables control whether ‘pushd’
behaves like ‘cd’ if no argument is given (shell-pushd-tohome), pop rather than
rotate with a numeric argument (shell-pushd-dextract), and only add directories
to the directory stack if they are not already on it (shell-pushd-dunique). The
values you choose should match the underlying shell, of course.
31.3.8 Emacs Terminal Emulator
To run a subshell in a terminal emulator, use M-x term. This creates (or reuses)
a buffer named ‘*terminal*’, and runs a subshell with input coming from your
keyboard, and output going to that buffer.
The terminal emulator uses Term mode, which has two input modes. In
line mode, Term basically acts like Shell mode (see Section 31.3.3 [Shell Mode],
page 403).
In char mode, each character is sent directly to the subshell, as “terminal input”.
Any “echoing” of your input is the responsibility of the subshell. The sole exception
is the terminal escape character, which by default is C-c (see Section 31.3.9 [Term
Mode], page 411). Any “terminal output” from the subshell goes into the buffer,
advancing point.
Some programs (such as Emacs itself) need to control the appearance on the
terminal screen in detail. They do this by sending special control codes. The exact
control codes needed vary from terminal to terminal, but nowadays most terminals
and terminal emulators (including xterm) understand the ANSI-standard (VT100style) escape sequences. Term mode recognizes these escape sequences, and handles
each one appropriately, changing the buffer so that the appearance of the window
matches what it would be on a real terminal. You can actually run Emacs inside
an Emacs Term window.

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You can also Term mode to communicate with a device connected to a serial
port. See Section 31.3.11 [Serial Terminal], page 412.
The file name used to load the subshell is determined the same way as for Shell
mode. To make multiple terminal emulators, rename the buffer ‘*terminal*’ to
something different using M-x rename-uniquely, just as with Shell mode.
Unlike Shell mode, Term mode does not track the current directory by examining
your input. But some shells can tell Term what the current directory is. This is
done automatically by bash version 1.15 and later.
31.3.9 Term Mode
The terminal emulator uses Term mode, which has two input modes. In line mode,
Term basically acts like Shell mode (see Section 31.3.3 [Shell Mode], page 403).
In char mode, each character is sent directly to the subshell, except for the Term
escape character, normally C-c.
To switch between line and char mode, use these commands:
C-c C-j

Switch to line mode (term-line-mode). Do nothing if already in line
mode.

C-c C-k

Switch to char mode (term-char-mode). Do nothing if already in char
mode.

The following commands are only available in char mode:
C-c C-c

Send a literal C-C to the sub-shell.

C-c char

This is equivalent to C-x char in normal Emacs. For example, C-c o
invokes the global binding of C-x o, which is normally ‘other-window’.

Term mode has a page-at-a-time feature. When enabled, it makes output pause
at the end of each screenful:
C-c C-q

Toggle the page-at-a-time feature. This command works in both line
and char modes. When the feature is enabled, the mode-line displays
the word ‘page’, and each time Term receives more than a screenful
of output, it pauses and displays ‘**MORE**’ in the mode-line. Type
SPC to display the next screenful of output, or ? to see your other
options. The interface is similar to the more program.

31.3.10 Remote Host Shell
You can login to a remote computer, using whatever commands you would from a
regular terminal (e.g. using the telnet or rlogin commands), from a Term window.
A program that asks you for a password will normally suppress echoing of the
password, so the password will not show up in the buffer. This will happen just as
if you were using a real terminal, if the buffer is in char mode. If it is in line mode,
the password is temporarily visible, but will be erased when you hit return. (This
happens automatically; there is no special password processing.)
When you log in to a different machine, you need to specify the type of terminal
you’re using, by setting the TERM environment variable in the environment for the

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remote login command. (If you use bash, you do that by writing the variable assignment before the remote login command, without a separating comma.) Terminal
types ‘ansi’ or ‘vt100’ will work on most systems.
31.3.11 Serial Terminal
If you have a device connected to a serial port of your computer, you can communicate with it by typing M-x serial-term. This command asks for a serial port name
and speed, and switches to a new Term mode buffer. Emacs communicates with
the serial device through this buffer just like it does with a terminal in ordinary
Term mode.
The speed of the serial port is measured in bits per second. The most common
speed is 9600 bits per second. You can change the speed interactively by clicking
on the mode line.
A serial port can be configured even more by clicking on “8N1” in the mode
line. By default, a serial port is configured as “8N1”, which means that each byte
consists of 8 data bits, No parity check bit, and 1 stopbit.
If the speed or the configuration is wrong, you cannot communicate with your
device and will probably only see garbage output in the window.

31.4 Using Emacs as a Server
Various programs can invoke your choice of editor to edit a particular piece of text.
For instance, version control programs invoke an editor to enter version control logs
(see Section 25.1 [Version Control], page 292), and the Unix mail utility invokes an
editor to enter a message to send. By convention, your choice of editor is specified
by the environment variable EDITOR. If you set EDITOR to ‘emacs’, Emacs would
be invoked, but in an inconvenient way—by starting a new Emacs process. This
is inconvenient because the new Emacs process doesn’t share buffers, a command
history, or other kinds of information with any existing Emacs process.
You can solve this problem by setting up Emacs as an edit server, so that it
“listens” for external edit requests and acts accordingly. There are two ways to
start an Emacs server:
• Run the command server-start in an existing Emacs process: either type
M-x server-start, or put the expression (server-start) in your init file (see
Section 33.4 [Init File], page 461). The existing Emacs process is the server;
when you exit Emacs, the server dies with the Emacs process.
• Run Emacs as a daemon, using the ‘--daemon’ command-line option. See
Section C.2 [Initial Options], page 507. When Emacs is started this way,
it calls server-start after initialization, and returns control to the calling
terminal instead of opening an initial frame; it then waits in the background,
listening for edit requests.
Either way, once an Emacs server is started, you can use a shell command called
emacsclient to connect to the Emacs process and tell it to visit a file. You can then

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set the EDITOR environment variable to ‘emacsclient’, so that external programs
will use the existing Emacs process for editing.4
You can run multiple Emacs servers on the same machine by giving each
one a unique “server name”, using the variable server-name. For example, M-x
set-variable RET server-name RET foo RET sets the server name to ‘foo’. The
emacsclient program can specify a server by name, using the ‘-s’ option (see
Section 31.4.2 [emacsclient Options], page 414).
If you have defined a server by a unique server name, it is possible to connect
to the server from another Emacs instance and evaluate Lisp expressions on the
server, using the server-eval-at function. For instance, (server-eval-at "foo"
’(+ 1 2)) evaluates the expression (+ 1 2) on the ‘foo’ server, and returns 3. (If
there is no server with that name, an error is signaled.) Currently, this feature is
mainly useful for developers.
31.4.1 Invoking emacsclient
The simplest way to use the emacsclient program is to run the shell command
‘emacsclient file ’, where file is a file name. This connects to an Emacs server,
and tells that Emacs process to visit file in one of its existing frames—either a
graphical frame, or one in a text terminal (see Chapter 18 [Frames], page 165). You
can then select that frame to begin editing.
If there is no Emacs server, the emacsclient program halts with an error message. If the Emacs process has no existing frame—which can happen if it was started
as a daemon (see Section 31.4 [Emacs Server], page 412)—then Emacs opens a frame
on the terminal in which you called emacsclient.
You can also force emacsclient to open a new frame on a graphical display, or
on a text terminal, using the ‘-c’ and ‘-t’ options. See Section 31.4.2 [emacsclient
Options], page 414.
If you are running on a single text terminal, you can switch between
emacsclient’s shell and the Emacs server using one of two methods: (i) run the
Emacs server and emacsclient on different virtual terminals, and switch to the
Emacs server’s virtual terminal after calling emacsclient; or (ii) call emacsclient
from within the Emacs server itself, using Shell mode (see Section 31.3.2
[Interactive Shell], page 403) or Term mode (see Section 31.3.9 [Term Mode],
page 411); emacsclient blocks only the subshell under Emacs, and you can still
use Emacs to edit the file.
When you finish editing file in the Emacs server, type C-x # (server-edit) in its
buffer. This saves the file and sends a message back to the emacsclient program,
telling it to exit. Programs that use EDITOR usually wait for the “editor”—in this
case emacsclient—to exit before doing something else.
You can also call emacsclient with multiple file name arguments: ‘emacsclient
file1 file2 ...’ tells the Emacs server to visit file1, file2, and so forth. Emacs
selects the buffer visiting file1, and buries the other buffers at the bottom of the
4

Some programs use a different environment variable; for example, to make TEX use
‘emacsclient’, set the TEXEDIT environment variable to ‘emacsclient +%d %s’.

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buffer list (see Chapter 16 [Buffers], page 150). The emacsclient program exits
once all the specified files are finished (i.e., once you have typed C-x # in each server
buffer).
Finishing with a server buffer also kills the buffer, unless it already existed in
the Emacs session before the server was asked to create it. However, if you set
server-kill-new-buffers to nil, then a different criterion is used: finishing with
a server buffer kills it if the file name matches the regular expression server-tempfile-regexp. This is set up to distinguish certain “temporary” files.
Each C-x # checks for other pending external requests to edit various files, and
selects the next such file. You can switch to a server buffer manually if you wish;
you don’t have to arrive at it with C-x #. But C-x # is the way to tell emacsclient
that you are finished.
If you set the value of the variable server-window to a window or a frame, C-x
# always displays the next server buffer in that window or in that frame.
31.4.2 emacsclient Options
You can pass some optional arguments to the emacsclient program, such as:
emacsclient -c +12 file1 +4:3 file2
The ‘+line ’ or ‘+line :column ’ arguments specify line numbers, or line and column
numbers, for the next file argument. These behave like the command line arguments
for Emacs itself. See Section C.1 [Action Arguments], page 505.
The other optional arguments recognized by emacsclient are listed below:
‘-a command ’
‘--alternate-editor=command ’
Specify a command to run if emacsclient fails to contact Emacs. This
is useful when running emacsclient in a script.
As a special exception, if command is the empty string, then
emacsclient starts Emacs in daemon mode (as emacs --daemon)
and then tries connecting again.
The environment variable ALTERNATE_EDITOR has the same effect as
the ‘-a’ option. If both are present, the latter takes precedence.
‘-c’

Create a new graphical client frame, instead of using an existing Emacs
frame. If you omit a filename argument while supplying the ‘-c’ option, the new frame displays the ‘*scratch*’ buffer (see Chapter 16
[Buffers], page 150). See below for the special behavior of C-x C-c in
a client frame.
If Emacs is unable to create a new graphical frame (e.g. if it is unable
to connect to the X server), it tries to create a text terminal client
frame, as though you had supplied the ‘-t’ option instead (see below).
On MS-Windows, a single Emacs session cannot display frames on
both graphical and text terminals, nor on multiple text terminals.
Thus, if the Emacs server is running on a text terminal, the ‘-c’ option,
like the ‘-t’ option, creates a new frame in the server’s current text
terminal. See Section G.1 [Windows Startup], page 535.

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‘-F alist ’
‘--frame-parameters=alist ’
Set the parameters for a newly-created graphical frame (see
Section 18.11 [Frame Parameters], page 175).
‘-d display ’
‘--display=display ’
Tell Emacs to open the given files on the X display display (assuming
there is more than one X display available).
‘-e’
‘--eval’

Tell Emacs to evaluate some Emacs Lisp code, instead of visiting some
files. When this option is given, the arguments to emacsclient are
interpreted as a list of expressions to evaluate, not as a list of files to
visit.

‘-f server-file ’
‘--server-file=server-file ’
Specify a server file for connecting to an Emacs server via TCP.
An Emacs server usually uses an operating system feature called a “local socket” to listen for connections. Some operating systems, such as
Microsoft Windows, do not support local sockets; in that case, Emacs
uses TCP instead. When you start the Emacs server, Emacs creates a server file containing some TCP information that emacsclient
needs for making the connection. By default, the server file is in
‘~/.emacs.d/server/’. On Microsoft Windows, if emacsclient does
not find the server file there, it looks in the ‘.emacs.d/server/’ subdirectory of the directory pointed to by the APPDATA environment variable. You can tell emacsclient to use a specific server file with the
‘-f’ or ‘--server-file’ option, or by setting the EMACS_SERVER_FILE
environment variable.
Even if local sockets are available, you can tell Emacs to use TCP by
setting the variable server-use-tcp to t. One advantage of TCP is
that the server can accept connections from remote machines. For this
to work, you must (i) set the variable server-host to the hostname
or IP address of the machine on which the Emacs server runs, and (ii)
provide emacsclient with the server file. (One convenient way to do
the latter is to put the server file on a networked file system such as
NFS.)
When the Emacs server is using TCP, the variable server-port determines the port number to listen on; the default value, nil, means
to choose a random port when the server starts.
‘-n’
‘--no-wait’
Let emacsclient exit immediately, instead of waiting until all server
buffers are finished. You can take as long as you like to edit the server

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buffers within Emacs, and they are not killed when you type C-x # in
them.
‘--parent-id ID ’
Open an emacsclient frame as a client frame in the parent X window
with id ID, via the XEmbed protocol. Currently, this option is mainly
useful for developers.
‘-q’
‘--quiet’

Do not let emacsclient display messages about waiting for Emacs or
connecting to remote server sockets.

‘-s server-name ’
‘--socket-name=server-name ’
Connect to the Emacs server named server-name. The server name is
given by the variable server-name on the Emacs server. If this option
is omitted, emacsclient connects to the first server it finds. (This
option is not supported on MS-Windows.)
‘-t’
‘--tty’
‘-nw’

Create a new client frame on the current text terminal, instead of
using an existing Emacs frame. This is similar to the ‘-c’ option,
above, except that it creates a text terminal frame (see Section 18.19
[Non-Window Terminals], page 179). If you omit a filename argument
while supplying this option, the new frame displays the ‘*scratch*’
buffer (see Chapter 16 [Buffers], page 150). See below for the special
behavior of C-x C-c in a client frame.
On MS-Windows, a single Emacs session cannot display frames on
both graphical and text terminals, nor on multiple text terminals.
Thus, if the Emacs server is using the graphical display, ‘-t’ behaves
like ‘-c’ (see above); whereas if the Emacs server is running on a
text terminal, it creates a new frame in its current text terminal. See
Section G.1 [Windows Startup], page 535.

The new graphical or text terminal frames created by the ‘-c’ or ‘-t’ options are
considered client frames. Any new frame that you create from a client frame is also
considered a client frame. If you type C-x C-c (save-buffers-kill-terminal)
in a client frame, that command does not kill the Emacs session as it normally
does (see Section 3.2 [Exiting], page 15). Instead, Emacs deletes the client frame;
furthermore, if the client frame has an emacsclient waiting to regain control (i.e.
if you did not supply the ‘-n’ option), Emacs deletes all other frames of the same
client, and marks the client’s server buffers as finished, as though you had typed
C-x # in all of them. If it so happens that there are no remaining frames after the
client frame(s) are deleted, the Emacs session exits.
As an exception, when Emacs is started as a daemon, all frames are considered
client frames, and C-x C-c never kills Emacs. To kill a daemon session, type M-x
kill-emacs.

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Note that the ‘-t’ and ‘-n’ options are contradictory: ‘-t’ says to take control
of the current text terminal to create a new client frame, while ‘-n’ says not to take
control of the text terminal. If you supply both options, Emacs visits the specified
files(s) in an existing frame rather than a new client frame, negating the effect of
‘-t’.

31.5 Printing Hard Copies
Emacs provides commands for printing hardcopies of either an entire buffer or part
of one. You can invoke the printing commands directly, as detailed below, or using
the ‘File’ menu on the menu bar.
Aside from the commands described in this section, you can also print hardcopies
from Dired (see Section 27.7 [Operating on Files], page 335) and the diary (see
Section 28.10.1 [Displaying the Diary], page 359). You can also “print” an Emacs
buffer to HTML with the command M-x htmlfontify-buffer, which converts the
current buffer to a HTML file, replacing Emacs faces with CSS-based markup.
Furthermore, Org mode allows you to “print” Org files to a variety of formats, such
as PDF (see Section 22.9 [Org Mode], page 229).
M-x print-buffer
Print hardcopy of current buffer with page headings containing the file
name and page number.
M-x lpr-buffer
Print hardcopy of current buffer without page headings.
M-x print-region
Like print-buffer but print only the current region.
M-x lpr-region
Like lpr-buffer but print only the current region.
On most operating system, the above hardcopy commands submit files for printing by calling the lpr program. To change the printer program, customize the variable lpr-command. To specify extra switches to give the printer program, customize
the list variable lpr-switches. Its value should be a list of option strings, each of
which should start with ‘-’ (e.g. the option string "-w80" specifies a line width of
80 columns). The default is the empty list, nil.
To specify the printer to use, set the variable printer-name. The default, nil,
specifies the default printer. If you set it to a printer name (a string), that name is
passed to lpr with the ‘-P’ switch; if you are not using lpr, you should specify the
switch with lpr-printer-switch.
The variable lpr-headers-switches similarly specifies the extra switches to
use to make page headers. The variable lpr-add-switches controls whether to
supply ‘-T’ and ‘-J’ options (suitable for lpr) to the printer program: nil means
don’t add them (this should be the value if your printer program is not compatible
with lpr).

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31.5.1 PostScript Hardcopy
These commands convert buffer contents to PostScript, either printing it or leaving
it in another Emacs buffer.
M-x ps-print-buffer
Print hardcopy of the current buffer in PostScript form.
M-x ps-print-region
Print hardcopy of the current region in PostScript form.
M-x ps-print-buffer-with-faces
Print hardcopy of the current buffer in PostScript form, showing the
faces used in the text by means of PostScript features.
M-x ps-print-region-with-faces
Print hardcopy of the current region in PostScript form, showing the
faces used in the text.
M-x ps-spool-buffer
Generate and spool a PostScript image for the current buffer text.
M-x ps-spool-region
Generate and spool a PostScript image for the current region.
M-x ps-spool-buffer-with-faces
Generate and spool a PostScript image for the current buffer, showing
the faces used.
M-x ps-spool-region-with-faces
Generate and spool a PostScript image for the current region, showing
the faces used.
M-x ps-despool
Send the spooled PostScript to the printer.
M-x handwrite
Generate/print PostScript for the current buffer as if handwritten.
The ps-print-buffer and ps-print-region commands print buffer contents
in PostScript form. One command prints the entire buffer; the other, just the region. The commands ps-print-buffer-with-faces and ps-print-region-withfaces behave similarly, but use PostScript features to show the faces (fonts and
colors) of the buffer text.
Interactively, when you use a prefix argument (C-u), the command prompts the
user for a file name, and saves the PostScript image in that file instead of sending
it to the printer.
The commands whose names have ‘spool’ instead of ‘print’, generate the PostScript output in an Emacs buffer instead of sending it to the printer.
Use the command ps-despool to send the spooled images to the printer. This
command sends the PostScript generated by ‘-spool-’ commands (see commands
above) to the printer. With a prefix argument (C-u), it prompts for a file name, and
saves the spooled PostScript image in that file instead of sending it to the printer.

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M-x handwrite is more frivolous. It generates a PostScript rendition of the
current buffer as a cursive handwritten document. It can be customized in group
handwrite. This function only supports ISO 8859-1 characters.
31.5.2 Variables for PostScript Hardcopy
All the PostScript hardcopy commands use the variables ps-lpr-command and pslpr-switches to specify how to print the output. ps-lpr-command specifies the
command name to run, ps-lpr-switches specifies command line options to use,
and ps-printer-name specifies the printer. If you don’t set the first two variables
yourself, they take their initial values from lpr-command and lpr-switches. If
ps-printer-name is nil, printer-name is used.
The variable ps-print-header controls whether these commands add header
lines to each page—set it to nil to turn headers off.
If your printer doesn’t support colors, you should turn off color processing by
setting ps-print-color-p to nil. By default, if the display supports colors, Emacs
produces hardcopy output with color information; on black-and-white printers, colors are emulated with shades of gray. This might produce illegible output, even if
your screen colors only use shades of gray.
Alternatively, you can set ps-print-color-p to black-white to print colors on
black/white printers.
By default, PostScript printing ignores the background colors of the faces, unless the variable ps-use-face-background is non-nil. This is to avoid unwanted
interference with the zebra stripes and background image/text.
The variable ps-paper-type specifies which size of paper to format for; legitimate values include a4, a3, a4small, b4, b5, executive, ledger, legal, letter,
letter-small, statement, tabloid. The default is letter. You can define additional paper sizes by changing the variable ps-page-dimensions-database.
The variable ps-landscape-mode specifies the orientation of printing on the
page. The default is nil, which stands for “portrait” mode. Any non-nil value
specifies “landscape” mode.
The variable ps-number-of-columns specifies the number of columns; it takes
effect in both landscape and portrait mode. The default is 1.
The variable ps-font-family specifies which font family to use for printing
ordinary text. Legitimate values include Courier, Helvetica, NewCenturySchlbk,
Palatino and Times. The variable ps-font-size specifies the size of the font for
ordinary text. It defaults to 8.5 points.
Emacs supports more scripts and characters than a typical PostScript printer.
Thus, some of the characters in your buffer might not be printable using the fonts
built into your printer. You can augment the fonts supplied with the printer with
those from the GNU Intlfonts package, or you can instruct Emacs to use Intlfonts
exclusively. The variable ps-multibyte-buffer controls this: the default value,
nil, is appropriate for printing ASCII and Latin-1 characters; a value of non-latinprinter is for printers which have the fonts for ASCII, Latin-1, Japanese, and
Korean characters built into them. A value of bdf-font arranges for the BDF
fonts from the Intlfonts package to be used for all characters. Finally, a value of

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bdf-font-except-latin instructs the printer to use built-in fonts for ASCII and
Latin-1 characters, and Intlfonts BDF fonts for the rest.
To be able to use the BDF fonts, Emacs needs to know where to find
them. The variable bdf-directory-list holds the list of directories where
Emacs should look for the fonts; the default value includes a single directory
‘/usr/local/share/emacs/fonts/bdf’.
Many other customization variables for these commands are defined and described in the Lisp files ‘ps-print.el’ and ‘ps-mule.el’.
31.5.3 Printing Package
The basic Emacs facilities for printing hardcopy can be extended using the Printing
package. This provides an easy-to-use interface for choosing what to print, previewing PostScript files before printing, and setting various printing options such
as print headers, landscape or portrait modes, duplex modes, and so forth. On
GNU/Linux or Unix systems, the Printing package relies on the ‘gs’ and ‘gv’ utilities, which are distributed as part of the GhostScript program. On MS-Windows,
the ‘gstools’ port of Ghostscript can be used.
To use the Printing package, add (require ’printing) to your init file (see
Section 33.4 [Init File], page 461), followed by (pr-update-menus). This function
replaces the usual printing commands in the menu bar with a ‘Printing’ submenu
that contains various printing options. You can also type M-x pr-interface RET;
this creates a ‘*Printing Interface*’ buffer, similar to a customization buffer,
where you can set the printing options. After selecting what and how to print, you
start the print job using the ‘Print’ button (click mouse-2 on it, or move point over
it and type RET). For further information on the various options, use the ‘Interface
Help’ button.

31.6 Sorting Text
Emacs provides several commands for sorting text in the buffer. All operate on the
contents of the region. They divide the text of the region into many sort records,
identify a sort key for each record, and then reorder the records into the order
determined by the sort keys. The records are ordered so that their keys are in
alphabetical order, or, for numeric sorting, in numeric order. In alphabetic sorting,
all upper-case letters ‘A’ through ‘Z’ come before lower-case ‘a’, in accord with the
ASCII character sequence.
The various sort commands differ in how they divide the text into sort records
and in which part of each record is used as the sort key. Most of the commands
make each line a separate sort record, but some commands use paragraphs or pages
as sort records. Most of the sort commands use each entire sort record as its own
sort key, but some use only a portion of the record as the sort key.
M-x sort-lines
Divide the region into lines, and sort by comparing the entire text of
a line. A numeric argument means sort into descending order.

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M-x sort-paragraphs
Divide the region into paragraphs, and sort by comparing the entire
text of a paragraph (except for leading blank lines). A numeric argument means sort into descending order.
M-x sort-pages
Divide the region into pages, and sort by comparing the entire text of
a page (except for leading blank lines). A numeric argument means
sort into descending order.
M-x sort-fields
Divide the region into lines, and sort by comparing the contents of one
field in each line. Fields are defined as separated by whitespace, so the
first run of consecutive non-whitespace characters in a line constitutes
field 1, the second such run constitutes field 2, etc.
Specify which field to sort by with a numeric argument: 1 to sort by
field 1, etc. A negative argument means count fields from the right
instead of from the left; thus, minus 1 means sort by the last field.
If several lines have identical contents in the field being sorted, they
keep the same relative order that they had in the original buffer.
M-x sort-numeric-fields
Like M-x sort-fields except the specified field is converted to an
integer for each line, and the numbers are compared. ‘10’ comes before
‘2’ when considered as text, but after it when considered as a number.
By default, numbers are interpreted according to sort-numeric-base,
but numbers beginning with ‘0x’ or ‘0’ are interpreted as hexadecimal
and octal, respectively.
M-x sort-columns
Like M-x sort-fields except that the text within each line used for
comparison comes from a fixed range of columns. See below for an
explanation.
M-x reverse-region
Reverse the order of the lines in the region. This is useful for sorting
into descending order by fields or columns, since those sort commands
do not have a feature for doing that.
For example, if the buffer contains this:
On systems where clash detection (locking of files being edited) is
implemented, Emacs also checks the first time you modify a buffer
whether the file has changed on disk since it was last visited or
saved. If it has, you are asked to confirm that you want to change
the buffer.

applying M-x sort-lines to the entire buffer produces this:
On systems where clash detection (locking of files being edited) is
implemented, Emacs also checks the first time you modify a buffer
saved. If it has, you are asked to confirm that you want to change
the buffer.

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whether the file has changed on disk since it was last visited or

where the upper-case ‘O’ sorts before all lower-case letters. If you use C-u 2 M-x
sort-fields instead, you get this:
implemented, Emacs also checks the first time you modify a buffer
saved. If it has, you are asked to confirm that you want to change
the buffer.
On systems where clash detection (locking of files being edited) is
whether the file has changed on disk since it was last visited or

where the sort keys were ‘Emacs’, ‘If’, ‘buffer’, ‘systems’ and ‘the’.
M-x sort-columns requires more explanation. You specify the columns by
putting point at one of the columns and the mark at the other column. Because
this means you cannot put point or the mark at the beginning of the first line of
the text you want to sort, this command uses an unusual definition of “region”: all
of the line point is in is considered part of the region, and so is all of the line the
mark is in, as well as all the lines in between.
For example, to sort a table by information found in columns 10 to 15, you could
put the mark on column 10 in the first line of the table, and point on column 15 in
the last line of the table, and then run sort-columns. Equivalently, you could run
it with the mark on column 15 in the first line and point on column 10 in the last
line.
This can be thought of as sorting the rectangle specified by point and the mark,
except that the text on each line to the left or right of the rectangle moves along
with the text inside the rectangle. See Section 9.5 [Rectangles], page 63.
Many of the sort commands ignore case differences when comparing, if sortfold-case is non-nil.

31.7 Editing Binary Files
There is a special major mode for editing binary files: Hexl mode. To use it, use
M-x hexl-find-file instead of C-x C-f to visit the file. This command converts
the file’s contents to hexadecimal and lets you edit the translation. When you save
the file, it is converted automatically back to binary.
You can also use M-x hexl-mode to translate an existing buffer into hex. This
is useful if you visit a file normally and then discover it is a binary file.
Ordinary text characters overwrite in Hexl mode. This is to reduce the risk of
accidentally spoiling the alignment of data in the file. There are special commands
for insertion. Here is a list of the commands of Hexl mode:
C-M-d

Insert a byte with a code typed in decimal.

C-M-o

Insert a byte with a code typed in octal.

C-M-x

Insert a byte with a code typed in hex.

C-x [

Move to the beginning of a 1k-byte “page”.

C-x ]

Move to the end of a 1k-byte “page”.

M-g

Move to an address specified in hex.

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M-j

Move to an address specified in decimal.

C-c C-c

Leave Hexl mode, going back to the major mode this buffer had before
you invoked hexl-mode.

Other Hexl commands let you insert strings (sequences) of binary bytes, move by
shorts or ints, etc.; type C-h a hexl-RET for details.

31.8 Saving Emacs Sessions
Use the desktop library to save the state of Emacs from one session to another. Once
you save the Emacs desktop—the buffers, their file names, major modes, buffer
positions, and so on—then subsequent Emacs sessions reload the saved desktop.
You can save the desktop manually with the command M-x desktop-save. You
can also enable automatic saving of the desktop when you exit Emacs, and automatic restoration of the last saved desktop when Emacs starts: use the Customization buffer (see Section 33.1 [Easy Customization], page 434) to set desktop-savemode to t for future sessions, or add this line in your init file (see Section 33.4 [Init
File], page 461):
(desktop-save-mode 1)
If you turn on desktop-save-mode in your init file, then when Emacs starts, it
looks for a saved desktop in the current directory. (More precisely, it looks in the
directories specified by desktop-path, and uses the first desktop it finds.) Thus, you
can have separate saved desktops in different directories, and the starting directory
determines which one Emacs reloads. You can save the current desktop and reload
one saved in another directory by typing M-x desktop-change-dir. Typing M-x
desktop-revert reverts to the desktop previously reloaded.
Specify the option ‘--no-desktop’ on the command line when you don’t want
it to reload any saved desktop. This turns off desktop-save-mode for the current
session. Starting Emacs with the ‘--no-init-file’ option also disables desktop
reloading, since it bypasses the init file, where desktop-save-mode is usually turned
on.
By default, all the buffers in the desktop are restored at one go. However,
this may be slow if there are a lot of buffers in the desktop. You can specify the
maximum number of buffers to restore immediately with the variable desktoprestore-eager; the remaining buffers are restored “lazily”, when Emacs is idle.
Type M-x desktop-clear to empty the Emacs desktop. This kills all buffers
except for internal ones, and clears the global variables listed in desktop-globalsto-clear. If you want this to preserve certain buffers, customize the variable
desktop-clear-preserve-buffers-regexp, whose value is a regular expression
matching the names of buffers not to kill.
If you want to save minibuffer history from one session to another, use the
savehist library.

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31.9 Recursive Editing Levels
A recursive edit is a situation in which you are using Emacs commands to perform
arbitrary editing while in the middle of another Emacs command. For example,
when you type C-r inside of a query-replace, you enter a recursive edit in which
you can change the current buffer. On exiting from the recursive edit, you go back
to the query-replace.
Exiting the recursive edit means returning to the unfinished command, which
continues execution. The command to exit is C-M-c (exit-recursive-edit).
You can also abort the recursive edit. This is like exiting, but also quits the
unfinished command immediately. Use the command C-] (abort-recursive-edit)
to do this. See Section 34.1 [Quitting], page 468.
The mode line shows you when you are in a recursive edit by displaying square
brackets around the parentheses that always surround the major and minor mode
names. Every window’s mode line shows this in the same way, since being in a
recursive edit is true of Emacs as a whole rather than any particular window or
buffer.
It is possible to be in recursive edits within recursive edits. For example, after
typing C-r in a query-replace, you may type a command that enters the debugger.
This begins a recursive editing level for the debugger, within the recursive editing
level for C-r. Mode lines display a pair of square brackets for each recursive editing
level currently in progress.
Exiting the inner recursive edit (such as with the debugger c command) resumes
the command running in the next level up. When that command finishes, you can
then use C-M-c to exit another recursive editing level, and so on. Exiting applies to
the innermost level only. Aborting also gets out of only one level of recursive edit;
it returns immediately to the command level of the previous recursive edit. If you
wish, you can then abort the next recursive editing level.
Alternatively, the command M-x top-level aborts all levels of recursive edits,
returning immediately to the top-level command reader. It also exits the minibuffer,
if it is active.
The text being edited inside the recursive edit need not be the same text that
you were editing at top level. It depends on what the recursive edit is for. If
the command that invokes the recursive edit selects a different buffer first, that
is the buffer you will edit recursively. In any case, you can switch buffers within
the recursive edit in the normal manner (as long as the buffer-switching keys have
not been rebound). You could probably do all the rest of your editing inside the
recursive edit, visiting files and all. But this could have surprising effects (such as
stack overflow) from time to time. So remember to exit or abort the recursive edit
when you no longer need it.
In general, we try to minimize the use of recursive editing levels in GNU Emacs.
This is because they constrain you to “go back” in a particular order—from the
innermost level toward the top level. When possible, we present different activities
in separate buffers so that you can switch between them as you please. Some
commands switch to a new major mode which provides a command to switch back.

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These approaches give you more flexibility to go back to unfinished tasks in the
order you choose.

31.10 Emulation
GNU Emacs can be programmed to emulate (more or less) most other editors.
Standard facilities can emulate these:
CRiSP/Brief (PC editor)
M-x crisp-mode enables key bindings to emulate the CRiSP/Brief editor. Note that this rebinds M-x to exit Emacs unless you set the
variable crisp-override-meta-x. You can also use the command
M-x scroll-all-mode or set the variable crisp-load-scroll-all to
emulate CRiSP’s scroll-all feature (scrolling all windows together).
EDT (DEC VMS editor)
Turn on EDT emulation with M-x edt-emulation-on; restore normal
command bindings with M-x edt-emulation-off.
Most of the EDT emulation commands are keypad keys, and most
standard Emacs key bindings are still available. The EDT emulation rebindings are done in the global keymap, so there is no problem
switching buffers or major modes while in EDT emulation.
TPU (DEC VMS editor)
M-x tpu-edt-on turns on emulation of the TPU editor emulating
EDT.
vi (Berkeley editor)
Viper is the newest emulator for vi. It implements several levels of
emulation; level 1 is closest to vi itself, while level 5 departs somewhat
from strict emulation to take advantage of the capabilities of Emacs.
To invoke Viper, type M-x viper-mode; it will guide you the rest of
the way and ask for the emulation level. See Info file ‘viper’, node
‘Top’.
vi (another emulator)
M-x vi-mode enters a major mode that replaces the previously established major mode. All of the vi commands that, in real vi, enter
“input” mode are programmed instead to return to the previous major mode. Thus, ordinary Emacs serves as vi’s “input” mode.
Because vi emulation works through major modes, it does not work
to switch buffers during emulation. Return to normal Emacs first.
If you plan to use vi emulation much, you probably want to bind a
key to the vi-mode command.
vi (alternate emulator)
M-x vip-mode invokes another vi emulator, said to resemble real vi
more thoroughly than M-x vi-mode. “Input” mode in this emulator
is changed from ordinary Emacs so you can use ESC to go back to

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emulated vi command mode. To get from emulated vi command mode
back to ordinary Emacs, type C-z.
This emulation does not work through major modes, and it is possible
to switch buffers in various ways within the emulator. It is not so
necessary to assign a key to the command vip-mode as it is with vimode because terminating insert mode does not use it.
See Info file ‘vip’, node ‘Top’, for full information.
WordStar (old wordprocessor)
M-x wordstar-mode provides a major mode with WordStar-like key
bindings.

31.11 Hyperlinking and Navigation Features
The following subsections describe convenience features for handling URLs and
other types of links occurring in Emacs buffer text.
31.11.1 Following URLs
M-x browse-url RET url RET
Load a URL into a Web browser.
The Browse-URL package allows you to easily follow URLs from within Emacs.
Most URLs are followed by invoking a web browser; ‘mailto:’ URLs are followed by
invoking the compose-mail Emacs command to send mail to the specified address
(see Chapter 29 [Sending Mail], page 367).
The command M-x browse-url prompts for a URL, and follows it. If point is
located near a plausible URL, that URL is offered as the default. The Browse-URL
package also provides other commands which you might like to bind to keys, such
as browse-url-at-point and browse-url-at-mouse.
You can customize Browse-URL’s behavior via various options in the browseurl Customize group. In particular, the option browse-url-mailto-function lets
you define how to follow ‘mailto:’ URLs, while browse-url-browser-function
lets you define how to follow other types of URLs. For more information, view the
package commentary by typing C-h P browse-url RET.
31.11.2 Activating URLs
M-x goto-address-mode
Activate URLs and e-mail addresses in the current buffer.
You can make Emacs mark out URLs specially in the current buffer, by typing
M-x goto-address-mode. When this buffer-local minor mode is enabled, it finds
all the URLs in the buffer, highlights them, and turns them into clickable buttons.
You can follow the URL by typing C-c RET (goto-address-at-point) while point
is on its text; or by clicking with Mouse-2, or by clicking Mouse-1 quickly (see
Section 18.3 [Mouse References], page 167). Following a URL is done by calling
browse-url as a subroutine (see Section 31.11.1 [Browse-URL], page 426).

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It can be useful to add goto-address-mode to mode hooks and hooks for displaying an incoming message (e.g. rmail-show-message-hook for Rmail, and mhshow-mode-hook for MH-E). This is not needed for Gnus, which has a similar feature
of its own.
31.11.3 Finding Files and URLs at Point
The FFAP package replaces certain key bindings for finding files, such as C-x C-f,
with commands that provide more sensitive defaults. These commands behave like
the ordinary ones when given a prefix argument. Otherwise, they get the default
file name or URL from the text around point. If what is found in the buffer has the
form of a URL rather than a file name, the commands use browse-url to view it
(see Section 31.11.1 [Browse-URL], page 426).
This feature is useful for following references in mail or news buffers, ‘README’
files, ‘MANIFEST’ files, and so on. For more information, view the package commentary by typing C-h P ffap RET.
To enable FFAP, type M-x ffap-bindings. This makes the following key bindings, and also installs hooks for additional FFAP functionality in Rmail, Gnus and
VM article buffers.
C-x C-f filename RET
Find filename, guessing a default from text around point (find-fileat-point).
C-x C-r

ffap-read-only, analogous to find-file-read-only.

C-x C-v

ffap-alternate-file, analogous to find-alternate-file.

C-x d directory RET
Start Dired on directory, defaulting to the directory name at point
(dired-at-point).
C-x C-d

ffap-list-directory, analogous to list-directory.

C-x 4 f

ffap-other-window, analogous to find-file-other-window.

C-x 4 r

ffap-read-only-other-window,
only-other-window.

C-x 4 d

ffap-dired-other-window, like dired-other-window.

C-x 5 f

ffap-other-frame, analogous to find-file-other-frame.

C-x 5 r

ffap-read-only-other-frame, analogous to find-file-read-onlyother-frame.

C-x 5 d

ffap-dired-other-frame, analogous to dired-other-frame.

analogous to find-file-read-

M-x ffap-next
Search buffer for next file name or URL, then find that file or URL.
S-Mouse-3

ffap-at-mouse finds the file guessed from text around the position of
a mouse click.

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C-S-Mouse-3
Display a menu of files and URLs mentioned in current buffer, then
find the one you select (ffap-menu).

31.12 Other Amusements
The animate package makes text dance (e.g. M-x animate-birthday-present).
M-x blackbox, M-x mpuz and M-x 5x5 are puzzles. blackbox challenges you
to determine the location of objects inside a box by tomography. mpuz displays
a multiplication puzzle with letters standing for digits in a code that you must
guess—to guess a value, type a letter and then the digit you think it stands for.
The aim of 5x5 is to fill in all the squares.
M-x bubbles is a game in which the object is to remove as many bubbles as you
can in the smallest number of moves.
M-x decipher helps you to cryptanalyze a buffer which is encrypted in a simple
monoalphabetic substitution cipher.
M-x dissociated-press scrambles the text in the current Emacs buffer,
word by word or character by character, writing its output to a buffer named
‘*Dissociation*’. A positive argument tells it to operate character by character,
and specifies the number of overlap characters. A negative argument tells it to
operate word by word, and specifies the number of overlap words. Dissociated
Press produces results fairly like those of a Markov chain, but is however, an
independent, ignoriginal invention; it techniquitously copies several consecutive
characters from the sample text between random jumps, unlike a Markov chain
which would jump randomly after each word or character. Keep dissociwords out
of your documentation, if you want it to be well userenced and properbose.
M-x dunnet runs an text-based adventure game.
If you want a little more personal involvement, try M-x gomoku, which plays the
game Go Moku with you.
If you are a little bit bored, you can try M-x hanoi. If you are considerably
bored, give it a numeric argument. If you are very, very bored, try an argument of
9. Sit back and watch.
M-x life runs Conway’s “Life” cellular automaton.
M-x landmark runs a relatively non-participatory game in which a robot attempts to maneuver towards a tree at the center of the window based on unique
olfactory cues from each of the four directions.
M-x morse-region converts the text in the region to Morse code; M-x
unmorse-region converts it back. M-x nato-region converts the text in the
region to NATO phonetic alphabet; M-x denato-region converts it back.
M-x pong, M-x snake and M-x tetris are implementations of the well-known
Pong, Snake and Tetris games.
M-x solitaire plays a game of solitaire in which you jump pegs across other
pegs.
The command M-x zone plays games with the display when Emacs is idle.

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Finally, if you find yourself frustrated, try describing your problems to the famous psychotherapist Eliza. Just do M-x doctor. End each input by typing RET
twice.

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32 Emacs Lisp Packages
Emacs includes a facility that lets you easily download and install packages that
implement additional features. Each package is a separate Emacs Lisp program,
sometimes including other components such as an Info manual.
M-x list-packages brings up a buffer named ‘*Packages*’ with a list of all
packages. You can install or uninstall packages via this buffer. See Section 32.1
[Package Menu], page 430.
The command C-h P (describe-package) prompts for the name of a package,
and displays a help buffer describing the attributes of the package and the features
that it implements.
By default, Emacs downloads packages from a package archive maintained by
the Emacs developers and hosted by the GNU project. Optionally, you can also
download packages from archives maintained by third parties. See Section 32.2
[Package Installation], page 431.
For information about turning an Emacs Lisp program into an installable package, See Section “Packaging” in The Emacs Lisp Reference Manual. For information
about finding third-party packages and other Emacs Lisp extensions, See Section
“Packages that do not come with Emacs” in GNU Emacs FAQ.

32.1 The Package Menu Buffer
The command M-x list-packages brings up the package menu. This is a buffer
listing all the packages that Emacs knows about, one on each line, with the following
information:
• The package name (e.g. ‘auctex’).
• The package’s version number (e.g. ‘11.86’).
• The package’s status—normally one of ‘available’ (can be downloaded from
the package archive), ‘installed’, or ‘built-in’ (included in Emacs by default).
In some instances, the status can be ‘held’, ‘disabled’, or ‘obsolete’. See
Section 32.2 [Package Installation], page 431.
• A short description of the package.
The list-packages command accesses the network, to retrieve the list of available
packages from the package archive server. If the network is unavailable, it falls back
on the most recently retrieved list.
The following commands are available in the package menu:
h
?
RET

Print a short message summarizing how to use the package menu
(package-menu-quick-help).
Display a help buffer for the package on the current line (packagemenu-describe-package), similar to the help window displayed by
the C-h P command (see Chapter 32 [Packages], page 430).

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i

Mark the package on the current line for installation (package-menumark-install). If the package status is ‘available’, this adds an ‘I’
character to the start of the line; typing x (see below) will download
and install the package.

d

Mark the package on the current line for deletion (package-menumark-delete). If the package status is ‘installed’, this adds a ‘D’
character to the start of the line; typing x (see below) will delete the
package. See Section 32.3 [Package Files], page 432, for information
about what package deletion entails.

u

Remove any installation or deletion mark previously added to the current line by an i or d command.

U

Mark all package with a newer available version for “upgrading”
(package-menu-mark-upgrades). This places an installation mark
on the new available versions, and a deletion mark on the old installed
versions.

x

Download and install all packages marked with i, and their dependencies; also, delete all packages marked with d (package-menu-execute).
This also removes the marks.

r

Refresh the package list (package-menu-refresh). This fetches the
list of available packages from the package archive again, and recomputes the package list.

For example, you can install a package by typing i on the line listing that package,
followed by x.

32.2 Package Installation
Packages are most conveniently installed using the package menu (see
Section 32.1 [Package Menu], page 430), but you can also use the command M-x
package-install. This prompts for the name of a package with the ‘available’
status, then downloads and installs it.
A package may require certain other packages to be installed, because it relies
on functionality provided by them. When Emacs installs such a package, it also
automatically downloads and installs any required package that is not already installed. (If a required package is somehow unavailable, Emacs signals an error and
stops installation.) A package’s requirements list is shown in its help buffer.
By default, packages are downloaded from a single package archive maintained
by the Emacs developers. This is controlled by the variable package-archives,
whose value is a list of package archives known to Emacs. Each list element must
have the form (id . location ), where id is the name of a package archive and
location is the HTTP address or directory name of the package archive. You can
alter this list if you wish to use third party package archives—but do so at your
own risk, and use only third parties that you think you can trust!
Once a package is downloaded and installed, it is loaded into the current Emacs
session. Loading a package is not quite the same as loading a Lisp library (see

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Section 24.8 [Lisp Libraries], page 287); its effect varies from package to package.
Most packages just make some new commands available, while others have more
wide-ranging effects on the Emacs session. For such information, consult the package’s help buffer.
By default, Emacs also automatically loads all installed packages in subsequent Emacs sessions. This happens at startup, after processing the init file (see
Section 33.4 [Init File], page 461). As an exception, Emacs does not load packages
at startup if invoked with the ‘-q’ or ‘--no-init-file’ options (see Section C.2
[Initial Options], page 507).
To disable automatic package loading, change the variable package-enableat-startup to nil.
The reason automatic package loading occurs after loading the init file is that
user options only receive their customized values after loading the init file, including
user options which affect the packaging system. In some circumstances, you may
want to load packages explicitly in your init file (usually because some other code
in your init file depends on a package). In that case, your init file should call
the function package-initialize. It is up to you to ensure that relevant user
options, such as package-load-list (see below), are set up prior to the packageinitialize call. You should also set package-enable-at-startup to nil, to avoid
loading the packages again after processing the init file. Alternatively, you may
choose to completely inhibit package loading at startup, and invoke the command
M-x package-initialize to load your packages manually.
For finer control over package loading, you can use the variable package-loadlist. Its value should be a list. A list element of the form (name version ) tells
Emacs to load version version of the package named name. Here, version should
be a version string (corresponding to a specific version of the package), or t (which
means to load any installed version), or nil (which means no version; this “disables”
the package, preventing it from being loaded). A list element can also be the symbol
all, which means to load the latest installed version of any package not named by
the other list elements. The default value is just ’(all).
For example, if you set package-load-list to ’((muse "3.20") all), then
Emacs only loads version 3.20 of the ‘muse’ package, plus any installed version of
packages other than ‘muse’. Any other version of ‘muse’ that happens to be installed
will be ignored. The ‘muse’ package will be listed in the package menu with the
‘held’ status.

32.3 Package Files and Directory Layout
Each package is downloaded from the package archive in the form of a single package
file—either an Emacs Lisp source file, or a tar file containing multiple Emacs Lisp
source and other files. Package files are automatically retrieved, processed, and disposed of by the Emacs commands that install packages. Normally, you will not need
to deal directly with them, unless you are making a package (see Section “Packaging” in The Emacs Lisp Reference Manual). Should you ever need to install a
package directly from a package file, use the command M-x package-install-file.

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Once installed, the contents of a package are placed in a subdirectory of
‘~/.emacs.d/elpa/’ (you can change the name of that directory by changing the
variable package-user-dir). The package subdirectory is named ‘name-version ’,
where name is the package name and version is its version string.
In addition to package-user-dir, Emacs looks for installed packages in the
directories listed in package-directory-list. These directories are meant for
system administrators to make Emacs packages available system-wide; Emacs itself
never installs packages there. The package subdirectories for package-directorylist are laid out in the same way as in package-user-dir.
Deleting a package (see Section 32.1 [Package Menu], page 430) involves deleting
the corresponding package subdirectory. This only works for packages installed in
package-user-dir; if told to act on a package in a system-wide package directory,
the deletion command signals an error.

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33 Customization
This chapter describes some simple methods to customize the behavior of Emacs.
Apart from the methods described here, see Appendix D [X Resources], page 521
for information about using X resources to customize Emacs, and see Chapter 14
[Keyboard Macros], page 116 for information about recording and replaying keyboard macros. Making more far-reaching and open-ended changes involves writing
Emacs Lisp code; see The Emacs Lisp Reference Manual.

33.1 Easy Customization Interface
Emacs has many settings which you can change. Most settings are customizable
variables (see Section 33.2 [Variables], page 443), which are also called user options.
There is a huge number of customizable variables, controlling numerous aspects of
Emacs behavior; the variables documented in this manual are listed in [Variable
Index], page 604. A separate class of settings are the faces, which determine the
fonts, colors, and other attributes of text (see Section 11.8 [Faces], page 75).
To browse and alter settings (both variables and faces), type M-x customize.
This creates a customization buffer, which lets you navigate through a logically
organized list of settings, edit and set their values, and save them permanently.
33.1.1 Customization Groups
Customization settings are organized into customization groups. These groups are
collected into bigger groups, all the way up to a master group called Emacs.
M-x customize creates a customization buffer that shows the top-level Emacs
group. It looks like this, in part:
To apply changes, use the Save or Set buttons.
For details, see [Saving Customizations] in the [Emacs manual].
________________________________________ [ Search ]
Operate on all settings in this buffer:
[ Set for current session ] [ Save for future sessions ]
[ Undo edits ] [ Reset to saved ] [ Erase customizations ] [ Exit ]

Emacs group: Customization of the One True Editor.
[State]: visible group members are all at standard values.
See also [Manual].
[Editing] : Basic text editing facilities.
[Convenience] : Convenience features for faster editing.
more second-level groups

The main part of this buffer shows the ‘Emacs’ customization group, which contains
several other groups (‘Editing’, ‘Convenience’, etc.). The contents of those groups
are not listed here, only one line of documentation each.

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The state of the group indicates whether setting in that group has been edited,
set or saved. See Section 33.1.3 [Changing a Variable], page 436.
Most of the customization buffer is read-only, but it includes some editable fields
that you can edit. For example, at the top of the customization buffer is an editable
field for searching for settings (see Section 33.1.2 [Browsing Custom], page 435).
There are also buttons and links, which you can activate by either clicking with
the mouse, or moving point there and typing RET. For example, the group names
like ‘[Editing]’ are links; activating one of these links brings up the customization
buffer for that group.
In the customizable buffer, you can type TAB (widget-forward) to move forward to the next button or editable field. S-TAB (widget-backward) moves back
to the previous button or editable field.
33.1.2 Browsing and Searching for Settings
From the top-level customization buffer created by M-x customize, you can follow
the links to the subgroups of the ‘Emacs’ customization group. These subgroups
may contain settings for you to customize; they may also contain further subgroups,
dealing with yet more specialized subsystems of Emacs. As you navigate the hierarchy of customization groups, you should find some settings that you want to
customize.
If you are interested in customizing a particular setting or customization
group, you can go straight there with the commands M-x customize-option, M-x
customize-face, or M-x customize-group. See Section 33.1.6 [Specific Customization], page 440.
If you don’t know exactly what groups or settings you want to customize, you
can search for them using the editable search field at the top of each customization
buffer. Here, you can type in a search term—either one or more words separated
by spaces, or a regular expression (see Section 12.5 [Regexps], page 97). Then
type RET in the field, or activate the ‘Search’ button next to it, to switch to a
customization buffer containing groups and settings that match those terms. Note,
however, that this feature only finds groups and settings that are loaded in the
current Emacs session.
If you don’t want customization buffers to show the search field, change the
variable custom-search-field to nil.
The command M-x customize-apropos is similar to using the search field, except that it reads the search term(s) using the minibuffer. See Section 33.1.6 [Specific Customization], page 440.
M-x customize-browse is another way to browse the available settings. This
command creates a special customization buffer which shows only the names of
groups and settings, in a structured layout. You can show the contents of a group,
in the same buffer, by invoking the ‘[+]’ button next to the group name. When the
group contents are shown, the button changes to ‘[-]’; invoking that hides the group
contents again. Each group or setting in this buffer has a link which says ‘[Group]’,
‘[Option]’ or ‘[Face]’. Invoking this link creates an ordinary customization buffer

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showing just that group, option, or face; this is the way to change settings that you
find with M-x customize-browse.
33.1.3 Changing a Variable
Here is an example of what a variable, or user option, looks like in the customization
buffer:
[Hide] Kill Ring Max: 60
[State]: STANDARD.
Maximum length of kill ring before oldest elements are thrown away.

The first line shows that the variable is named kill-ring-max, formatted as
‘Kill Ring Max’ for easier viewing. Its value is ‘60’. The button labeled ‘[Hide]’,
if activated, hides the variable’s value and state; this is useful to avoid cluttering
up the customization buffer with very long values (for this reason, variables that
have very long values may start out hidden). If you use the ‘[Hide]’ button, it
changes to ‘[Show Value]’, which you can activate to reveal the value and state.
On a graphical display, the ‘[Hide]’ and ‘[Show Value]’ buttons are replaced with
graphical triangles pointing downwards and rightwards respectively.
The line after the variable name indicates the customization state of the variable:
in this example, ‘STANDARD’ means you have not changed the variable, so its value is
the default one. The ‘[State]’ button gives a menu of operations for customizing
the variable.
Below the customization state is the documentation for the variable. This is the
same documentation that would be shown by the C-h v command (see Section 33.2.1
[Examining], page 443). If the documentation is more than one line long, only one
line may be shown. If so, that line ends with a ‘[More]’ button; activate this to see
the full documentation.
To enter a new value for ‘Kill Ring Max’, just move point to the value and edit
it. For example, type M-d to delete the ‘60’ and type in another number. As you
begin to alter the text, the ‘[State]’ line will change:
[State]: EDITED, shown value does not take effect until you
set or save it.

Editing the value does not make it take effect right away. To do that, you must
set the variable by activating the ‘[State]’ button and choosing ‘Set for Current
Session’. Then the variable’s state becomes:
[State]: SET for current session only.

You don’t have to worry about specifying a value that is not valid; the ‘Set for
Current Session’ operation checks for validity and will not install an unacceptable
value.
While editing certain kinds of values, such as file names, directory names,
and Emacs command names, you can perform completion with C-M-i (widgetcomplete), or the equivalent keys M-TAB or ESC TAB. This behaves much like minibuffer completion (see Section 5.3 [Completion], page 29).
Typing RET on an editable value field moves point forward to the next field or
button, like TAB. You can thus type RET when you are finished editing a field, to

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move on to the next button or field. To insert a newline within an editable field,
use C-o or C-q C-j.
For some variables, there is only a fixed set of legitimate values, and you are not
allowed to edit the value directly. Instead, a ‘[Value Menu]’ button appears before
the value; activating this button presents a choice of values. For a boolean “on or
off” value, the button says ‘[Toggle]’, and flips the value. After using the ‘[Value
Menu]’ or ‘[Toggle]’ button, you must again set the variable to make the chosen
value take effect.
Some variables have values with complex structure. For example, the value
of minibuffer-frame-alist is an association list. Here is how it appears in the
customization buffer:
[Hide] Minibuffer Frame Alist:
[INS] [DEL] Parameter: width
Value: 80
[INS] [DEL] Parameter: height
Value: 2
[INS]
[ State ]: STANDARD.
Alist of parameters for the initial minibuffer frame. [Hide]
[. . . more lines of documentation. . . ]

In this case, each association in the list consists of two items, one labeled
‘Parameter’ and one labeled ‘Value’; both are editable fields. You can delete an
association from the list with the ‘[DEL]’ button next to it. To add an association,
use the ‘[INS]’ button at the position where you want to insert it; the very last
‘[INS]’ button inserts at the end of the list.
When you set a variable, the new value takes effect only in the current Emacs
session. To save the value for future sessions, use the ‘[State]’ button and select
the ‘Save for Future Sessions’ operation. See Section 33.1.4 [Saving Customizations], page 438.
You can also restore the variable to its standard value by using the ‘[State]’
button and selecting the ‘Erase Customization’ operation. There are actually four
reset operations:
‘Undo Edits’
If you have modified but not yet set the variable, this restores the text
in the customization buffer to match the actual value.
‘Reset to Saved’
This restores the value of the variable to the last saved value, and
updates the text accordingly.
‘Erase Customization’
This sets the variable to its standard value. Any saved value that you
have is also eliminated.
‘Set to Backup Value’
This sets the variable to a previous value that was set in the customization buffer in this session. If you customize a variable and then reset it,

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which discards the customized value, you can get the discarded value
back again with this operation.
Sometimes it is useful to record a comment about a specific customization. Use
the ‘Add Comment’ item from the ‘[State]’ menu to create a field for entering the
comment.
Near the top of the customization buffer are two lines of buttons:
[Set for Current Session] [Save for Future Sessions]
[Undo Edits] [Reset to Saved] [Erase Customization]

[Exit]

Each of the first five buttons performs the stated operation—set, save, reset, etc.—
on all the settings in the buffer that could meaningfully be affected. They do not
operate on settings that are hidden, nor on subgroups that are hidden or not visible
in the buffer.
The command C-c C-c (Custom-set) is equivalent using to the ‘[Set for
Current Session]’ button. The command C-x C-s (Custom-save) is like using
the ‘[Save for Future Sessions]’ button.
The ‘[Exit]’ button switches out of the customization buffer, and buries the
buffer at the bottom of the buffer list. To make it kill the customization buffer
instead, change the variable custom-buffer-done-kill to t.
33.1.4 Saving Customizations
In the customization buffer, you can save a customization setting by choosing
the ‘Save for Future Sessions’ choice from its ‘[State]’ button. The C-x C-s
(Custom-save) command, or the ‘[Save for Future Sessions]’ button at the top
of the customization buffer, saves all applicable settings in the buffer.
Saving works by writing code to a file, usually your initialization file (see
Section 33.4 [Init File], page 461). Future Emacs sessions automatically read this
file at startup, which sets up the customizations again.
You can choose to save customizations somewhere other than your initialization
file. To make this work, you must add a couple of lines of code to your initialization
file, to set the variable custom-file to the name of the desired file, and to load
that file. For example:
(setq custom-file "~/.emacs-custom.el")
(load custom-file)
You can even specify different customization files for different Emacs versions,
like this:
(cond ((< emacs-major-version 22)
;; Emacs 21 customization.
(setq custom-file "~/.custom-21.el"))
((and (= emacs-major-version 22)
(< emacs-minor-version 3))
;; Emacs 22 customization, before version 22.3.
(setq custom-file "~/.custom-22.el"))
(t
;; Emacs version 22.3 or later.
(setq custom-file "~/.emacs-custom.el")))

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(load custom-file)
If Emacs was invoked with the ‘-q’ or ‘--no-init-file’ options (see Section C.2
[Initial Options], page 507), it will not let you save your customizations in your
initialization file. This is because saving customizations from such a session would
wipe out all the other customizations you might have on your initialization file.
33.1.5 Customizing Faces
You can customize faces (see Section 11.8 [Faces], page 75), which determine how
Emacs displays different types of text. Customization groups can contain both
variables and faces.
For example, in programming language modes, source code comments are shown
with font-lock-comment-face (see Section 11.12 [Font Lock], page 80). In a customization buffer, that face appears like this:
[Hide] Font Lock Comment Face:[sample]
[State] : STANDARD.
Font Lock mode face used to highlight comments.
[ ] Font Family: -[ ] Font Foundry: -[ ] Width: -[ ] Height: -[ ] Weight: -[ ] Slant: -[ ] Underline: -[ ] Overline: -[ ] Strike-through: -[ ] Box around text: -[ ] Inverse-video: -[X] Foreground: Firebrick
[Choose] (sample)
[ ] Background: -[ ] Stipple: -[ ] Inherit: -[Hide Unused Attributes]

The first three lines show the name, ‘[State]’ button, and documentation for the
face. Below that is a list of face attributes. In front of each attribute is a checkbox.
A filled checkbox, ‘[X]’, means that the face specifies a value for this attribute; an
empty checkbox, ‘[ ]’, means that the face does not specify any special value for
the attribute. You can activate a checkbox to specify or unspecify its attribute.
Most faces only specify a few attributes (in the above example, font-lockcomment-face only specifies the foreground color). Emacs has a special face,
default, whose attributes are all specified; it determines the attributes left unspecified by other faces.
The ‘Hide Unused Attributes’ button, at the end of the attribute list, hides
the unspecified attributes of the face. When attributes are being hidden, the button
changes to ‘[Show All Attributes]’, which reveals the entire attribute list. The
customization buffer may start out with unspecified attributes hidden, to avoid
cluttering the interface.

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When an attribute is specified, you can change its value in the usual ways.
Foreground and background colors can be specified using either color names or
RGB triplets (see Section 11.9 [Colors], page 76). You can also use the ‘[Choose]’
button to switch to a list of color names; select a color with RET in that buffer to
put the color name in the value field.
Setting, saving and resetting a face work like the same operations for variables
(see Section 33.1.3 [Changing a Variable], page 436).
A face can specify different appearances for different types of displays. For
example, a face can make text red on a color display, but use a bold font on a
monochrome display. To specify multiple appearances for a face, select ‘For All
Kinds of Displays’ in the menu you get from invoking ‘[State]’.
33.1.6 Customizing Specific Items
M-x customize-option RET option RET
M-x customize-variable RET option RET
Set up a customization buffer for just one user option, option.
M-x customize-face RET face RET
Set up a customization buffer for just one face, face.
M-x customize-group RET group RET
Set up a customization buffer for just one group, group.
M-x customize-apropos RET regexp RET
Set up a customization buffer for all the settings and groups that match
regexp.
M-x customize-changed RET version RET
Set up a customization buffer with all the settings and groups whose
meaning has changed since Emacs version version.
M-x customize-saved
Set up a customization buffer containing all settings that you have
saved with customization buffers.
M-x customize-unsaved
Set up a customization buffer containing all settings that you have set
but not saved.
If you want to customize a particular user option, type M-x customize-option.
This reads the variable name, and sets up the customization buffer with just that
one user option. When entering the variable name into the minibuffer, completion
is available, but only for the names of variables that have been loaded into Emacs.
Likewise, you can customize a specific face using M-x customize-face. You
can set up a customization buffer for a specific customization group using M-x
customize-group.
M-x customize-apropos prompts for a search term—either one or more words
separated by spaces, or a regular expression—and sets up a customization buffer
for all loaded settings and groups with matching names. This is like using the

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search field at the top of the customization buffer (see Section 33.1.1 [Customization
Groups], page 434).
When you upgrade to a new Emacs version, you might want to consider customizing new settings, and settings whose meanings or default values have changed.
To do this, use M-x customize-changed and specify a previous Emacs version number using the minibuffer. It creates a customization buffer which shows all the settings and groups whose definitions have been changed since the specified version,
loading them if necessary.
If you change settings and then decide the change was a mistake, you can use
two commands to revisit your changes. Use M-x customize-saved to customize
settings that you have saved. Use M-x customize-unsaved to customize settings
that you have set but not saved.
33.1.7 Custom Themes
Custom themes are collections of settings that can be enabled or disabled as a unit.
You can use Custom themes to switch easily between various collections of settings,
and to transfer such collections from one computer to another.
A Custom theme is stored an Emacs Lisp source file. If the name of the Custom
theme is name, the theme file is named ‘name-theme.el’. See Section 33.1.8 [Creating Custom Themes], page 442, for the format of a theme file and how to make
one.
Type M-x customize-themes to switch to a buffer named ‘*Custom Themes*’,
which lists the Custom themes that Emacs knows about. By default, Emacs
looks for theme files in two locations: the directory specified by the variable
custom-theme-directory (which defaults to ‘~/.emacs.d/’), and a directory
named ‘etc/themes’ in your Emacs installation (see the variable data-directory).
The latter contains several Custom themes which are distributed with Emacs, which
customize Emacs’s faces to fit various color schemes. (Note, however, that Custom
themes need not be restricted to this purpose; they can be used to customize variables too).
If you want Emacs to look for Custom themes in some other directory, add
the directory name to the list variable custom-theme-load-path. Its default value
is (custom-theme-directory t); here, the symbol custom-theme-directory has
the special meaning of the value of the variable custom-theme-directory, while
t stands for the built-in theme directory ‘etc/themes’. The themes listed in the
‘*Custom Themes*’ buffer are those found in the directories specified by customtheme-load-path.
In the ‘*Custom Themes*’ buffer, you can activate the checkbox next to a Custom
theme to enable or disable the theme for the current Emacs session. When a Custom
theme is enabled, all of its settings (variables and faces) take effect in the Emacs
session. To apply the choice of theme(s) to future Emacs sessions, type C-x C-s
(custom-theme-save) or use the ‘[Save Theme Settings]’ button.
When you first enable a Custom theme, Emacs displays the contents of the
theme file and asks if you really want to load it. Because loading a Custom theme
can execute arbitrary Lisp code, you should only say yes if you know that the theme

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is safe; in that case, Emacs offers to remember in the future that the theme is safe
(this is done by saving the theme file’s SHA-256 hash to the variable custom-safethemes; if you want to treat all themes as safe, change its value to t). Themes that
come with Emacs (in the ‘etc/themes’ directory) are exempt from this check, and
are always considered safe.
Setting or saving Custom themes actually works by customizing the variable
custom-enabled-themes. The value of this variable is a list of Custom theme
names (as Lisp symbols, e.g. tango). Instead of using the ‘*Custom Themes*’ buffer
to set custom-enabled-themes, you can customize the variable using the usual customization interface, e.g. with M-x customize-option. Note that Custom themes
are not allowed to set custom-enabled-themes themselves.
Any customizations that you make through the customization buffer take precedence over theme settings. This lets you easily override individual theme settings
that you disagree with. If settings from two different themes overlap, the theme
occurring earlier in custom-enabled-themes takes precedence. In the customization buffer, if a setting has been changed from its default by a Custom theme, its
‘State’ display shows ‘THEMED’ instead of ‘STANDARD’.
You can enable a specific Custom theme in the current Emacs session by typing
M-x load-theme. This prompts for a theme name, loads the theme from the theme
file, and enables it. If a theme file has been loaded before, you can enable the theme
without loading its file by typing M-x enable-theme. To disable a Custom theme,
type M-x disable-theme.
To see a description of a Custom theme, type ? on its line in the ‘*Custom
Themes*’ buffer; or type M-x describe-theme anywhere in Emacs and enter the
theme name.
33.1.8 Creating Custom Themes
You can define a Custom theme using an interface similar to the customization
buffer, by typing M-x customize-create-theme. This switches to a buffer named
‘*Custom Theme*’. It also offers to insert some common Emacs faces into the theme
(a convenience, since Custom themes are often used to customize faces). If you
answer no, the theme will initially contain no settings.
Near the top of the ‘*Custom Theme*’ buffer are editable fields where you can
enter the theme’s name and description. The name can be anything except ‘user’.
The description is the one that will be shown when you invoke M-x describe-theme
for the theme. Its first line should be a brief one-sentence summary; in the buffer
made by M-x customize-themes, this sentence is displayed next to the theme name.
To add a new setting to the theme, use the ‘[Insert Additional Face]’ or
‘[Insert Additional Variable]’ buttons. Each button reads a face or variable
name using the minibuffer, with completion, and inserts a customization entry for
the face or variable. You can edit the variable values or face attributes in the same
way as in a normal customization buffer. To remove a face or variable from the
theme, uncheck the checkbox next to its name.
After specifying the Custom theme’s faces and variables, type C-x C-s (customtheme-write) or use the buffer’s ‘[Save Theme]’ button. This saves the theme file,

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named ‘name-theme.el’ where name is the theme name, in the directory named by
custom-theme-directory.
From the ‘*Custom Theme*’ buffer, you can view and edit an existing Custom
theme by activating the ‘[Visit Theme]’ button and specifying the theme name.
You can also add the settings of another theme into the buffer, using the ‘[Merge
Theme]’ button. You can import your non-theme settings into a Custom theme by
using the ‘[Merge Theme]’ button and specifying the special theme named ‘user’.
A theme file is simply an Emacs Lisp source file, and loading the Custom theme
works by loading the Lisp file. Therefore, you can edit a theme file directly instead
of using the ‘*Custom Theme*’ buffer. See Section “Custom Themes” in The Emacs
Lisp Reference Manual, for details.

33.2 Variables
A variable is a Lisp symbol which has a value. The symbol’s name is also called
the variable name. A variable name can contain any characters that can appear in
a file, but most variable names consist of ordinary words separated by hyphens.
The name of the variable serves as a compact description of its role. Most
variables also have a documentation string, which describes what the variable’s
purpose is, what kind of value it should have, and how the value will be used. You
can view this documentation using the help command C-h v (describe-variable).
See Section 33.2.1 [Examining], page 443.
Emacs uses many Lisp variables for internal record keeping, but the most interesting variables for a non-programmer user are those meant for users to change—
these are called customizable variables or user options (see Section 33.1 [Easy Customization], page 434). In the following sections, we will describe other aspects of
Emacs variables, such as how to set them outside Customize.
Emacs Lisp allows any variable (with a few exceptions) to have any kind of value.
However, many variables are meaningful only if assigned values of a certain type. For
example, only numbers are meaningful values for kill-ring-max, which specifies
the maximum length of the kill ring (see Section 9.2.2 [Earlier Kills], page 58); if
you give kill-ring-max a string value, commands such as C-y (yank) will signal
an error. On the other hand, some variables don’t care about type; for instance,
if a variable has one effect for nil values and another effect for “non-nil” values,
then any value that is not the symbol nil induces the second effect, regardless of
its type (by convention, we usually use the value t—a symbol which stands for
“true”—to specify a non-nil value). If you set a variable using the customization
buffer, you need not worry about giving it an invalid type: the customization buffer
usually only allows you to enter meaningful values. When in doubt, use C-h v
(describe-variable) to check the variable’s documentation string to see kind of
value it expects (see Section 33.2.1 [Examining], page 443).
33.2.1 Examining and Setting Variables

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C-h v var RET
Display the value and documentation of variable var (describevariable).
M-x set-variable RET var RET value RET
Change the value of variable var to value.
To examine the value of a variable, use C-h v (describe-variable). This reads
a variable name using the minibuffer, with completion, and displays both the value
and the documentation of the variable. For example,
C-h v fill-column RET
displays something like this:
fill-column is a variable defined in ‘C source code’.
fill-column’s value is 70
Automatically becomes buffer-local when set in any fashion.
This variable is safe as a file local variable if its value
satisfies the predicate ‘integerp’.
Documentation:
Column beyond which automatic line-wrapping should happen.
Interactively, you can set the local value with C-x f.
You can customize this variable.
The line that says “You can customize the variable” indicates that this variable is
a user option. C-h v is not restricted to user options; it allows non-customizable
variables too.
The most convenient way to set a specific customizable variable is with M-x
set-variable. This reads the variable name with the minibuffer (with completion),
and then reads a Lisp expression for the new value using the minibuffer a second
time (you can insert the old value into the minibuffer for editing via M-n). For
example,
M-x set-variable RET fill-column RET 75 RET
sets fill-column to 75.
M-x set-variable is limited to customizable variables, but you can set any
variable with a Lisp expression like this:
(setq fill-column 75)
To execute such an expression, type M-: (eval-expression) and enter the expression in the minibuffer (see Section 24.9 [Lisp Eval], page 288). Alternatively, go to
the ‘*scratch*’ buffer, type in the expression, and then type C-j (see Section 24.10
[Lisp Interaction], page 290).
Setting variables, like all means of customizing Emacs except where otherwise
stated, affects only the current Emacs session. The only way to alter the variable in
future sessions is to put something in your initialization file (see Section 33.4 [Init
File], page 461).

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33.2.2 Hooks
Hooks are an important mechanism for customizing Emacs. A hook is a Lisp
variable which holds a list of functions, to be called on some well-defined occasion.
(This is called running the hook.) The individual functions in the list are called
the hook functions of the hook. For example, the hook kill-emacs-hook runs just
before exiting Emacs (see Section 3.2 [Exiting], page 15).
Most hooks are normal hooks. This means that when Emacs runs the hook, it
calls each hook function in turn, with no arguments. We have made an effort to
keep most hooks normal, so that you can use them in a uniform way. Every variable
whose name ends in ‘-hook’ is a normal hook.
A few hooks are abnormal hooks. Their names end in ‘-hooks’ or ‘-functions’,
instead of ‘-hook’. What makes these hooks abnormal is the way its functions are
called—perhaps they are given arguments, or perhaps the values they return are
used in some way. For example, find-file-not-found-functions is abnormal
because as soon as one hook function returns a non-nil value, the rest are not
called at all (see Section 15.2 [Visiting], page 125). The documentation of each
abnormal hook variable explains how its functions are used.
You can set a hook variable with setq like any other Lisp variable, but the
recommended way to add a function to a hook (either normal or abnormal) is to
use add-hook, as shown by the following examples. See Section “Hooks” in The
Emacs Lisp Reference Manual, for details.
Most major modes run one or more mode hooks as the last step of initialization.
Mode hooks are a convenient way to customize the behavior of individual modes;
they are always normal. For example, here’s how to set up a hook to turn on Auto
Fill mode in Text mode and other modes based on Text mode:
(add-hook ’text-mode-hook ’auto-fill-mode)
This works by calling auto-fill-mode, which enables the minor mode when no
argument is supplied (see Section 20.2 [Minor Modes], page 205). Next, suppose
you don’t want Auto Fill mode turned on in LaTEX mode, which is one of the modes
based on Text mode. You can do this with the following additional line:
(add-hook ’latex-mode-hook (lambda () (auto-fill-mode -1)))
Here we have used the special macro lambda to construct an anonymous function (see Section “Lambda Expressions” in The Emacs Lisp Reference Manual),
which calls auto-fill-mode with an argument of -1 to disable the minor mode.
Because LaTEX mode runs latex-mode-hook after running text-mode-hook, the
result leaves Auto Fill mode disabled.
Here is a more complex example, showing how to use a hook to customize the
indentation of C code:
(setq my-c-style
’((c-comment-only-line-offset . 4)
(c-cleanup-list . (scope-operator
empty-defun-braces
defun-close-semi))))

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(add-hook ’c-mode-common-hook
(lambda () (c-add-style "my-style" my-c-style t)))
Major mode hooks also apply to other major modes derived from the original
mode (see Section “Derived Modes” in The Emacs Lisp Reference Manual). For
instance, HTML mode is derived from Text mode (see Section 22.11 [HTML Mode],
page 236); when HTML mode is enabled, it runs text-mode-hook before running
html-mode-hook. This provides a convenient way to use a single hook to affect
several related modes. In particular, if you want to apply a hook function to any
programming language mode, add it to prog-mode-hook; Prog mode is a major
mode that does little else than to let other major modes inherit from it, exactly for
this purpose.
It is best to design your hook functions so that the order in which they are
executed does not matter. Any dependence on the order is asking for trouble.
However, the order is predictable: the hook functions are executed in the order
they appear in the hook.
If you play with adding various different versions of a hook function by calling
add-hook over and over, remember that all the versions you added will remain
in the hook variable together. You can clear out individual functions by calling
remove-hook, or do (setq hook-variable nil) to remove everything.
If the hook variable is buffer-local, the buffer-local variable will be used instead
of the global variable. However, if the buffer-local variable contains the element t,
the global hook variable will be run as well.
33.2.3 Local Variables
M-x make-local-variable RET var RET
Make variable var have a local value in the current buffer.
M-x kill-local-variable RET var RET
Make variable var use its global value in the current buffer.
M-x make-variable-buffer-local RET var RET
Mark variable var so that setting it will make it local to the buffer
that is current at that time.
Almost any variable can be made local to a specific Emacs buffer. This means
that its value in that buffer is independent of its value in other buffers. A few
variables are always local in every buffer. Every other Emacs variable has a global
value which is in effect in all buffers that have not made the variable local.
M-x make-local-variable reads the name of a variable and makes it local to
the current buffer. Changing its value subsequently in this buffer will not affect
others, and changes in its global value will not affect this buffer.
M-x make-variable-buffer-local marks a variable so it will become local automatically whenever it is set. More precisely, once a variable has been marked
in this way, the usual ways of setting the variable automatically do make-localvariable first. We call such variables per-buffer variables. Many variables in
Emacs are normally per-buffer; the variable’s document string tells you when this

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is so. A per-buffer variable’s global value is normally never effective in any buffer,
but it still has a meaning: it is the initial value of the variable for each new buffer.
Major modes (see Section 20.1 [Major Modes], page 204) always make variables
local to the buffer before setting the variables. This is why changing major modes
in one buffer has no effect on other buffers. Minor modes also work by setting
variables—normally, each minor mode has one controlling variable which is non-nil
when the mode is enabled (see Section 20.2 [Minor Modes], page 205). For many
minor modes, the controlling variable is per buffer, and thus always buffer-local.
Otherwise, you can make it local in a specific buffer like any other variable.
A few variables cannot be local to a buffer because they are always local to each
display instead (see Section 18.10 [Multiple Displays], page 175). If you try to make
one of these variables buffer-local, you’ll get an error message.
M-x kill-local-variable makes a specified variable cease to be local to the
current buffer. The global value of the variable henceforth is in effect in this buffer.
Setting the major mode kills all the local variables of the buffer except for a few
variables specially marked as permanent locals.
To set the global value of a variable, regardless of whether the variable has a
local value in the current buffer, you can use the Lisp construct setq-default.
This construct is used just like setq, but it sets variables’ global values instead of
their local values (if any). When the current buffer does have a local value, the
new global value may not be visible until you switch to another buffer. Here is an
example:
(setq-default fill-column 75)
setq-default is the only way to set the global value of a variable that has been
marked with make-variable-buffer-local.
Lisp programs can use default-value to look at a variable’s default value. This
function takes a symbol as argument and returns its default value. The argument is
evaluated; usually you must quote it explicitly. For example, here’s how to obtain
the default value of fill-column:
(default-value ’fill-column)
33.2.4 Local Variables in Files
A file can specify local variable values to use when editing the file with Emacs.
Visiting the file checks for local variable specifications; it automatically makes these
variables local to the buffer, and sets them to the values specified in the file.
33.2.4.1 Specifying File Variables
There are two ways to specify file local variable values: in the first line, or with a
local variables list. Here’s how to specify them in the first line:
-*- mode: modename ; var : value ; ... -*You can specify any number of variable/value pairs in this way, each pair with a
colon and semicolon. The special variable/value pair mode: modename ;, if present,
specifies a major mode. The values are used literally, and not evaluated.

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You can use M-x add-file-local-variable-prop-line instead of adding entries by hand. This command prompts for a variable and value, and adds them to the
first line in the appropriate way. M-x delete-file-local-variable-prop-line
prompts for a variable, and deletes its entry from the line. The command M-x
copy-dir-locals-to-file-locals-prop-line copies the current directory-local
variables to the first line (see Section 33.2.5 [Directory Variables], page 450).
Here is an example first line that specifies Lisp mode and sets two variables with
numeric values:
;; -*- mode: Lisp; fill-column: 75; comment-column: 50; -*-

Aside from mode, other keywords that have special meanings as file variables are
coding, unibyte, and eval. These are described below.
In shell scripts, the first line is used to identify the script interpreter, so you
cannot put any local variables there. To accommodate this, Emacs looks for local
variable specifications in the second line if the first line specifies an interpreter. The
same is true for man pages which start with the magic string ‘’\"’ to specify a list
of troff preprocessors (not all do, however).
Apart from using a ‘-*-’ line, you can define file local variables using a local
variables list near the end of the file. The start of the local variables list should be
no more than 3000 characters from the end of the file, and must be on the last page
if the file is divided into pages.
If a file has both a local variables list and a ‘-*-’ line, Emacs processes everything
in the ‘-*-’ line first, and everything in the local variables list afterward. The
exception to this is a major mode specification. Emacs applies this first, wherever it
appears, since most major modes kill all local variables as part of their initialization.
A local variables list starts with a line containing the string ‘Local Variables:’,
and ends with a line containing the string ‘End:’. In between come the variable
names and values, one set per line, like this:
/* Local Variables: */
/* mode: c
*/
/* comment-column: 0 */
/* End:
*/
In this example, each line starts with the prefix ‘/*’ and ends with the suffix ‘*/’.
Emacs recognizes the prefix and suffix by finding them surrounding the magic string
‘Local Variables:’, on the first line of the list; it then automatically discards them
from the other lines of the list. The usual reason for using a prefix and/or suffix is
to embed the local variables list in a comment, so it won’t confuse other programs
that the file is intended for. The example above is for the C programming language,
where comments start with ‘/*’ and end with ‘*/’.
Instead of typing in the local variables list directly, you can use the command
M-x add-file-local-variable. This prompts for a variable and value, and adds
them to the list, adding the ‘Local Variables:’ string and start and end markers
as necessary. The command M-x delete-file-local-variable deletes a variable
from the list. M-x copy-dir-locals-to-file-locals copies directory-local variables to the list (see Section 33.2.5 [Directory Variables], page 450).

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As with the ‘-*-’ line, the variables in a local variables list are used literally, and
are not evaluated first. If you want to split a long string value across multiple lines
of the file, you can use backslash-newline, which is ignored in Lisp string constants;
you should put the prefix and suffix on each line, even lines that start or end within
the string, as they will be stripped off when processing the list. Here is an example:
# Local Variables:
# compile-command: "cc foo.c -Dfoo=bar -Dhack=whatever \
#
-Dmumble=blaah"
# End:
Some “variable names” have special meanings in a local variables list:
• mode enables the specified major mode.
• eval evaluates the specified Lisp expression (the value returned by that expression is ignored).
• coding specifies the coding system for character code conversion of this file.
See Section 19.6 [Coding Systems], page 188.
• unibyte says to load or compile a file of Emacs Lisp in unibyte mode, if the
value is t. See Section 19.2 [Disabling Multibyte], page 182.
These four keywords are not really variables; setting them in any other context has
no special meaning.
Do not use the mode keyword for minor modes. To enable or disable a minor
mode in a local variables list, use the eval keyword with a Lisp expression that
runs the mode command (see Section 20.2 [Minor Modes], page 205). For example,
the following local variables list enables Eldoc mode (see Section 23.6.3 [Lisp Doc],
page 263) by calling eldoc-mode with no argument (calling it with an argument of
1 would do the same), and disables Font Lock mode (see Section 11.12 [Font Lock],
page 80) by calling font-lock-mode with an argument of -1.
;; Local Variables:
;; eval: (eldoc-mode)
;; eval: (font-lock-mode -1)
;; End:
Note, however, that it is often a mistake to specify minor modes this way. Minor
modes represent individual user preferences, and it may be inappropriate to impose
your preferences on another user who might edit the file. If you wish to automatically enable or disable a minor mode in a situation-dependent way, it is often better
to do it in a major mode hook (see Section 33.2.2 [Hooks], page 445).
Use the command M-x normal-mode to reset the local variables and major mode
of a buffer according to the file name and contents, including the local variables list
if any. See Section 20.3 [Choosing Modes], page 207.
33.2.4.2 Safety of File Variables
File-local variables can be dangerous; when you visit someone else’s file, there’s no
telling what its local variables list could do to your Emacs. Improper values of the
eval “variable”, and other variables such as load-path, could execute Lisp code
you didn’t intend to run.

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Therefore, whenever Emacs encounters file local variable values that are not
known to be safe, it displays the file’s entire local variables list, and asks you for
confirmation before setting them. You can type y or SPC to put the local variables
list into effect, or n to ignore it. When Emacs is run in batch mode (see Section C.2
[Initial Options], page 507), it can’t really ask you, so it assumes the answer n.
Emacs normally recognizes certain variable/value pairs as safe. For instance, it
is safe to give comment-column or fill-column any integer value. If a file specifies
only known-safe variable/value pairs, Emacs does not ask for confirmation before
setting them. Otherwise, you can tell Emacs to record all the variable/value pairs
in this file as safe, by typing ! at the confirmation prompt. When Emacs encounters
these variable/value pairs subsequently, in the same file or others, it will assume
they are safe.
Some variables, such as load-path, are considered particularly risky: there is
seldom any reason to specify them as local variables, and changing them can be
dangerous. If a file contains only risky local variables, Emacs neither offers nor
accepts ! as input at the confirmation prompt. If some of the local variables in a
file are risky, and some are only potentially unsafe, you can enter ! at the prompt. It
applies all the variables, but only marks the non-risky ones as safe for the future. If
you really want to record safe values for risky variables, do it directly by customizing
‘safe-local-variable-values’ (see Section 33.1 [Easy Customization], page 434).
The variable enable-local-variables allows you to change the way Emacs
processes local variables. Its default value is t, which specifies the behavior described above. If it is nil, Emacs simply ignores all file local variables. :safe
means use only the safe values and ignore the rest. Any other value says to query
you about each file that has local variables, without trying to determine whether
the values are known to be safe.
The variable enable-local-eval controls whether Emacs processes eval variables. The three possibilities for the variable’s value are t, nil, and anything else,
just as for enable-local-variables. The default is maybe, which is neither t nor
nil, so normally Emacs does ask for confirmation about processing eval variables.
As an exception, Emacs never asks for confirmation to evaluate any eval form
if that form occurs within the variable safe-local-eval-forms.
33.2.5 Per-Directory Local Variables
Sometimes, you may wish to define the same set of local variables to all the files
in a certain directory and its subdirectories, such as the directory tree of a large
software project. This can be accomplished with directory-local variables.
The usual way to define directory-local variables is to put a file named
‘.dir-locals.el’1 in a directory. Whenever Emacs visits any file in that directory or any of its subdirectories, it will apply the directory-local variables specified in ‘.dir-locals.el’, as though they had been defined as file-local variables
1

On MS-DOS, the name of this file should be ‘_dir-locals.el’, due to limitations of
the DOS filesystems. If the filesystem is limited to 8+3 file names, the name of the file
will be truncated by the OS to ‘_dir-loc.el’.

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for that file (see Section 33.2.4 [File Variables], page 447). Emacs searches for
‘.dir-locals.el’ starting in the directory of the visited file, and moving up the
directory tree. To avoid slowdown, this search is skipped for remote files.
The ‘.dir-locals.el’ file should hold a specially-constructed list, which maps
major mode names (symbols) to alists (see Section “Association Lists” in The Emacs
Lisp Reference Manual). Each alist entry consists of a variable name and the
directory-local value to assign to that variable, when the specified major mode is
enabled. Instead of a mode name, you can specify ‘nil’, which means that the alist
applies to any mode; or you can specify a subdirectory name (a string), in which
case the alist applies to all files in that subdirectory.
Here’s an example of a ‘.dir-locals.el’ file:
((nil . ((indent-tabs-mode . t)
(fill-column . 80)))
(c-mode . ((c-file-style . "BSD")))
(subdirs . nil)))
("src/imported"
. ((nil . ((change-log-default-name
. "ChangeLog.local"))))))
This sets ‘indent-tabs-mode’ and fill-column for any file in the directory tree,
and the indentation style for any C source file. The special subdirs element is not
a variable, but a special keyword which indicates that the C mode settings are only
to be applied in the current directory, not in any subdirectories. Finally, it specifies
a different ‘ChangeLog’ file name for any file in the ‘src/imported’ subdirectory.
Instead of editing the ‘.dir-locals.el’ file by hand, you can use the
command M-x add-dir-local-variable.
This prompts for a mode or
subdirectory name, and for variable and value, and adds the entry defining the
directory-local variable. M-x delete-dir-local-variable deletes an entry. M-x
copy-file-locals-to-dir-locals copies the file-local variables in the current
file into ‘.dir-locals.el’.
Another method of specifying directory-local variables is to define a group
of variables/value pairs in a directory class, using the dir-locals-set-classvariables function; then, tell Emacs which directories correspond to the class by
using the dir-locals-set-directory-class function. These function calls normally go in your initialization file (see Section 33.4 [Init File], page 461). This
method is useful when you can’t put ‘.dir-locals.el’ in a directory for some
reason. For example, you could apply settings to an unwritable directory this way:
(dir-locals-set-class-variables ’unwritable-directory
’((nil . ((some-useful-setting . value)))))
(dir-locals-set-directory-class
"/usr/include/" ’unwritable-directory)
If a variable has both a directory-local and file-local value specified, the file-local
value takes effect. Unsafe directory-local variables are handled in the same way as
unsafe file-local variables (see Section 33.2.4.2 [Safe File Variables], page 449).

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Directory-local variables also take effect in certain buffers that do not visit a file
directly but perform work within a directory, such as Dired buffers (see Chapter 27
[Dired], page 329).

33.3 Customizing Key Bindings
This section describes key bindings, which map keys to commands, and keymaps,
which record key bindings. It also explains how to customize key bindings, which
is done by editing your init file (see Section 33.3.6 [Init Rebinding], page 455).
33.3.1 Keymaps
As described in Section 2.3 [Commands], page 12, each Emacs command is a Lisp
function whose definition provides for interactive use. Like every Lisp function,
a command has a function name, which usually consists of lower-case letters and
hyphens.
A key sequence (key, for short) is a sequence of input events that have a meaning
as a unit. Input events include characters, function keys and mouse buttons—all
the inputs that you can send to the computer. A key sequence gets its meaning
from its binding, which says what command it runs.
The bindings between key sequences and command functions are recorded in
data structures called keymaps. Emacs has many of these, each used on particular
occasions.
The global keymap is the most important keymap because it is always in effect.
The global keymap defines keys for Fundamental mode (see Section 20.1 [Major
Modes], page 204); most of these definitions are common to most or all major
modes. Each major or minor mode can have its own keymap which overrides the
global definitions of some keys.
For example, a self-inserting character such as g is self-inserting because the
global keymap binds it to the command self-insert-command. The standard
Emacs editing characters such as C-a also get their standard meanings from the
global keymap. Commands to rebind keys, such as M-x global-set-key, work by
storing the new binding in the proper place in the global map (see Section 33.3.5
[Rebinding], page 454).
Most modern keyboards have function keys as well as character keys. Function
keys send input events just as character keys do, and keymaps can have bindings
for them. Key sequences can mix function keys and characters. For example,
if your keyboard has a HOME function key, Emacs can recognize key sequences
like C-x HOME. You can even mix mouse events with keyboard events, such as
S-down-mouse-1.
On text terminals, typing a function key actually sends the computer a sequence
of characters; the precise details of the sequence depends on the function key and on
the terminal type. (Often the sequence starts with ESC [.) If Emacs understands
your terminal type properly, it automatically handles such sequences as single input
events.

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33.3.2 Prefix Keymaps
Internally, Emacs records only single events in each keymap. Interpreting a key
sequence of multiple events involves a chain of keymaps: the first keymap gives a
definition for the first event, which is another keymap, which is used to look up the
second event in the sequence, and so on. Thus, a prefix key such as C-x or ESC has
its own keymap, which holds the definition for the event that immediately follows
that prefix.
The definition of a prefix key is usually the keymap to use for looking up the
following event. The definition can also be a Lisp symbol whose function definition
is the following keymap; the effect is the same, but it provides a command name for
the prefix key that can be used as a description of what the prefix key is for. Thus,
the binding of C-x is the symbol Control-X-prefix, whose function definition is
the keymap for C-x commands. The definitions of C-c, C-x, C-h and ESC as prefix
keys appear in the global map, so these prefix keys are always available.
Aside from ordinary prefix keys, there is a fictitious “prefix key” which represents
the menu bar; see Section “Menu Bar” in The Emacs Lisp Reference Manual, for
special information about menu bar key bindings. Mouse button events that invoke
pop-up menus are also prefix keys; see Section “Menu Keymaps” in The Emacs Lisp
Reference Manual, for more details.
Some prefix keymaps are stored in variables with names:
• ctl-x-map is the variable name for the map used for characters that follow
C-x.
• help-map is for characters that follow C-h.
• esc-map is for characters that follow ESC. Thus, all Meta characters are
actually defined by this map.
• ctl-x-4-map is for characters that follow C-x 4.
• mode-specific-map is for characters that follow C-c.
33.3.3 Local Keymaps
So far, we have explained the ins and outs of the global map. Major modes customize
Emacs by providing their own key bindings in local keymaps. For example, C mode
overrides TAB to make it indent the current line for C code. Minor modes can
also have local keymaps; whenever a minor mode is in effect, the definitions in
its keymap override both the major mode’s local keymap and the global keymap.
In addition, portions of text in the buffer can specify their own keymaps, which
override all other keymaps.
A local keymap can redefine a key as a prefix key by defining it as a prefix
keymap. If the key is also defined globally as a prefix, its local and global definitions
(both keymaps) effectively combine: both definitions are used to look up the event
that follows the prefix key. For example, if a local keymap defines C-c as a prefix
keymap, and that keymap defines C-z as a command, this provides a local meaning
for C-c C-z. This does not affect other sequences that start with C-c; if those
sequences don’t have their own local bindings, their global bindings remain in effect.

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Another way to think of this is that Emacs handles a multi-event key sequence
by looking in several keymaps, one by one, for a binding of the whole key sequence.
First it checks the minor mode keymaps for minor modes that are enabled, then it
checks the major mode’s keymap, and then it checks the global keymap. This is not
precisely how key lookup works, but it’s good enough for understanding the results
in ordinary circumstances.
33.3.4 Minibuffer Keymaps
The minibuffer has its own set of local keymaps; they contain various completion
and exit commands.
• minibuffer-local-map is used for ordinary input (no completion).
• minibuffer-local-ns-map is similar, except that SPC exits just like RET.
• minibuffer-local-completion-map is for permissive completion.
• minibuffer-local-must-match-map is for strict completion and for cautious
completion.
• minibuffer-local-filename-completion-map and minibuffer-localfilename-must-match-map are like the two previous ones, but they are
specifically for file name completion. They do not bind SPC.
33.3.5 Changing Key Bindings Interactively
The way to redefine an Emacs key is to change its entry in a keymap. You can
change the global keymap, in which case the change is effective in all major modes
(except those that have their own overriding local bindings for the same key). Or
you can change a local keymap, which affects all buffers using the same major mode.
In this section, we describe how to rebind keys for the present Emacs session.
See Section 33.3.6 [Init Rebinding], page 455, for a description of how to make key
rebindings affect future Emacs sessions.
M-x global-set-key RET key cmd RET
Define key globally to run cmd.
M-x local-set-key RET key cmd RET
Define key locally (in the major mode now in effect) to run cmd.
M-x global-unset-key RET key
Make key undefined in the global map.
M-x local-unset-key RET key
Make key undefined locally (in the major mode now in effect).
For example, the following binds C-z to the shell command (see Section 31.3.2
[Interactive Shell], page 403), replacing the normal global definition of C-z:
M-x global-set-key RET C-z shell RET
The global-set-key command reads the command name after the key. After you
press the key, a message like this appears so that you can confirm that you are
binding the key you want:

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Set key C-z to command:
You can redefine function keys and mouse events in the same way; just type the
function key or click the mouse when it’s time to specify the key to rebind.
You can rebind a key that contains more than one event in the same way. Emacs
keeps reading the key to rebind until it is a complete key (that is, not a prefix key).
Thus, if you type C-f for key, that’s the end; it enters the minibuffer immediately
to read cmd. But if you type C-x, since that’s a prefix, it reads another character;
if that is 4, another prefix character, it reads one more character, and so on. For
example,
M-x global-set-key RET C-x 4 $ spell-other-window RET
redefines C-x 4 $ to run the (fictitious) command spell-other-window.
You can remove the global definition of a key with global-unset-key. This
makes the key undefined; if you type it, Emacs will just beep. Similarly, localunset-key makes a key undefined in the current major mode keymap, which makes
the global definition (or lack of one) come back into effect in that major mode.
If you have redefined (or undefined) a key and you subsequently wish to retract
the change, undefining the key will not do the job—you need to redefine the key
with its standard definition. To find the name of the standard definition of a key, go
to a Fundamental mode buffer in a fresh Emacs and use C-h c. The documentation
of keys in this manual also lists their command names.
If you want to prevent yourself from invoking a command by mistake, it is better
to disable the command than to undefine the key. A disabled command is less work
to invoke when you really want to. See Section 33.3.11 [Disabling], page 460.
33.3.6 Rebinding Keys in Your Init File
If you have a set of key bindings that you like to use all the time, you can specify
them in your initialization file by writing Lisp code. See Section 33.4 [Init File],
page 461, for a description of the initialization file.
There are several ways to write a key binding using Lisp. The simplest is to use
the kbd macro, which converts a textual representation of a key sequence—similar
to how we have written key sequences in this manual—into a form that can be
passed as an argument to global-set-key. For example, here’s how to bind C-z
to the shell command (see Section 31.3.2 [Interactive Shell], page 403):
(global-set-key (kbd "C-z") ’shell)
The single-quote before the command name, shell, marks it as a constant symbol
rather than a variable. If you omit the quote, Emacs would try to evaluate shell
as a variable. This probably causes an error; it certainly isn’t what you want.
Here are some additional examples, including binding function keys and mouse
events:
(global-set-key (kbd "C-c y") ’clipboard-yank)
(global-set-key (kbd "C-M-q") ’query-replace)
(global-set-key (kbd "") ’flyspell-mode)
(global-set-key (kbd "C-") ’linum-mode)
(global-set-key (kbd "C-") ’forward-sentence)

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(global-set-key (kbd "") ’mouse-save-then-kill)
Instead of using the kbd macro, you can use a Lisp string or vector to specify
the key sequence. Using a string is simpler, but only works for ASCII characters
and Meta-modified ASCII characters. For example, here’s how to bind C-x M-l to
make-symbolic-link (see Section 15.10 [Misc File Ops], page 143):
(global-set-key "\C-x\M-l" ’make-symbolic-link)
To put TAB, RET, ESC, or DEL in the string, use the Emacs Lisp escape
sequences ‘\t’, ‘\r’, ‘\e’, and ‘\d’ respectively. Here is an example which binds C-x
TAB to indent-rigidly (see Chapter 21 [Indentation], page 210):
(global-set-key "\C-x\t" ’indent-rigidly)
When the key sequence includes function keys or mouse button events, or nonASCII characters such as C-= or H-a, you can use a vector to specify the key sequence. Each element in the vector stands for an input event; the elements are
separated by spaces and surrounded by a pair of square brackets. If a vector element is a character, write it as a Lisp character constant: ‘?’ followed by the
character as it would appear in a string. Function keys are represented by symbols
(see Section 33.3.8 [Function Keys], page 457); simply write the symbol’s name,
with no other delimiters or punctuation. Here are some examples:
(global-set-key [?\C-=] ’make-symbolic-link)
(global-set-key [?\M-\C-=] ’make-symbolic-link)
(global-set-key [?\H-a] ’make-symbolic-link)
(global-set-key [f7] ’make-symbolic-link)
(global-set-key [C-mouse-1] ’make-symbolic-link)
You can use a vector for the simple cases too:
(global-set-key [?\C-z ?\M-l] ’make-symbolic-link)
Language and coding systems may cause problems with key bindings for nonASCII characters. See Section 33.4.5 [Init Non-ASCII], page 466.
As described in Section 33.3.3 [Local Keymaps], page 453, major modes and
minor modes can define local keymaps. These keymaps are constructed when the
mode is used for the first time in a session. If you wish to change one of these
keymaps, you must use the mode hook (see Section 33.2.2 [Hooks], page 445).
For example, Texinfo mode runs the hook texinfo-mode-hook. Here’s how you
can use the hook to add local bindings for C-c n and C-c p in Texinfo mode:
(add-hook ’texinfo-mode-hook
’(lambda ()
(define-key texinfo-mode-map "\C-cp"
’backward-paragraph)
(define-key texinfo-mode-map "\C-cn"
’forward-paragraph)))
33.3.7 Modifier Keys
The default key bindings in Emacs are set up so that modified alphabetical characters are case-insensitive. In other words, C-A does the same thing as C-a, and M-A
does the same thing as M-a. This concerns only alphabetical characters, and does

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not apply to “shifted” versions of other keys; for instance, C-@ is not the same as
C-2.
A CONTROL-modified alphabetical character is always considered caseinsensitive: Emacs always treats C-A as C-a, C-B as C-b, and so forth. The reason
for this is historical.
For all other modifiers, you can make the modified alphabetical characters casesensitive when you customize Emacs. For instance, you could make M-a and M-A
run different commands.
Although only the CONTROL and META modifier keys are commonly used,
Emacs supports three other modifier keys. These are called SUPER, HYPER and
ALT. Few terminals provide ways to use these modifiers; the key labeled ALT on
most keyboards usually issues the META modifier, not ALT. The standard key
bindings in Emacs do not include any characters with these modifiers. However,
you can customize Emacs to assign meanings to them. The modifier bits are labeled
as ‘s-’, ‘H-’ and ‘A-’ respectively.
Even if your keyboard lacks these additional modifier keys, you can enter it
using C-x @: C-x @ h adds the “hyper” flag to the next character, C-x @ s adds the
“super” flag, and C-x @ a adds the “alt” flag. For instance, C-x @ h C-a is a way to
enter Hyper-Control-a. (Unfortunately, there is no way to add two modifiers by
using C-x @ twice for the same character, because the first one goes to work on the
C-x.)
33.3.8 Rebinding Function Keys
Key sequences can contain function keys as well as ordinary characters. Just as Lisp
characters (actually integers) represent keyboard characters, Lisp symbols represent
function keys. If the function key has a word as its label, then that word is also the
name of the corresponding Lisp symbol. Here are the conventional Lisp names for
common function keys:
left, up, right, down
Cursor arrow keys.
begin, end, home, next, prior
Other cursor repositioning keys.
select, print, execute, backtab
insert, undo, redo, clearline
insertline, deleteline, insertchar, deletechar
Miscellaneous function keys.
f1, f2, . . . f35
Numbered function keys (across the top of the keyboard).
kp-add, kp-subtract, kp-multiply, kp-divide
kp-backtab, kp-space, kp-tab, kp-enter
kp-separator, kp-decimal, kp-equal
Keypad keys (to the right of the regular keyboard), with names or
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kp-0, kp-1, . . . kp-9
Keypad keys with digits.
kp-f1, kp-f2, kp-f3, kp-f4
Keypad PF keys.
These names are conventional, but some systems (especially when using X) may
use different names. To make certain what symbol is used for a given function key
on your terminal, type C-h c followed by that key.
See Section 33.3.6 [Init Rebinding], page 455, for examples of binding function
keys.
Many keyboards have a “numeric keypad” on the right hand side. The numeric
keys in the keypad double up as cursor motion keys, toggled by a key labeled ‘Num
Lock’. By default, Emacs translates these keys to the corresponding keys in the
main keyboard. For example, when ‘Num Lock’ is on, the key labeled ‘8’ on the
numeric keypad produces kp-8, which is translated to 8; when ‘Num Lock’ is off, the
same key produces kp-up, which is translated to UP. If you rebind a key such as 8
or UP, it affects the equivalent keypad key too. However, if you rebind a ‘kp-’ key
directly, that won’t affect its non-keypad equivalent. Note that the modified keys
are not translated: for instance, if you hold down the META key while pressing the
‘8’ key on the numeric keypad, that generates M-KP-8.
Emacs provides a convenient method for binding the numeric keypad keys, using the variables keypad-setup, keypad-numlock-setup, keypad-shifted-setup,
and keypad-numlock-shifted-setup. These can be found in the ‘keyboard’ customization group (see Section 33.1 [Easy Customization], page 434). You can rebind
the keys to perform other tasks, such as issuing numeric prefix arguments.
33.3.9 Named ASCII Control Characters
TAB, RET, BS, LFD, ESC and DEL started out as names for certain ASCII control
characters, used so often that they have special keys of their own. For instance,
TAB was another name for C-i. Later, users found it convenient to distinguish in
Emacs between these keys and the “same” control characters typed with the CTRL
key. Therefore, on most modern terminals, they are no longer the same: TAB is
different from C-i.
Emacs can distinguish these two kinds of input if the keyboard does. It treats the
“special” keys as function keys named tab, return, backspace, linefeed, escape,
and delete. These function keys translate automatically into the corresponding
ASCII characters if they have no bindings of their own. As a result, neither users
nor Lisp programs need to pay attention to the distinction unless they care to.
If you do not want to distinguish between (for example) TAB and C-i, make
just one binding, for the ASCII character TAB (octal code 011). If you do want
to distinguish, make one binding for this ASCII character, and another for the
“function key” tab.
With an ordinary ASCII terminal, there is no way to distinguish between TAB
and C-i (and likewise for other such pairs), because the terminal sends the same
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33.3.10 Rebinding Mouse Buttons
Emacs uses Lisp symbols to designate mouse buttons, too. The ordinary mouse
events in Emacs are click events; these happen when you press a button and release
it without moving the mouse. You can also get drag events, when you move the
mouse while holding the button down. Drag events happen when you finally let go
of the button.
The symbols for basic click events are mouse-1 for the leftmost button, mouse-2
for the next, and so on. Here is how you can redefine the second mouse button to
split the current window:
(global-set-key [mouse-2] ’split-window-below)
The symbols for drag events are similar, but have the prefix ‘drag-’ before the
word ‘mouse’. For example, dragging the first button generates a drag-mouse-1
event.
You can also define bindings for events that occur when a mouse button is
pressed down. These events start with ‘down-’ instead of ‘drag-’. Such events are
generated only if they have key bindings. When you get a button-down event, a
corresponding click or drag event will always follow.
If you wish, you can distinguish single, double, and triple clicks. A double click
means clicking a mouse button twice in approximately the same place. The first
click generates an ordinary click event. The second click, if it comes soon enough,
generates a double-click event instead. The event type for a double-click event starts
with ‘double-’: for example, double-mouse-3.
This means that you can give a special meaning to the second click at the same
place, but it must act on the assumption that the ordinary single click definition
has run when the first click was received.
This constrains what you can do with double clicks, but user interface designers
say that this constraint ought to be followed in any case. A double click should
do something similar to the single click, only “more so”. The command for the
double-click event should perform the extra work for the double click.
If a double-click event has no binding, it changes to the corresponding singleclick event. Thus, if you don’t define a particular double click specially, it executes
the single-click command twice.
Emacs also supports triple-click events whose names start with ‘triple-’.
Emacs does not distinguish quadruple clicks as event types; clicks beyond the third
generate additional triple-click events. However, the full number of clicks is recorded
in the event list, so if you know Emacs Lisp you can distinguish if you really want
to (see Section “Click Events” in The Emacs Lisp Reference Manual). We don’t
recommend distinct meanings for more than three clicks, but sometimes it is useful
for subsequent clicks to cycle through the same set of three meanings, so that four
clicks are equivalent to one click, five are equivalent to two, and six are equivalent
to three.
Emacs also records multiple presses in drag and button-down events. For example, when you press a button twice, then move the mouse while holding the button,
Emacs gets a ‘double-drag-’ event. And at the moment when you press it down

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for the second time, Emacs gets a ‘double-down-’ event (which is ignored, like all
button-down events, if it has no binding).
The variable double-click-time specifies how much time can elapse between
clicks and still allow them to be grouped as a multiple click. Its value is in units of
milliseconds. If the value is nil, double clicks are not detected at all. If the value
is t, then there is no time limit. The default is 500.
The variable double-click-fuzz specifies how much the mouse can move between clicks and still allow them to be grouped as a multiple click. Its value is
in units of pixels on windowed displays and in units of 1/8 of a character cell on
text-mode terminals; the default is 3.
The symbols for mouse events also indicate the status of the modifier keys, with
the usual prefixes ‘C-’, ‘M-’, ‘H-’, ‘s-’, ‘A-’ and ‘S-’. These always precede ‘double-’
or ‘triple-’, which always precede ‘drag-’ or ‘down-’.
A frame includes areas that don’t show text from the buffer, such as the mode
line and the scroll bar. You can tell whether a mouse button comes from a special
area of the screen by means of dummy “prefix keys”. For example, if you click
the mouse in the mode line, you get the prefix key mode-line before the ordinary
mouse-button symbol. Thus, here is how to define the command for clicking the
first button in a mode line to run scroll-up-command:
(global-set-key [mode-line mouse-1] ’scroll-up-command)
Here is the complete list of these dummy prefix keys and their meanings:
mode-line

The mouse was in the mode line of a window.

vertical-line
The mouse was in the vertical line separating side-by-side windows.
(If you use scroll bars, they appear in place of these vertical lines.)
vertical-scroll-bar
The mouse was in a vertical scroll bar. (This is the only kind of scroll
bar Emacs currently supports.)
menu-bar

The mouse was in the menu bar.

header-line
The mouse was in a header line.
You can put more than one mouse button in a key sequence, but it isn’t usual
to do so.
33.3.11 Disabling Commands
Disabling a command means that invoking it interactively asks for confirmation from
the user. The purpose of disabling a command is to prevent users from executing it
by accident; we do this for commands that might be confusing to the uninitiated.
Attempting to invoke a disabled command interactively in Emacs displays a
window containing the command’s name, its documentation, and some instructions
on what to do immediately; then Emacs asks for input saying whether to execute the command as requested, enable it and execute it, or cancel. If you decide

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to enable the command, you must then answer another question—whether to do
this permanently, or just for the current session. (Enabling permanently works by
automatically editing your initialization file.) You can also type ! to enable all
commands, for the current session only.
The direct mechanism for disabling a command is to put a non-nil disabled
property on the Lisp symbol for the command. Here is the Lisp program to do this:
(put ’delete-region ’disabled t)
If the value of the disabled property is a string, that string is included in the
message displayed when the command is used:
(put ’delete-region ’disabled
"It’s better to use ‘kill-region’ instead.\n")
You can make a command disabled either by editing the initialization file directly, or with the command M-x disable-command, which edits the initialization
file for you. Likewise, M-x enable-command edits the initialization file to enable a
command permanently. See Section 33.4 [Init File], page 461.
If Emacs was invoked with the ‘-q’ or ‘--no-init-file’ options (see Section C.2
[Initial Options], page 507), it will not edit your initialization file. Doing so could
lose information because Emacs has not read your initialization file.
Whether a command is disabled is independent of what key is used to invoke it;
disabling also applies if the command is invoked using M-x. However, disabling a
command has no effect on calling it as a function from Lisp programs.

33.4 The Emacs Initialization File
When Emacs is started, it normally tries to load a Lisp program from an initialization file, or init file for short. This file, if it exists, specifies how to initialize Emacs for you. Emacs looks for your init file using the filenames ‘~/.emacs’,
‘~/.emacs.el’, or ‘~/.emacs.d/init.el’; you can choose to use any one of these
three names (see Section 33.4.4 [Find Init], page 466). Here, ‘~/’ stands for your
home directory.
You can use the command line switch ‘-q’ to prevent loading your init file,
and ‘-u’ (or ‘--user’) to specify a different user’s init file (see Section C.2 [Initial
Options], page 507).
There can also be a default init file, which is the library named ‘default.el’,
found via the standard search path for libraries. The Emacs distribution contains
no such library; your site may create one for local customizations. If this library
exists, it is loaded whenever you start Emacs (except when you specify ‘-q’). But
your init file, if any, is loaded first; if it sets inhibit-default-init non-nil, then
‘default’ is not loaded.
Your site may also have a site startup file; this is named ‘site-start.el’, if
it exists. Like ‘default.el’, Emacs finds this file via the standard search path for
Lisp libraries. Emacs loads this library before it loads your init file. To inhibit
loading of this library, use the option ‘--no-site-file’. See Section C.2 [Initial
Options], page 507. We recommend against using ‘site-start.el’ for changes that

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some users may not like. It is better to put them in ‘default.el’, so that users
can more easily override them.
You can place ‘default.el’ and ‘site-start.el’ in any of the directories
which Emacs searches for Lisp libraries. The variable load-path (see Section 24.8
[Lisp Libraries], page 287) specifies these directories. Many sites put these files
in the ‘site-lisp’ subdirectory of the Emacs installation directory, typically
‘/usr/local/share/emacs/site-lisp’.
Byte-compiling your init file is not recommended (see Section “Byte Compilation” in the Emacs Lisp Reference Manual). It generally does not speed up startup
very much, and often leads to problems when you forget to recompile the file. A
better solution is to use the Emacs server to reduce the number of times you have
to start Emacs (see Section 31.4 [Emacs Server], page 412). If your init file defines
many functions, consider moving them to a separate (byte-compiled) file that you
load in your init file.
If you are going to write actual Emacs Lisp programs that go beyond minor
customization, you should read the Emacs Lisp Reference Manual.
33.4.1 Init File Syntax
The init file contains one or more Lisp expressions. Each of these consists of a
function name followed by arguments, all surrounded by parentheses. For example,
(setq fill-column 60) calls the function setq to set the variable fill-column
(see Section 22.5 [Filling], page 218) to 60.
You can set any Lisp variable with setq, but with certain variables setq won’t
do what you probably want in the ‘.emacs’ file. Some variables automatically
become buffer-local when set with setq; what you want in ‘.emacs’ is to set the
default value, using setq-default. Some customizable minor mode variables do
special things to enable the mode when you set them with Customize, but ordinary
setq won’t do that; to enable the mode in your ‘.emacs’ file, call the minor mode
command. The following section has examples of both of these methods.
The second argument to setq is an expression for the new value of the variable.
This can be a constant, a variable, or a function call expression. In ‘.emacs’,
constants are used most of the time. They can be:
Numbers:

Numbers are written in decimal, with an optional initial minus sign.

Strings:

Lisp string syntax is the same as C string syntax with a few extra
features. Use a double-quote character to begin and end a string constant.
In a string, you can include newlines and special characters literally.
But often it is cleaner to use backslash sequences for them: ‘\n’ for
newline, ‘\b’ for backspace, ‘\r’ for carriage return, ‘\t’ for tab, ‘\f’
for formfeed (control-L), ‘\e’ for escape, ‘\\’ for a backslash, ‘\"’ for
a double-quote, or ‘\ooo ’ for the character whose octal code is ooo.
Backslash and double-quote are the only characters for which backslash sequences are mandatory.

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‘\C-’ can be used as a prefix for a control character, as in ‘\C-s’ for
ASCII control-S, and ‘\M-’ can be used as a prefix for a Meta character,
as in ‘\M-a’ for Meta-A or ‘\M-\C-a’ for Control-Meta-A.
See Section 33.4.5 [Init Non-ASCII], page 466, for information about
including non-ASCII in your init file.
Characters: Lisp character constant syntax consists of a ‘?’ followed by either a
character or an escape sequence starting with ‘\’. Examples: ?x, ?\n,
?\", ?\). Note that strings and characters are not interchangeable in
Lisp; some contexts require one and some contexts require the other.
See Section 33.4.5 [Init Non-ASCII], page 466, for information about
binding commands to keys which send non-ASCII characters.
True:

t stands for ‘true’.

False:

nil stands for ‘false’.

Other Lisp objects:
Write a single-quote (’) followed by the Lisp object you want.
33.4.2 Init File Examples
Here are some examples of doing certain commonly desired things with Lisp expressions:
• Add a directory to the variable load-path. You can then put Lisp libraries
that are not included with Emacs in this directory, and load them with M-x
load-library. See Section 24.8 [Lisp Libraries], page 287.
(add-to-list ’load-path "/path/to/lisp/libraries")
• Make TAB in C mode just insert a tab if point is in the middle of a line.
(setq c-tab-always-indent nil)
Here we have a variable whose value is normally t for ‘true’ and the alternative
is nil for ‘false’.
• Make searches case sensitive by default (in all buffers that do not override
this).
(setq-default case-fold-search nil)
This sets the default value, which is effective in all buffers that do not have local
values for the variable (see Section 33.2.3 [Locals], page 446). Setting casefold-search with setq affects only the current buffer’s local value, which is
probably not what you want to do in an init file.
• Specify your own email address, if Emacs can’t figure it out correctly.
(setq user-mail-address "cheney@torture.gov")
Various Emacs packages, such as Message mode, consult user-mail-address
when they need to know your email address. See Section 29.2 [Mail Headers],
page 368.
• Make Text mode the default mode for new buffers.

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(setq-default major-mode ’text-mode)
Note that text-mode is used because it is the command for entering Text mode.
The single-quote before it makes the symbol a constant; otherwise, text-mode
would be treated as a variable name.
Set up defaults for the Latin-1 character set which supports most of the languages of Western Europe.
(set-language-environment "Latin-1")
Turn off Line Number mode, a global minor mode.
(line-number-mode 0)
Turn on Auto Fill mode automatically in Text mode and related modes (see
Section 33.2.2 [Hooks], page 445).
(add-hook ’text-mode-hook ’auto-fill-mode)
Load the installed Lisp library named ‘foo’ (actually a file ‘foo.elc’ or
‘foo.el’ in a standard Emacs directory).
(load "foo")
When the argument to load is a relative file name, not starting with ‘/’ or ‘~’,
load searches the directories in load-path (see Section 24.8 [Lisp Libraries],
page 287).
Load the compiled Lisp file ‘foo.elc’ from your home directory.
(load "~/foo.elc")
Here a full file name is used, so no searching is done.
Tell Emacs to find the definition for the function myfunction by loading a Lisp
library named ‘mypackage’ (i.e. a file ‘mypackage.elc’ or ‘mypackage.el’):
(autoload ’myfunction "mypackage" "Do what I say." t)
Here the string "Do what I say." is the function’s documentation string. You
specify it in the autoload definition so it will be available for help commands
even when the package is not loaded. The last argument, t, indicates that this
function is interactive; that is, it can be invoked interactively by typing M-x
myfunction RET or by binding it to a key. If the function is not interactive,
omit the t or use nil.
Rebind the key C-x l to run the function make-symbolic-link (see
Section 33.3.6 [Init Rebinding], page 455).
(global-set-key "\C-xl" ’make-symbolic-link)
or
(define-key global-map "\C-xl" ’make-symbolic-link)
Note once again the single-quote used to refer to the symbol make-symboliclink instead of its value as a variable.
Do the same thing for Lisp mode only.
(define-key lisp-mode-map "\C-xl" ’make-symbolic-link)
Redefine all keys which now run next-line in Fundamental mode so that they
run forward-line instead.

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(substitute-key-definition ’next-line ’forward-line
global-map)
Make C-x C-v undefined.
(global-unset-key "\C-x\C-v")
One reason to undefine a key is so that you can make it a prefix. Simply
defining C-x C-v anything will make C-x C-v a prefix, but C-x C-v must first
be freed of its usual non-prefix definition.
Make ‘$’ have the syntax of punctuation in Text mode. Note the use of a
character constant for ‘$’.
(modify-syntax-entry ?\$ "." text-mode-syntax-table)
Enable the use of the command narrow-to-region without confirmation.
(put ’narrow-to-region ’disabled nil)
Adjusting the configuration to various platforms and Emacs versions.
Users typically want Emacs to behave the same on all systems, so the same init
file is right for all platforms. However, sometimes it happens that a function
you use for customizing Emacs is not available on some platforms or in older
Emacs versions. To deal with that situation, put the customization inside a
conditional that tests whether the function or facility is available, like this:
(if (fboundp ’blink-cursor-mode)
(blink-cursor-mode 0))
(if (boundp ’coding-category-utf-8)
(set-coding-priority ’(coding-category-utf-8)))
You can also simply disregard the errors that occur if the function is not
defined.
(condition case ()
(set-face-background ’region "grey75")
(error nil))
A setq on a variable which does not exist is generally harmless, so those do
not need a conditional.

33.4.3 Terminal-specific Initialization
Each terminal type can have a Lisp library to be loaded into Emacs when it is run
on that type of terminal. For a terminal type named termtype, the library is called
‘term/termtype ’ and it is found by searching the directories load-path as usual
and trying the suffixes ‘.elc’ and ‘.el’. Normally it appears in the subdirectory
‘term’ of the directory where most Emacs libraries are kept.
The usual purpose of the terminal-specific library is to map the escape sequences
used by the terminal’s function keys onto more meaningful names, using inputdecode-map (or function-key-map before it). See the file ‘term/lk201.el’ for
an example of how this is done. Many function keys are mapped automatically
according to the information in the Termcap data base; the terminal-specific library
needs to map only the function keys that Termcap does not specify.

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When the terminal type contains a hyphen, only the part of the name before
the first hyphen is significant in choosing the library name. Thus, terminal types
‘aaa-48’ and ‘aaa-30-rv’ both use the library ‘term/aaa’. The code in the library
can use (getenv "TERM") to find the full terminal type name.
The library’s name is constructed by concatenating the value of the variable
term-file-prefix and the terminal type. Your ‘.emacs’ file can prevent the loading of the terminal-specific library by setting term-file-prefix to nil.
Emacs runs the hook term-setup-hook at the end of initialization, after both
your ‘.emacs’ file and any terminal-specific library have been read in. Add hook
functions to this hook if you wish to override part of any of the terminal-specific
libraries and to define initializations for terminals that do not have a library. See
Section 33.2.2 [Hooks], page 445.
33.4.4 How Emacs Finds Your Init File
Normally Emacs uses the environment variable HOME (see Section C.4.1 [General Variables], page 510) to find ‘.emacs’; that’s what ‘~’ means in a file
name. If ‘.emacs’ is not found inside ‘~/’ (nor ‘.emacs.el’), Emacs looks for
‘~/.emacs.d/init.el’ (which, like ‘~/.emacs.el’, can be byte-compiled).
However, if you run Emacs from a shell started by su, Emacs tries to find your
own ‘.emacs’, not that of the user you are currently pretending to be. The idea is
that you should get your own editor customizations even if you are running as the
super user.
More precisely, Emacs first determines which user’s init file to use. It gets your
user name from the environment variables LOGNAME and USER; if neither of those
exists, it uses effective user-ID. If that user name matches the real user-ID, then
Emacs uses HOME; otherwise, it looks up the home directory corresponding to that
user name in the system’s data base of users.
33.4.5 Non-ASCII Characters in Init Files
Language and coding systems may cause problems if your init file contains nonASCII characters, such as accented letters, in strings or key bindings.
If you want to use non-ASCII characters in your init file, you should put a
‘-*-coding: coding-system-*-’ tag on the first line of the init file, and specify a
coding system that supports the character(s) in question. See Section 19.7 [Recognize Coding], page 190. This is because the defaults for decoding non-ASCII text
might not yet be set up by the time Emacs reads those parts of your init file which
use such strings, possibly leading Emacs to decode those strings incorrectly. You
should then avoid adding Emacs Lisp code that modifies the coding system in other
ways, such as calls to set-language-environment.
To bind non-ASCII keys, you must use a vector (see Section 33.3.6 [Init Rebinding], page 455). The string syntax cannot be used, since the non-ASCII characters
will be interpreted as meta keys. For instance:
(global-set-key [?char ] ’some-function)
Type C-q, followed by the key you want to bind, to insert char.

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Warning: if you change the keyboard encoding, or change between multibyte
and unibyte mode, or anything that would alter which code C-q would insert for
that character, this key binding may stop working. It is therefore advisable to use
one and only one coding system, for your init file as well as the files you edit. For
example, don’t mix the ‘latin-1’ and ‘latin-9’ coding systems.

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34 Dealing with Common Problems
If you type an Emacs command you did not intend, the results are often mysterious. This chapter tells what you can do to cancel your mistake or recover from a
mysterious situation. Emacs bugs and system crashes are also considered.

34.1 Quitting and Aborting
C-g
C-BREAK (MS-DOS only)
Quit: cancel running or partially typed command.
C-]

Abort innermost recursive editing level and cancel the command which
invoked it (abort-recursive-edit).

ESC ESC ESC
Either quit or abort, whichever makes sense (keyboard-escapequit).
M-x top-level
Abort all recursive editing levels that are currently executing.
C-/
C-x u
C-_

Cancel a previously made change in the buffer contents (undo).

There are two ways of canceling a command before it has finished: quitting with
C-g, and aborting with C-] or M-x top-level. Quitting cancels a partially typed
command, or one which is still running. Aborting exits a recursive editing level and
cancels the command that invoked the recursive edit (see Section 31.9 [Recursive
Edit], page 424).
Quitting with C-g is the way to get rid of a partially typed command, or a
numeric argument that you don’t want. Furthermore, if you are in the middle of
a command that is running, C-g stops the command in a relatively safe way. For
example, if you quit out of a kill command that is taking a long time, either your
text will all still be in the buffer, or it will all be in the kill ring, or maybe both.
If the region is active, C-g deactivates the mark, unless Transient Mark mode is off
(see Section 8.7 [Disabled Transient Mark], page 52). If you are in the middle of an
incremental search, C-g behaves specially; it may take two successive C-g characters
to get out of a search. See Section 12.1 [Incremental Search], page 91, for details.
On MS-DOS, the character C-BREAK serves as a quit character like C-g. The
reason is that it is not feasible, on MS-DOS, to recognize C-g while a command is
running, between interactions with the user. By contrast, it is feasible to recognize C-BREAK at all times. See Section “MS-DOS Keyboard” in Specialized Emacs
Features.
C-g works by setting the variable quit-flag to t the instant C-g is typed;
Emacs Lisp checks this variable frequently, and quits if it is non-nil. C-g is only
actually executed as a command if you type it while Emacs is waiting for input. In
that case, the command it runs is keyboard-quit.

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On a text terminal, if you quit with C-g a second time before the first C-g is
recognized, you activate the “emergency escape” feature and return to the shell.
See Section 34.2.7 [Emergency Escape], page 472.
There are some situations where you cannot quit. When Emacs is waiting for
the operating system to do something, quitting is impossible unless special pains
are taken for the particular system call within Emacs where the waiting occurs. We
have done this for the system calls that users are likely to want to quit from, but it’s
possible you will encounter a case not handled. In one very common case—waiting
for file input or output using NFS—Emacs itself knows how to quit, but many NFS
implementations simply do not allow user programs to stop waiting for NFS when
the NFS server is hung.
Aborting with C-] (abort-recursive-edit) is used to get out of a recursive
editing level and cancel the command which invoked it. Quitting with C-g does not
do this, and could not do this, because it is used to cancel a partially typed command
within the recursive editing level. Both operations are useful. For example, if you
are in a recursive edit and type C-u 8 to enter a numeric argument, you can cancel
that argument with C-g and remain in the recursive edit.
The sequence ESC ESC ESC (keyboard-escape-quit) can either quit or abort.
(We defined it this way because ESC means “get out” in many PC programs.) It
can cancel a prefix argument, clear a selected region, or get out of a Query Replace,
like C-g. It can get out of the minibuffer or a recursive edit, like C-]. It can also
get out of splitting the frame into multiple windows, as with C-x 1. One thing it
cannot do, however, is stop a command that is running. That’s because it executes
as an ordinary command, and Emacs doesn’t notice it until it is ready for the next
command.
The command M-x top-level is equivalent to “enough” C-] commands to get
you out of all the levels of recursive edits that you are in; it also exits the minibuffer
if it is active. C-] gets you out one level at a time, but M-x top-level goes out
all levels at once. Both C-] and M-x top-level are like all other commands, and
unlike C-g, in that they take effect only when Emacs is ready for a command. C-]
is an ordinary key and has its meaning only because of its binding in the keymap.
See Section 31.9 [Recursive Edit], page 424.
C-/ (undo) is not strictly speaking a way of canceling a command, but you can
think of it as canceling a command that already finished executing. See Section 13.1
[Undo], page 110, for more information about the undo facility.

34.2 Dealing with Emacs Trouble
This section describes how to recognize and deal with situations in which Emacs
does not work as you expect, such as keyboard code mixups, garbled displays,
running out of memory, and crashes and hangs.
See Section 34.3 [Bugs], page 473, for what to do when you think you have found
a bug in Emacs.

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34.2.1 If DEL Fails to Delete
Every keyboard has a large key, usually labeled BACKSPACE, which is ordinarily
used to erase the last character that you typed. In Emacs, this key is supposed to
be equivalent to DEL.
When Emacs starts up on a graphical display, it determines automatically which
key should be DEL. In some unusual cases, Emacs gets the wrong information from
the system, and BACKSPACE ends up deleting forwards instead of backwards.
Some keyboards also have a DELETE key, which is ordinarily used to delete
forwards. If this key deletes backward in Emacs, that too suggests Emacs got the
wrong information—but in the opposite sense.
On a text terminal, if you find that BACKSPACE prompts for a Help command,
like Control-h, instead of deleting a character, it means that key is actually sending
the BS character. Emacs ought to be treating BS as DEL, but it isn’t.
In all of those cases, the immediate remedy is the same: use the command
M-x normal-erase-is-backspace-mode. This toggles between the two modes that
Emacs supports for handling DEL, so if Emacs starts in the wrong mode, this should
switch to the right mode. On a text terminal, if you want to ask for help when BS
is treated as DEL, use F1; C-? may also work, if it sends character code 127.
To fix the problem in every Emacs session, put one of the following lines into
your initialization file (see Section 33.4 [Init File], page 461). For the first case
above, where BACKSPACE deletes forwards instead of backwards, use this line to
make BACKSPACE act as DEL:
(normal-erase-is-backspace-mode 0)
For the other two cases, use this line:
(normal-erase-is-backspace-mode 1)
Another way to fix the problem for every Emacs session is to customize the
variable normal-erase-is-backspace: the value t specifies the mode where BS or
BACKSPACE is DEL, and nil specifies the other mode. See Section 33.1 [Easy
Customization], page 434.
34.2.2 Recursive Editing Levels
Recursive editing levels are important and useful features of Emacs, but they can
seem like malfunctions if you do not understand them.
If the mode line has square brackets ‘[...]’ around the parentheses that contain
the names of the major and minor modes, you have entered a recursive editing level.
If you did not do this on purpose, or if you don’t understand what that means, you
should just get out of the recursive editing level. To do so, type M-x top-level.
See Section 31.9 [Recursive Edit], page 424.
34.2.3 Garbage on the Screen
If the text on a text terminal looks wrong, the first thing to do is see whether
it is wrong in the buffer. Type C-l to redisplay the entire screen. If the screen
appears correct after this, the problem was entirely in the previous screen update.
(Otherwise, see the following section.)

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Display updating problems often result from an incorrect terminfo entry for the
terminal you are using. The file ‘etc/TERMS’ in the Emacs distribution gives the
fixes for known problems of this sort. ‘INSTALL’ contains general advice for these
problems in one of its sections. If you seem to be using the right terminfo entry, it
is possible that there is a bug in the terminfo entry, or a bug in Emacs that appears
for certain terminal types.
34.2.4 Garbage in the Text
If C-l shows that the text is wrong, first type C-h l to see what commands you
typed to produce the observed results. Then try undoing the changes step by step
using C-x u, until it gets back to a state you consider correct.
If a large portion of text appears to be missing at the beginning or end of the
buffer, check for the word ‘Narrow’ in the mode line. If it appears, the text you
don’t see is probably still present, but temporarily off-limits. To make it accessible
again, type C-x n w. See Section 11.5 [Narrowing], page 74.
34.2.5 Running out of Memory
If you get the error message ‘Virtual memory exceeded’, save your modified buffers
with C-x s. This method of saving them has the smallest need for additional memory. Emacs keeps a reserve of memory which it makes available when this error
happens; that should be enough to enable C-x s to complete its work. When the
reserve has been used, ‘!MEM FULL!’ appears at the beginning of the mode line,
indicating there is no more reserve.
Once you have saved your modified buffers, you can exit this Emacs session and
start another, or you can use M-x kill-some-buffers to free space in the current
Emacs job. If this frees up sufficient space, Emacs will refill its memory reserve,
and ‘!MEM FULL!’ will disappear from the mode line. That means you can safely go
on editing in the same Emacs session.
Do not use M-x buffer-menu to save or kill buffers when you run out of memory,
because the buffer menu needs a fair amount of memory itself, and the reserve supply
may not be enough.
34.2.6 Recovery After a Crash
If Emacs or the computer crashes, you can recover the files you were editing at the
time of the crash from their auto-save files. To do this, start Emacs again and type
the command M-x recover-session.
This command initially displays a buffer which lists interrupted session files,
each with its date. You must choose which session to recover from. Typically the
one you want is the most recent one. Move point to the one you choose, and type
C-c C-c.
Then recover-session considers each of the files that you were editing during
that session; for each such file, it asks whether to recover that file. If you answer y
for a file, it shows the dates of that file and its auto-save file, then asks once again
whether to recover that file. For the second question, you must confirm with yes.
If you do, Emacs visits the file but gets the text from the auto-save file.

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When recover-session is done, the files you’ve chosen to recover are present
in Emacs buffers. You should then save them. Only this—saving them—updates
the files themselves.
As a last resort, if you had buffers with content which were not associated with
any files, or if the autosave was not recent enough to have recorded important
changes, you can use the ‘etc/emacs-buffer.gdb’ script with GDB (the GNU
Debugger) to retrieve them from a core dump–provided that a core dump was
saved, and that the Emacs executable was not stripped of its debugging symbols.
As soon as you get the core dump, rename it to another name such as
‘core.emacs’, so that another crash won’t overwrite it.
To use this script, run gdb with the file name of your Emacs executable and the file name of the core dump, e.g.
‘gdb /usr/bin/emacs
core.emacs’.
At the (gdb) prompt, load the recovery script: ‘source
/usr/src/emacs/etc/emacs-buffer.gdb’. Then type the command ybufferlist to see which buffers are available. For each buffer, it lists a buffer number.
To save a buffer, use ysave-buffer; you specify the buffer number, and the file
name to write that buffer into. You should use a file name which does not already
exist; if the file does exist, the script does not make a backup of its old contents.
34.2.7 Emergency Escape
On text terminals, the emergency escape feature suspends Emacs immediately if
you type C-g a second time before Emacs can actually respond to the first one by
quitting. This is so you can always get out of GNU Emacs no matter how badly it
might be hung. When things are working properly, Emacs recognizes and handles
the first C-g so fast that the second one won’t trigger emergency escape. However, if
some problem prevents Emacs from handling the first C-g properly, then the second
one will get you back to the shell.
When you resume Emacs after a suspension caused by emergency escape, it asks
two questions before going back to what it had been doing:
Auto-save? (y or n)
Abort (and dump core)? (y or n)
Answer each one with y or n followed by RET.
Saying y to ‘Auto-save?’ causes immediate auto-saving of all modified buffers
in which auto-saving is enabled. Saying n skips this.
Saying y to ‘Abort (and dump core)?’ causes Emacs to crash, dumping core.
This is to enable a wizard to figure out why Emacs was failing to quit in the first
place. Execution does not continue after a core dump.
If you answer this question n, Emacs execution resumes. With luck, Emacs will
ultimately do the requested quit. If not, each subsequent C-g invokes emergency
escape again.
If Emacs is not really hung, just slow, you may invoke the double C-g feature
without really meaning to. Then just resume and answer n to both questions, and
you will get back to the former state. The quit you requested will happen by and
by.

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Emergency escape is active only for text terminals. On graphical displays, you
can use the mouse to kill Emacs or switch to another program.
On MS-DOS, you must type C-BREAK (twice) to cause emergency escape—but
there are cases where it won’t work, when system call hangs or when Emacs is stuck
in a tight loop in C code.

34.3 Reporting Bugs
If you think you have found a bug in Emacs, please report it. We cannot promise
to fix it, or always to agree that it is a bug, but we certainly want to hear about
it. The same applies for new features you would like to see added. The following
sections will help you to construct an effective bug report.
34.3.1 Reading Existing Bug Reports and Known Problems
Before reporting a bug, if at all possible please check to see if it is already known
about. Indeed, it may already have been fixed in a later release of Emacs, or in the
development version. Here is a list of the main places you can read about known
issues:
• The ‘etc/PROBLEMS’ file; type C-h C-p to read it. This file contains a list
of particularly well-known issues that have been encountered in compiling,
installing and running Emacs. Often, there are suggestions for workarounds
and solutions.
• Some additional user-level problems can be found in Section “Bugs and problems” in GNU Emacs FAQ.
• The GNU Bug Tracker at http://debbugs.gnu.org. Emacs bugs are filed in
the tracker under the ‘emacs’ package. The tracker records information about
the status of each bug, the initial bug report, and the follow-up messages by
the bug reporter and Emacs developers. You can search for bugs by subject,
severity, and other criteria.
Instead of browsing the bug tracker as a webpage, you can browse it from
Emacs using the debbugs package, which can be downloaded via the Package
Menu (see Chapter 32 [Packages], page 430). This package provides the command M-x debbugs-gnu to list bugs, and M-x debbugs-gnu-search to search
for a specific bug.
• The ‘bug-gnu-emacs’ mailing list (also available as the newsgroup
‘gnu.emacs.bug’).
You can read the archives of this mailing list at
http://lists.gnu.org/mailman/listinfo/bug-gnu-emacs. This list works
as a “mirror” of the Emacs bug reports and follow-up messages which are
sent to the bug tracker. It also contains old bug reports from before the bug
tracker was introduced (in early 2008).
If you like, you can subscribe to the list. Be aware that its purpose is to provide the Emacs maintainers with information about bugs and feature requests,
so reports may contain fairly large amounts of data; spectators should not
complain about this.

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• The ‘emacs-devel’ mailing list. Sometimes people report bugs to this mailing
list. This is not the main purpose of the list, however, and it is much better
to send bug reports to the bug list. You should not feel obliged to read this
list before reporting a bug.

34.3.2 When Is There a Bug
If Emacs accesses an invalid memory location (“segmentation fault”), or exits with
an operating system error message that indicates a problem in the program (as
opposed to something like “disk full”), then it is certainly a bug.
If the Emacs display does not correspond properly to the contents of the buffer,
then it is a bug. But you should check that features like buffer narrowing (see
Section 11.5 [Narrowing], page 74), which can hide parts of the buffer or change
how it is displayed, are not responsible.
Taking forever to complete a command can be a bug, but you must make sure
that it is really Emacs’s fault. Some commands simply take a long time. Type C-g
(C-BREAK on MS-DOS) and then C-h l to see whether the input Emacs received was
what you intended to type; if the input was such that you know it should have been
processed quickly, report a bug. If you don’t know whether the command should
take a long time, find out by looking in the manual or by asking for assistance.
If a command you are familiar with causes an Emacs error message in a case
where its usual definition ought to be reasonable, it is probably a bug.
If a command does the wrong thing, that is a bug. But be sure you know for
certain what it ought to have done. If you aren’t familiar with the command, it
might actually be working right. If in doubt, read the command’s documentation
(see Section 7.2 [Name Help], page 40).
A command’s intended definition may not be the best possible definition for
editing with. This is a very important sort of problem, but it is also a matter of
judgment. Also, it is easy to come to such a conclusion out of ignorance of some
of the existing features. It is probably best not to complain about such a problem
until you have checked the documentation in the usual ways, feel confident that you
understand it, and know for certain that what you want is not available. Ask other
Emacs users, too. If you are not sure what the command is supposed to do after a
careful reading of the manual, check the index and glossary for any terms that may
be unclear.
If after careful rereading of the manual you still do not understand what the
command should do, that indicates a bug in the manual, which you should report.
The manual’s job is to make everything clear to people who are not Emacs experts—
including you. It is just as important to report documentation bugs as program
bugs.
If the built-in documentation for a function or variable disagrees with the manual, one of them must be wrong; that is a bug.

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34.3.3 Understanding Bug Reporting
When you decide that there is a bug, it is important to report it and to report it in a
way which is useful. What is most useful is an exact description of what commands
you type, starting with the shell command to run Emacs, until the problem happens.
The most important principle in reporting a bug is to report facts. Hypotheses
and verbal descriptions are no substitute for the detailed raw data. Reporting the
facts is straightforward, but many people strain to posit explanations and report
them instead of the facts. If the explanations are based on guesses about how Emacs
is implemented, they will be useless; meanwhile, lacking the facts, we will have no
real information about the bug. If you want to actually debug the problem, and
report explanations that are more than guesses, that is useful—but please include
the raw facts as well.
For example, suppose that you type C-x C-f /glorp/baz.ugh RET, visiting a file
which (you know) happens to be rather large, and Emacs displays ‘I feel pretty
today’. The bug report would need to provide all that information. You should not
assume that the problem is due to the size of the file and say, “I visited a large file,
and Emacs displayed ‘I feel pretty today’.” This is what we mean by “guessing
explanations”. The problem might be due to the fact that there is a ‘z’ in the file
name. If this is so, then when we got your report, we would try out the problem
with some “large file”, probably with no ‘z’ in its name, and not see any problem.
There is no way we could guess that we should try visiting a file with a ‘z’ in its
name.
You should not even say “visit a file” instead of C-x C-f. Similarly, rather than
saying “if I have three characters on the line”, say “after I type RET A B C RET C-p”,
if that is the way you entered the text.
If possible, try quickly to reproduce the bug by invoking Emacs with emacs
-Q (so that Emacs starts with no initial customizations; see Section C.2 [Initial
Options], page 507), and repeating the steps that you took to trigger the bug. If you
can reproduce the bug this way, that rules out bugs in your personal customizations.
Then your bug report should begin by stating that you started Emacs with emacs
-Q, followed by the exact sequence of steps for reproducing the bug. If possible,
inform us of the exact contents of any file that is needed to reproduce the bug.
Some bugs are not reproducible from emacs -Q; some are not easily reproducible
at all. In that case, you should report what you have—but, as before, please stick
to the raw facts about what you did to trigger the bug the first time.
34.3.4 Checklist for Bug Reports
Before reporting a bug, first try to see if the problem has already been reported
(see Section 34.3.1 [Known Problems], page 473).
If you are able to, try the latest release of Emacs to see if the problem has already
been fixed. Even better is to try the latest development version. We recognize that
this is not easy for some people, so do not feel that you absolutely must do this
before making a report.
The best way to write a bug report for Emacs is to use the command M-x
report-emacs-bug. This sets up a mail buffer (see Chapter 29 [Sending Mail],

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page 367) and automatically inserts some of the essential information. However,
it cannot supply all the necessary information; you should still read and follow the
guidelines below, so you can enter the other crucial information by hand before
you send the message. You may feel that some of the information inserted by M-x
report-emacs-bug is not relevant, but unless you are absolutely sure it is best to
leave it, so that the developers can decide for themselves.
When you have finished writing your report, type C-c C-c and it will be sent
to the Emacs maintainers at bug-gnu-emacs@gnu.org. (If you want to suggest an
improvement or new feature, use the same address.) If you cannot send mail from
inside Emacs, you can copy the text of your report to your normal mail client (if
your system supports it, you can type C-c m to have Emacs do this for you) and
send it to that address. Or you can simply send an email to that address describing
the problem.
Your report will be sent to the ‘bug-gnu-emacs’ mailing list, and stored in
the GNU Bug Tracker at http://debbugs.gnu.org. Please include a valid reply
email address, in case we need to ask you for more information about your report.
Submissions are moderated, so there may be a delay before your report appears.
You do not need to know how the Gnu Bug Tracker works in order to report a
bug, but if you want to, you can read the tracker’s online documentation to see the
various features you can use.
All mail sent to the ‘bug-gnu-emacs’ mailing list is also gatewayed to the
‘gnu.emacs.bug’ newsgroup. The reverse is also true, but we ask you not to post
bug reports (or replies) via the newsgroup. It can make it much harder to contact
you if we need to ask for more information, and it does not integrate well with the
bug tracker.
If your data is more than 500,000 bytes, please don’t include it directly in the
bug report; instead, offer to send it on request, or make it available by ftp and say
where.
To enable maintainers to investigate a bug, your report should include all these
things:
• The version number of Emacs. Without this, we won’t know whether there is
any point in looking for the bug in the current version of GNU Emacs.
M-x report-emacs-bug includes this information automatically, but if you are
not using that command for your report you can get the version number by
typing M-x emacs-version RET. If that command does not work, you probably
have something other than GNU Emacs, so you will have to report the bug
somewhere else.
• The type of machine you are using, and the operating system name and version number (again, automatically included by M-x report-emacs-bug). M-x
emacs-version RET provides this information too. Copy its output from the
‘*Messages*’ buffer, so that you get it all and get it accurately.
• The operands given to the configure command when Emacs was installed
(automatically included by M-x report-emacs-bug).
• A complete list of any modifications you have made to the Emacs source. (We

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may not have time to investigate the bug unless it happens in an unmodified
Emacs. But if you’ve made modifications and you don’t tell us, you are sending
us on a wild goose chase.)
Be precise about these changes. A description in English is not enough—send
a context diff for them.
Adding files of your own, or porting to another machine, is a modification of
the source.
Details of any other deviations from the standard procedure for installing GNU
Emacs.
The complete text of any files needed to reproduce the bug.
If you can tell us a way to cause the problem without visiting any files, please
do so. This makes it much easier to debug. If you do need files, make sure you
arrange for us to see their exact contents. For example, it can matter whether
there are spaces at the ends of lines, or a newline after the last line in the buffer
(nothing ought to care whether the last line is terminated, but try telling the
bugs that).
The precise commands we need to type to reproduce the bug. If at all possible,
give a full recipe for an Emacs started with the ‘-Q’ option (see Section C.2
[Initial Options], page 507). This bypasses your personal customizations.
One way to record the input to Emacs precisely is to write a dribble file. To
start the file, use the M-x open-dribble-file RET command. From then on,
Emacs copies all your input to the specified dribble file until the Emacs process
is killed.
For possible display bugs, the terminal type (the value of environment variable
TERM), the complete termcap entry for the terminal from ‘/etc/termcap’ (since
that file is not identical on all machines), and the output that Emacs actually
sent to the terminal.
The way to collect the terminal output is to execute the Lisp expression
(open-termscript "~/termscript")
using M-: or from the ‘*scratch*’ buffer just after starting Emacs. From then
on, Emacs copies all terminal output to the specified termscript file as well,
until the Emacs process is killed. If the problem happens when Emacs starts
up, put this expression into your Emacs initialization file so that the termscript
file will be open when Emacs displays the screen for the first time.
Be warned: it is often difficult, and sometimes impossible, to fix a terminaldependent bug without access to a terminal of the type that stimulates the
bug.
If non-ASCII text or internationalization is relevant, the locale that was current
when you started Emacs. On GNU/Linux and Unix systems, or if you use a
Posix-style shell such as Bash, you can use this shell command to view the
relevant values:
echo LC_ALL=$LC_ALL LC_COLLATE=$LC_COLLATE LC_CTYPE=$LC_CTYPE \
LC_MESSAGES=$LC_MESSAGES LC_TIME=$LC_TIME LANG=$LANG

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Alternatively, use the locale command, if your system has it, to display your
locale settings.
You can use the M-! command to execute these commands from Emacs, and
then copy the output from the ‘*Messages*’ buffer into the bug report. Alternatively, M-x getenv RET LC_ALL RET will display the value of LC_ALL in the
echo area, and you can copy its output from the ‘*Messages*’ buffer.
• A description of what behavior you observe that you believe is incorrect. For
example, “The Emacs process gets a fatal signal”, or, “The resulting text is as
follows, which I think is wrong.”
Of course, if the bug is that Emacs gets a fatal signal, then one can’t miss it.
But if the bug is incorrect text, the maintainer might fail to notice what is
wrong. Why leave it to chance?
Even if the problem you experience is a fatal signal, you should still say so
explicitly. Suppose something strange is going on, such as, your copy of the
source is out of sync, or you have encountered a bug in the C library on your
system. (This has happened!) Your copy might crash and the copy here might
not. If you said to expect a crash, then when Emacs here fails to crash, we
would know that the bug was not happening. If you don’t say to expect a
crash, then we would not know whether the bug was happening—we would
not be able to draw any conclusion from our observations.
• If the bug is that the Emacs Manual or the Emacs Lisp Reference Manual fails
to describe the actual behavior of Emacs, or that the text is confusing, copy
in the text from the online manual which you think is at fault. If the section
is small, just the section name is enough.
• If the manifestation of the bug is an Emacs error message, it is important to
report the precise text of the error message, and a backtrace showing how the
Lisp program in Emacs arrived at the error.
To get the error message text accurately, copy it from the ‘*Messages*’ buffer
into the bug report. Copy all of it, not just part.
To make a backtrace for the error, use M-x toggle-debug-on-error before
the error happens (that is to say, you must give that command and then make
the bug happen). This causes the error to start the Lisp debugger, which
shows you a backtrace. Copy the text of the debugger’s backtrace into the
bug report. See Section “The Lisp Debugger” in the Emacs Lisp Reference
Manual, for information on debugging Emacs Lisp programs with the Edebug
package.
This use of the debugger is possible only if you know how to make the bug
happen again. If you can’t make it happen again, at least copy the whole error
message.
If Emacs appears to be stuck in an infinite loop or in a very long operation,
typing C-g with the variable debug-on-quit non-nil will start the Lisp debugger and show a backtrace. This backtrace is useful for debugging such long
loops, so if you can produce it, copy it into the bug report.

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If you cannot get Emacs to respond to C-g (e.g., because inhibit-quit is
set), then you can try sending the signal specified by debug-on-event (default
SIGUSR2) from outside Emacs to cause it to enter the debugger.
Check whether any programs you have loaded into the Lisp world, including
your initialization file, set any variables that may affect the functioning of
Emacs. Also, see whether the problem happens in a freshly started Emacs
without loading your initialization file (start Emacs with the -Q switch to
prevent loading the init files). If the problem does not occur then, you must
report the precise contents of any programs that you must load into the Lisp
world in order to cause the problem to occur.
If the problem does depend on an init file or other Lisp programs that are not
part of the standard Emacs system, then you should make sure it is not a bug
in those programs by complaining to their maintainers first. After they verify
that they are using Emacs in a way that is supposed to work, they should
report the bug.
If you wish to mention something in the GNU Emacs source, show the line of
code with a few lines of context. Don’t just give a line number.
The line numbers in the development sources don’t match those in your sources.
It would take extra work for the maintainers to determine what code is in your
version at a given line number, and we could not be certain.
Additional information from a C debugger such as GDB might enable someone
to find a problem on a machine which he does not have available. If you don’t
know how to use GDB, please read the GDB manual—it is not very long,
and using GDB is easy. You can find the GDB distribution, including the
GDB manual in online form, in most of the same places you can find the
Emacs distribution. To run Emacs under GDB, you should switch to the
‘src’ subdirectory in which Emacs was compiled, then do ‘gdb emacs’. It is
important for the directory ‘src’ to be current so that GDB will read the
‘.gdbinit’ file in this directory.
However, you need to think when you collect the additional information if you
want it to show what causes the bug.
For example, many people send just a backtrace, but that is not very useful
by itself. A simple backtrace with arguments often conveys little about what
is happening inside GNU Emacs, because most of the arguments listed in the
backtrace are pointers to Lisp objects. The numeric values of these pointers
have no significance whatever; all that matters is the contents of the objects
they point to (and most of the contents are themselves pointers).
To provide useful information, you need to show the values of Lisp objects in
Lisp notation. Do this for each variable which is a Lisp object, in several stack
frames near the bottom of the stack. Look at the source to see which variables
are Lisp objects, because the debugger thinks of them as integers.
To show a variable’s value in Lisp syntax, first print its value, then use the
user-defined GDB command pr to print the Lisp object in Lisp syntax. (If you
must use another debugger, call the function debug_print with the object as

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an argument.) The pr command is defined by the file ‘.gdbinit’, and it works
only if you are debugging a running process (not with a core dump).
To make Lisp errors stop Emacs and return to GDB, put a breakpoint at
Fsignal.
For a short listing of Lisp functions running, type the GDB command
xbacktrace.
The file ‘.gdbinit’ defines several other commands that are useful for examining the data types and contents of Lisp objects. Their names begin with ‘x’.
These commands work at a lower level than pr, and are less convenient, but
they may work even when pr does not, such as when debugging a core dump
or when Emacs has had a fatal signal.
More detailed advice and other useful techniques for debugging Emacs are
available in the file ‘etc/DEBUG’ in the Emacs distribution. That file also includes instructions for investigating problems whereby Emacs stops responding
(many people assume that Emacs is “hung”, whereas in fact it might be in an
infinite loop).
To find the file ‘etc/DEBUG’ in your Emacs installation, use the directory name
stored in the variable data-directory.
Here are some things that are not necessary in a bug report:
• A description of the envelope of the bug—this is not necessary for a reproducible bug.
Often people who encounter a bug spend a lot of time investigating which
changes to the input file will make the bug go away and which changes will
not affect it.
This is often time-consuming and not very useful, because the way we will find
the bug is by running a single example under the debugger with breakpoints,
not by pure deduction from a series of examples. You might as well save time
by not searching for additional examples. It is better to send the bug report
right away, go back to editing, and find another bug to report.
Of course, if you can find a simpler example to report instead of the original
one, that is a convenience. Errors in the output will be easier to spot, running
under the debugger will take less time, etc.
However, simplification is not vital; if you can’t do this or don’t have time to
try, please report the bug with your original test case.
• A core dump file.
Debugging the core dump might be useful, but it can only be done on your
machine, with your Emacs executable. Therefore, sending the core dump file
to the Emacs maintainers won’t be useful. Above all, don’t include the core file
in an email bug report! Such a large message can be extremely inconvenient.
• A system-call trace of Emacs execution.
System-call traces are very useful for certain special kinds of debugging, but
in most cases they give little useful information. It is therefore strange that

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many people seem to think that the way to report information about a crash
is to send a system-call trace. Perhaps this is a habit formed from experience
debugging programs that don’t have source code or debugging symbols.
In most programs, a backtrace is normally far, far more informative than a
system-call trace. Even in Emacs, a simple backtrace is generally more informative, though to give full information you should supplement the backtrace
by displaying variable values and printing them as Lisp objects with pr (see
above).
• A patch for the bug.
A patch for the bug is useful if it is a good one. But don’t omit the other
information that a bug report needs, such as the test case, on the assumption
that a patch is sufficient. We might see problems with your patch and decide
to fix the problem another way, or we might not understand it at all. And if
we can’t understand what bug you are trying to fix, or why your patch should
be an improvement, we mustn’t install it.
• A guess about what the bug is or what it depends on.
Such guesses are usually wrong. Even experts can’t guess right about such
things without first using the debugger to find the facts.
34.3.5 Sending Patches for GNU Emacs
If you would like to write bug fixes or improvements for GNU Emacs, that is very
helpful. When you send your changes, please follow these guidelines to make it
easy for the maintainers to use them. If you don’t follow these guidelines, your
information might still be useful, but using it will take extra work. Maintaining
GNU Emacs is a lot of work in the best of circumstances, and we can’t keep up
unless you do your best to help.
• Send an explanation with your changes of what problem they fix or what
improvement they bring about. For a fix for an existing bug, it is best to reply
to the relevant discussion on the ‘bug-gnu-emacs’ list, or the bug entry in the
GNU Bug Tracker at http://debbugs.gnu.org. Explain why your change
fixes the bug.
• Always include a proper bug report for the problem you think you have fixed.
We need to convince ourselves that the change is right before installing it.
Even if it is correct, we might have trouble understanding it if we don’t have
a way to reproduce the problem.
• Include all the comments that are appropriate to help people reading the source
in the future understand why this change was needed.
• Don’t mix together changes made for different reasons. Send them individually.
If you make two changes for separate reasons, then we might not want to install
them both. We might want to install just one. If you send them all jumbled
together in a single set of diffs, we have to do extra work to disentangle them—
to figure out which parts of the change serve which purpose. If we don’t have
time for this, we might have to ignore your changes entirely.

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If you send each change as soon as you have written it, with its own explanation,
then two changes never get tangled up, and we can consider each one properly
without any extra work to disentangle them.
• Send each change as soon as that change is finished. Sometimes people think
they are helping us by accumulating many changes to send them all together.
As explained above, this is absolutely the worst thing you could do.
Since you should send each change separately, you might as well send it right
away. That gives us the option of installing it immediately if it is important.
• Use ‘diff -c’ to make your diffs. Diffs without context are hard to install
reliably. More than that, they are hard to study; we must always study a
patch to decide whether we want to install it. Unidiff format is better than
contextless diffs, but not as easy to read as ‘-c’ format.
If you have GNU diff, use ‘diff -c -F’^[_a-zA-Z0-9$]+ *(’’ when making
diffs of C code. This shows the name of the function that each change occurs
in.
• Avoid any ambiguity as to which is the old version and which is the new.
Please make the old version the first argument to diff, and the new version
the second argument. And please give one version or the other a name that
indicates whether it is the old version or your new changed one.
• Write the change log entries for your changes. This is both to save us the extra
work of writing them, and to help explain your changes so we can understand
them.
The purpose of the change log is to show people where to find what was
changed. So you need to be specific about what functions you changed; in
large functions, it’s often helpful to indicate where within the function the
change was.
On the other hand, once you have shown people where to find the change, you
need not explain its purpose in the change log. Thus, if you add a new function,
all you need to say about it is that it is new. If you feel that the purpose needs
explaining, it probably does—but put the explanation in comments in the code.
It will be more useful there.
Please read the ‘ChangeLog’ files in the ‘src’ and ‘lisp’ directories to see
what sorts of information to put in, and to learn the style that we use. See
Section 25.2 [Change Log], page 309.
• When you write the fix, keep in mind that we can’t install a change that would
break other systems. Please think about what effect your change will have if
compiled on another type of system.
Sometimes people send fixes that might be an improvement in general—but it
is hard to be sure of this. It’s hard to install such changes because we have to
study them very carefully. Of course, a good explanation of the reasoning by
which you concluded the change was correct can help convince us.
The safest changes are changes to the configuration files for a particular machine. These are safe because they can’t create new bugs on other machines.

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Please help us keep up with the workload by designing the patch in a form
that is clearly safe to install.

34.4 Contributing to Emacs Development
If you would like to help pretest Emacs releases to assure they work well, or if
you would like to work on improving Emacs, please contact the maintainers at
emacs-devel@gnu.org. A pretester should be prepared to investigate bugs as well
as report them. If you’d like to work on improving Emacs, please ask for suggested
projects or suggest your own ideas.
If you have already written an improvement, please tell us about it. If you have
not yet started work, it is useful to contact emacs-devel@gnu.org before you start;
it might be possible to suggest ways to make your extension fit in better with the
rest of Emacs.
The development version of Emacs can be downloaded from the repository where
it is actively maintained by a group of developers. See the Emacs project page
http://savannah.gnu.org/projects/emacs/ for details.
For more information on how to contribute, see the ‘etc/CONTRIBUTE’ file in the
Emacs distribution.

34.5 How To Get Help with GNU Emacs
If you need help installing, using or changing GNU Emacs, there are two ways to
find it:
• Send a message to the mailing list help-gnu-emacs@gnu.org, or post your
request on newsgroup gnu.emacs.help. (This mailing list and newsgroup
interconnect, so it does not matter which one you use.)
• Look in the service directory for someone who might help you for a fee. The
service directory is found in the file named ‘etc/SERVICE’ in the Emacs distribution.

Appendix A: GNU GENERAL PUBLIC LICENSE

484

Appendix A GNU GENERAL PUBLIC LICENSE
Version 3, 29 June 2007
Copyright c 2007 Free Software Foundation, Inc. http://fsf.org/
Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.

Preamble
The GNU General Public License is a free, copyleft license for software and other
kinds of works.
The licenses for most software and other practical works are designed to take
away your freedom to share and change the works. By contrast, the GNU General
Public License is intended to guarantee your freedom to share and change all versions
of a program—to make sure it remains free software for all its users. We, the Free
Software Foundation, use the GNU General Public License for most of our software;
it applies also to any other work released this way by its authors. You can apply it
to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our
General Public Licenses are designed to make sure that you have the freedom to
distribute copies of free software (and charge for them if you wish), that you receive
source code or can get it if you want it, that you can change the software or use
pieces of it in new free programs, and that you know you can do these things.
To protect your rights, we need to prevent others from denying you these rights
or asking you to surrender the rights. Therefore, you have certain responsibilities if
you distribute copies of the software, or if you modify it: responsibilities to respect
the freedom of others.
For example, if you distribute copies of such a program, whether gratis or for a
fee, you must pass on to the recipients the same freedoms that you received. You
must make sure that they, too, receive or can get the source code. And you must
show them these terms so they know their rights.
Developers that use the GNU GPL protect your rights with two steps: (1) assert
copyright on the software, and (2) offer you this License giving you legal permission
to copy, distribute and/or modify it.
For the developers’ and authors’ protection, the GPL clearly explains that there
is no warranty for this free software. For both users’ and authors’ sake, the GPL
requires that modified versions be marked as changed, so that their problems will
not be attributed erroneously to authors of previous versions.
Some devices are designed to deny users access to install or run modified versions of the software inside them, although the manufacturer can do so. This is
fundamentally incompatible with the aim of protecting users’ freedom to change
the software. The systematic pattern of such abuse occurs in the area of products
for individuals to use, which is precisely where it is most unacceptable. Therefore,
we have designed this version of the GPL to prohibit the practice for those products.
If such problems arise substantially in other domains, we stand ready to extend this

Appendix A: GNU GENERAL PUBLIC LICENSE

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provision to those domains in future versions of the GPL, as needed to protect the
freedom of users.
Finally, every program is threatened constantly by software patents. States
should not allow patents to restrict development and use of software on generalpurpose computers, but in those that do, we wish to avoid the special danger that
patents applied to a free program could make it effectively proprietary. To prevent
this, the GPL assures that patents cannot be used to render the program non-free.
The precise terms and conditions for copying, distribution and modification
follow.

TERMS AND CONDITIONS
0. Definitions.
“This License” refers to version 3 of the GNU General Public License.
“Copyright” also means copyright-like laws that apply to other kinds of works,
such as semiconductor masks.
“The Program” refers to any copyrightable work licensed under this License.
Each licensee is addressed as “you”. “Licensees” and “recipients” may be
individuals or organizations.
To “modify” a work means to copy from or adapt all or part of the work in
a fashion requiring copyright permission, other than the making of an exact
copy. The resulting work is called a “modified version” of the earlier work or
a work “based on” the earlier work.
A “covered work” means either the unmodified Program or a work based on
the Program.
To “propagate” a work means to do anything with it that, without permission,
would make you directly or secondarily liable for infringement under applicable copyright law, except executing it on a computer or modifying a private
copy. Propagation includes copying, distribution (with or without modification), making available to the public, and in some countries other activities as
well.
To “convey” a work means any kind of propagation that enables other parties
to make or receive copies. Mere interaction with a user through a computer
network, with no transfer of a copy, is not conveying.
An interactive user interface displays “Appropriate Legal Notices” to the extent
that it includes a convenient and prominently visible feature that (1) displays
an appropriate copyright notice, and (2) tells the user that there is no warranty
for the work (except to the extent that warranties are provided), that licensees
may convey the work under this License, and how to view a copy of this License.
If the interface presents a list of user commands or options, such as a menu, a
prominent item in the list meets this criterion.
1. Source Code.
The “source code” for a work means the preferred form of the work for making
modifications to it. “Object code” means any non-source form of a work.

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A “Standard Interface” means an interface that either is an official standard
defined by a recognized standards body, or, in the case of interfaces specified for
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The “System Libraries” of an executable work include anything, other than
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The Corresponding Source need not include anything that users can regenerate
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The Corresponding Source for a work in source code form is that same work.
2. Basic Permissions.
All rights granted under this License are granted for the term of copyright
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You may make, run and propagate covered works that you do not convey,
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or running the covered works for you must do so exclusively on your behalf,
under your direction and control, on terms that prohibit them from making
any copies of your copyrighted material outside their relationship with you.

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Conveying under any other circumstances is permitted solely under the conditions stated below. Sublicensing is not allowed; section 10 makes it unnecessary.
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When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected
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You may charge any price or no price for each copy that you convey, and you
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You may convey a work based on the Program, or the modifications to produce
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b. The work must carry prominent notices stating that it is released under
this License and any conditions added under section 7. This requirement
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c. You must license the entire work, as a whole, under this License to anyone
who comes into possession of a copy. This License will therefore apply,
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d. If the work has interactive user interfaces, each must display Appropriate
Legal Notices; however, if the Program has interactive interfaces that do
not display Appropriate Legal Notices, your work need not make them do
so.

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A compilation of a covered work with other separate and independent works,
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Source under the terms of this License, in one of these ways:
a. Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding
Source fixed on a durable physical medium customarily used for software
interchange.
b. Convey the object code in, or embodied in, a physical product (including
a physical distribution medium), accompanied by a written offer, valid
for at least three years and valid for as long as you offer spare parts or
customer support for that product model, to give anyone who possesses
the object code either (1) a copy of the Corresponding Source for all
the software in the product that is covered by this License, on a durable
physical medium customarily used for software interchange, for a price no
more than your reasonable cost of physically performing this conveying
of source, or (2) access to copy the Corresponding Source from a network
server at no charge.
c. Convey individual copies of the object code with a copy of the written
offer to provide the Corresponding Source. This alternative is allowed
only occasionally and noncommercially, and only if you received the object
code with such an offer, in accord with subsection 6b.
d. Convey the object code by offering access from a designated place (gratis
or for a charge), and offer equivalent access to the Corresponding Source
in the same way through the same place at no further charge. You need
not require recipients to copy the Corresponding Source along with the
object code. If the place to copy the object code is a network server, the
Corresponding Source may be on a different server (operated by you or
a third party) that supports equivalent copying facilities, provided you
maintain clear directions next to the object code saying where to find the
Corresponding Source. Regardless of what server hosts the Corresponding
Source, you remain obligated to ensure that it is available for as long as
needed to satisfy these requirements.
e. Convey the object code using peer-to-peer transmission, provided you
inform other peers where the object code and Corresponding Source of the
work are being offered to the general public at no charge under subsection
6d.

Appendix A: GNU GENERAL PUBLIC LICENSE

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A separable portion of the object code, whose source code is excluded from the
Corresponding Source as a System Library, need not be included in conveying
the object code work.
A “User Product” is either (1) a “consumer product”, which means any tangible personal property which is normally used for personal, family, or household
purposes, or (2) anything designed or sold for incorporation into a dwelling.
In determining whether a product is a consumer product, doubtful cases shall
be resolved in favor of coverage. For a particular product received by a particular user, “normally used” refers to a typical or common use of that class
of product, regardless of the status of the particular user or of the way in
which the particular user actually uses, or expects or is expected to use, the
product. A product is a consumer product regardless of whether the product
has substantial commercial, industrial or non-consumer uses, unless such uses
represent the only significant mode of use of the product.
“Installation Information” for a User Product means any methods, procedures,
authorization keys, or other information required to install and execute modified versions of a covered work in that User Product from a modified version
of its Corresponding Source. The information must suffice to ensure that the
continued functioning of the modified object code is in no case prevented or
interfered with solely because modification has been made.
If you convey an object code work under this section in, or with, or specifically
for use in, a User Product, and the conveying occurs as part of a transaction in
which the right of possession and use of the User Product is transferred to the
recipient in perpetuity or for a fixed term (regardless of how the transaction is
characterized), the Corresponding Source conveyed under this section must be
accompanied by the Installation Information. But this requirement does not
apply if neither you nor any third party retains the ability to install modified
object code on the User Product (for example, the work has been installed in
ROM).
The requirement to provide Installation Information does not include a requirement to continue to provide support service, warranty, or updates for a work
that has been modified or installed by the recipient, or for the User Product
in which it has been modified or installed. Access to a network may be denied
when the modification itself materially and adversely affects the operation of
the network or violates the rules and protocols for communication across the
network.
Corresponding Source conveyed, and Installation Information provided, in accord with this section must be in a format that is publicly documented (and
with an implementation available to the public in source code form), and must
require no special password or key for unpacking, reading or copying.
7. Additional Terms.
“Additional permissions” are terms that supplement the terms of this License
by making exceptions from one or more of its conditions. Additional permissions that are applicable to the entire Program shall be treated as though they

Appendix A: GNU GENERAL PUBLIC LICENSE

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were included in this License, to the extent that they are valid under applicable law. If additional permissions apply only to part of the Program, that
part may be used separately under those permissions, but the entire Program
remains governed by this License without regard to the additional permissions.
When you convey a copy of a covered work, you may at your option remove
any additional permissions from that copy, or from any part of it. (Additional
permissions may be written to require their own removal in certain cases when
you modify the work.) You may place additional permissions on material,
added by you to a covered work, for which you have or can give appropriate
copyright permission.
Notwithstanding any other provision of this License, for material you add to a
covered work, you may (if authorized by the copyright holders of that material)
supplement the terms of this License with terms:
a. Disclaiming warranty or limiting liability differently from the terms of
sections 15 and 16 of this License; or
b. Requiring preservation of specified reasonable legal notices or author attributions in that material or in the Appropriate Legal Notices displayed
by works containing it; or
c. Prohibiting misrepresentation of the origin of that material, or requiring
that modified versions of such material be marked in reasonable ways as
different from the original version; or
d. Limiting the use for publicity purposes of names of licensors or authors
of the material; or
e. Declining to grant rights under trademark law for use of some trade
names, trademarks, or service marks; or
f. Requiring indemnification of licensors and authors of that material by
anyone who conveys the material (or modified versions of it) with contractual assumptions of liability to the recipient, for any liability that
these contractual assumptions directly impose on those licensors and authors.
All other non-permissive additional terms are considered “further restrictions”
within the meaning of section 10. If the Program as you received it, or any
part of it, contains a notice stating that it is governed by this License along
with a term that is a further restriction, you may remove that term. If a license
document contains a further restriction but permits relicensing or conveying
under this License, you may add to a covered work material governed by the
terms of that license document, provided that the further restriction does not
survive such relicensing or conveying.
If you add terms to a covered work in accord with this section, you must place,
in the relevant source files, a statement of the additional terms that apply to
those files, or a notice indicating where to find the applicable terms.
Additional terms, permissive or non-permissive, may be stated in the form of
a separately written license, or stated as exceptions; the above requirements
apply either way.

Appendix A: GNU GENERAL PUBLIC LICENSE

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8. Termination.
You may not propagate or modify a covered work except as expressly provided
under this License. Any attempt otherwise to propagate or modify it is void,
and will automatically terminate your rights under this License (including any
patent licenses granted under the third paragraph of section 11).
However, if you cease all violation of this License, then your license from a
particular copyright holder is reinstated (a) provisionally, unless and until the
copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some
reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable
means, this is the first time you have received notice of violation of this License
(for any work) from that copyright holder, and you cure the violation prior to
30 days after your receipt of the notice.
Termination of your rights under this section does not terminate the licenses
of parties who have received copies or rights from you under this License. If
your rights have been terminated and not permanently reinstated, you do not
qualify to receive new licenses for the same material under section 10.
9. Acceptance Not Required for Having Copies.
You are not required to accept this License in order to receive or run a copy
of the Program. Ancillary propagation of a covered work occurring solely as a
consequence of using peer-to-peer transmission to receive a copy likewise does
not require acceptance. However, nothing other than this License grants you
permission to propagate or modify any covered work. These actions infringe
copyright if you do not accept this License. Therefore, by modifying or propagating a covered work, you indicate your acceptance of this License to do
so.
10. Automatic Licensing of Downstream Recipients.
Each time you convey a covered work, the recipient automatically receives a
license from the original licensors, to run, modify and propagate that work,
subject to this License. You are not responsible for enforcing compliance by
third parties with this License.
An “entity transaction” is a transaction transferring control of an organization,
or substantially all assets of one, or subdividing an organization, or merging
organizations. If propagation of a covered work results from an entity transaction, each party to that transaction who receives a copy of the work also
receives whatever licenses to the work the party’s predecessor in interest had
or could give under the previous paragraph, plus a right to possession of the
Corresponding Source of the work from the predecessor in interest, if the predecessor has it or can get it with reasonable efforts.
You may not impose any further restrictions on the exercise of the rights
granted or affirmed under this License. For example, you may not impose
a license fee, royalty, or other charge for exercise of rights granted under this

Appendix A: GNU GENERAL PUBLIC LICENSE

492

License, and you may not initiate litigation (including a cross-claim or counterclaim in a lawsuit) alleging that any patent claim is infringed by making,
using, selling, offering for sale, or importing the Program or any portion of it.
11. Patents.
A “contributor” is a copyright holder who authorizes use under this License of
the Program or a work on which the Program is based. The work thus licensed
is called the contributor’s “contributor version”.
A contributor’s “essential patent claims” are all patent claims owned or controlled by the contributor, whether already acquired or hereafter acquired, that
would be infringed by some manner, permitted by this License, of making, using, or selling its contributor version, but do not include claims that would
be infringed only as a consequence of further modification of the contributor
version. For purposes of this definition, “control” includes the right to grant
patent sublicenses in a manner consistent with the requirements of this License.
Each contributor grants you a non-exclusive, worldwide, royalty-free patent
license under the contributor’s essential patent claims, to make, use, sell, offer
for sale, import and otherwise run, modify and propagate the contents of its
contributor version.
In the following three paragraphs, a “patent license” is any express agreement
or commitment, however denominated, not to enforce a patent (such as an
express permission to practice a patent or covenant not to sue for patent infringement). To “grant” such a patent license to a party means to make such
an agreement or commitment not to enforce a patent against the party.
If you convey a covered work, knowingly relying on a patent license, and the
Corresponding Source of the work is not available for anyone to copy, free
of charge and under the terms of this License, through a publicly available
network server or other readily accessible means, then you must either (1) cause
the Corresponding Source to be so available, or (2) arrange to deprive yourself
of the benefit of the patent license for this particular work, or (3) arrange, in a
manner consistent with the requirements of this License, to extend the patent
license to downstream recipients. “Knowingly relying” means you have actual
knowledge that, but for the patent license, your conveying the covered work
in a country, or your recipient’s use of the covered work in a country, would
infringe one or more identifiable patents in that country that you have reason
to believe are valid.
If, pursuant to or in connection with a single transaction or arrangement, you
convey, or propagate by procuring conveyance of, a covered work, and grant
a patent license to some of the parties receiving the covered work authorizing
them to use, propagate, modify or convey a specific copy of the covered work,
then the patent license you grant is automatically extended to all recipients of
the covered work and works based on it.
A patent license is “discriminatory” if it does not include within the scope of
its coverage, prohibits the exercise of, or is conditioned on the non-exercise
of one or more of the rights that are specifically granted under this License.

Appendix A: GNU GENERAL PUBLIC LICENSE

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You may not convey a covered work if you are a party to an arrangement
with a third party that is in the business of distributing software, under which
you make payment to the third party based on the extent of your activity of
conveying the work, and under which the third party grants, to any of the
parties who would receive the covered work from you, a discriminatory patent
license (a) in connection with copies of the covered work conveyed by you (or
copies made from those copies), or (b) primarily for and in connection with
specific products or compilations that contain the covered work, unless you
entered into that arrangement, or that patent license was granted, prior to 28
March 2007.
Nothing in this License shall be construed as excluding or limiting any implied
license or other defenses to infringement that may otherwise be available to
you under applicable patent law.
12. No Surrender of Others’ Freedom.
If conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you
from the conditions of this License. If you cannot convey a covered work so
as to satisfy simultaneously your obligations under this License and any other
pertinent obligations, then as a consequence you may not convey it at all. For
example, if you agree to terms that obligate you to collect a royalty for further
conveying from those to whom you convey the Program, the only way you
could satisfy both those terms and this License would be to refrain entirely
from conveying the Program.
13. Use with the GNU Affero General Public License.
Notwithstanding any other provision of this License, you have permission to
link or combine any covered work with a work licensed under version 3 of
the GNU Affero General Public License into a single combined work, and to
convey the resulting work. The terms of this License will continue to apply to
the part which is the covered work, but the special requirements of the GNU
Affero General Public License, section 13, concerning interaction through a
network will apply to the combination as such.
14. Revised Versions of this License.
The Free Software Foundation may publish revised and/or new versions of the
GNU General Public License from time to time. Such new versions will be
similar in spirit to the present version, but may differ in detail to address new
problems or concerns.
Each version is given a distinguishing version number. If the Program specifies
that a certain numbered version of the GNU General Public License “or any
later version” applies to it, you have the option of following the terms and
conditions either of that numbered version or of any later version published
by the Free Software Foundation. If the Program does not specify a version
number of the GNU General Public License, you may choose any version ever
published by the Free Software Foundation.

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If the Program specifies that a proxy can decide which future versions of the
GNU General Public License can be used, that proxy’s public statement of
acceptance of a version permanently authorizes you to choose that version for
the Program.
Later license versions may give you additional or different permissions. However, no additional obligations are imposed on any author or copyright holder
as a result of your choosing to follow a later version.
15. Disclaimer of Warranty.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT
PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE
STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
PARTIES PROVIDE THE PROGRAM “AS IS” WITHOUT WARRANTY
OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK
AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS
WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
16. Limitation of Liability.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED
TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER
PARTY WHO MODIFIES AND/OR CONVEYS THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING
ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA
BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU
OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR
OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
17. Interpretation of Sections 15 and 16.
If the disclaimer of warranty and limitation of liability provided above cannot
be given local legal effect according to their terms, reviewing courts shall apply
local law that most closely approximates an absolute waiver of all civil liability
in connection with the Program, unless a warranty or assumption of liability
accompanies a copy of the Program in return for a fee.

END OF TERMS AND CONDITIONS

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How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest possible use to
the public, the best way to achieve this is to make it free software which everyone
can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them
to the start of each source file to most effectively state the exclusion of warranty;
and each file should have at least the “copyright” line and a pointer to where the
full notice is found.
one line to give the program’s name and a brief idea of what it does.
Copyright (C) year name of author
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see http://www.gnu.org/licenses/.

Also add information on how to contact you by electronic and paper mail.
If the program does terminal interaction, make it output a short notice like this
when it starts in an interactive mode:
program Copyright (C) year name of author
This program comes with ABSOLUTELY NO WARRANTY; for details type ‘show w’.
This is free software, and you are welcome to redistribute it
under certain conditions; type ‘show c’ for details.

The hypothetical commands ‘show w’ and ‘show c’ should show the appropriate
parts of the General Public License. Of course, your program’s commands might
be different; for a GUI interface, you would use an “about box”.
You should also get your employer (if you work as a programmer) or school,
if any, to sign a “copyright disclaimer” for the program, if necessary. For
more information on this, and how to apply and follow the GNU GPL, see
http://www.gnu.org/licenses/.
The GNU General Public License does not permit incorporating your
program into proprietary programs. If your program is a subroutine library,
you may consider it more useful to permit linking proprietary applications
with the library.
If this is what you want to do, use the GNU Lesser
General Public License instead of this License.
But first, please read
http://www.gnu.org/philosophy/why-not-lgpl.html.

Appendix B: GNU Free Documentation License

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Appendix B GNU Free Documentation License
Version 1.3, 3 November 2008
Copyright c 2000, 2001, 2002, 2007, 2008, 2009 Free Software Foundation, Inc.
http://fsf.org/
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other functional
and useful document free in the sense of freedom: to assure everyone the
effective freedom to copy and redistribute it, with or without modifying it,
either commercially or noncommercially. Secondarily, this License preserves
for the author and publisher a way to get credit for their work, while not being
considered responsible for modifications made by others.
This License is a kind of “copyleft”, which means that derivative works of the
document must themselves be free in the same sense. It complements the GNU
General Public License, which is a copyleft license designed for free software.
We have designed this License in order to use it for manuals for free software,
because free software needs free documentation: a free program should come
with manuals providing the same freedoms that the software does. But this
License is not limited to software manuals; it can be used for any textual work,
regardless of subject matter or whether it is published as a printed book. We
recommend this License principally for works whose purpose is instruction or
reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium, that contains
a notice placed by the copyright holder saying it can be distributed under the
terms of this License. Such a notice grants a world-wide, royalty-free license,
unlimited in duration, to use that work under the conditions stated herein.
The “Document”, below, refers to any such manual or work. Any member of
the public is a licensee, and is addressed as “you”. You accept the license if
you copy, modify or distribute the work in a way requiring permission under
copyright law.
A “Modified Version” of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or
translated into another language.
A “Secondary Section” is a named appendix or a front-matter section of the
Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document’s overall subject (or to related matters) and contains nothing that could fall directly within that overall subject.
(Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter
of historical connection with the subject or with related matters, or of legal,
commercial, philosophical, ethical or political position regarding them.

Appendix B: GNU Free Documentation License

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The “Invariant Sections” are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the
Document is released under this License. If a section does not fit the above
definition of Secondary then it is not allowed to be designated as Invariant.
The Document may contain zero Invariant Sections. If the Document does not
identify any Invariant Sections then there are none.
The “Cover Texts” are certain short passages of text that are listed, as FrontCover Texts or Back-Cover Texts, in the notice that says that the Document
is released under this License. A Front-Cover Text may be at most 5 words,
and a Back-Cover Text may be at most 25 words.
A “Transparent” copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is
suitable for revising the document straightforwardly with generic text editors
or (for images composed of pixels) generic paint programs or (for drawings)
some widely available drawing editor, and that is suitable for input to text
formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format
whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format
is not Transparent if used for any substantial amount of text. A copy that is
not “Transparent” is called “Opaque”.
Examples of suitable formats for Transparent copies include plain ascii without markup, Texinfo input format, LaTEX input format, SGML or XML using a
publicly available DTD, and standard-conforming simple HTML, PostScript or
PDF designed for human modification. Examples of transparent image formats
include PNG, XCF and JPG. Opaque formats include proprietary formats that
can be read and edited only by proprietary word processors, SGML or XML
for which the DTD and/or processing tools are not generally available, and the
machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.
The “Title Page” means, for a printed book, the title page itself, plus such
following pages as are needed to hold, legibly, the material this License requires
to appear in the title page. For works in formats which do not have any title
page as such, “Title Page” means the text near the most prominent appearance
of the work’s title, preceding the beginning of the body of the text.
The “publisher” means any person or entity that distributes copies of the
Document to the public.
A section “Entitled XYZ” means a named subunit of the Document whose
title either is precisely XYZ or contains XYZ in parentheses following text
that translates XYZ in another language. (Here XYZ stands for a specific
section name mentioned below, such as “Acknowledgements”, “Dedications”,
“Endorsements”, or “History”.) To “Preserve the Title” of such a section
when you modify the Document means that it remains a section “Entitled
XYZ” according to this definition.

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The Document may include Warranty Disclaimers next to the notice which
states that this License applies to the Document. These Warranty Disclaimers
are considered to be included by reference in this License, but only as regards
disclaiming warranties: any other implication that these Warranty Disclaimers
may have is void and has no effect on the meaning of this License.
2. VERBATIM COPYING
You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices,
and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those
of this License. You may not use technical measures to obstruct or control
the reading or further copying of the copies you make or distribute. However,
you may accept compensation in exchange for copies. If you distribute a large
enough number of copies you must also follow the conditions in section 3.
You may also lend copies, under the same conditions stated above, and you
may publicly display copies.
3. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly have printed
covers) of the Document, numbering more than 100, and the Document’s license notice requires Cover Texts, you must enclose the copies in covers that
carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front
cover, and Back-Cover Texts on the back cover. Both covers must also clearly
and legibly identify you as the publisher of these copies. The front cover must
present the full title with all words of the title equally prominent and visible.
You may add other material on the covers in addition. Copying with changes
limited to the covers, as long as they preserve the title of the Document and
satisfy these conditions, can be treated as verbatim copying in other respects.
If the required texts for either cover are too voluminous to fit legibly, you
should put the first ones listed (as many as fit reasonably) on the actual cover,
and continue the rest onto adjacent pages.
If you publish or distribute Opaque copies of the Document numbering more
than 100, you must either include a machine-readable Transparent copy along
with each Opaque copy, or state in or with each Opaque copy a computernetwork location from which the general network-using public has access to
download using public-standard network protocols a complete Transparent
copy of the Document, free of added material. If you use the latter option, you
must take reasonably prudent steps, when you begin distribution of Opaque
copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you
distribute an Opaque copy (directly or through your agents or retailers) of that
edition to the public.
It is requested, but not required, that you contact the authors of the Document
well before redistributing any large number of copies, to give them a chance to
provide you with an updated version of the Document.

Appendix B: GNU Free Documentation License

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4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document under the
conditions of sections 2 and 3 above, provided that you release the Modified
Version under precisely this License, with the Modified Version filling the role
of the Document, thus licensing distribution and modification of the Modified
Version to whoever possesses a copy of it. In addition, you must do these
things in the Modified Version:
A. Use in the Title Page (and on the covers, if any) a title distinct from that
of the Document, and from those of previous versions (which should, if
there were any, be listed in the History section of the Document). You
may use the same title as a previous version if the original publisher of
that version gives permission.
B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together
with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this
requirement.
C. State on the Title page the name of the publisher of the Modified Version,
as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications adjacent to
the other copyright notices.
F. Include, immediately after the copyright notices, a license notice giving
the public permission to use the Modified Version under the terms of this
License, in the form shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document’s license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled “History”, Preserve its Title, and add to
it an item stating at least the title, year, new authors, and publisher of
the Modified Version as given on the Title Page. If there is no section
Entitled “History” in the Document, create one stating the title, year,
authors, and publisher of the Document as given on its Title Page, then
add an item describing the Modified Version as stated in the previous
sentence.
J. Preserve the network location, if any, given in the Document for public
access to a Transparent copy of the Document, and likewise the network
locations given in the Document for previous versions it was based on.
These may be placed in the “History” section. You may omit a network
location for a work that was published at least four years before the
Document itself, or if the original publisher of the version it refers to
gives permission.
K. For any section Entitled “Acknowledgements” or “Dedications”, Preserve
the Title of the section, and preserve in the section all the substance

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500

and tone of each of the contributor acknowledgements and/or dedications
given therein.
L. Preserve all the Invariant Sections of the Document, unaltered in their
text and in their titles. Section numbers or the equivalent are not considered part of the section titles.
M. Delete any section Entitled “Endorsements”. Such a section may not be
included in the Modified Version.
N. Do not retitle any existing section to be Entitled “Endorsements” or to
conflict in title with any Invariant Section.
O. Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or appendices that
qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as
invariant. To do this, add their titles to the list of Invariant Sections in the
Modified Version’s license notice. These titles must be distinct from any other
section titles.
You may add a section Entitled “Endorsements”, provided it contains nothing
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The author(s) and publisher(s) of the Document do not by this License give
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5. COMBINING DOCUMENTS
You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified versions,
provided that you include in the combination all of the Invariant Sections
of all of the original documents, unmodified, and list them all as Invariant
Sections of your combined work in its license notice, and that you preserve all
their Warranty Disclaimers.
The combined work need only contain one copy of this License, and multiple
identical Invariant Sections may be replaced with a single copy. If there are
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the title of each such section unique by adding at the end of it, in parentheses,
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Appendix B: GNU Free Documentation License

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unique number. Make the same adjustment to the section titles in the list of
Invariant Sections in the license notice of the combined work.
In the combination, you must combine any sections Entitled “History” in the
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8. TRANSLATION
Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders,
but you may include translations of some or all Invariant Sections in addition
to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any
Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers.
In case of a disagreement between the translation and the original version of
this License or a notice or disclaimer, the original version will prevail.
If a section in the Document is Entitled “Acknowledgements”, “Dedications”,
or “History”, the requirement (section 4) to Preserve its Title (section 1) will
typically require changing the actual title.

Appendix B: GNU Free Documentation License

502

9. TERMINATION
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11. RELICENSING
“Massive Multiauthor Collaboration Site” (or “MMC Site”) means any World
Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can
edit is an example of such a server. A “Massive Multiauthor Collaboration”
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published on the MMC site.
“CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0 license
published by Creative Commons Corporation, a not-for-profit corporation with

Appendix B: GNU Free Documentation License

503

a principal place of business in San Francisco, California, as well as future
copyleft versions of that license published by that same organization.
“Incorporate” means to publish or republish a Document, in whole or in part,
as part of another Document.
An MMC is “eligible for relicensing” if it is licensed under this License, and
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this MMC, and subsequently incorporated in whole or in part into the MMC,
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prior to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the site
under CC-BY-SA on the same site at any time before August 1, 2009, provided
the MMC is eligible for relicensing.

Appendix B: GNU Free Documentation License

504

ADDENDUM: How to use this License for your documents
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If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace
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If you have Invariant Sections without Cover Texts, or some other combination
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If your document contains nontrivial examples of program code, we recommend
releasing these examples in parallel under your choice of free software license, such
as the GNU General Public License, to permit their use in free software.

Appendix C: Command Line Arguments for Emacs Invocation

505

Appendix C Command Line Arguments for Emacs
Invocation
Emacs supports command line arguments to request various actions when invoking
Emacs. These are for compatibility with other editors and for sophisticated activities. We don’t recommend using them for ordinary editing (See Section 31.4 [Emacs
Server], page 412, for a way to access an existing Emacs job from the command line).
Arguments starting with ‘-’ are options, and so is ‘+linenum ’. All other arguments specify files to visit. Emacs visits the specified files while it starts up. The
last file specified on the command line becomes the current buffer; the other files
are also visited in other buffers. As with most programs, the special argument ‘--’
says that all subsequent arguments are file names, not options, even if they start
with ‘-’.
Emacs command options can specify many things, such as the size and position
of the X window Emacs uses, its colors, and so on. A few options support advanced
usage, such as running Lisp functions on files in batch mode. The sections of this
chapter describe the available options, arranged according to their purpose.
There are two ways of writing options: the short forms that start with a single
‘-’, and the long forms that start with ‘--’. For example, ‘-d’ is a short form and
‘--display’ is the corresponding long form.
The long forms with ‘--’ are easier to remember, but longer to type. However,
you don’t have to spell out the whole option name; any unambiguous abbreviation
is enough. When a long option takes an argument, you can use either a space
or an equal sign to separate the option name and the argument. Thus, you can
write either ‘--display sugar-bombs:0.0’ or ‘--display=sugar-bombs:0.0’. We
recommend an equal sign because it makes the relationship clearer, and the tables
below always show an equal sign.
Most options specify how to initialize Emacs, or set parameters for the Emacs
session. We call them initial options. A few options specify things to do, such as
loading libraries or calling Lisp functions. These are called action options. These
and file names together are called action arguments. The action arguments are
stored as a list of strings in the variable command-line-args. (Actually, when
Emacs starts up, command-line-args contains all the arguments passed from the
command line; during initialization, the initial arguments are removed from this list
when they are processed, leaving only the action arguments.)

C.1 Action Arguments
Here is a table of action arguments:
‘file ’
‘--file=file ’
‘--find-file=file ’
‘--visit=file ’
Visit file using find-file. See Section 15.2 [Visiting], page 125.

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When Emacs starts up, it displays the startup buffer in one window,
and the buffer visiting file in another window (see Chapter 17 [Windows], page 159). If you supply more than one file argument, the
displayed file is the last one specified on the command line; the other
files are visited but their buffers are not shown.
If the startup buffer is disabled (see Section 3.1 [Entering Emacs],
page 14), then file is visited in a single window if one file argument
was supplied; with two file arguments, Emacs displays the files in two
different windows; with more than two file argument, Emacs displays
the last file specified in one window, plus a Buffer Menu in a different window (see Section 16.5 [Several Buffers], page 154). To inhibit
using the Buffer Menu for this, change the variable inhibit-startupbuffer-menu to t.
‘+linenum file ’
Visit file using find-file, then go to line number linenum in it.
‘+linenum :columnnum file ’
Visit file using find-file, then go to line number linenum and put
point at column number columnnum.
‘-l file ’
‘--load=file ’
Load a Lisp library named file with the function load. If file is not an
absolute file name, Emacs first looks for it in the current directory, then
in the directories listed in load-path (see Section 24.8 [Lisp Libraries],
page 287).
Warning: If previous command-line arguments have visited files, the
current directory is the directory of the last file visited.
‘-L dir ’
‘--directory=dir ’
Add directory dir to the variable load-path.
‘-f function ’
‘--funcall=function ’
Call Lisp function function. If it is an interactive function (a command), it reads the arguments interactively just as if you had called
the same function with a key sequence. Otherwise, it calls the function
with no arguments.
‘--eval=expression ’
‘--execute=expression ’
Evaluate Lisp expression expression.
‘--insert=file ’
Insert the contents of file into the ‘*scratch*’ buffer (see Section 24.10
[Lisp Interaction], page 290). This is like what M-x insert-file does
(see Section 15.10 [Misc File Ops], page 143).

Appendix C: Command Line Arguments for Emacs Invocation

507

‘--kill’

Exit from Emacs without asking for confirmation.

‘--help’

Print a usage message listing all available options, then exit successfully.

‘--version’
Print Emacs version, then exit successfully.

C.2 Initial Options
The initial options specify parameters for the Emacs session. This section describes
the more general initial options; some other options specifically related to the X
Window System appear in the following sections.
Some initial options affect the loading of the initialization file. Normally, Emacs
first loads ‘site-start.el’ if it exists, then your own initialization file if it exists,
and finally the default initialization file ‘default.el’ if it exists (see Section 33.4
[Init File], page 461). Certain options prevent loading of some of these files or
substitute other files for them.
‘-chdir directory ’
‘--chdir=directory ’
Change to directory before doing anything else. This is mainly used by
session management in X so that Emacs starts in the same directory
as it stopped. This makes desktop saving and restoring easier.
‘-t device ’
‘--terminal=device ’
Use device as the device for terminal input and output. This option
implies ‘--no-window-system’.
‘-d display ’
‘--display=display ’
Use the X Window System and use the display named display to open
the initial Emacs frame. See Section C.5 [Display X], page 514, for
more details.
‘-nw’
‘--no-window-system’
Don’t communicate directly with the window system, disregarding the
DISPLAY environment variable even if it is set. This means that Emacs
uses the terminal from which it was launched for all its display and
input.
‘-batch’
‘--batch’

Run Emacs in batch mode. Batch mode is used for running programs
written in Emacs Lisp from shell scripts, makefiles, and so on. To
invoke a Lisp program, use the ‘-batch’ option in conjunction with one
or more of ‘-l’, ‘-f’ or ‘--eval’ (see Section C.1 [Action Arguments],
page 505). See Section C.3 [Command Example], page 509, for an
example.

Appendix C: Command Line Arguments for Emacs Invocation

508

In batch mode, Emacs does not display the text being edited, and the
standard terminal interrupt characters such as C-z and C-c have their
usual effect. Emacs functions that normally print a message in the echo
area will print to either the standard output stream (stdout) or the
standard error stream (stderr) instead. (To be precise, functions like
prin1, princ and print print to stdout, while message and error
print to stderr.) Functions that normally read keyboard input from
the minibuffer take their input from the terminal’s standard input
stream (stdin) instead.
‘--batch’ implies ‘-q’ (do not load an initialization file), but
‘site-start.el’ is loaded nonetheless. It also causes Emacs to exit
after processing all the command options. In addition, it disables
auto-saving except in buffers for which auto-saving is explicitly
requested.
‘--script file ’
Run Emacs in batch mode, like ‘--batch’, and then read and execute
the Lisp code in file.
The normal use of this option is in executable script files that run
Emacs. They can start with this text on the first line
#!/usr/bin/emacs --script
which will invoke Emacs with ‘--script’ and supply the name of the
script file as file. Emacs Lisp then treats the ‘#!’ on this first line as
a comment delimiter.
‘-q’
‘--no-init-file’
Do not load any initialization file (see Section 33.4 [Init File],
page 461). When Emacs is invoked with this option, the Customize
facility does not allow options to be saved (see Section 33.1 [Easy
Customization], page 434). This option does not disable loading
‘site-start.el’.
‘--no-site-file’
Do not load ‘site-start.el’ (see Section 33.4 [Init File], page 461).
The ‘-Q’ option does this too, but other options like ‘-q’ do not.
‘--no-site-lisp’
Do not include the ‘site-lisp’ directories in load-path (see
Section 33.4 [Init File], page 461). The ‘-Q’ option does this too.
‘--no-splash’
Do not display a startup screen. You can also achieve this effect by
setting the variable inhibit-startup-screen to non-nil in your initialization file (see Section 3.1 [Entering Emacs], page 14).
‘-Q’
‘--quick’

Start emacs with minimum customizations. This is similar to using ‘-q’, ‘--no-site-file’, ‘--no-site-lisp’, and ‘--no-splash’ to-

Appendix C: Command Line Arguments for Emacs Invocation

509

gether. This also stops Emacs from processing X resources by setting
inhibit-x-resources to t (see Section D.1 [Resources], page 521).
‘-daemon’
‘--daemon’

Start Emacs as a daemon—after Emacs starts up, it starts the Emacs
server and disconnects from the terminal without opening any frames.
You can then use the emacsclient command to connect to Emacs for
editing. See Section 31.4 [Emacs Server], page 412, for information
about using Emacs as a daemon.

‘-daemon=SERVER-NAME ’
Start emacs in background as a daemon, and use SERVER-NAME as
the server name.
‘--no-desktop’
Do not reload any saved desktop. See Section 31.8 [Saving Emacs
Sessions], page 423.
‘-u user ’
‘--user=user ’
Load user’s initialization file instead of your own1 .
‘--debug-init’
Enable the Emacs Lisp debugger for errors in the init file. See Section
“Entering the Debugger on an Error” in The GNU Emacs Lisp Reference Manual.

C.3 Command Argument Example
Here is an example of using Emacs with arguments and options. It assumes you
have a Lisp program file called ‘hack-c.el’ which, when loaded, performs some
useful operation on the current buffer, expected to be a C program.
emacs --batch foo.c -l hack-c -f save-buffer >& log
This says to visit ‘foo.c’, load ‘hack-c.el’ (which makes changes in the visited
file), save ‘foo.c’ (note that save-buffer is the function that C-x C-s is bound to),
and then exit back to the shell (because of ‘--batch’). ‘--batch’ also guarantees
there will be no problem redirecting output to ‘log’, because Emacs will not assume
that it has a display terminal to work with.

C.4 Environment Variables
The environment is a feature of the operating system; it consists of a collection of
variables with names and values. Each variable is called an environment variable;
environment variable names are case-sensitive, and it is conventional to use upper
case letters only. The values are all text strings.
What makes the environment useful is that subprocesses inherit the environment
automatically from their parent process. This means you can set up an environment
1

This option has no effect on MS-Windows.

Appendix C: Command Line Arguments for Emacs Invocation

510

variable in your login shell, and all the programs you run (including Emacs) will
automatically see it. Subprocesses of Emacs (such as shells, compilers, and version
control programs) inherit the environment from Emacs, too.
Inside Emacs, the command M-x getenv reads the name of an environment variable, and prints its value in the echo area. M-x setenv sets a variable in the Emacs
environment, and C-u M-x setenv removes a variable. (Environment variable substitutions with ‘$’ work in the value just as in file names; see [File Names with
$], page 125.) The variable initial-environment stores the initial environment
inherited by Emacs.
The way to set environment variables outside of Emacs depends on the operating
system, and especially the shell that you are using. For example, here’s how to set
the environment variable ORGANIZATION to ‘not very much’ using Bash:
export ORGANIZATION="not very much"
and here’s how to do it in csh or tcsh:
setenv ORGANIZATION "not very much"
When Emacs is using the X Window System, various environment variables that
control X work for Emacs as well. See the X documentation for more information.
C.4.1 General Variables
Here is an alphabetical list of environment variables that have special meanings in
Emacs. Most of these variables are also used by some other programs. Emacs does
not require any of these environment variables to be set, but it uses their values if
they are set.
CDPATH

Used by the cd command to search for the directory you specify, when
you specify a relative directory name.

EMACSDATA

Directory for the architecture-independent files that come with Emacs.
This is used to initialize the variable data-directory.

EMACSDOC

Directory for the documentation string file, which is used to initialize
the Lisp variable doc-directory.

EMACSLOADPATH
A colon-separated list of directories2 to search for Emacs Lisp files. If
set, it overrides the usual initial value of the load-path variable (see
Section 24.8 [Lisp Libraries], page 287).
EMACSPATH

A colon-separated list of directories to search for executable files. If
set, Emacs uses this in addition to PATH (see below) when initializing
the variable exec-path (see Section 31.3 [Shell], page 401).

EMAIL

Your email address; used to initialize the Lisp variable user-mailaddress, which the Emacs mail interface puts into the ‘From’ header
of outgoing messages (see Section 29.2 [Mail Headers], page 368).

2

Here and below, whenever we say “colon-separated list of directories”, it pertains
to Unix and GNU/Linux systems. On MS-DOS and MS-Windows, the directories
are separated by semi-colons instead, since DOS/Windows file names might include a
colon after a drive letter.

Appendix C: Command Line Arguments for Emacs Invocation

511

ESHELL

Used for shell-mode to override the SHELL environment variable (see
Section 31.3.2 [Interactive Shell], page 403).

HISTFILE

The name of the file that shell commands are saved in between logins. This variable defaults to ‘~/.bash_history’ if you use Bash, to
‘~/.sh_history’ if you use ksh, and to ‘~/.history’ otherwise.

HOME

The location of your files in the directory tree; used for expansion of
file names starting with a tilde (‘~’). On MS-DOS, it defaults to the
directory from which Emacs was started, with ‘/bin’ removed from the
end if it was present. On Windows, the default value of HOME is the
‘Application Data’ subdirectory of the user profile directory (normally, this is ‘C:/Documents and Settings/username /Application
Data’, where username is your user name), though for backwards compatibility ‘C:/’ will be used instead if a ‘.emacs’ file is found there.

HOSTNAME

The name of the machine that Emacs is running on.

INCPATH

A colon-separated list of directories. Used by the complete package
to search for files.

INFOPATH

A colon-separated list of directories in which to search for Info files.

LC_ALL
LC_COLLATE
LC_CTYPE
LC_MESSAGES
LC_MONETARY
LC_NUMERIC
LC_TIME
LANG
The user’s preferred locale. The locale has six categories, specified
by the environment variables LC_COLLATE for sorting, LC_CTYPE for
character encoding, LC_MESSAGES for system messages, LC_MONETARY
for monetary formats, LC_NUMERIC for numbers, and LC_TIME for dates
and times. If one of these variables is not set, the category defaults to
the value of the LANG environment variable, or to the default ‘C’ locale
if LANG is not set. But if LC_ALL is specified, it overrides the settings
of all the other locale environment variables.
On MS-Windows, if LANG is not already set in the environment when
Emacs starts, Emacs sets it based on the system-wide default language,
which you can set in the ‘Regional Settings’ Control Panel on some
versions of MS-Windows.
The value of the LC_CTYPE category is matched against entries in
locale-language-names, locale-charset-language-names, and
locale-preferred-coding-systems, to select a default language
environment and coding system.
See Section 19.3 [Language
Environments], page 183.
LOGNAME

The user’s login name. See also USER.

Appendix C: Command Line Arguments for Emacs Invocation

512

MAIL

The name of your system mail inbox.

NAME

Your real-world name. This is used to initialize the variable userfull-name (see Section 29.2 [Mail Headers], page 368).

NNTPSERVER
The name of the news server. Used by the mh and Gnus packages.
ORGANIZATION
The name of the organization to which you belong. Used for setting
the ‘Organization:’ header in your posts from the Gnus package.
PATH

A colon-separated list of directories containing executable files. This
is used to initialize the variable exec-path (see Section 31.3 [Shell],
page 401).

PWD

If set, this should be the default directory when Emacs was started.

REPLYTO

If set, this specifies an initial value for the variable mail-defaultreply-to (see Section 29.2 [Mail Headers], page 368).

SAVEDIR

The name of a directory in which news articles are saved by default.
Used by the Gnus package.

SHELL

The name of an interpreter used to parse and execute programs run
from inside Emacs.

SMTPSERVER
The name of the outgoing mail server. This is used to initialize the
variable smtpmail-smtp-server (see Section 29.4.1 [Mail Sending],
page 370).
TERM

The type of the terminal that Emacs is using. This variable must be
set unless Emacs is run in batch mode. On MS-DOS, it defaults to
‘internal’, which specifies a built-in terminal emulation that handles
the machine’s own display.

TERMCAP

The name of the termcap library file describing how to program the
terminal specified by TERM. This defaults to ‘/etc/termcap’.

TMPDIR
TMP
TEMP

TZ

These environment variables are used to initialize the variable
temporary-file-directory, which specifies a directory in which to
put temporary files (see Section 15.3.2 [Backup], page 130). Emacs
tries to use TMPDIR first; if that is unset, it tries TMP, then TEMP, and
finally ‘/tmp’. But on MS-Windows and MS-DOS, Emacs tries TEMP,
then TMPDIR, then TMP, and finally ‘c:/temp’.
This specifies the current time zone and possibly also daylight saving
time information. On MS-DOS, if TZ is not set in the environment
when Emacs starts, Emacs defines a default value as appropriate for
the country code returned by DOS. On MS-Windows, Emacs does not
use TZ at all.

Appendix C: Command Line Arguments for Emacs Invocation
USER

513

The user’s login name. See also LOGNAME. On MS-DOS, this defaults
to ‘root’.

VERSION_CONTROL
Used to initialize the version-control variable (see Section 15.3.2.1
[Backup Names], page 130).
C.4.2 Miscellaneous Variables
These variables are used only on particular configurations:
COMSPEC

On MS-DOS and MS-Windows, the name of the command interpreter
to use when invoking batch files and commands internal to the shell.
On MS-DOS this is also used to make a default value for the SHELL
environment variable.

NAME

On MS-DOS, this variable defaults to the value of the USER variable.

EMACSTEST

On MS-DOS, this specifies a file to use to log the operation of the
internal terminal emulator. This feature is useful for submitting bug
reports.

EMACSCOLORS
On MS-DOS, this specifies the screen colors. It is useful to set them
this way, since otherwise Emacs would display the default colors momentarily when it starts up.
The value of this variable should be the two-character encoding of
the foreground (the first character) and the background (the second
character) colors of the default face. Each character should be the
hexadecimal code for the desired color on a standard PC text-mode
display. For example, to get blue text on a light gray background,
specify ‘EMACSCOLORS=17’, since 1 is the code of the blue color and 7
is the code of the light gray color.
The PC display usually supports only eight background colors. However, Emacs switches the DOS display to a mode where all 16 colors
can be used for the background, so all four bits of the background
color are actually used.
PRELOAD_WINSOCK
On MS-Windows, if you set this variable, Emacs will load and initialize
the network library at startup, instead of waiting until the first time
it is required.
emacs_dir

On MS-Windows, emacs_dir is a special environment variable, which
indicates the full path of the directory in which Emacs is installed.
If Emacs is installed in the standard directory structure, it calculates
this value automatically. It is not much use setting this variable yourself unless your installation is non-standard, since unlike other environment variables, it will be overridden by Emacs at startup. When
setting other environment variables, such as EMACSLOADPATH, you may

Appendix C: Command Line Arguments for Emacs Invocation

514

find it useful to use emacs_dir rather than hard-coding an absolute
path. This allows multiple versions of Emacs to share the same environment variable settings, and it allows you to move the Emacs
installation directory, without changing any environment or registry
settings.
C.4.3 The MS-Windows System Registry
On MS-Windows, the installation program addpm.exe adds values for
emacs_dir, EMACSLOADPATH, EMACSDATA, EMACSPATH, EMACSDOC, SHELL and
TERM to the ‘HKEY_LOCAL_MACHINE’ section of the system registry, under
‘/Software/GNU/Emacs’. It does this because there is no standard place to set
environment variables across different versions of Windows. Running addpm.exe is
no longer strictly necessary in recent versions of Emacs, but if you are upgrading
from an older version, running addpm.exe ensures that you do not have older
registry entries from a previous installation, which may not be compatible with
the latest version of Emacs.
When Emacs starts, as well as checking the environment, it also checks the
System Registry for those variables and for HOME, LANG and PRELOAD_WINSOCK.
To determine the value of those variables, Emacs goes through the following
procedure. First, the environment is checked. If the variable is not found there,
Emacs looks for registry keys by that name under ‘/Software/GNU/Emacs’; first
in the ‘HKEY_CURRENT_USER’ section of the registry, and if not found there, in the
‘HKEY_LOCAL_MACHINE’ section. Finally, if Emacs still cannot determine the values,
compiled-in defaults are used.
In addition to the environment variables above, you can also add many of the
settings which on X belong in the ‘.Xdefaults’ file (see Appendix D [X Resources],
page 521) to the ‘/Software/GNU/Emacs’ registry key.

C.5 Specifying the Display Name
The environment variable DISPLAY tells all X clients, including Emacs, where to
display their windows. Its value is set by default in ordinary circumstances, when
you start an X server and run jobs locally. You can specify the display yourself; one
reason to do this is if you want to log into another system and run Emacs there,
and have the window displayed at your local terminal.
DISPLAY has the syntax ‘host :display.screen ’, where host is the host name
of the X Window System server machine, display is an arbitrarily-assigned number
that distinguishes your server (X terminal) from other servers on the same machine,
and screen is a field that allows an X server to control multiple terminal screens.
The period and the screen field are optional. If included, screen is usually zero.
For example, if your host is named ‘glasperle’ and your server is the
first (or perhaps the only) server listed in the configuration, your DISPLAY is
‘glasperle:0.0’.

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You can specify the display name explicitly when you run Emacs, either
by changing the DISPLAY variable, or with the option ‘-d display ’ or
‘--display=display ’. Here is an example:
emacs --display=glasperle:0 &

You can inhibit the use of the X window system with the ‘-nw’ option. Then
Emacs uses its controlling text terminal for display. See Section C.2 [Initial Options],
page 507.
Sometimes, security arrangements prevent a program on a remote system from
displaying on your local system. In this case, trying to run Emacs produces messages
like this:
Xlib:

connection to "glasperle:0.0" refused by server

You might be able to overcome this problem by using the xhost command on the
local system to give permission for access from your remote machine.

C.6 Font Specification Options
You can use the command line option ‘-fn font ’ (or ‘--font’, which is an alias for
‘-fn’) to specify a default font:
‘-fn font ’
‘--font=font ’
Use font as the default font.
When passing a font name to Emacs on the command line, you may need to
“quote” it, by enclosing it in quotation marks, if it contains characters that the
shell treats specially (e.g. spaces). For example:
emacs -fn "DejaVu Sans Mono-12"

See Section 18.8 [Fonts], page 171, for details about font names and other ways
to specify the default font.

C.7 Window Color Options
You can use the following command-line options to specify the colors to use for
various parts of the Emacs display. Colors may be specified using either color
names or RGB triplets (see Section 11.9 [Colors], page 76).
‘-fg color ’
‘--foreground-color=color ’
Specify the foreground color, overriding the color specified by the
default face (see Section 11.8 [Faces], page 75).
‘-bg color ’
‘--background-color=color ’
Specify the background color, overriding the color specified by the
default face.
‘-bd color ’
‘--border-color=color ’
Specify the color of the border of the X window. This has no effect if
Emacs is compiled with GTK+ support.

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‘-cr color ’
‘--cursor-color=color ’
Specify the color of the Emacs cursor which indicates where point is.
‘-ms color ’
‘--mouse-color=color ’
Specify the color for the mouse cursor when the mouse is in the Emacs
window.
‘-r’
‘-rv’
‘--reverse-video’
Reverse video—swap the foreground and background colors.
‘--color=mode ’
Set the color support mode when Emacs is run on a text terminal.
This option overrides the number of supported colors that the character terminal advertises in its termcap or terminfo database. The
parameter mode can be one of the following:
‘never’
‘no’
‘default’
‘auto’

‘always’
‘yes’
‘ansi8’

‘num ’

Don’t use colors even if the terminal’s capabilities specify
color support.
Same as when ‘--color’ is not used at all: Emacs detects
at startup whether the terminal supports colors, and if
it does, turns on colored display.

Turn on the color support unconditionally, and use color
commands specified by the ANSI escape sequences for
the 8 standard colors.
Use color mode for num colors. If num is -1, turn off color
support (equivalent to ‘never’); if it is 0, use the default
color support for this terminal (equivalent to ‘auto’);
otherwise use an appropriate standard mode for num colors. Depending on your terminal’s capabilities, Emacs
might be able to turn on a color mode for 8, 16, 88, or
256 as the value of num. If there is no mode that supports num colors, Emacs acts as if num were 0, i.e. it uses
the terminal’s default color support mode.

If mode is omitted, it defaults to ansi8.
For example, to use a coral mouse cursor and a slate blue text cursor, enter:
emacs -ms coral -cr ’slate blue’ &
You can reverse the foreground and background colors through the ‘-rv’ option
or with the X resource ‘reverseVideo’.

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The ‘-fg’, ‘-bg’, and ‘-rv’ options function on text terminals as well as on
graphical displays.

C.8 Options for Window Size and Position
Here is a list of the command-line options for specifying size and position of the
initial Emacs frame:
‘-g width xheight [{+-}xoffset {+-}yoffset ]]’
‘--geometry=width xheight [{+-}xoffset {+-}yoffset ]]’
Specify the size width and height (measured in character columns and
lines), and positions xoffset and yoffset (measured in pixels). The
width and height parameters apply to all frames, whereas xoffset and
yoffset only to the initial frame.
‘-fs’
‘--fullscreen’
Specify that width and height shall be the size of the screen. Normally
no window manager decorations are shown.
‘-mm’
‘--maximized’
Specify that the Emacs frame shall be maximized. This normally
means that the frame has window manager decorations.
‘-fh’
‘--fullheight’
Specify that the height shall be the height of the screen.
‘-fw’
‘--fullwidth’
Specify that the width shall be the width of the screen.
In the ‘--geometry’ option, {+-} means either a plus sign or a minus sign. A plus
sign before xoffset means it is the distance from the left side of the screen; a minus
sign means it counts from the right side. A plus sign before yoffset means it is the
distance from the top of the screen, and a minus sign there indicates the distance
from the bottom. The values xoffset and yoffset may themselves be positive or
negative, but that doesn’t change their meaning, only their direction.
Emacs uses the same units as xterm does to interpret the geometry. The width
and height are measured in characters, so a large font creates a larger frame than
a small font. (If you specify a proportional font, Emacs uses its maximum bounds
width as the width unit.) The xoffset and yoffset are measured in pixels.
You do not have to specify all of the fields in the geometry specification. If you
omit both xoffset and yoffset, the window manager decides where to put the Emacs
frame, possibly by letting you place it with the mouse. For example, ‘164x55’
specifies a window 164 columns wide, enough for two ordinary width windows side
by side, and 55 lines tall.
The default frame width is 80 characters and the default height is 40 lines. You
can omit either the width or the height or both. If you start the geometry with an

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integer, Emacs interprets it as the width. If you start with an ‘x’ followed by an
integer, Emacs interprets it as the height. Thus, ‘81’ specifies just the width; ‘x45’
specifies just the height.
If you start with ‘+’ or ‘-’, that introduces an offset, which means both sizes
are omitted. Thus, ‘-3’ specifies the xoffset only. (If you give just one offset, it is
always xoffset.) ‘+3-3’ specifies both the xoffset and the yoffset, placing the frame
near the bottom left of the screen.
You can specify a default for any or all of the fields in your X resource file
(see Section D.1 [Resources], page 521), and then override selected fields with a
‘--geometry’ option.
Since the mode line and the echo area occupy the last 2 lines of the frame, the
height of the initial text window is 2 less than the height specified in your geometry.
In non-X-toolkit versions of Emacs, the menu bar also takes one line of the specified
number. But in the X toolkit version, the menu bar is additional and does not count
against the specified height. The tool bar, if present, is also additional.
Enabling or disabling the menu bar or tool bar alters the amount of space
available for ordinary text. Therefore, if Emacs starts up with a tool bar (which is
the default), and handles the geometry specification assuming there is a tool bar,
and then your initialization file disables the tool bar, you will end up with a frame
geometry different from what you asked for. To get the intended size with no tool
bar, use an X resource to specify “no tool bar” (see Section D.2 [Table of Resources],
page 522); then Emacs will already know there’s no tool bar when it processes the
specified geometry.
When using one of ‘--fullscreen’, ‘--maximized’, ‘--fullwidth’ or
‘--fullheight’ there may be some space around the frame anyway. That is
because Emacs rounds the sizes so they are an even number of character heights
and widths.
Some window managers have options that can make them ignore both programspecified and user-specified positions. If these are set, Emacs fails to position the
window correctly.

C.9 Internal and External Borders
An Emacs frame has an internal border and an external border. The internal
border is an extra strip of the background color around the text portion of the
frame. Emacs itself draws the internal border. The external border is added by the
window manager outside the frame; depending on the window manager you use, it
may contain various boxes you can click on to move or iconify the window.
‘-ib width ’
‘--internal-border=width ’
Specify width as the width of the internal border (between the text
and the main border), in pixels.
‘-bw width ’
‘--border-width=width ’
Specify width as the width of the main border, in pixels.

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When you specify the size of the frame, that does not count the borders. The
frame’s position is measured from the outside edge of the external border.
Use the ‘-ib n ’ option to specify an internal border n pixels wide. The default
is 1. Use ‘-bw n ’ to specify the width of the external border (though the window
manager may not pay attention to what you specify). The default width of the
external border is 2.

C.10 Frame Titles
An Emacs frame may or may not have a specified title. The frame title, if specified, appears in window decorations and icons as the name of the frame. If an
Emacs frame has no specified title, the default title has the form ‘invocationname @machine ’ (if there is only one frame) or the selected window’s buffer name
(if there is more than one frame).
You can specify a title for the initial Emacs frame with a command line option:
‘-T title ’
‘--title=title ’
Specify title as the title for the initial Emacs frame.
The ‘--name’ option (see Section D.1 [Resources], page 521) also specifies the
title for the initial Emacs frame.

C.11 Icons
‘-iconic’
‘--iconic’

Start Emacs in an iconified (“minimized”) state.

‘-nbi’
‘--no-bitmap-icon’
Disable the use of the Emacs icon.
Most window managers allow you to “iconify” (or “minimize”) an Emacs frame,
hiding it from sight. Some window managers replace iconified windows with tiny
“icons”, while others remove them entirely from sight. The ‘-iconic’ option tells
Emacs to begin running in an iconified state, rather than showing a frame right
away. The text frame doesn’t appear until you deiconify (or “un-minimize”) it.
By default, Emacs uses an icon containing the Emacs logo. On desktop environments such as Gnome, this icon is also displayed in other contexts, e.g. when
switching into an Emacs frame. The ‘-nbi’ or ‘--no-bitmap-icon’ option tells
Emacs to let the window manager choose what sort of icon to use—usually just a
small rectangle containing the frame’s title.

C.12 Other Display Options
‘--parent-id ID ’
Open Emacs as a client X window via the XEmbed protocol, with ID
as the parent X window id. Currently, this option is mainly useful for
developers.

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‘-vb’
‘--vertical-scroll-bars’
Enable vertical scroll bars.
‘-lsp pixels ’
‘--line-spacing=pixels ’
Specify pixels as additional space to put between lines, in pixels.
‘-nbc’
‘--no-blinking-cursor’
Disable the blinking cursor on graphical displays.
‘-D’
‘--basic-display’
Disable the menu-bar, the tool-bar, the scroll-bars, and tool tips, and
turn off the blinking cursor. This can be useful for making a test case
that simplifies debugging of display problems.
The ‘--xrm’ option (see Section D.1 [Resources], page 521) specifies additional
X resource values.

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521

Appendix D X Options and Resources
You can customize some X-related aspects of Emacs behavior using X resources, as
is usual for programs that use X.
When Emacs is compiled with GTK+ support, the appearance of various graphical widgets, such as the menu-bar, scroll-bar, and dialog boxes, is determined by
“GTK resources”. When Emacs is built without GTK+ support, the appearance of
these widgets is determined by additional X resources.
On MS-Windows, you can customize some of the same aspects using the system
registry (see Section C.4.3 [MS-Windows Registry], page 514).

D.1 X Resources
Programs running under the X Window System organize their user options under a
hierarchy of classes and resources. You can specify default values for these options in
your X resource file, usually named ‘~/.Xdefaults’ or ‘~/.Xresources’. Changes
in this file do not take effect immediately, because the X server stores its own list of
resources; to update it, use the command xrdb—for instance, ‘xrdb ~/.Xdefaults’.
(MS-Windows systems do not support X resource files; on such systems, Emacs looks for X resources in the Windows Registry, first under
the key ‘HKEY_CURRENT_USER\SOFTWARE\GNU\Emacs’, which affects only the
current user and override the system-wide settings, and then under the key
‘HKEY_LOCAL_MACHINE\SOFTWARE\GNU\Emacs’, which affects all users of the
system. The menu and scroll bars are native widgets on MS-Windows, so they are
only customizable via the system-wide settings in the Display Control Panel. You
can also set resources using the ‘-xrm’ command line option, as explained below.)
Each line in the X resource file specifies a value for one option or for a collection
of related options. The order in which the lines appear in the file does not matter.
Each resource specification consists of a program name and a resource name. Case
distinctions are significant in each of these names. Here is an example:
emacs.cursorColor: dark green
The program name is the name of the executable file to which the resource
applies. For Emacs, this is normally ‘emacs’. To specify a definition that applies to
all instances of Emacs, regardless of the name of the Emacs executable, use ‘Emacs’.
The resource name is the name of a program setting. For instance, Emacs
recognizes a ‘cursorColor’ resource that controls the color of the text cursor.
Resources are grouped into named classes. For instance, the ‘Foreground’
class contains the ‘cursorColor’, ‘foreground’ and ‘pointerColor’ resources (see
Section D.2 [Table of Resources], page 522). Instead of using a resource name, you
can use a class name to specify the default value for all resources in that class, like
this:
emacs.Foreground: dark green
Emacs does not process X resources at all if you set the variable inhibit-xresources to a non-nil value. If you invoke Emacs with the ‘-Q’ (or ‘--quick’)

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command-line option, inhibit-x-resources is automatically set to t (see
Section C.2 [Initial Options], page 507).

D.2 Table of X Resources for Emacs
This table lists the X resource names that Emacs recognizes, excluding those that
control the appearance of graphical widgets like the menu bar:
background (class Background)
Background color (see Section 11.9 [Colors], page 76).
bitmapIcon (class BitmapIcon)
Tell the window manager to display the Emacs icon if ‘on’; don’t do
so if ‘off’. See Section C.11 [Icons X], page 519, for a description of
the icon.
cursorColor (class Foreground)
Text cursor color. If this resource is specified when Emacs starts up,
Emacs sets its value as the background color of the cursor face (see
Section 11.8 [Faces], page 75).
cursorBlink (class CursorBlink)
If the value of this resource is ‘off’ or ‘false’ or ‘0’ at startup,
Emacs disables Blink Cursor mode (see Section 11.20 [Cursor Display],
page 88).
font (class Font)
Font name for the default face (see Section 18.8 [Fonts], page 171).
You can also specify a fontset name (see Section 19.14 [Fontsets],
page 197).
fontBackend (class FontBackend)
Comma-delimited list of backend(s) to use for drawing fonts, in order
of precedence. For instance, the value ‘x,xft’ tells Emacs to draw
fonts using the X core font driver, falling back on the Xft font driver
if that fails. Normally, you should leave this resource unset, in which
case Emacs tries using all available font backends.
foreground (class Foreground)
Default foreground color for text.
geometry (class Geometry)
Window size and position. The value should be a size and position specification, of the same form as in the ‘-g’ or ‘--geometry’
command-line option (see Section C.8 [Window Size X], page 517).
The size applies to all frames in the Emacs session, but the position
applies only to the initial Emacs frame (or, in the case of a resource
for a specific frame name, only that frame).
Be careful not to specify this resource as ‘emacs*geometry’, as that
may affect individual menus as well as the main Emacs frame.

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fullscreen (class Fullscreen)
The desired fullscreen size. The value can be one of fullboth,
maximized, fullwidth or fullheight, which correspond to the
command-line options ‘-fs’, ‘-mm’, ‘-fw’, and ‘-fh’ (see Section C.8
[Window Size X], page 517). Note that this applies to the initial frame
only.
lineSpacing (class LineSpacing)
Additional space between lines, in pixels.
menuBar (class MenuBar)
If the value of this resource is ‘off’ or ‘false’ or ‘0’, Emacs disables
Menu Bar mode at startup (see Section 18.14 [Menu Bars], page 176).
pointerColor (class Foreground)
Color of the mouse cursor. This has no effect in many graphical desktop environments, as they do not let Emacs change the mouse cursor
this way.
title (class Title)
Name to display in the title bar of the initial Emacs frame.
toolBar (class ToolBar)
If the value of this resource is ‘off’ or ‘false’ or ‘0’, Emacs disables
Tool Bar mode at startup (see Section 18.15 [Tool Bars], page 177).
useXIM (class UseXIM)
Disable use of X input methods (XIM) if ‘false’ or ‘off’. This is only
relevant if your Emacs is built with XIM support. It might be useful
to turn off XIM on slow X client/server links.
verticalScrollBars (class ScrollBars)
Give frames scroll bars if ‘on’; don’t have scroll bars if ‘off’.
You can also use X resources to customize individual Emacs faces
(see Section 11.8 [Faces], page 75).
For example, setting the resource
‘face.attributeForeground’ is equivalent to customizing the ‘foreground’
attribute of the face face. However, we recommend customizing faces from within
Emacs, instead of using X resources. See Section 33.1.5 [Face Customization],
page 439.

D.3 GTK resources
If Emacs is compiled with GTK+ toolkit support, the simplest way to customize
its GTK+ widgets (e.g. menus, dialogs, tool bars and scroll bars) is to choose an
appropriate GTK+ theme, for example with the GNOME theme selector.
In GTK+ version 2, you can also use GTK+ resources to customize the appearance of GTK+ widgets used by Emacs. These resources are specified in either the file
‘~/.emacs.d/gtkrc’ (for Emacs-specific GTK+ resources), or ‘~/.gtkrc-2.0’ (for
general GTK+ resources). We recommend using ‘~/.emacs.d/gtkrc’, since GTK+

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seems to ignore ‘~/.gtkrc-2.0’ when running GConf with GNOME. Note, however, that some GTK themes may override customizations in ‘~/.emacs.d/gtkrc’;
there is nothing we can do about this. GTK+ resources do not affect aspects of
Emacs unrelated to GTK+ widgets, such as fonts and colors in the main Emacs
window; those are governed by normal X resources (see Section D.1 [Resources],
page 521).
The following sections describe how to customize GTK+ resources for
Emacs. For details about GTK+ resources, see the GTK+ API document at
http://developer.gnome.org/doc/API/2.0/gtk/gtk-Resource-Files.html.
In GTK+ version 3, GTK+ resources have been replaced by a completely
different system. The appearance of GTK+ widgets is now determined by
CSS-like style files: ‘gtk-3.0/gtk.css’ in the GTK+ installation directory, and
‘~/.themes/theme /gtk-3.0/gtk.css’ for local style settings (where theme is the
name of the current GTK+ theme). Therefore, the description of GTK+ resources
in this section does not apply to GTK+ 3. For details about the GTK+ 3 styling
system, see http://developer.gnome.org/gtk3/3.0/GtkCssProvider.html.
D.3.1 GTK Resource Basics
In a GTK+ 2 resource file (usually ‘~/.emacs.d/gtkrc’), the simplest kinds of resource settings simply assign a value to a variable. For example, putting the following line in the resource file changes the font on all GTK+ widgets to ‘courier-12’:
gtk-font-name = "courier 12"

Note that in this case the font name must be supplied as a GTK font pattern
(also called a Pango font name), not as a Fontconfig-style font name or XLFD. See
Section 18.8 [Fonts], page 171.
To customize widgets you first define a style, and then apply the style to the
widgets. Here is an example that sets the font for menus (‘#’ characters indicate
comments):
# Define the style ‘my_style’.
style "my_style"
{
font_name = "helvetica bold 14"
}
# Specify that widget type ‘*emacs-menuitem*’ uses ‘my_style’.
widget "*emacs-menuitem*" style "my_style"

The widget name in this example contains wildcards, so the style is applied to all
widgets matching ‘*emacs-menuitem*’. The widgets are named by the way they
are contained, from the outer widget to the inner widget. Here is another example
that applies ‘my_style’ specifically to the Emacs menu bar:
widget "Emacs.pane.menubar.*" style "my_style"

Here is a more elaborate example, showing how to change the parts of the scroll
bar:
style "scroll"
{
fg[NORMAL] = "red"

# Arrow color.

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525

bg[NORMAL] = "yellow" # Thumb and background around arrow.
bg[ACTIVE] = "blue"
# Trough color.
bg[PRELIGHT] = "white" # Thumb color when the mouse is over it.
}
widget "*verticalScrollBar*" style "scroll"

D.3.2 GTK widget names
A GTK+ widget is specified by a widget name and a widget class. The widget name
refers to a specific widget (e.g. ‘emacs-menuitem’), while the widget class refers to
a collection of similar widgets (e.g. ‘GtkMenuItem’). A widget always has a class,
but need not have a name.
Absolute names are sequences of widget names or widget classes, corresponding
to hierarchies of widgets embedded within other widgets. For example, if a
GtkWindow named top contains a GtkVBox named box, which in turn contains
a GtkMenuBar called menubar, the absolute class name of the menu-bar
widget is GtkWindow.GtkVBox.GtkMenuBar, and its absolute widget name is
top.box.menubar.
GTK+ resource files can contain two types of commands for specifying widget
appearances:

widget

specifies a style for widgets based on the class name, or just the class.

widget_class
specifies a style for widgets based on the class name.
See the previous subsection for examples of using the widget command; the widget_
class command is used similarly. Note that the widget name/class and the style
must be enclosed in double-quotes, and these commands must be at the top level
in the GTK+ resource file.
As previously noted, you may specify a widget name or class with shell wildcard
syntax: ‘*’ matches zero or more characters and ‘?’ matches one character. This
example assigns a style to all widgets:
widget "*" style "my_style"

D.3.3 GTK Widget Names in Emacs
The GTK+ widgets used by an Emacs frame are listed below:

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Emacs (class GtkWindow)
pane (class GtkVBox)
menubar (class GtkMenuBar)
[menu item widgets]
[unnamed widget] (class GtkHandleBox)
emacs-toolbar (class GtkToolbar)
[tool bar item widgets]
emacs (class GtkFixed)
verticalScrollBar (class
GtkVScrollbar)
The contents of Emacs windows are drawn in the emacs widget. Note that
even if there are multiple Emacs windows, each scroll bar widget is named
verticalScrollBar.
For example, here are two different ways to set the menu bar style:
widget "Emacs.pane.menubar.*" style "my_style"
widget_class "GtkWindow.GtkVBox.GtkMenuBar.*" style "my_style"

For GTK+ dialogs, Emacs uses a widget named emacs-dialog, of class
GtkDialog. For file selection, Emacs uses a widget named emacs-filedialog, of
class GtkFileSelection.
Because the widgets for pop-up menus and dialogs are free-standing windows
and not “contained” in the Emacs widget, their GTK+ absolute names do not start
with ‘Emacs’. To customize these widgets, use wildcards like this:
widget "*emacs-dialog*" style "my_dialog_style"
widget "*emacs-filedialog* style "my_file_style"
widget "*emacs-menuitem* style "my_menu_style"

If you want to apply a style to all menus in Emacs, use this:
widget_class "*Menu*" style "my_menu_style"

D.3.4 GTK styles
Here is an example of two GTK+ style declarations:
pixmap_path "/usr/share/pixmaps:/usr/include/X11/pixmaps"
style "default"
{
font_name = "helvetica 12"
bg[NORMAL] = { 0.83, 0.80, 0.73 }
bg[SELECTED] = { 0.0, 0.55, 0.55 }
bg[INSENSITIVE] = { 0.77, 0.77, 0.66 }
bg[ACTIVE] = { 0.0, 0.55, 0.55 }
bg[PRELIGHT] = { 0.0, 0.55, 0.55 }
fg[NORMAL] =
fg[SELECTED]
fg[ACTIVE] =
fg[PRELIGHT]

"black"
= { 0.9, 0.9, 0.9 }
"black"
= { 0.9, 0.9, 0.9 }

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base[INSENSITIVE] = "#777766"
text[INSENSITIVE] = { 0.60, 0.65, 0.57 }
bg_pixmap[NORMAL] = "background.xpm"
bg_pixmap[INSENSITIVE] = "background.xpm"
bg_pixmap[ACTIVE] = "background.xpm"
bg_pixmap[PRELIGHT] = ""
}
style "ruler" = "default"
{
font_name = "helvetica 8"
}

The style ‘ruler’ inherits from ‘default’. This way you can build on existing
styles. The syntax for fonts and colors is described below.
As this example shows, it is possible to specify several values for foreground and
background depending on the widget’s state. The possible states are:
NORMAL

This is the default state for widgets.

ACTIVE

This is the state for a widget that is ready to do something. It is also
for the trough of a scroll bar, i.e. bg[ACTIVE] = "red" sets the scroll
bar trough to red. Buttons that have been pressed but not released
yet (“armed”) are in this state.

PRELIGHT

This is the state for a widget that can be manipulated, when the mouse
pointer is over it—for example when the mouse is over the thumb in
the scroll bar or over a menu item. When the mouse is over a button
that is not pressed, the button is in this state.

SELECTED

This is the state for data that has been selected by the user. It can
be selected text or items selected in a list. This state is not used in
Emacs.

INSENSITIVE
This is the state for widgets that are visible, but they can not be
manipulated in the usual way—for example, buttons that can’t be
pressed, and disabled menu items. To display disabled menu items in
yellow, use fg[INSENSITIVE] = "yellow".
Here are the things that can go in a style declaration:
bg[state ] = color
This specifies the background color for the widget. Note that editable
text doesn’t use bg; it uses base instead.
base[state ] = color
This specifies the background color for editable text. In Emacs, this
color is used for the background of the text fields in the file dialog.

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bg_pixmap[state ] = "pixmap "
This specifies an image background (instead of a background color).
pixmap should be the image file name. GTK can use a number of
image file formats, including XPM, XBM, GIF, JPEG and PNG. If
you want a widget to use the same image as its parent, use ‘’.
If you don’t want any image, use ‘’. ‘’ is the way to
cancel a background image inherited from a parent style.
You can’t specify the file by its absolute file name. GTK looks for
the pixmap file in directories specified in pixmap_path. pixmap_path
is a colon-separated list of directories within double quotes, specified
at the top level in a ‘gtkrc’ file (i.e. not inside a style definition; see
example above):
pixmap_path "/usr/share/pixmaps:/usr/include/X11/pixmaps"

fg[state ] = color
This specifies the foreground color for widgets to use. It is the color of
text in menus and buttons, and the color for the arrows in the scroll
bar. For editable text, use text.
text[state ] = color
This is the color for editable text. In Emacs, this color is used for the
text fields in the file dialog.
font_name = "font "
This specifies the font for text in the widget. font is a GTK-style (or
Pango) font name, like ‘Sans Italic 10’. See Section 18.8 [Fonts],
page 171. The names are case insensitive.
There are three ways to specify a color: a color name, an RGB triplet, or a
GTK-style RGB triplet. See Section 11.9 [Colors], page 76, for a description of
color names and RGB triplets. Color names should be enclosed with double quotes,
e.g. ‘"red"’. RGB triplets should be written without double quotes, e.g. ‘#ff0000’.
GTK-style RGB triplets have the form { r, g, b }, where r, g and b are either
integers in the range 0-65535 or floats in the range 0.0-1.0.

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Appendix E Emacs 23 Antinews
For those users who live backwards in time, here is information about downgrading
to Emacs version 23.4. We hope you will enjoy the greater simplicity that results
from the absence of many Emacs 24.2 features.
• Support for displaying and editing “bidirectional” text has been removed. Text
is now always displayed on the screen in a single consistent direction—left to
right—regardless of the underlying script. Similarly, C-f and C-b always move
the text cursor to the right and left respectively. Also, RIGHT and LEFT
are now equivalent to C-f and C-b, as you might expect, rather than moving
forward or backward based on the underlying “paragraph direction”.
Users of “right-to-left” languages, like Arabic and Hebrew, may adapt by reading and/or editing text in left-to-right order.
• The Emacs Lisp package manager has been removed. Instead of using a “user
interface” (M-x list-packages), additional Lisp packages must now be installed by hand, which is the most flexible and “Lispy” method anyway. Typically, this just involves editing your init file to add the package installation
directory to the load path and defining some autoloads; see each package’s
commentary section and/or README file for details.
• The option delete-active-region has been deleted. When the region is
active, typing DEL or DELETE no longer deletes the text in the region; it
deletes a single character instead.
• We have reworked how Emacs handles the clipboard and the X primary selection. Commands for killing and yanking, like C-w and C-y, use the primary
selection and not the clipboard, so you can use these commands without interfering with “cutting” or “pasting” in other programs. The ‘Cut’/‘Copy’/‘Paste’
menu items are bound to separate clipboard commands, not to the same commands as C-w/M-w/C-y.
Selecting text by dragging with the mouse now puts the text in the kill ring,
in addition to the primary selection. But note that selecting an active region
with C-SPC does not alter the kill ring nor the primary selection, even though
the text highlighting is visually identical.
• In Isearch, C-y and M-y are no longer bound to isearch-yank-kill and
isearch-yank-pop respectively. Instead, C-y yanks the rest of the current
line into the search string (isearch-yank-line), whereas M-y does isearchyank-kill. The mismatch with the usual meanings of C-y and M-y is unintended.
• Various completion features have been simplified. The option completioncategory-overrides has been removed, so Emacs uses a single consistent
scheme to generate completions, instead of using a separate scheme for (say)
buffer name completion. Several major modes, such as Shell mode, now implement their own inline completion commands instead of using completionat-point.

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• We have removed several options for controlling how windows are used,
such as display-buffer-base-action, display-buffer-alist, windowcombination-limit, and window-combination-resize.
• The command M-x customize-themes has been removed. Emacs no longer
comes with pre-defined themes (you can write your own).
• Emacs no longer adapts various aspects of its display to GTK+ settings, opting
instead for a uniform toolkit-independent look. GTK+ scroll bars are placed
on the left, the same position as non-GTK+ X scroll bars. Emacs no longer
refers to GTK+ to set the default region face, nor for drawing tooltips.
• Setting the option delete-by-moving-to-trash to a non-nil now causes all
file deletions to use the system trash, even temporary files created by Lisp programs; furthermore, the M-x delete-file and M-x delete-directory commands no longer accept prefix arguments to force true deletion.
• On GNU/Linux and Unix, the default method for sending mail (as specified
by send-mail-function) is to use the sendmail program. Emacs no longer
asks for a delivery method the first time you try to send mail, trusting instead
that the system is configured for mail delivery, as it ought to be.
• Several VC features have been removed, including the C-x v + and C-x v m
commands for pulling and merging on distributed version control systems, and
the ability to view inline log entries in the log buffers made by C-x v L.
• To keep up with decreasing computer memory capacity and disk space, many
other functions and files have been eliminated in Emacs 23.4.

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Appendix F Emacs and Mac OS / GNUstep
This section describes the peculiarities of using Emacs built with the GNUstep
libraries on GNU/Linux or other operating systems, or on Mac OS X with native
window system support. On Mac OS X, Emacs can be built either without window
system support, with X11, or with the Cocoa interface; this section only applies to
the Cocoa build. This does not support versions of Mac OS X earlier than 10.4.
For various historical and technical reasons, Emacs uses the term ‘Nextstep’ internally, instead of “Cocoa” or “Mac OS X”; for instance, most of the commands and
variables described in this section begin with ‘ns-’, which is short for ‘Nextstep’.
NeXTstep was an application interface released by NeXT Inc during the 1980s, of
which Cocoa is a direct descendant. Apart from Cocoa, there is another NeXTstepstyle system: GNUstep, which is free software. As of this writing, Emacs GNUstep
support is alpha status (see Section F.4 [GNUstep Support], page 534), but we hope
to improve it in the future.

F.1 Basic Emacs usage under Mac OS and GNUstep
By default, the ALT and OPTION keys are the same as META. The Mac CMD
key is the same as SUPER, and Emacs provides a set of key bindings using this
modifier key that mimic other Mac / GNUstep applications (see Section F.3 [Mac /
GNUstep Events], page 532). You can change these bindings in the usual way (see
Section 33.3 [Key Bindings], page 452).
The variable ns-right-alternate-modifier controls the behavior of the right
ALT and OPTION keys. These keys behave like the left-hand keys if the value is
left (the default). A value of control, meta, alt, super, or hyper makes them
behave like the corresponding modifier keys; a value of none tells Emacs to ignore
them.
S-Mouse-1 adjusts the region to the click position, just like Mouse-3 (mousesave-then-kill); it does not pop up a menu for changing the default face, as
S-Mouse-1 normally does (see Section 11.11 [Text Scale], page 79). This change
makes Emacs behave more like other Mac / GNUstep applications.
When you open or save files using the menus, or using the Cmd-o and Cmd-S
bindings, Emacs uses graphical file dialogs to read file names. However, if you use
the regular Emacs key sequences, such as C-x C-f, Emacs uses the minibuffer to
read file names.
On GNUstep, in an X-windows environment you need to use Cmd-c instead
of one of the C-w or M-w commands to transfer text to the X primary selection;
otherwise, Emacs will use the “clipboard” selection. Likewise, Cmd-y (instead of
C-y) yanks from the X primary selection instead of the kill-ring or clipboard.
F.1.1 Grabbing environment variables
Many programs which may run under Emacs, like latex or man, depend on the
settings of environment variables. If Emacs is launched from the shell, it will automatically inherit these environment variables and its subprocesses will inherit them

Appendix F: Emacs and Mac OS / GNUstep

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from it. But if Emacs is launched from the Finder it is not a descendant of any shell,
so its environment variables haven’t been set, which often causes the subprocesses
it launches to behave differently than they would when launched from the shell.
For the PATH and MANPATH variables, a system-wide method of setting PATH
is recommended on Mac OS X 10.5 and later, using the ‘/etc/paths’ files and the
‘/etc/paths.d’ directory.

F.2 Mac / GNUstep Customization
Emacs can be customized in several ways in addition to the standard customization
buffers and the Options menu.
F.2.1 Font and Color Panels
The standard Mac / GNUstep font and color panels are accessible via Lisp commands. The Font Panel may be accessed with M-x ns-popup-font-panel. It will
set the default font in the frame most recently used or clicked on.
You can bring up a color panel with M-x ns-popup-color-panel and drag the
color you want over the Emacs face you want to change. Normal dragging will alter
the foreground color. Shift dragging will alter the background color. To discard the
settings, create a new frame and close the altered one.
Useful in this context is the listing of all faces obtained by M-x
list-faces-display.
F.2.2 Customization options specific to Mac OS / GNUstep
The following customization options are specific to the Nextstep port.
ns-auto-hide-menu-bar
Non-nil means the menu-bar is hidden by default, but appears if you
move the mouse pointer over it. (Requires Mac OS X 10.6 or later.)

F.3 Windowing System Events under Mac OS / GNUstep
Nextstep applications receive a number of special events which have no X equivalent.
These are sent as specially defined “keys”, which do not correspond to any sequence
of keystrokes. Under Emacs, these “key” events can be bound to functions just like
ordinary keystrokes. Here is a list of these events.
NS-OPEN-FILE
This event occurs when another Nextstep application requests that
Emacs open a file. A typical reason for this would be a user doubleclicking a file in the Finder application. By default, Emacs responds
to this event by opening a new frame and visiting the file in that
frame (ns-find-file). As an exception, if the selected buffer is the
‘*scratch*’ buffer, Emacs visits the file in the selected frame.
You can change how Emacs responds to a ns-open-file event by
changing the variable ns-pop-up-frames. Its default value, ‘fresh’,

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is what we have just described. A value of t means to always visit the
file in a new frame. A value of nil means to always visit the file in an
existing frame.
NS-OPEN-TEMP-FILE
This event occurs when another application requests that Emacs open
a temporary file. By default, this is handled by just generating a
ns-open-file event, the results of which are described above.
NS-OPEN-FILE-LINE
Some applications, such as ProjectBuilder and gdb, request not only a
particular file, but also a particular line or sequence of lines in the file.
Emacs handles this by visiting that file and highlighting the requested
line (ns-open-file-select-line).
NS-DRAG-FILE
This event occurs when a user drags files from another application into
an Emacs frame. The default behavior is to insert the contents of all
the dragged files into the current buffer (ns-insert-files). The list
of dragged files is stored in the variable ns-input-file.
NS-DRAG-COLOR
This event occurs when a user drags a color from the color well (or some
other source) into an Emacs frame. The default behavior is to alter
the foreground color of the area the color was dragged onto (ns-setforeground-at-mouse). If this event is issued with a SHIFT modifier,
Emacs changes the background color instead (ns-set-backgroundat-mouse). The name of the dragged color is stored in the variable
ns-input-color.
NS-CHANGE-FONT
This event occurs when the user selects a font in a Nextstep font
panel (which can be opened with Cmd-t). The default behavior is to
adjust the font of the selected frame (ns-respond-to-changefont).
The name and size of the selected font are stored in the variables
ns-input-font and ns-input-fontsize, respectively.
NS-POWER-OFF
This event occurs when the user logs out and Emacs is still running, or
when ‘Quit Emacs’ is chosen from the application menu. The default
behavior is to save all file-visiting buffers.
Emacs also allows users to make use of Nextstep services, via a set of commands
whose names begin with ‘ns-service-’ and end with the name of the service. Type
M-x ns-service-TAB to see a list of these commands. These functions either operate
on marked text (replacing it with the result) or take a string argument and return
the result as a string. You can also use the Lisp function ns-perform-service to
pass arbitrary strings to arbitrary services and receive the results back. Note that
you may need to restart Emacs to access newly-available services.

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F.4 GNUstep Support
Emacs can be built and run under GNUstep, but there are still issues to be addressed. Interested developers should contact emacs-devel@gnu.org.

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Appendix G Emacs and Microsoft Windows/MSDOS
This section describes peculiarities of using Emacs on Microsoft Windows. Some
of these peculiarities are also relevant to Microsoft’s older MS-DOS “operating
system” (also known as “MS-DOG”). However, Emacs features that are relevant
only to MS-DOS are described in a separate manual (see Section “MS-DOS” in
Specialized Emacs Features).
The behavior of Emacs on MS-Windows is reasonably similar to what is documented in the rest of the manual, including support for long file names, multiple
frames, scroll bars, mouse menus, and subprocesses. However, a few special considerations apply, and they are described here.

G.1 How to Start Emacs on MS-Windows
There are several ways of starting Emacs on MS-Windows:
1. From the desktop shortcut icon: either double-click the left mouse button on
the icon, or click once, then press RET. The desktop shortcut should specify as
its “Target” (in the “Properties” of the shortcut) the full absolute file name of
‘runemacs.exe’, not of ‘emacs.exe’. This is because ‘runemacs.exe’ hides the
console window that would have been created if the target of the shortcut were
‘emacs.exe’ (which is a console program, as far as Windows is concerned). If
you use this method, Emacs starts in the directory specified by the shortcut.
To control where that is, right-click on the shortcut, select “Properties”, and
in the “Shortcut” tab modify the “Start in” field to your liking.
2. From the Command Prompt window, by typing emacs RET at the prompt.
The Command Prompt window where you did that will not be available for
invoking other commands until Emacs exits. In this case, Emacs will start in
the current directory of the Windows shell.
3. From the Command Prompt window, by typing runemacs RET at the prompt.
The Command Prompt window where you did that will be immediately available for invoking other commands. In this case, Emacs will start in the current
directory of the Windows shell.
4. Via ‘emacsclient.exe’ or ‘emacsclientw.exe’, which allow you to invoke
Emacs from other programs, and to reuse a running Emacs process for serving
editing jobs required by other programs. See Section 31.4 [Emacs Server],
page 412. The difference between ‘emacsclient.exe’ and ‘emacsclientw.exe’
is that the former is a console program, while the latter is a Windows GUI
program. Both programs wait for Emacs to signal that the editing job is
finished, before they exit and return control to the program that invoked them.
Which one of them to use in each case depends on the expectations of the
program that needs editing services. If that program is itself a console (textmode) program, you should use ‘emacsclient.exe’, so that any of its messages
and prompts appear in the same command window as those of the invoking
program. By contrast, if the invoking program is a GUI program, you will be

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better off using ‘emacsclientw.exe’, because ‘emacsclient.exe’ will pop up
a command window if it is invoked from a GUI program. A notable situation
where you would want ‘emacsclientw.exe’ is when you right-click on a file in
the Windows Explorer and select “Open With” from the pop-up menu. Use
the ‘--alternate-editor=’ or ‘-a’ options if Emacs might not be running (or
not running as a server) when emacsclient is invoked—that will always give
you an editor. When invoked via emacsclient, Emacs will start in the current
directory of the program that invoked emacsclient.
Note that, due to limitations of MS-Windows, Emacs cannot have both GUI and
text-mode frames in the same session. It also cannot open text-mode frames on more
than a single Command Prompt window, because each Windows program can have
only one console at any given time. For these reasons, if you invoke emacsclient
with the ‘-c’ option, and the Emacs server runs in a text-mode session, Emacs will
always create a new text-mode frame in the same Command Prompt window where
it was started; a GUI frame will be created only if the server runs in a GUI session.
Similarly, if you invoke emacsclient with the ‘-t’ option, Emacs will create a GUI
frame if the server runs in a GUI session, or a text-mode frame when the session
runs in text mode in a Command Prompt window. See Section 31.4.2 [emacsclient
Options], page 414.

G.2 Text Files and Binary Files
GNU Emacs uses newline characters to separate text lines. This is the convention
used on GNU, Unix, and other Posix-compliant systems.
By contrast, MS-DOS and MS-Windows normally use carriage-return linefeed,
a two-character sequence, to separate text lines. (Linefeed is the same character as
newline.) Therefore, convenient editing of typical files with Emacs requires conversion of these end-of-line (EOL) sequences. And that is what Emacs normally does:
it converts carriage-return linefeed into newline when reading files, and converts
newline into carriage-return linefeed when writing files. The same mechanism that
handles conversion of international character codes does this conversion also (see
Section 19.6 [Coding Systems], page 188).
One consequence of this special format-conversion of most files is that character
positions as reported by Emacs (see Section 4.9 [Position Info], page 23) do not
agree with the file size information known to the operating system.
In addition, if Emacs recognizes from a file’s contents that it uses newline rather
than carriage-return linefeed as its line separator, it does not perform EOL conversion when reading or writing that file. Thus, you can read and edit files from
GNU and Unix systems on MS-DOS with no special effort, and they will retain
their Unix-style end-of-line convention after you edit them.
The mode line indicates whether end-of-line translation was used for the current
buffer. If MS-DOS end-of-line translation is in use for the buffer, the MS-Windows
build of Emacs displays a backslash ‘\’ after the coding system mnemonic near
the beginning of the mode line (see Section 1.3 [Mode Line], page 8). If no EOL

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translation was performed, the string ‘(Unix)’ is displayed instead of the backslash,
to alert you that the file’s EOL format is not the usual carriage-return linefeed.
To visit a file and specify whether it uses DOS-style or Unix-style end-of-line,
specify a coding system (see Section 19.10 [Text Coding], page 193). For example,
C-x RET c unix RET C-x C-f foobar.txt visits the file ‘foobar.txt’ without converting the EOLs; if some line ends with a carriage-return linefeed pair, Emacs will
display ‘^M’ at the end of that line. Similarly, you can direct Emacs to save a buffer
in a specified EOL format with the C-x RET f command. For example, to save a
buffer with Unix EOL format, type C-x RET f unix RET C-x C-s. If you visit a file
with DOS EOL conversion, then save it with Unix EOL format, that effectively
converts the file to Unix EOL style, like the dos2unix program.
When you use NFS, Samba, or some other similar method to access file systems
that reside on computers using GNU or Unix systems, Emacs should not perform
end-of-line translation on any files in these file systems—not even when you create a
new file. To request this, designate these file systems as untranslated file systems by
calling the function add-untranslated-filesystem. It takes one argument: the
file system name, including a drive letter and optionally a directory. For example,
(add-untranslated-filesystem "Z:")
designates drive Z as an untranslated file system, and
(add-untranslated-filesystem "Z:\\foo")
designates directory ‘\foo’ on drive Z as an untranslated file system.
Most often you would use add-untranslated-filesystem in your ‘.emacs’ file,
or in ‘site-start.el’ so that all the users at your site get the benefit of it.
To countermand the effect of add-untranslated-filesystem, use the
function remove-untranslated-filesystem. This function takes one argument,
which should be a string just like the one that was used previously with
add-untranslated-filesystem.
Designating a file system as untranslated does not affect character set conversion,
only end-of-line conversion. Essentially, it directs Emacs to create new files with
the Unix-style convention of using newline at the end of a line. See Section 19.6
[Coding Systems], page 188.
Some kinds of files should not be converted at all, because their contents are not
really text. Therefore, Emacs on MS-Windows distinguishes certain files as binary
files. (This distinction is not part of MS-Windows; it is made by Emacs only.)
Binary files include executable programs, compressed archives, etc. Emacs uses
the file name to decide whether to treat a file as binary: the variable file-namebuffer-file-type-alist defines the file-name patterns that indicate binary files.
If a file name matches one of the patterns for binary files (those whose associations
are of the type (pattern . t), Emacs reads and writes that file using the noconversion coding system (see Section 19.6 [Coding Systems], page 188) which
turns off all coding-system conversions, not only the EOL conversion. file-namebuffer-file-type-alist also includes file-name patterns for files which are known
to be Windows-style text files with carriage-return linefeed EOL format, such as
‘CONFIG.SYS’; Emacs always writes those files with Windows-style EOLs.

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If a file that belongs to an untranslated file system matches one of the file-name
patterns in file-name-buffer-file-type-alist, the EOL conversion is determined by file-name-buffer-file-type-alist.

G.3 File Names on MS-Windows
MS-Windows and MS-DOS normally use a backslash, ‘\’, to separate name units
within a file name, instead of the slash used on other systems. Emacs on MSDOS/MS-Windows permits use of either slash or backslash, and also knows about
drive letters in file names.
On MS-DOS/MS-Windows, file names are case-insensitive, so Emacs by default
ignores letter-case in file names during completion.
The variable w32-get-true-file-attributes controls whether Emacs should
issue additional system calls to determine more accurately file attributes in primitives like file-attributes and directory-files-and-attributes. These additional calls are needed to report correct file ownership, link counts and file types
for special files such as pipes. Without these system calls, file ownership will be
attributed to the current user, link counts will be always reported as 1, and special
files will be reported as regular files.
If the value of this variable is local (the default), Emacs will issue these additional system calls only for files on local fixed drives. Any other non-nil value
means do this even for removable and remote volumes, where this could potentially slow down Dired and other related features. The value of nil means never
issue those system calls. Non-nil values are more useful on NTFS volumes, which
support hard links and file security, than on FAT, FAT32, and XFAT volumes.

G.4 Emulation of ls on MS-Windows
Dired normally uses the external program ls to produce the directory listing displayed in Dired buffers (see Chapter 27 [Dired], page 329). However, MS-Windows
and MS-DOS systems don’t come with such a program, although several ports of
gnu ls are available. Therefore, Emacs on those systems emulates ls in Lisp, by
using the ‘ls-lisp.el’ package. While ‘ls-lisp.el’ provides a reasonably full
emulation of ls, there are some options and features peculiar to that emulation;
for more details, see the documentation of the variables whose names begin with
ls-lisp.

G.5 HOME and Startup Directories on MS-Windows
The Windows equivalent of HOME is the user-specific application data directory.
The actual location depends on the Windows version; typical
values are ‘C:\Documents and Settings\username \Application Data’ (for
Windows
2000/XP/2K3),
‘C:\Users\username \AppData\Roaming’
(for
Windows Vista/7/2008), and either ‘C:\WINDOWS\Application Data’ or
‘C:\WINDOWS\Profiles\username \Application Data’ (Windows 9X/ME). If this

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directory does not exist or cannot be accessed, Emacs falls back to ‘C:\’ as the
default value of HOME.
You can override this default value of HOME by explicitly setting the environment
variable HOME to point to any directory on your system. HOME can be set either from
the command shell prompt or from ‘Properties’ dialog of ‘My Computer’. HOME
can also be set in the system registry, see Section C.4.3 [MS-Windows Registry],
page 514.
For compatibility with older versions of Emacs1 , if there is a file named ‘.emacs’
in ‘C:\’, the root directory of drive ‘C:’, and HOME is set neither in the environment
nor in the Registry, Emacs will treat ‘C:\’ as the default HOME location, and will
not look in the application data directory, even if it exists. Note that only ‘.emacs’
is looked for in ‘C:\’; the older name ‘_emacs’ (see below) is not. This use of
‘C:\.emacs’ to define HOME is deprecated.
Whatever the final place is, Emacs sets the internal value of the HOME environment variable to point to it, and it will use that location for other files and
directories it normally looks for or creates in your home directory.
You can always find out what Emacs thinks is your home directory’s location
by typing C-x d ~/ RET. This should present the list of files in the home directory,
and show its full name on the first line. Likewise, to visit your init file, type C-x
C-f ~/.emacs RET (assuming the file’s name is ‘.emacs’).
The home directory is where your init file is stored. It can have any name
mentioned in Section 33.4 [Init File], page 461.
Because MS-DOS does not allow file names with leading dots, and older Windows systems made it hard to create files with such names, the Windows port of
Emacs supports an init file name ‘_emacs’, if such a file exists in the home directory
and ‘.emacs’ does not. This name is considered obsolete.

G.6 Keyboard Usage on MS-Windows
This section describes the Windows-specific features related to keyboard input in
Emacs.
Many key combinations (known as “keyboard shortcuts”) that have conventional
uses in MS-Windows programs conflict with traditional Emacs key bindings. (These
Emacs key bindings were established years before Microsoft was founded.) Examples
of conflicts include C-c, C-x, C-z, C-a, and W-SPC. You can redefine some of them
with meanings more like the MS-Windows meanings by enabling CUA Mode (see
Section 9.6 [CUA Bindings], page 64).
The F10 key on Windows activates the menu bar in a way that makes it possible
to use the menus without a mouse. In this mode, the arrow keys traverse the menus,
RET selects a highlighted menu item, and ESC closes the menu.
See Info file ‘emacs’, node ‘Windows Keyboard’, for information about additional
Windows-specific variables in this category.
The variable w32-apps-modifier controls the effect of the APPS key (usually
located between the right ALT and the right CTRL keys). Its value can be one of
1

Older versions of Emacs didn’t check the application data directory.

Appendix G: Emacs and Microsoft Windows/MS-DOS

540

the symbols hyper, super, meta, alt, control, or shift for the respective modifier,
or nil to appear as the key apps. The default is nil.
The variable w32-lwindow-modifier determines the effect of the left Windows
key (usually labeled with START and the Windows logo). If its value is nil (the
default), the key will produce the symbol lwindow. Setting it to one of the symbols
hyper, super, meta, alt, control, or shift will produce the respective modifier.
A similar variable w32-rwindow-modifier controls the effect of the right Windows
key, and w32-scroll-lock-modifier does the same for the SCRLOCK key. If
these variables are set to nil, the right Windows key produces the symbol rwindow
and SCRLOCK produces the symbol scroll.
Emacs compiled as a native Windows application normally turns off the Windows feature that tapping the ALT key invokes the Windows menu. The reason
is that the ALT serves as META in Emacs. When using Emacs, users often press
the META key temporarily and then change their minds; if this has the effect of
bringing up the Windows menu, it alters the meaning of subsequent commands.
Many users find this frustrating.
You can re-enable Windows’s default handling of tapping the ALT key by setting
w32-pass-alt-to-system to a non-nil value.

G.7 Mouse Usage on MS-Windows
This section describes the Windows-specific variables related to the mouse.
The variable w32-mouse-button-tolerance specifies the time interval, in milliseconds, for faking middle mouse button press on 2-button mice. If both mouse
buttons are depressed within this time interval, Emacs generates a middle mouse
button click event instead of a double click on one of the buttons.
If the variable w32-pass-extra-mouse-buttons-to-system is non-nil, Emacs
passes the fourth and fifth mouse buttons to Windows.
The variable w32-swap-mouse-buttons controls which of the 3 mouse buttons
generates the mouse-2 events. When it is nil (the default), the middle button
generates mouse-2 and the right button generates mouse-3 events. If this variable
is non-nil, the roles of these two buttons are reversed.

G.8 Subprocesses on Windows 9X/ME and Windows
NT/2K/XP
Emacs compiled as a native Windows application (as opposed to the DOS version)
includes full support for asynchronous subprocesses. In the Windows version, synchronous and asynchronous subprocesses work fine on both Windows 9X/ME and
Windows NT/2K/XP as long as you run only 32-bit Windows applications. However, when you run a DOS application in a subprocess, you may encounter problems
or be unable to run the application at all; and if you run two DOS applications at
the same time in two subprocesses, you may have to reboot your system.
Since the standard command interpreter (and most command line utilities) on
Windows 9X are DOS applications, these problems are significant when using that
system. But there’s nothing we can do about them; only Microsoft can fix them.

Appendix G: Emacs and Microsoft Windows/MS-DOS

541

If you run just one DOS application subprocess, the subprocess should work as
expected as long as it is “well-behaved” and does not perform direct screen access
or other unusual actions. If you have a CPU monitor application, your machine will
appear to be 100% busy even when the DOS application is idle, but this is only an
artifact of the way CPU monitors measure processor load.
You must terminate the DOS application before you start any other DOS application in a different subprocess. Emacs is unable to interrupt or terminate a DOS
subprocess. The only way you can terminate such a subprocess is by giving it a
command that tells its program to exit.
If you attempt to run two DOS applications at the same time in separate subprocesses, the second one that is started will be suspended until the first one finishes,
even if either or both of them are asynchronous.
If you can go to the first subprocess, and tell it to exit, the second subprocess
should continue normally. However, if the second subprocess is synchronous, Emacs
itself will be hung until the first subprocess finishes. If it will not finish without user
input, then you have no choice but to reboot if you are running on Windows 9X. If
you are running on Windows NT/2K/XP, you can use a process viewer application
to kill the appropriate instance of NTVDM instead (this will terminate both DOS
subprocesses).
If you have to reboot Windows 9X in this situation, do not use the Shutdown
command on the Start menu; that usually hangs the system. Instead, type
CTL-ALT-DEL and then choose Shutdown. That usually works, although it may
take a few minutes to do its job.
The variable w32-quote-process-args controls how Emacs quotes the process
arguments. Non-nil means quote with the " character. If the value is a character,
Emacs uses that character to escape any quote characters that appear; otherwise it
chooses a suitable escape character based on the type of the program.

G.9 Printing and MS-Windows
Printing commands, such as lpr-buffer (see Section 31.5 [Printing], page 417) and
ps-print-buffer (see Section 31.5.1 [PostScript], page 418) work in MS-DOS and
MS-Windows by sending the output to one of the printer ports, if a Posix-style lpr
program is unavailable. The same Emacs variables control printing on all systems,
but in some cases they have different default values on MS-DOS and MS-Windows.
Emacs on MS Windows attempts to determine your default printer automatically (using the function default-printer-name). But in some rare cases this can
fail, or you may wish to use a different printer from within Emacs. The rest of this
section explains how to tell Emacs which printer to use.
If you want to use your local printer, then set the Lisp variable lpr-command
to "" (its default value on Windows) and printer-name to the name of the printer
port—for example, "PRN", the usual local printer port, or "LPT2", or "COM1" for a
serial printer. You can also set printer-name to a file name, in which case “printed”
output is actually appended to that file. If you set printer-name to "NUL", printed
output is silently discarded (sent to the system null device).

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You can also use a printer shared by another machine by setting printer-name
to the UNC share name for that printer—for example, "//joes_pc/hp4si". (It
doesn’t matter whether you use forward slashes or backslashes here.) To find out
the names of shared printers, run the command ‘net view’ from the command
prompt to obtain a list of servers, and ‘net view server-name ’ to see the names of
printers (and directories) shared by that server. Alternatively, click the ‘Network
Neighborhood’ icon on your desktop, and look for machines that share their printers
via the network.
If the printer doesn’t appear in the output of ‘net view’, or if setting printername to the UNC share name doesn’t produce a hardcopy on that printer, you can
use the ‘net use’ command to connect a local print port such as "LPT2" to the
networked printer. For example, typing net use LPT2: \\joes_pc\hp4si2 causes
Windows to capture the LPT2 port and redirect the printed material to the printer
connected to the machine joes_pc. After this command, setting printer-name to
"LPT2" should produce the hardcopy on the networked printer.
With some varieties of Windows network software, you can instruct Windows
to capture a specific printer port such as "LPT2", and redirect it to a networked
printer via the Control Panel->Printers applet instead of ‘net use’.
If you set printer-name to a file name, it’s best to use an absolute file name.
Emacs changes the working directory according to the default directory of the current buffer, so if the file name in printer-name is relative, you will end up with
several such files, each one in the directory of the buffer from which the printing
was done.
If the value of printer-name is correct, but printing does not produce the hardcopy on your printer, it is possible that your printer does not support printing plain
text (some cheap printers omit this functionality). In that case, try the PostScript
print commands, described below.
The commands print-buffer and print-region call the pr program, or use
special switches to the lpr program, to produce headers on each printed page.
MS-DOS and MS-Windows don’t normally have these programs, so by default, the
variable lpr-headers-switches is set so that the requests to print page headers
are silently ignored. Thus, print-buffer and print-region produce the same
output as lpr-buffer and lpr-region, respectively. If you do have a suitable pr
program (for example, from GNU Coreutils), set lpr-headers-switches to nil;
Emacs will then call pr to produce the page headers, and print the resulting output
as specified by printer-name.
Finally, if you do have an lpr work-alike, you can set the variable lpr-command
to "lpr". Then Emacs will use lpr for printing, as on other systems. (If the
name of the program isn’t lpr, set lpr-command to the appropriate value.) The
variable lpr-switches has its standard meaning when lpr-command is not "". If
the variable printer-name has a string value, it is used as the value for the -P
option to lpr, as on Unix.
2

Note that the ‘net use’ command requires the UNC share name to be typed with
the Windows-style backslashes, while the value of printer-name can be set with either
forward- or backslashes.

Appendix G: Emacs and Microsoft Windows/MS-DOS

543

A parallel set of variables, ps-lpr-command, ps-lpr-switches, and
ps-printer-name (see Section 31.5.2 [PostScript Variables], page 419), defines
how PostScript files should be printed. These variables are used in the same
way as the corresponding variables described above for non-PostScript printing.
Thus, the value of ps-printer-name is used as the name of the device (or file) to
which PostScript output is sent, just as printer-name is used for non-PostScript
printing. (There are two distinct sets of variables in case you have two printers
attached to two different ports, and only one of them is a PostScript printer.)
The default value of the variable ps-lpr-command is "", which causes PostScript
output to be sent to the printer port specified by ps-printer-name; but ps-lprcommand can also be set to the name of a program which will accept PostScript files.
Thus, if you have a non-PostScript printer, you can set this variable to the name of
a PostScript interpreter program (such as Ghostscript). Any switches that need to
be passed to the interpreter program are specified using ps-lpr-switches. (If the
value of ps-printer-name is a string, it will be added to the list of switches as the
value for the -P option. This is probably only useful if you are using lpr, so when
using an interpreter typically you would set ps-printer-name to something other
than a string so it is ignored.)
For example, to use Ghostscript for printing on the system’s default printer, put
this in your ‘.emacs’ file:
(setq ps-printer-name t)
(setq ps-lpr-command "D:/gs6.01/bin/gswin32c.exe")
(setq ps-lpr-switches ’("-q" "-dNOPAUSE" "-dBATCH"
"-sDEVICE=mswinpr2"
"-sPAPERSIZE=a4"))
(This assumes that Ghostscript is installed in the ‘D:/gs6.01’ directory.)

G.10 Specifying Fonts on MS-Windows
Starting with Emacs 23, fonts are specified by their name, size and optional properties. The format for specifying fonts comes from the fontconfig library used in
modern Free desktops:
[Family[-PointSize]][:Option1=Value1[:Option2=Value2[...]]]
The old XLFD based format is also supported for backwards compatibility.
Emacs 23 and later supports a number of font backends. Currently, the
gdi and uniscribe backends are supported on Windows. The gdi font backend is available on all versions of Windows, and supports all fonts that are natively supported by Windows. The uniscribe font backend is available on Windows 2000 and later, and supports TrueType and OpenType fonts. Some languages requiring complex layout can only be properly supported by the Uniscribe
backend. By default, both backends are enabled if supported, with uniscribe
taking priority over gdi. To override that and use the GDI backend even
if Uniscribe is available, invoke Emacs with the -xrm Emacs.fontBackend:gdi
command-line argument, or add a Emacs.fontBackend resource with the value
gdi in the Registry under either the ‘HKEY_CURRENT_USER\SOFTWARE\GNU\Emacs’ or

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the ‘HKEY_LOCAL_MACHINE\SOFTWARE\GNU\Emacs’ key (see Section D.1 [Resources],
page 521).
Optional properties common to all font backends on MS-Windows are:
weight

Specifies the weight of the font. Special values light, medium,
demibold, bold, and black can be specified without weight= (e.g.,
Courier New-12:bold). Otherwise, the weight should be a numeric
value between 100 and 900, or one of the named weights in fontweight-table. If unspecified, a regular font is assumed.

slant

Specifies whether the font is italic. Special values roman, italic
and oblique can be specified without slant= (e.g., Courier
New-12:italic). Otherwise, the slant should be a numeric value, or
one of the named slants in font-slant-table. On Windows, any
slant above 150 is treated as italics, and anything below as roman.

family

Specifies the font family, but normally this will be specified at the start
of the font name.

pixelsize

Specifies the font size in pixels. This can be used instead of the point
size specified after the family name.

adstyle

Specifies additional style information for the font. On MS-Windows,
the values mono, sans, serif, script and decorative are recognized.
These are most useful as a fallback with the font family left unspecified.

registry

Specifies the character set registry that the font is expected to cover.
Most TrueType and OpenType fonts will be Unicode fonts that cover
several national character sets, but you can narrow down the selection
of fonts to those that support a particular character set by using a
specific registry from w32-charset-info-alist here.

spacing

Specifies how the font is spaced. The p spacing specifies a proportional
font, and m or c specify a monospaced font.

foundry

Not used on Windows, but for informational purposes and to prevent
problems with code that expects it to be set, is set internally to raster
for bitmapped fonts, outline for scalable fonts, or unknown if the type
cannot be determined as one of those.

Options specific to GDI fonts:
script

Specifies a Unicode subrange the font should support.
The following scripts are recognized on Windows: latin, greek,
coptic, cyrillic, armenian, hebrew, arabic, syriac, nko,
thaana, devanagari, bengali, gurmukhi, gujarati, oriya, tamil,
telugu, kannada, malayam, sinhala, thai, lao, tibetan, myanmar,
georgian, hangul, ethiopic, cherokee, canadian-aboriginal,
ogham, runic, khmer, mongolian, symbol, braille, han,
ideographic-description, cjk-misc, kana, bopomofo, kanbun, yi,
byzantine-musical-symbol, musical-symbol, and mathematical.

Appendix G: Emacs and Microsoft Windows/MS-DOS
antialias

545

Specifies the antialiasing method. The value none means no antialiasing, standard means use standard antialiasing, subpixel means use
subpixel antialiasing (known as Cleartype on Windows), and natural
means use subpixel antialiasing with adjusted spacing between letters.
If unspecified, the font will use the system default antialiasing.

G.11 Miscellaneous Windows-specific features
This section describes miscellaneous Windows-specific features.
The variable w32-use-visible-system-caret is a flag that determines whether
to make the system caret visible. The default when no screen reader software is
in use is nil, which means Emacs draws its own cursor to indicate the position of
point. A non-nil value means Emacs will indicate point location with the system
caret; this facilitates use of screen reader software, and is the default when such
software is detected when running Emacs. When this variable is non-nil, other
variables affecting the cursor display have no effect.
See Info file ‘emacs’, node ‘Windows Misc’, for information about additional
Windows-specific variables in this category.

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546

The GNU Manifesto
The GNU Manifesto which appears below was written by Richard Stallman at the beginning of the GNU project, to ask for participation and
support. For the first few years, it was updated in minor ways to account
for developments, but now it seems best to leave it unchanged as most
people have seen it.
Since that time, we have learned about certain common misunderstandings that different wording could help avoid. Footnotes added in 1993
help clarify these points.
For up-to-date information about available GNU software, please see our
web site, http://www.gnu.org. For software tasks and other ways to
contribute, see http://www.gnu.org/help.

What’s GNU? Gnu’s Not Unix!
GNU, which stands for Gnu’s Not Unix, is the name for the complete Unixcompatible software system which I am writing so that I can give it away free to
everyone who can use it.1 Several other volunteers are helping me. Contributions
of time, money, programs and equipment are greatly needed.
So far we have an Emacs text editor with Lisp for writing editor commands,
a source level debugger, a yacc-compatible parser generator, a linker, and around
35 utilities. A shell (command interpreter) is nearly completed. A new portable
optimizing C compiler has compiled itself and may be released this year. An initial
kernel exists but many more features are needed to emulate Unix. When the kernel
and compiler are finished, it will be possible to distribute a GNU system suitable for
program development. We will use TEX as our text formatter, but an nroff is being
worked on. We will use the free, portable X window system as well. After this we
will add a portable Common Lisp, an Empire game, a spreadsheet, and hundreds of
other things, plus on-line documentation. We hope to supply, eventually, everything
useful that normally comes with a Unix system, and more.
GNU will be able to run Unix programs, but will not be identical to Unix. We
will make all improvements that are convenient, based on our experience with other
operating systems. In particular, we plan to have longer file names, file version numbers, a crashproof file system, file name completion perhaps, terminal-independent
1

The wording here was careless. The intention was that nobody would have to pay for
permission to use the GNU system. But the words don’t make this clear, and people
often interpret them as saying that copies of GNU should always be distributed at
little or no charge. That was never the intent; later on, the manifesto mentions the
possibility of companies providing the service of distribution for a profit. Subsequently
I have learned to distinguish carefully between “free” in the sense of freedom and “free”
in the sense of price. Free software is software that users have the freedom to distribute
and change. Some users may obtain copies at no charge, while others pay to obtain
copies—and if the funds help support improving the software, so much the better. The
important thing is that everyone who has a copy has the freedom to cooperate with
others in using it.

The GNU Manifesto

547

display support, and perhaps eventually a Lisp-based window system through which
several Lisp programs and ordinary Unix programs can share a screen. Both C and
Lisp will be available as system programming languages. We will try to support
UUCP, MIT Chaosnet, and Internet protocols for communication.
GNU is aimed initially at machines in the 68000/16000 class with virtual memory, because they are the easiest machines to make it run on. The extra effort to
make it run on smaller machines will be left to someone who wants to use it on
them.
To avoid horrible confusion, please pronounce the ‘G’ in the word ‘GNU’ when
it is the name of this project.

Why I Must Write GNU
I consider that the golden rule requires that if I like a program I must share it
with other people who like it. Software sellers want to divide the users and conquer
them, making each user agree not to share with others. I refuse to break solidarity
with other users in this way. I cannot in good conscience sign a nondisclosure
agreement or a software license agreement. For years I worked within the Artificial
Intelligence Lab to resist such tendencies and other inhospitalities, but eventually
they had gone too far: I could not remain in an institution where such things are
done for me against my will.
So that I can continue to use computers without dishonor, I have decided to put
together a sufficient body of free software so that I will be able to get along without
any software that is not free. I have resigned from the AI lab to deny MIT any legal
excuse to prevent me from giving GNU away.

Why GNU Will Be Compatible with Unix
Unix is not my ideal system, but it is not too bad. The essential features of Unix
seem to be good ones, and I think I can fill in what Unix lacks without spoiling
them. And a system compatible with Unix would be convenient for many other
people to adopt.

How GNU Will Be Available
GNU is not in the public domain. Everyone will be permitted to modify and redistribute GNU, but no distributor will be allowed to restrict its further redistribution.
That is to say, proprietary modifications will not be allowed. I want to make sure
that all versions of GNU remain free.

Why Many Other Programmers Want to Help
I have found many other programmers who are excited about GNU and want to
help.
Many programmers are unhappy about the commercialization of system software. It may enable them to make more money, but it requires them to feel in

The GNU Manifesto

548

conflict with other programmers in general rather than feel as comrades. The fundamental act of friendship among programmers is the sharing of programs; marketing arrangements now typically used essentially forbid programmers to treat others
as friends. The purchaser of software must choose between friendship and obeying
the law. Naturally, many decide that friendship is more important. But those who
believe in law often do not feel at ease with either choice. They become cynical and
think that programming is just a way of making money.
By working on and using GNU rather than proprietary programs, we can be
hospitable to everyone and obey the law. In addition, GNU serves as an example
to inspire and a banner to rally others to join us in sharing. This can give us a
feeling of harmony which is impossible if we use software that is not free. For about
half the programmers I talk to, this is an important happiness that money cannot
replace.

How You Can Contribute
I am asking computer manufacturers for donations of machines and money. I’m
asking individuals for donations of programs and work.
One consequence you can expect if you donate machines is that GNU will run
on them at an early date. The machines should be complete, ready to use systems,
approved for use in a residential area, and not in need of sophisticated cooling or
power.
I have found very many programmers eager to contribute part-time work for
GNU. For most projects, such part-time distributed work would be very hard to
coordinate; the independently-written parts would not work together. But for the
particular task of replacing Unix, this problem is absent. A complete Unix system
contains hundreds of utility programs, each of which is documented separately.
Most interface specifications are fixed by Unix compatibility. If each contributor
can write a compatible replacement for a single Unix utility, and make it work
properly in place of the original on a Unix system, then these utilities will work
right when put together. Even allowing for Murphy to create a few unexpected
problems, assembling these components will be a feasible task. (The kernel will
require closer communication and will be worked on by a small, tight group.)
If I get donations of money, I may be able to hire a few people full or part time.
The salary won’t be high by programmers’ standards, but I’m looking for people
for whom building community spirit is as important as making money. I view this
as a way of enabling dedicated people to devote their full energies to working on
GNU by sparing them the need to make a living in another way.

Why All Computer Users Will Benefit
Once GNU is written, everyone will be able to obtain good system software free,
just like air.2
2

This is another place I failed to distinguish carefully between the two different meanings
of “free.” The statement as it stands is not false—you can get copies of GNU software
at no charge, from your friends or over the net. But it does suggest the wrong idea.

The GNU Manifesto

549

This means much more than just saving everyone the price of a Unix license. It
means that much wasteful duplication of system programming effort will be avoided.
This effort can go instead into advancing the state of the art.
Complete system sources will be available to everyone. As a result, a user who
needs changes in the system will always be free to make them himself, or hire any
available programmer or company to make them for him. Users will no longer be
at the mercy of one programmer or company which owns the sources and is in sole
position to make changes.
Schools will be able to provide a much more educational environment by encouraging all students to study and improve the system code. Harvard’s computer
lab used to have the policy that no program could be installed on the system if
its sources were not on public display, and upheld it by actually refusing to install
certain programs. I was very much inspired by this.
Finally, the overhead of considering who owns the system software and what one
is or is not entitled to do with it will be lifted.
Arrangements to make people pay for using a program, including licensing of
copies, always incur a tremendous cost to society through the cumbersome mechanisms necessary to figure out how much (that is, which programs) a person must
pay for. And only a police state can force everyone to obey them. Consider a space
station where air must be manufactured at great cost: charging each breather per
liter of air may be fair, but wearing the metered gas mask all day and all night is
intolerable even if everyone can afford to pay the air bill. And the TV cameras everywhere to see if you ever take the mask off are outrageous. It’s better to support
the air plant with a head tax and chuck the masks.
Copying all or parts of a program is as natural to a programmer as breathing,
and as productive. It ought to be as free.

Some Easily Rebutted Objections to GNU’s Goals
“Nobody will use it if it is free, because that means they can’t rely on
any support.”
“You have to charge for the program to pay for providing the support.”
If people would rather pay for GNU plus service than get GNU free without
service, a company to provide just service to people who have obtained GNU free
ought to be profitable.3
We must distinguish between support in the form of real programming work
and mere handholding. The former is something one cannot rely on from a software
vendor. If your problem is not shared by enough people, the vendor will tell you to
get lost.
If your business needs to be able to rely on support, the only way is to have
all the necessary sources and tools. Then you can hire any available person to fix
your problem; you are not at the mercy of any individual. With Unix, the price
of sources puts this out of consideration for most businesses. With GNU this will
3

Several such companies now exist.

The GNU Manifesto

550

be easy. It is still possible for there to be no available competent person, but this
problem cannot be blamed on distribution arrangements. GNU does not eliminate
all the world’s problems, only some of them.
Meanwhile, the users who know nothing about computers need handholding:
doing things for them which they could easily do themselves but don’t know how.
Such services could be provided by companies that sell just hand-holding and
repair service. If it is true that users would rather spend money and get a product
with service, they will also be willing to buy the service having got the product free.
The service companies will compete in quality and price; users will not be tied to
any particular one. Meanwhile, those of us who don’t need the service should be
able to use the program without paying for the service.
“You cannot reach many people without advertising, and you must charge
for the program to support that.”
“It’s no use advertising a program people can get free.”
There are various forms of free or very cheap publicity that can be used to
inform numbers of computer users about something like GNU. But it may be true
that one can reach more microcomputer users with advertising. If this is really so,
a business which advertises the service of copying and mailing GNU for a fee ought
to be successful enough to pay for its advertising and more. This way, only the
users who benefit from the advertising pay for it.
On the other hand, if many people get GNU from their friends, and such companies don’t succeed, this will show that advertising was not really necessary to spread
GNU. Why is it that free market advocates don’t want to let the free market decide
this?4
“My company needs a proprietary operating system to get a competitive
edge.”
GNU will remove operating system software from the realm of competition. You
will not be able to get an edge in this area, but neither will your competitors be able
to get an edge over you. You and they will compete in other areas, while benefiting
mutually in this one. If your business is selling an operating system, you will not
like GNU, but that’s tough on you. If your business is something else, GNU can
save you from being pushed into the expensive business of selling operating systems.
I would like to see GNU development supported by gifts from many manufacturers and users, reducing the cost to each.5
“Don’t programmers deserve a reward for their creativity?”
If anything deserves a reward, it is social contribution. Creativity can be a social
contribution, but only in so far as society is free to use the results. If programmers
4

5

The Free Software Foundation raises most of its funds from a distribution service,
although it is a charity rather than a company. If no one chooses to obtain copies by
ordering from the FSF, it will be unable to do its work. But this does not mean that
proprietary restrictions are justified to force every user to pay. If a small fraction of
all the users order copies from the FSF, that is sufficient to keep the FSF afloat. So
we ask users to choose to support us in this way. Have you done your part?
A group of computer companies recently pooled funds to support maintenance of the
GNU C Compiler.

The GNU Manifesto

551

deserve to be rewarded for creating innovative programs, by the same token they
deserve to be punished if they restrict the use of these programs.
“Shouldn’t a programmer be able to ask for a reward for his creativity?”
There is nothing wrong with wanting pay for work, or seeking to maximize one’s
income, as long as one does not use means that are destructive. But the means
customary in the field of software today are based on destruction.
Extracting money from users of a program by restricting their use of it is destructive because the restrictions reduce the amount and the ways that the program
can be used. This reduces the amount of wealth that humanity derives from the
program. When there is a deliberate choice to restrict, the harmful consequences
are deliberate destruction.
The reason a good citizen does not use such destructive means to become wealthier is that, if everyone did so, we would all become poorer from the mutual destructiveness. This is Kantian ethics; or, the Golden Rule. Since I do not like the
consequences that result if everyone hoards information, I am required to consider
it wrong for one to do so. Specifically, the desire to be rewarded for one’s creativity
does not justify depriving the world in general of all or part of that creativity.
“Won’t programmers starve?”
I could answer that nobody is forced to be a programmer. Most of us cannot
manage to get any money for standing on the street and making faces. But we are
not, as a result, condemned to spend our lives standing on the street making faces,
and starving. We do something else.
But that is the wrong answer because it accepts the questioner’s implicit assumption: that without ownership of software, programmers cannot possibly be
paid a cent. Supposedly it is all or nothing.
The real reason programmers will not starve is that it will still be possible for
them to get paid for programming; just not paid as much as now.
Restricting copying is not the only basis for business in software. It is the most
common basis because it brings in the most money. If it were prohibited, or rejected
by the customer, software business would move to other bases of organization which
are now used less often. There are always numerous ways to organize any kind of
business.
Probably programming will not be as lucrative on the new basis as it is now.
But that is not an argument against the change. It is not considered an injustice
that sales clerks make the salaries that they now do. If programmers made the
same, that would not be an injustice either. (In practice they would still make
considerably more than that.)
“Don’t people have a right to control how their creativity is used?”
“Control over the use of one’s ideas” really constitutes control over other people’s
lives; and it is usually used to make their lives more difficult.

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People who have studied the issue of intellectual property rights6 carefully (such
as lawyers) say that there is no intrinsic right to intellectual property. The kinds of
supposed intellectual property rights that the government recognizes were created
by specific acts of legislation for specific purposes.
For example, the patent system was established to encourage inventors to disclose the details of their inventions. Its purpose was to help society rather than to
help inventors. At the time, the life span of 17 years for a patent was short compared with the rate of advance of the state of the art. Since patents are an issue
only among manufacturers, for whom the cost and effort of a license agreement are
small compared with setting up production, the patents often do not do much harm.
They do not obstruct most individuals who use patented products.
The idea of copyright did not exist in ancient times, when authors frequently
copied other authors at length in works of non-fiction. This practice was useful,
and is the only way many authors’ works have survived even in part. The copyright
system was created expressly for the purpose of encouraging authorship. In the
domain for which it was invented—books, which could be copied economically only
on a printing press—it did little harm, and did not obstruct most of the individuals
who read the books.
All intellectual property rights are just licenses granted by society because it was
thought, rightly or wrongly, that society as a whole would benefit by granting them.
But in any particular situation, we have to ask: are we really better off granting
such license? What kind of act are we licensing a person to do?
The case of programs today is very different from that of books a hundred years
ago. The fact that the easiest way to copy a program is from one neighbor to
another, the fact that a program has both source code and object code which are
distinct, and the fact that a program is used rather than read and enjoyed, combine
to create a situation in which a person who enforces a copyright is harming society
as a whole both materially and spiritually; in which a person should not do so
regardless of whether the law enables him to.
“Competition makes things get done better.”
The paradigm of competition is a race: by rewarding the winner, we encourage
everyone to run faster. When capitalism really works this way, it does a good job;
but its defenders are wrong in assuming it always works this way. If the runners
forget why the reward is offered and become intent on winning, no matter how,
they may find other strategies—such as, attacking other runners. If the runners get
into a fist fight, they will all finish late.
6

In the 80s I had not yet realized how confusing it was to speak of “the issue”
of “intellectual property.” That term is obviously biased; more subtle is the
fact that it lumps together various disparate laws which raise very different issues. Nowadays I urge people to reject the term “intellectual property” entirely,
lest it lead others to suppose that those laws form one coherent issue. The way
to be clear is to discuss patents, copyrights, and trademarks separately. See
http://www.gnu.org/philosophy/not-ipr.xhtml for more explanation of how this
term spreads confusion and bias.

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Proprietary and secret software is the moral equivalent of runners in a fist fight.
Sad to say, the only referee we’ve got does not seem to object to fights; he just
regulates them (“For every ten yards you run, you can fire one shot”). He really
ought to break them up, and penalize runners for even trying to fight.
“Won’t everyone stop programming without a monetary incentive?”
Actually, many people will program with absolutely no monetary incentive. Programming has an irresistible fascination for some people, usually the people who
are best at it. There is no shortage of professional musicians who keep at it even
though they have no hope of making a living that way.
But really this question, though commonly asked, is not appropriate to the
situation. Pay for programmers will not disappear, only become less. So the right
question is, will anyone program with a reduced monetary incentive? My experience
shows that they will.
For more than ten years, many of the world’s best programmers worked at the
Artificial Intelligence Lab for far less money than they could have had anywhere
else. They got many kinds of non-monetary rewards: fame and appreciation, for
example. And creativity is also fun, a reward in itself.
Then most of them left when offered a chance to do the same interesting work
for a lot of money.
What the facts show is that people will program for reasons other than riches;
but if given a chance to make a lot of money as well, they will come to expect and
demand it. Low-paying organizations do poorly in competition with high-paying
ones, but they do not have to do badly if the high-paying ones are banned.
“We need the programmers desperately. If they demand that we stop
helping our neighbors, we have to obey.”
You’re never so desperate that you have to obey this sort of demand. Remember:
millions for defense, but not a cent for tribute!
“Programmers need to make a living somehow.”
In the short run, this is true. However, there are plenty of ways that programmers could make a living without selling the right to use a program. This way is
customary now because it brings programmers and businessmen the most money,
not because it is the only way to make a living. It is easy to find other ways if you
want to find them. Here are a number of examples.
A manufacturer introducing a new computer will pay for the porting of operating
systems onto the new hardware.
The sale of teaching, hand-holding and maintenance services could also employ
programmers.

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People with new ideas could distribute programs as freeware7 , asking for donations from satisfied users, or selling hand-holding services. I have met people who
are already working this way successfully.
Users with related needs can form users’ groups, and pay dues. A group would
contract with programming companies to write programs that the group’s members
would like to use.
All sorts of development can be funded with a Software Tax:
Suppose everyone who buys a computer has to pay x percent of the price
as a software tax. The government gives this to an agency like the NSF
to spend on software development.
But if the computer buyer makes a donation to software development
himself, he can take a credit against the tax. He can donate to the project
of his own choosing—often, chosen because he hopes to use the results
when it is done. He can take a credit for any amount of donation up to
the total tax he had to pay.
The total tax rate could be decided by a vote of the payers of the tax,
weighted according to the amount they will be taxed on.
The consequences:
• The computer-using community supports software development.
• This community decides what level of support is needed.
• Users who care which projects their share is spent on can choose this
for themselves.
In the long run, making programs free is a step toward the post-scarcity world,
where nobody will have to work very hard just to make a living. People will be
free to devote themselves to activities that are fun, such as programming, after
spending the necessary ten hours a week on required tasks such as legislation, family
counseling, robot repair and asteroid prospecting. There will be no need to be able
to make a living from programming.
We have already greatly reduced the amount of work that the whole society
must do for its actual productivity, but only a little of this has translated itself into
leisure for workers because much nonproductive activity is required to accompany
productive activity. The main causes of this are bureaucracy and isometric struggles
against competition. Free software will greatly reduce these drains in the area of
software production. We must do this, in order for technical gains in productivity
to translate into less work for us.

7

Subsequently we have discovered the need to distinguish between “free software” and
“freeware”. The term “freeware” means software you are free to redistribute, but
usually you are not free to study and change the source code, so most of it is not
free software. See http://www.gnu.org/philosophy/words-to-avoid.html for more
explanation.

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Glossary
Abbrev

An abbrev is a text string that expands into a different text string when
present in the buffer. For example, you might define a few letters as
an abbrev for a long phrase that you want to insert frequently. See
Chapter 26 [Abbrevs], page 322.

Aborting

Aborting means getting out of a recursive edit (q.v.). The commands
C-] and M-x top-level are used for this. See Section 34.1 [Quitting],
page 468.

Alt

Alt is the name of a modifier bit that a keyboard input character may
have. To make a character Alt, type it while holding down the ALT
key. Such characters are given names that start with Alt- (usually
written A- for short). (Note that many terminals have a key labeled
ALT that is really a META key.) See Section 2.1 [User Input], page 11.

Argument

See [Glossary - Numeric Argument], page 571.

ASCII character

An ASCII character is either an ASCII control character or an ASCII
printing character. See Section 2.1 [User Input], page 11.
ASCII control character
An ASCII control character is the Control version of an upper-case

letter, or the Control version of one of the characters ‘@[\]^_?’.
ASCII printing character
ASCII letters, digits, space, and the following punctuation characters:

‘!@#$%^&*()_-+=|\~‘{}[]:;"’<>,.?/’.
Auto Fill Mode
Auto Fill mode is a minor mode (q.v.) in which text that you insert
is automatically broken into lines of a given maximum width. See
Section 22.5 [Filling], page 218.
Auto Saving
Auto saving is the practice of periodically saving the contents of an
Emacs buffer in a specially-named file, so that the information will be
preserved if the buffer is lost due to a system error or user error. See
Section 15.5 [Auto Save], page 136.
Autoloading
Emacs can automatically load Lisp libraries when a Lisp program requests a function from those libraries. This is called ‘autoloading’. See
Section 24.8 [Lisp Libraries], page 287.
Backtrace

A backtrace is a trace of a series of function calls showing how a
program arrived at a certain point. It is used mainly for finding and
correcting bugs (q.v.). Emacs can display a backtrace when it signals
an error or when you type C-g (see [Glossary - Quitting], page 573).
See Section 34.3.4 [Checklist], page 475.

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Backup File
A backup file records the contents that a file had before the current editing session. Emacs makes backup files automatically to
help you track down or cancel changes you later regret making. See
Section 15.3.2 [Backup], page 130.
Balancing Parentheses
Emacs can balance parentheses (or other matching delimiters) either
manually or automatically. You do manual balancing with the commands to move over parenthetical groupings (see Section 23.4.2 [Moving by Parens], page 257). Automatic balancing works by blinking or
highlighting the delimiter that matches the one you just inserted, or
inserting the matching delimiter for you (see Section 23.4.3 [Matching
Parens], page 258).
Balanced Expressions
A balanced expression is a syntactically recognizable expression, such
as a symbol, number, string constant, block, or parenthesized expression in C. See Section 23.4.1 [Expressions], page 256.
Balloon Help
See [Glossary - Tooltips], page 577.
Base Buffer
A base buffer is a buffer whose text is shared by an indirect buffer
(q.v.).
Bidirectional Text
Some human languages, such as English, are written from left to right.
Others, such as Arabic, are written from right to left. Emacs supports
both of these forms, as well as any mixture of them—this is ‘bidirectional text’. See Section 19.20 [Bidirectional Editing], page 202.
Bind

To bind a key sequence means to give it a binding (q.v.).
Section 33.3.5 [Rebinding], page 454.

See

Binding

A key sequence gets its meaning in Emacs by having a binding, which
is a command (q.v.), a Lisp function that is run when you type that
sequence. See Section 2.3 [Commands], page 12. Customization often
involves rebinding a character to a different command function. The
bindings of all key sequences are recorded in the keymaps (q.v.). See
Section 33.3.1 [Keymaps], page 452.

Blank Lines
Blank lines are lines that contain only whitespace. Emacs has several commands for operating on the blank lines in the buffer. See
Section 4.7 [Blank Lines], page 22.
Bookmark

Bookmarks are akin to registers (q.v.) in that they record positions in
buffers to which you can return later. Unlike registers, bookmarks persist between Emacs sessions. See Section 10.7 [Bookmarks], page 68.

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Border

A border is a thin space along the edge of the frame, used just for
spacing, not for displaying anything. An Emacs frame has an ordinary
external border, outside of everything including the menu bar, plus an
internal border that surrounds the text windows, their scroll bars and
fringes, and separates them from the menu bar and tool bar. You can
customize both borders with options and resources (see Section C.9
[Borders X], page 518). Borders are not the same as fringes (q.v.).

Buffer

The buffer is the basic editing unit; one buffer corresponds to one text
being edited. You normally have several buffers, but at any time you
are editing only one, the ‘current buffer’, though several can be visible
when you are using multiple windows or frames (q.v.). Most buffers
are visiting (q.v.) some file. See Chapter 16 [Buffers], page 150.

Buffer Selection History
Emacs keeps a buffer selection history that records how recently each
Emacs buffer has been selected. This is used for choosing a buffer to
select. See Chapter 16 [Buffers], page 150.
Bug

A bug is an incorrect or unreasonable behavior of a program, or inaccurate or confusing documentation. Emacs developers treat bug reports,
both in Emacs code and its documentation, very seriously and ask you
to report any bugs you find. See Section 34.3 [Bugs], page 473.

Button Down Event
A button down event is the kind of input event (q.v.) generated right
away when you press down on a mouse button. See Section 33.3.10
[Mouse Buttons], page 459.
By Default See [Glossary - Default], page 560.
Byte Compilation
See [Glossary - Compilation], page 558.
C-

C- in the name of a character is an abbreviation for Control. See
Section 2.1 [User Input], page 11.

C-M-

C-M- in the name of a character is an abbreviation for Control-Meta.
If your terminal lacks a real META key, you type a Control-Meta
character by typing ESC and then typing the corresponding Control
character. See Section 2.1 [User Input], page 11.

Case Conversion
Case conversion means changing text from upper case to lower case or
vice versa. See Section 22.6 [Case], page 223.
Character

Characters form the contents of an Emacs buffer. Also, key sequences
(q.v.) are usually made up of characters (though they may include
other input events as well). See Section 2.1 [User Input], page 11.

Character Set
Emacs supports a number of character sets, each of which represents a
particular alphabet or script. See Chapter 19 [International], page 180.

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558

Character Terminal
See [Glossary - Text Terminal], page 577.
Click Event
A click event is the kind of input event (q.v.) generated when you
press a mouse button and release it without moving the mouse. See
Section 33.3.10 [Mouse Buttons], page 459.
Client

See [Glossary - Server], page 575.

Clipboard

A clipboard is a buffer provided by the window system for transferring
text between applications. On the X Window System, the clipboard is
provided in addition to the primary selection (q.v.); on MS-Windows
and Mac, the clipboard is used instead of the primary selection. See
Section 9.3.1 [Clipboard], page 59.

Coding System
A coding system is an encoding for representing text characters in a
file or in a stream of information. Emacs has the ability to convert
text to or from a variety of coding systems when reading or writing it.
See Section 19.6 [Coding Systems], page 188.
Command

A command is a Lisp function specially defined to be able to serve
as a key binding in Emacs. When you type a key sequence (q.v.), its
binding (q.v.) is looked up in the relevant keymaps (q.v.) to find the
command to run. See Section 2.3 [Commands], page 12.

Command History
See [Glossary - Minibuffer History], page 570.
Command Name
A command name is the name of a Lisp symbol that is a command
(see Section 2.3 [Commands], page 12). You can invoke any command
by its name using M-x (see Chapter 6 [Running Commands by Name],
page 37).
Comment

A comment is text in a program which is intended only for humans
reading the program, and which is specially marked so that it will
be ignored when the program is loaded or compiled. Emacs offers
special commands for creating, aligning and killing comments. See
Section 23.5 [Comments], page 258.

Common Lisp
Common Lisp is a dialect of Lisp (q.v.) much larger and more powerful
than Emacs Lisp. Emacs provides a subset of Common Lisp in the CL
package. See Section “Overview” in Common Lisp Extensions.
Compilation
Compilation is the process of creating an executable program from
source code. Emacs has commands for compiling files of Emacs Lisp
code (see Section “Byte Compilation” in the Emacs Lisp Reference

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559
Manual) and programs in C and other languages (see Section 24.1
[Compilation], page 271).

Complete Key
A complete key is a key sequence that fully specifies one action to be
performed by Emacs. For example, X and C-f and C-x m are complete
keys. Complete keys derive their meanings from being bound (q.v.) to
commands (q.v.). Thus, X is conventionally bound to a command to
insert ‘X’ in the buffer; C-x m is conventionally bound to a command
to begin composing a mail message. See Section 2.2 [Keys], page 11.
Completion Completion is what Emacs does when it automatically expands an
abbreviation for a name into the entire name. Completion is done
for minibuffer (q.v.) arguments when the set of possible valid inputs
is known; for example, on command names, buffer names, and file
names. Completion usually occurs when TAB, SPC or RET is typed.
See Section 5.3 [Completion], page 29.
Continuation Line
When a line of text is longer than the width of the window, it normally
(but see [Glossary - Truncation], page 578) takes up more than one
screen line when displayed. We say that the text line is continued,
and all screen lines used for it after the first are called continuation
lines. See Section 4.8 [Continuation Lines], page 23. A related Emacs
feature is ‘filling’ (q.v.).
Control Character
A control character is a character that you type by holding down the
CTRL key. Some control characters also have their own keys, so that
you can type them without using CTRL. For example, RET, TAB,
ESC and DEL are all control characters. See Section 2.1 [User Input],
page 11.
Copyleft

A copyleft is a notice giving the public legal permission to redistribute
and modify a program or other work of art, but requiring modified
versions to carry similar permission. Copyright is normally used to
keep users divided and helpless; with copyleft we turn that around to
empower users and encourage them to cooperate.
The particular form of copyleft used by the GNU project is called the
GNU General Public License. See Appendix A [Copying], page 484.

CTRL

The CTRL or “control” key is what you hold down in order to enter
a control character (q.v.). See [Glossary - C-], page 557.

Current Buffer
The current buffer in Emacs is the Emacs buffer on which most editing
commands operate. You can select any Emacs buffer as the current
one. See Chapter 16 [Buffers], page 150.

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560

Current Line
The current line is the line that point is on (see Section 1.1 [Point],
page 6).
Current Paragraph
The current paragraph is the paragraph that point is in. If point is
between two paragraphs, the current paragraph is the one that follows
point. See Section 22.3 [Paragraphs], page 216.
Current Defun
The current defun is the defun (q.v.) that point is in. If point is
between defuns, the current defun is the one that follows point. See
Section 23.2 [Defuns], page 250.
Cursor

The cursor is the rectangle on the screen which indicates the position
(called point; q.v.) at which insertion and deletion takes place. The
cursor is on or under the character that follows point. Often people
speak of ‘the cursor’ when, strictly speaking, they mean ‘point’. See
Section 1.1 [Point], page 6.

Customization
Customization is making minor changes in the way Emacs works, to
reflect your preferences or needs. It is often done by setting variables
(see Section 33.2 [Variables], page 443) or faces (see Section 33.1.5
[Face Customization], page 439), or by rebinding key sequences (see
Section 33.3.1 [Keymaps], page 452).
Cut and Paste
See [Glossary - Killing], page 568, and [Glossary - Yanking], page 579.
Daemon

A daemon is a standard term for a system-level process that runs in the
background. Daemons are often started when the system first starts
up. When Emacs runs in daemon-mode, it runs in the background
and does not open a display. You can then connect to it with the
emacsclient program. See Section 31.4 [Emacs Server], page 412.

Default Argument
The default for an argument is the value that will be assumed if you
do not specify one. When the minibuffer is used to read an argument,
the default argument is used if you just type RET. See Chapter 5
[Minibuffer], page 27.
Default

A default is the value that is used for a certain purpose when you do
not explicitly specify a value to use.

Default Directory
When you specify a file name that does not start with ‘/’ or ‘~’, it is
interpreted relative to the current buffer’s default directory. (On MS
systems, file names that start with a drive letter ‘x :’ are treated as
absolute, not relative.) See Section 5.1 [Minibuffer File], page 27.

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Defun

A defun is a major definition at the top level in a program. The name
‘defun’ comes from Lisp, where most such definitions use the construct
defun. See Section 23.2 [Defuns], page 250.

DEL

DEL is a character that runs the command to delete one character
of text before the cursor. It is typically either the DELETE key or
the BACKSPACE key, whichever one is easy to type. See Section 4.3
[Erasing], page 20.

Deletion

Deletion means erasing text without copying it into the kill ring (q.v.).
The alternative is killing (q.v.). See Chapter 9 [Killing], page 54.

Deletion of Files
Deleting a file means erasing it from the file system. (Note that some
systems use the concept of a “trash can”, or “recycle bin”, to allow you
to “undelete” files.) See Section 15.10 [Miscellaneous File Operations],
page 143.
Deletion of Messages
Deleting a message (in Rmail, and other mail clients) means flagging
it to be eliminated from your mail file. Until you expunge (q.v.) the
Rmail file, you can still undelete the messages you have deleted. See
Section 30.4 [Rmail Deletion], page 378.
Deletion of Windows
Deleting a window means eliminating it from the screen. Other windows expand to use up the space. The text that was in the window is
not lost, and you can create a new window with the same dimensions
as the old if you wish. See Chapter 17 [Windows], page 159.
Directory

File directories are named collections in the file system, within which
you can place individual files or subdirectories. They are sometimes
referred to as “folders”. See Section 15.7 [Directories], page 139.

Directory Local Variable
A directory local variable is a local variable (q.v.) that applies to
all the files within a certain directory. See Section 33.2.5 [Directory
Variables], page 450.
Dired

Dired is the Emacs facility that displays the contents of a file directory
and allows you to “edit the directory”, performing operations on the
files in the directory. See Chapter 27 [Dired], page 329.

Disabled Command
A disabled command is one that you may not run without special confirmation. The usual reason for disabling a command is that it is confusing for beginning users. See Section 33.3.11 [Disabling], page 460.
Down Event
Short for ‘button down event’ (q.v.).

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Drag Event A drag event is the kind of input event (q.v.) generated when you press
a mouse button, move the mouse, and then release the button. See
Section 33.3.10 [Mouse Buttons], page 459.
Dribble File
A dribble file is a file into which Emacs writes all the characters that
you type on the keyboard. Dribble files can be used to make a record
for debugging Emacs bugs. Emacs does not make a dribble file unless
you tell it to. See Section 34.3 [Bugs], page 473.
Echo Area

The echo area is the bottom line of the screen, used for echoing the
arguments to commands, for asking questions, and showing brief messages (including error messages). The messages are stored in the buffer
‘*Messages*’ so you can review them later. See Section 1.2 [Echo
Area], page 7.

Echoing

Echoing is acknowledging the receipt of input events by displaying
them (in the echo area). Emacs never echoes single-character key
sequences; longer key sequences echo only if you pause while typing
them.

Electric

We say that a character is electric if it is normally self-inserting (q.v.),
but the current major mode (q.v.) redefines it to do something else as
well. For example, some programming language major modes define
particular delimiter characters to reindent the line, or insert one or
more newlines in addition to self-insertion.

End Of Line
End of line is a character or a sequence of characters that indicate
the end of a text line. On GNU and Unix systems, this is a newline
(q.v.), but other systems have other conventions. See Section 19.6
[Coding Systems], page 188. Emacs can recognize several end-of-line
conventions in files and convert between them.
Environment Variable
An environment variable is one of a collection of variables stored by
the operating system, each one having a name and a value. Emacs
can access environment variables set by its parent shell, and it can
set variables in the environment it passes to programs it invokes. See
Section C.4 [Environment], page 509.
EOL

See [Glossary - End Of Line], page 562.

Error

An error occurs when an Emacs command cannot execute in the current circumstances. When an error occurs, execution of the command
stops (unless the command has been programmed to do otherwise)
and Emacs reports the error by displaying an error message (q.v.).

Error Message
An error message is output displayed by Emacs when you ask it to do
something impossible (such as, killing text forward when point is at

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563
the end of the buffer), or when a command malfunctions in some way.
Such messages appear in the echo area, accompanied by a beep.

ESC

ESC is a character used as a prefix for typing Meta characters on
keyboards lacking a META key. Unlike the META key (which, like
the SHIFT key, is held down while another character is typed), you
press the ESC key as you would press a letter key, and it applies to
the next character you type.

Expression

See [Glossary - Balanced Expression], page 556.

Expunging

Expunging an Rmail, Gnus newsgroup, or Dired buffer is an operation
that truly discards the messages or files you have previously flagged
for deletion.

Face

A face is a style of displaying characters. It specifies attributes such as
font family and size, foreground and background colors, underline and
strike-through, background stipple, etc. Emacs provides features to
associate specific faces with portions of buffer text, in order to display
that text as specified by the face attributes. See Section 11.8 [Faces],
page 75.

File Local Variable
A file local variable is a local variable (q.v.) specified in a given file.
See Section 33.2.4 [File Variables], page 447, and [Glossary - Directory
Local Variable], page 561.
File Locking
Emacs uses file locking to notice when two different users start to edit
one file at the same time. See Section 15.3.4 [Interlocking], page 133.
File Name

A file name is a name that refers to a file. File names may be relative
or absolute; the meaning of a relative file name depends on the current
directory, but an absolute file name refers to the same file regardless of
which directory is current. On GNU and Unix systems, an absolute file
name starts with a slash (the root directory) or with ‘~/’ or ‘~user /’
(a home directory). On MS-Windows/MS-DOS, an absolute file name
can also start with a drive letter and a colon, e.g. ‘d :’.
Some people use the term “pathname” for file names, but we do not;
we use the word “path” only in the term “search path” (q.v.).

File-Name Component
A file-name component names a file directly within a particular directory. On GNU and Unix systems, a file name is a sequence of
file-name components, separated by slashes. For example, ‘foo/bar’
is a file name containing two components, ‘foo’ and ‘bar’; it refers
to the file named ‘bar’ in the directory named ‘foo’ in the current
directory. MS-DOS/MS-Windows file names can also use backslashes
to separate components, as in ‘foo\bar’.

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Fill Prefix

The fill prefix is a string that should be expected at the beginning of
each line when filling is done. It is not regarded as part of the text to
be filled. See Section 22.5 [Filling], page 218.

Filling

Filling text means adjusting the position of line-breaks to shift text
between consecutive lines, so that all the lines are approximately the
same length. See Section 22.5 [Filling], page 218. Some other editors
call this feature “line wrapping”.

Font Lock

Font Lock is a mode that highlights parts of buffer text in different
faces, according to the syntax. Some other editors refer to this as
“syntax highlighting”. For example, all comments (q.v.) might be
colored red. See Section 11.12 [Font Lock], page 80.

Fontset

A fontset is a named collection of fonts. A fontset specification lists
character sets and which font to use to display each of them. Fontsets
make it easy to change several fonts at once by specifying the name of
a fontset, rather than changing each font separately. See Section 19.14
[Fontsets], page 197.

Formfeed Character
See [Glossary - Page], page 572.
Frame

A frame is a rectangular cluster of Emacs windows. Emacs starts
out with one frame, but you can create more. You can subdivide
each frame into Emacs windows (q.v.). When you are using a window
system (q.v.), more than one frame can be visible at the same time.
See Chapter 18 [Frames], page 165. Some other editors use the term
“window” for this, but in Emacs a window means something else.

Free Software
Free software is software that gives you the freedom to share, study
and modify it. Emacs is free software, part of the GNU project (q.v.),
and distributed under a copyleft (q.v.) license called the GNU General
Public License. See Appendix A [Copying], page 484.
Free Software Foundation
The Free Software Foundation (FSF) is a charitable foundation dedicated to promoting the development of free software (q.v.). For more
information, see the FSF website.
Fringe

On a graphical display (q.v.), there’s a narrow portion of the frame
(q.v.) between the text area and the window’s border. These “fringes”
are used to display symbols that provide information about the buffer
text (see Section 11.14 [Fringes], page 83). Emacs displays the fringe
using a special face (q.v.) called fringe. See Section 11.8 [Faces],
page 75.

FSF

See [Glossary - Free Software Foundation], page 564.

FTP

FTP is an acronym for File Transfer Protocol. This is one standard
method for retrieving remote files (q.v.).

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565

Function Key
A function key is a key on the keyboard that sends input but does
not correspond to any character. See Section 33.3.8 [Function Keys],
page 457.
Global

Global means “independent of the current environment; in effect
throughout Emacs”. It is the opposite of local (q.v.). Particular examples of the use of ‘global’ appear below.

Global Abbrev
A global definition of an abbrev (q.v.) is effective in all major modes
that do not have local (q.v.) definitions for the same abbrev. See
Chapter 26 [Abbrevs], page 322.
Global Keymap
The global keymap (q.v.) contains key bindings that are in effect everywhere, except when overridden by local key bindings in a major
mode’s local keymap (q.v.). See Section 33.3.1 [Keymaps], page 452.
Global Mark Ring
The global mark ring records the series of buffers you have recently
set a mark (q.v.) in. In many cases you can use this to backtrack
through buffers you have been editing, or in which you have found
tags (see [Glossary - Tags Table], page 577). See Section 8.5 [Global
Mark Ring], page 51.
Global Substitution
Global substitution means replacing each occurrence of one string by
another string throughout a large amount of text. See Section 12.9
[Replace], page 103.
Global Variable
The global value of a variable (q.v.) takes effect in all buffers that do
not have their own local (q.v.) values for the variable. See Section 33.2
[Variables], page 443.
GNU

GNU is a recursive acronym for GNU’s Not Unix, and it refers to a
Unix-compatible operating system which is free software (q.v.). See
[Manifesto], page 546. GNU is normally used with Linux as the kernel
since Linux works better than the GNU kernel. For more information,
see the GNU website.

Graphic Character
Graphic characters are those assigned pictorial images rather than
just names. All the non-Meta (q.v.) characters except for the Control
(q.v.) characters are graphic characters. These include letters, digits,
punctuation, and spaces; they do not include RET or ESC. In Emacs,
typing a graphic character inserts that character (in ordinary editing
modes). See Section 4.1 [Inserting Text], page 17.

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Graphical Display
A graphical display is one that can display images and multiple fonts.
Usually it also has a window system (q.v.).
Highlighting
Highlighting text means displaying it with a different foreground
and/or background color to make it stand out from the rest of the
text in the buffer.
Emacs uses highlighting in several ways. It highlights the region
whenever it is active (see Chapter 8 [Mark], page 47). Incremental
search also highlights matches (see Section 12.1 [Incremental Search],
page 91). See [Glossary - Font Lock], page 564.
Hardcopy

Hardcopy means printed output. Emacs has various commands for
printing the contents of Emacs buffers. See Section 31.5 [Printing],
page 417.

HELP

HELP is the Emacs name for C-h or F1. You can type HELP at any
time to ask what options you have, or to ask what a command does.
See Chapter 7 [Help], page 38.

Help Echo

Help echo is a short message displayed in the echo area (q.v.) when the
mouse pointer is located on portions of display that require some explanations. Emacs displays help echo for menu items, parts of the mode
line, tool-bar buttons, etc. On graphical displays, the messages can
be displayed as tooltips (q.v.). See Section 18.17 [Tooltips], page 178.

Home Directory
Your home directory contains your personal files. On a multi-user
GNU or Unix system, each user has his or her own home directory.
When you start a new login session, your home directory is the default
directory in which to start. A standard shorthand for your home
directory is ‘~’. Similarly, ‘~user ’ represents the home directory of
some other user.
Hook

A hook is a list of functions to be called on specific occasions, such as
saving a buffer in a file, major mode activation, etc. By customizing
the various hooks, you can modify Emacs’s behavior without changing
any of its code. See Section 33.2.2 [Hooks], page 445.

Hyper

Hyper is the name of a modifier bit that a keyboard input character
may have. To make a character Hyper, type it while holding down the
HYPER key. Such characters are given names that start with Hyper(usually written H- for short). See Section 2.1 [User Input], page 11.

Iff

“Iff” means “if and only if”. This terminology comes from mathematics. Try to avoid using this term in documentation, since many are
unfamiliar with it and mistake it for a typo.

Inbox

An inbox is a file in which mail is delivered by the operating system.
Rmail transfers mail from inboxes to Rmail files in which the mail is

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567
then stored permanently or until explicitly deleted. See Section 30.5
[Rmail Inbox], page 379.

Incremental Search
Emacs provides an incremental search facility, whereby Emacs begins
searching for a string as soon as you type the first character. As you
type more characters, it refines the search. See Section 12.1 [Incremental Search], page 91.
Indentation Indentation means blank space at the beginning of a line. Most programming languages have conventions for using indentation to illuminate the structure of the program, and Emacs has special commands
to adjust indentation. See Chapter 21 [Indentation], page 210.
Indirect Buffer
An indirect buffer is a buffer that shares the text of another buffer,
called its base buffer (q.v.). See Section 16.6 [Indirect Buffers],
page 156.
Info

Info is the hypertext format used by the GNU project for writing
documentation.

Input Event
An input event represents, within Emacs, one action taken by the user
on the terminal. Input events include typing characters, typing function keys, pressing or releasing mouse buttons, and switching between
Emacs frames. See Section 2.1 [User Input], page 11.
Input Method
An input method is a system for entering non-ASCII text characters
by typing sequences of ASCII characters (q.v.). See Section 19.4 [Input
Methods], page 185.
Insertion

Insertion means adding text into the buffer, either from the keyboard
or from some other place in Emacs.

Interlocking
See [Glossary - File Locking], page 563.
Isearch

See [Glossary - Incremental Search], page 567.

Justification
Justification means adding extra spaces within lines of text in order
to adjust the position of the text edges. See Section 22.5.2 [Fill Commands], page 219.
Key Binding
See [Glossary - Binding], page 556.
Keyboard Macro
Keyboard macros are a way of defining new Emacs commands from
sequences of existing ones, with no need to write a Lisp program. You

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568
can use a macro to record a sequence of commands, then play them
back as many times as you like. See Chapter 14 [Keyboard Macros],
page 116.

Keyboard Shortcut
A keyboard shortcut is a key sequence (q.v.) that invokes a command.
What some programs call “assigning a keyboard shortcut”, Emacs
calls “binding a key sequence”. See [Glossary - Binding], page 556.
Key Sequence
A key sequence (key, for short) is a sequence of input events (q.v.)
that are meaningful as a single unit. If the key sequence is enough to
specify one action, it is a complete key (q.v.); if it is not enough, it is
a prefix key (q.v.). See Section 2.2 [Keys], page 11.
Keymap

The keymap is the data structure that records the bindings (q.v.) of
key sequences to the commands that they run. For example, the global
keymap binds the character C-n to the command function next-line.
See Section 33.3.1 [Keymaps], page 452.

Keyboard Translation Table
The keyboard translation table is an array that translates the character
codes that come from the terminal into the character codes that make
up key sequences.
Kill Ring

The kill ring is where all text you have killed (see [Glossary - Killing],
page 568) recently is saved. You can reinsert any of the killed text still
in the ring; this is called yanking (q.v.). See Section 9.2 [Yanking],
page 57.

Killing

Killing means erasing text and saving it on the kill ring so it can be
yanked (q.v.) later. Some other systems call this “cutting”. Most
Emacs commands that erase text perform killing, as opposed to deletion (q.v.). See Chapter 9 [Killing], page 54.

Killing a Job
Killing a job (such as, an invocation of Emacs) means making it cease
to exist. Any data within it, if not saved in a file, is lost. See Section 3.2
[Exiting], page 15.
Language Environment
Your choice of language environment specifies defaults for the input
method (q.v.) and coding system (q.v.). See Section 19.3 [Language
Environments], page 183. These defaults are relevant if you edit nonASCII text (see Chapter 19 [International], page 180).
Line Wrapping
See [Glossary - Filling], page 564.
Lisp

Lisp is a programming language. Most of Emacs is written in a dialect
of Lisp, called Emacs Lisp, which is extended with special features that
make it especially suitable for text editing tasks.

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569

List

A list is, approximately, a text string beginning with an open parenthesis and ending with the matching close parenthesis. In C mode
and other non-Lisp modes, groupings surrounded by other kinds of
matched delimiters appropriate to the language, such as braces, are
also considered lists. Emacs has special commands for many operations on lists. See Section 23.4.2 [Moving by Parens], page 257.

Local

Local means “in effect only in a particular context”; the relevant kind
of context is a particular function execution, a particular buffer, or a
particular major mode. It is the opposite of ‘global’ (q.v.). Specific
uses of ‘local’ in Emacs terminology appear below.

Local Abbrev
A local abbrev definition is effective only if a particular major mode
is selected. In that major mode, it overrides any global definition for
the same abbrev. See Chapter 26 [Abbrevs], page 322.
Local Keymap
A local keymap is used in a particular major mode; the key bindings
(q.v.) in the current local keymap override global bindings of the same
key sequences. See Section 33.3.1 [Keymaps], page 452.
Local Variable
A local value of a variable (q.v.) applies to only one buffer.
Section 33.2.3 [Locals], page 446.

See

M-

M- in the name of a character is an abbreviation for META, one of
the modifier keys that can accompany any character. See Section 2.1
[User Input], page 11.

M-C-

M-C- in the name of a character is an abbreviation for Control-Meta;
it means the same thing as ‘C-M-’ (q.v.).

M-x

M-x is the key sequence that is used to call an Emacs command by
name. This is how you run commands that are not bound to key
sequences. See Chapter 6 [Running Commands by Name], page 37.

Mail

Mail means messages sent from one user to another through the computer system, to be read at the recipient’s convenience. Emacs has
commands for composing and sending mail, and for reading and editing
the mail you have received. See Chapter 29 [Sending Mail], page 367.
See Chapter 30 [Rmail], page 376, for one way to read mail with Emacs.

Mail Composition Method
A mail composition method is a program runnable within Emacs for
editing and sending a mail message. Emacs lets you select from several
alternative mail composition methods. See Section 29.7 [Mail Methods], page 375.
Major Mode
The Emacs major modes are a mutually exclusive set of options, each
of which configures Emacs for editing a certain sort of text. Ideally,

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570
each programming language has its own major mode. See Section 20.1
[Major Modes], page 204.

Margin

The space between the usable part of a window (including the fringe)
and the window edge.

Mark

The mark points to a position in the text. It specifies one end of the
region (q.v.), point being the other end. Many commands operate on
all the text from point to the mark. Each buffer has its own mark.
See Chapter 8 [Mark], page 47.

Mark Ring

The mark ring is used to hold several recent previous locations of the
mark, in case you want to move back to them. Each buffer has its own
mark ring; in addition, there is a single global mark ring (q.v.). See
Section 8.4 [Mark Ring], page 51.

Menu Bar

The menu bar is a line at the top of an Emacs frame. It contains words
you can click on with the mouse to bring up menus, or you can use
a keyboard interface to navigate it. See Section 18.14 [Menu Bars],
page 176.

Message

See [Glossary - Mail], page 569.

Meta

Meta is the name of a modifier bit which you can use in a command
character. To enter a meta character, you hold down the META key
while typing the character. We refer to such characters with names
that start with Meta- (usually written M- for short). For example,
M-< is typed by holding down META and at the same time typing <
(which itself is done, on most terminals, by holding down SHIFT and
typing ,). See Section 2.1 [User Input], page 11.
On some terminals, the META key is actually labeled ALT or EDIT.

Meta Character
A Meta character is one whose character code includes the Meta bit.
Minibuffer

The minibuffer is the window that appears when necessary inside
the echo area (q.v.), used for reading arguments to commands. See
Chapter 5 [Minibuffer], page 27.

Minibuffer History
The minibuffer history records the text you have specified in the past
for minibuffer arguments, so you can conveniently use the same text
again. See Section 5.4 [Minibuffer History], page 34.
Minor Mode
A minor mode is an optional feature of Emacs, which can be switched
on or off independently of all other features. Each minor mode has a
command to turn it on or off. Some minor modes are global (q.v.),
and some are local (q.v.). See Section 20.2 [Minor Modes], page 205.

Glossary

571

Minor Mode Keymap
A minor mode keymap is a keymap that belongs to a minor mode and
is active when that mode is enabled. Minor mode keymaps take precedence over the buffer’s local keymap, just as the local keymap takes
precedence over the global keymap. See Section 33.3.1 [Keymaps],
page 452.
Mode Line

The mode line is the line at the bottom of each window (q.v.), giving status information on the buffer displayed in that window. See
Section 1.3 [Mode Line], page 8.

Modified Buffer
A buffer (q.v.) is modified if its text has been changed since the last
time the buffer was saved (or since it was created, if it has never been
saved). See Section 15.3 [Saving], page 128.
Moving Text
Moving text means erasing it from one place and inserting it in another. The usual way to move text is by killing (q.v.) it and then
yanking (q.v.) it. See Chapter 9 [Killing], page 54.
MULE

MULE refers to the Emacs features for editing multilingual non-ASCII
text using multibyte characters (q.v.). See Chapter 19 [International],
page 180.

Multibyte Character
A multibyte character is a character that takes up several bytes in a
buffer. Emacs uses multibyte characters to represent non-ASCII text,
since the number of non-ASCII characters is much more than 256. See
Section 19.1 [International Chars], page 180.
Named Mark
A named mark is a register (q.v.), in its role of recording a location
in text so that you can move point to that location. See Chapter 10
[Registers], page 66.
Narrowing

Narrowing means creating a restriction (q.v.) that limits editing in the
current buffer to only a part of the text. Text outside that part is inaccessible for editing (or viewing) until the boundaries are widened again,
but it is still there, and saving the file saves it all. See Section 11.5
[Narrowing], page 74.

Newline

Control-J characters in the buffer terminate lines of text and are therefore also called newlines. See [Glossary - End Of Line], page 562.

nil

nil is a value usually interpreted as a logical “false”. Its opposite is
t, interpreted as “true”.

Numeric Argument
A numeric argument is a number, specified before a command, to
change the effect of the command. Often the numeric argument serves
as a repeat count. See Section 4.10 [Arguments], page 25.

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572

Overwrite Mode
Overwrite mode is a minor mode. When it is enabled, ordinary text
characters replace the existing text after point rather than pushing it
to one side. See Section 20.2 [Minor Modes], page 205.
Package

A package is a collection of Lisp code that you download and automatically install from within Emacs. Packages provide a convenient
way to add new features. See Chapter 32 [Packages], page 430.

Page

A page is a unit of text, delimited by formfeed characters (ASCII
control-L, code 014) at the beginning of a line. Some Emacs commands
are provided for moving over and operating on pages. See Section 22.4
[Pages], page 217.

Paragraph

Paragraphs are the medium-size unit of human-language text. There
are special Emacs commands for moving over and operating on paragraphs. See Section 22.3 [Paragraphs], page 216.

Parsing

We say that certain Emacs commands parse words or expressions in
the text being edited. Really, all they know how to do is find the other
end of a word or expression.

Point

Point is the place in the buffer at which insertion and deletion occur.
Point is considered to be between two characters, not at one character. The terminal’s cursor (q.v.) indicates the location of point. See
Section 1.1 [Point], page 6.

Prefix Argument
See [Glossary - Numeric Argument], page 571.
Prefix Key

A prefix key is a key sequence (q.v.) whose sole function is to introduce
a set of longer key sequences. C-x is an example of prefix key; any
two-character sequence starting with C-x is therefore a legitimate key
sequence. See Section 2.2 [Keys], page 11.

Primary Selection
The primary selection is one particular X selection (q.v.); it is the
selection that most X applications use for transferring text to and
from other applications.
The Emacs kill commands set the primary selection and the yank
command uses the primary selection when appropriate. See Chapter 9
[Killing], page 54.
Prompt

A prompt is text used to ask you for input. Displaying a prompt
is called prompting. Emacs prompts always appear in the echo area
(q.v.). One kind of prompting happens when the minibuffer is used to
read an argument (see Chapter 5 [Minibuffer], page 27); the echoing
that happens when you pause in the middle of typing a multi-character
key sequence is also a kind of prompting (see Section 1.2 [Echo Area],
page 7).

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573

Query-Replace
Query-replace is an interactive string replacement feature provided by
Emacs. See Section 12.9.4 [Query Replace], page 106.
Quitting

Quitting means canceling a partially typed command or a running
command, using C-g (or C-BREAK on MS-DOS). See Section 34.1 [Quitting], page 468.

Quoting

Quoting means depriving a character of its usual special significance.
The most common kind of quoting in Emacs is with C-q. What constitutes special significance depends on the context and on convention.
For example, an “ordinary” character as an Emacs command inserts
itself; so in this context, a special character is any character that does
not normally insert itself (such as DEL, for example), and quoting it
makes it insert itself as if it were not special. Not all contexts allow
quoting. See Section 4.1 [Inserting Text], page 17.

Quoting File Names
Quoting a file name turns off the special significance of constructs such
as ‘$’, ‘~’ and ‘:’. See Section 15.14 [Quoted File Names], page 146.
Read-Only Buffer
A read-only buffer is one whose text you are not allowed to change.
Normally Emacs makes buffers read-only when they contain text which
has a special significance to Emacs; for example, Dired buffers. Visiting a file that is write-protected also makes a read-only buffer. See
Chapter 16 [Buffers], page 150.
Rectangle

A rectangle consists of the text in a given range of columns on a given
range of lines. Normally you specify a rectangle by putting point at
one corner and putting the mark at the diagonally opposite corner.
See Section 9.5 [Rectangles], page 63.

Recursive Editing Level
A recursive editing level is a state in which part of the execution of
a command involves asking you to edit some text. This text may or
may not be the same as the text to which the command was applied.
The mode line indicates recursive editing levels with square brackets
(‘[’ and ‘]’). See Section 31.9 [Recursive Edit], page 424.
Redisplay

Redisplay is the process of correcting the image on the screen to correspond to changes that have been made in the text being edited. See
Chapter 1 [Screen], page 6.

Regexp

See [Glossary - Regular Expression], page 574.

Region

The region is the text between point (q.v.) and the mark (q.v.). Many
commands operate on the text of the region. See Chapter 8 [Mark],
page 47.

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574

Register

Registers are named slots in which text, buffer positions, or rectangles
can be saved for later use. See Chapter 10 [Registers], page 66. A
related Emacs feature is ‘bookmarks’ (q.v.).

Regular Expression
A regular expression is a pattern that can match various text strings;
for example, ‘a[0-9]+’ matches ‘a’ followed by one or more digits. See
Section 12.5 [Regexps], page 97.
Remote File
A remote file is a file that is stored on a system other than your
own. Emacs can access files on other computers provided that they
are connected to the same network as your machine, and (obviously)
that you have a supported method to gain access to those files. See
Section 15.13 [Remote Files], page 145.
Repeat Count
See [Glossary - Numeric Argument], page 571.
Replacement
See [Glossary - Global Substitution], page 565.
Restriction A buffer’s restriction is the amount of text, at the beginning or the
end of the buffer, that is temporarily inaccessible. Giving a buffer
a nonzero amount of restriction is called narrowing (q.v.); removing
a restriction is called widening (q.v.). See Section 11.5 [Narrowing],
page 74.
RET

RET is a character that in Emacs runs the command to insert a newline into the text. It is also used to terminate most arguments read in
the minibuffer (q.v.). See Section 2.1 [User Input], page 11.

Reverting

Reverting means returning to the original state. Emacs lets you revert
a buffer by re-reading its file from disk. See Section 15.4 [Reverting],
page 135.

Saving

Saving a buffer means copying its text into the file that was visited
(q.v.) in that buffer. This is the way text in files actually gets changed
by your Emacs editing. See Section 15.3 [Saving], page 128.

Scroll Bar

A scroll
window.
window.
systems.

Scrolling

Scrolling means shifting the text in the Emacs window so as to see a
different part of the buffer. See Section 11.1 [Scrolling], page 70.

Searching

Searching means moving point to the next occurrence of a specified string or the next match for a specified regular expression. See
Chapter 12 [Search], page 91.

bar is a tall thin hollow box that appears at the side of a
You can use mouse commands in the scroll bar to scroll the
The scroll bar feature is supported only under windowing
See Section 18.12 [Scroll Bars], page 176.

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575

Search Path
A search path is a list of directory names, to be used for searching
for files for certain purposes. For example, the variable load-path
holds a search path for finding Lisp library files. See Section 24.8
[Lisp Libraries], page 287.
Secondary Selection
The secondary selection is one particular X selection (q.v.); some X
applications can use it for transferring text to and from other applications. Emacs has special mouse commands for transferring text
using the secondary selection. See Section 9.3.3 [Secondary Selection],
page 61.
Selected Frame
The selected frame is the one your input currently operates on. See
Chapter 18 [Frames], page 165.
Selected Window
The selected window is the one your input currently operates on. See
Section 17.1 [Basic Window], page 159.
Selecting a Buffer
Selecting a buffer means making it the current (q.v.) buffer.
Section 16.1 [Select Buffer], page 150.
Selection

See

Windowing systems allow an application program to specify selections
whose values are text. A program can also read the selections that
other programs have set up. This is the principal way of transferring
text between window applications. Emacs has commands to work
with the primary (q.v.) selection and the secondary (q.v.) selection,
and also with the clipboard (q.v.).

Self-Documentation
Self-documentation is the feature of Emacs that can tell you what any
command does, or give you a list of all commands related to a topic
you specify. You ask for self-documentation with the help character,
C-h. See Chapter 7 [Help], page 38.
Self-Inserting Character
A character is self-inserting if typing that character inserts that character in the buffer. Ordinary printing and whitespace characters are
self-inserting in Emacs, except in certain special major modes.
Sentences

Emacs has commands for moving by or killing by sentences. See
Section 22.2 [Sentences], page 215.

Server

Within Emacs, you can start a ‘server’ process, which listens for connections from ‘clients’. This offers a faster alternative to starting several Emacs instances. See Section 31.4 [Emacs Server], page 412, and
[Glossary - Daemon], page 560.

Glossary
Sexp

576
A sexp (short for “s-expression”) is the basic syntactic unit of Lisp
in its textual form: either a list, or Lisp atom. Sexps are also the
balanced expressions (q.v.) of the Lisp language; this is why the commands for editing balanced expressions have ‘sexp’ in their name. See
Section 23.4.1 [Expressions], page 256.

Simultaneous Editing
Simultaneous editing means two users modifying the same file at once.
Simultaneous editing, if not detected, can cause one user to lose his
or her work. Emacs detects all cases of simultaneous editing, and
warns one of the users to investigate. See Section 15.3.4 [Simultaneous
Editing], page 133.
SPC

SPC is the space character, which you enter by pressing the space bar.

Speedbar

The speedbar is a special tall frame that provides fast access to Emacs
buffers, functions within those buffers, Info nodes, and other interesting parts of text within Emacs. See Section 18.9 [Speedbar], page 174.

Spell Checking
Spell checking means checking correctness of the written form of each
one of the words in a text. Emacs can use various external spellingchecker programs to check the spelling of parts of a buffer via a convenient user interface. See Section 13.4 [Spelling], page 112.
String

A string is a kind of Lisp data object that contains a sequence of
characters. Many Emacs variables are intended to have strings as
values. The Lisp syntax for a string consists of the characters in the
string with a ‘"’ before and another ‘"’ after. A ‘"’ that is part of
the string must be written as ‘\"’ and a ‘\’ that is part of the string
must be written as ‘\\’. All other characters, including newline, can
be included just by writing them inside the string; however, backslash
sequences as in C, such as ‘\n’ for newline or ‘\241’ using an octal
character code, are allowed as well.

String Substitution
See [Glossary - Global Substitution], page 565.
Syntax Highlighting
See [Glossary - Font Lock], page 564.
Syntax Table
The syntax table tells Emacs which characters are part of a word,
which characters balance each other like parentheses, etc. See Section
“Syntax Tables” in The Emacs Lisp Reference Manual.
Super

Super is the name of a modifier bit that a keyboard input character
may have. To make a character Super, type it while holding down the
SUPER key. Such characters are given names that start with Super(usually written s- for short). See Section 2.1 [User Input], page 11.

Glossary

577

Suspending Suspending Emacs means stopping it temporarily and returning control to its parent process, which is usually a shell. Unlike killing a
job (q.v.), you can later resume the suspended Emacs job without
losing your buffers, unsaved edits, undo history, etc. See Section 3.2
[Exiting], page 15.
TAB

TAB is the tab character. In Emacs it is typically used for indentation
or completion.

Tags Table A tags table is a file that serves as an index to the function definitions
in one or more other files. See Section 25.3 [Tags], page 311.
Termscript File
A termscript file contains a record of all characters sent by Emacs
to the terminal. It is used for tracking down bugs in Emacs redisplay. Emacs does not make a termscript file unless you tell it to. See
Section 34.3 [Bugs], page 473.
Text

‘Text’ has two meanings (see Chapter 22 [Text], page 214):
• Data consisting of a sequence of characters, as opposed to binary
numbers, executable programs, and the like. The basic contents
of an Emacs buffer (aside from the text properties, q.v.) are always text in this sense.
• Data consisting of written human language (as opposed to programs), or following the stylistic conventions of human language.

Text Terminal
A text terminal, or character terminal, is a display that is limited to
displaying text in character units. Such a terminal cannot control individual pixels it displays. Emacs supports a subset of display features
on text terminals.
Text Properties
Text properties are annotations recorded for particular characters in
the buffer. Images in the buffer are recorded as text properties; they
also specify formatting information. See Section 22.13.3 [Editing Format Info], page 239.
Theme

A theme is a set of customizations (q.v.) that give Emacs a particular
appearance or behavior. For example, you might use a theme for your
favorite set of faces (q.v.).

Tool Bar

The tool bar is a line (sometimes multiple lines) of icons at the top of
an Emacs frame. Clicking on one of these icons executes a command.
You can think of this as a graphical relative of the menu bar (q.v.).
See Section 18.15 [Tool Bars], page 177.

Tooltips

Tooltips are small windows displaying a help echo (q.v.) text, which
explains parts of the display, lists useful options available via mouse
clicks, etc. See Section 18.17 [Tooltips], page 178.

Glossary
Top Level

578
Top level is the normal state of Emacs, in which you are editing the
text of the file you have visited. You are at top level whenever you are
not in a recursive editing level (q.v.) or the minibuffer (q.v.), and not
in the middle of a command. You can get back to top level by aborting
(q.v.) and quitting (q.v.). See Section 34.1 [Quitting], page 468.

Transposition
Transposing two units of text means putting each one into the place
formerly occupied by the other. There are Emacs commands to transpose two adjacent characters, words, balanced expressions (q.v.) or
lines (see Section 13.2 [Transpose], page 111).
Trash Can

See [Glossary - Deletion of Files], page 561.

Truncation Truncating text lines in the display means leaving out any text on a
line that does not fit within the right margin of the window displaying
it. See Section 4.8 [Continuation Lines], page 23, and [Glossary Continuation Line], page 559.
TTY

See [Glossary - Text Terminal], page 577.

Undoing

Undoing means making your previous editing go in reverse, bringing back the text that existed earlier in the editing session. See
Section 13.1 [Undo], page 110.

Unix

Unix is a class of multi-user computer operating systems with a long
history. There are several implementations today. The GNU project
(q.v.) aims to develop a complete Unix-like operating system that is
free software (q.v.).

User Option
A user option is a face (q.v.) or a variable (q.v.) that exists so that you
can customize Emacs by setting it to a new value. See Section 33.1
[Easy Customization], page 434.
Variable

A variable is an object in Lisp that can store an arbitrary value. Emacs
uses some variables for internal purposes, and has others (known as
‘user options’; q.v.) just so that you can set their values to control the
behavior of Emacs. The variables used in Emacs that you are likely to
be interested in are listed in the Variables Index in this manual (see
[Variable Index], page 604). See Section 33.2 [Variables], page 443, for
information on variables.

Version Control
Version control systems keep track of multiple versions of a source
file. They provide a more powerful alternative to keeping backup files
(q.v.). See Section 25.1 [Version Control], page 292.
Visiting

Visiting a file means loading its contents into a buffer (q.v.) where
they can be edited. See Section 15.2 [Visiting], page 125.

Glossary

579

Whitespace Whitespace is any run of consecutive formatting characters (space,
tab, newline, and backspace).
Widening

Widening is removing any restriction (q.v.) on the current buffer; it
is the opposite of narrowing (q.v.). See Section 11.5 [Narrowing],
page 74.

Window

Emacs divides a frame (q.v.) into one or more windows, each of which
can display the contents of one buffer (q.v.) at any time. See Chapter 1
[Screen], page 6, for basic information on how Emacs uses the screen.
See Chapter 17 [Windows], page 159, for commands to control the use
of windows. Some other editors use the term “window” for what we
call a ‘frame’ (q.v.) in Emacs.

Window System
A window system is software that operates on a graphical display
(q.v.), to subdivide the screen so that multiple applications can have
their] own windows at the same time. All modern operating systems
include a window system.
Word Abbrev
See [Glossary - Abbrev], page 555.
Word Search
Word search is searching for a sequence of words, considering the punctuation between them as insignificant. See Section 12.3 [Word Search],
page 95.
Yanking

Yanking means reinserting text previously killed (q.v.). It can be used
to undo a mistaken kill, or for copying or moving text. Some other
systems call this “pasting”. See Section 9.2 [Yanking], page 57.

Key (Character) Index

580

Key (Character) Index
!

+

! (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

+ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
+ (DocView mode) . . . . . . . . . . . . . . . . . . . 400

"
" (TEX mode) . . . . . . . . . . . . . . . . . . . . . . . . 232

- (DocView mode) . . . . . . . . . . . . . . . . . . . 400

#
# (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331

.
. (Calendar mode) . . . . . . . . . . . . . . . . . . . 348
. (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
. (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377

$
$ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340

/
%
%
%
%
%
%
%
%
%
%
%

&
C
d
g
H
l
m
R
S
u

/ (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)
(Dired)

..........................
..........................
..........................
..........................
..........................
..........................
..........................
..........................
..........................
..........................

332
338
332
334
338
338
334
338
338
338

:d
:e
:s
:v

(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . .

336
336
336
336

<
< (Calendar mode) . . . . . . . . . . . . . . . . . . . 348
< (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
< (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378

*
*
*
*
*
*
*
*
*
*
*
*
*
*
*

:

! (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
% (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
* (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
/ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
? (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
@ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
c (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
C-n (Dired) . . . . . . . . . . . . . . . . . . . . . . . .
C-p (Dired) . . . . . . . . . . . . . . . . . . . . . . . .
DEL (Dired) . . . . . . . . . . . . . . . . . . . . . . . .
m (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
s (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
t (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .
u (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . .

333
334
333
333
333
333
334
333
334
333
333
333
334
333

=
= (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339

>
> (Calendar mode) . . . . . . . . . . . . . . . . . . . 348
> (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
> (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378

?
? (completion) . . . . . . . . . . . . . . . . . . . . . . . . 30

Key (Character) Index

581

^
^ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332

~
~ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331

A
a
A
a
A
A
A
A

(Calendar mode) . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
k (Gnus Group mode) . . . . . . . . . . . . . .
s (Gnus Group mode) . . . . . . . . . . . . . .
u (Gnus Group mode) . . . . . . . . . . . . . .
z (Gnus Group mode) . . . . . . . . . . . . . .

351
337
383
398
398
398
398

B
B (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
b (Rmail summary) . . . . . . . . . . . . . . . . . . 389
b (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376

C
C (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
c (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
C-/ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
C-@ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
C-] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
C-_ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
C-_ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 334
C-\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
C-a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-a (Calendar mode) . . . . . . . . . . . . . . . . . 347
C-b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-b (Calendar mode) . . . . . . . . . . . . . . . . . 346
C-c , j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
C-c , J . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
C-c , l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
C-c , SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
C-c . (C mode) . . . . . . . . . . . . . . . . . . . . . . 255
C-c . (Shell mode) . . . . . . . . . . . . . . . . . . . 407
C-c / (SGML mode) . . . . . . . . . . . . . . . . . 236
C-c < (GUD) . . . . . . . . . . . . . . . . . . . . . . . . 279
C-c > (GUD) . . . . . . . . . . . . . . . . . . . . . . . . 279
C-c ? (SGML mode) . . . . . . . . . . . . . . . . . 236
C-c @ (Outline minor mode) . . . . . . . . . . 225
C-c @ C-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
C-c @ C-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
C-c @ C-M-h . . . . . . . . . . . . . . . . . . . . . . . . . . 263
C-c @ C-M-s . . . . . . . . . . . . . . . . . . . . . . . . . . 263

C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c

@ C-r . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
@ C-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
[ (Enriched mode) . . . . . . . . . . . . . . . 240
[ (Org Mode) . . . . . . . . . . . . . . . . . . . . 230
] (Enriched mode) . . . . . . . . . . . . . . . 240
{ (TEX mode) . . . . . . . . . . . . . . . . . . . 232
} (TEX mode) . . . . . . . . . . . . . . . . . . . 232
8 (SGML mode) . . . . . . . . . . . . . . . . . 236
C-\ (C mode) . . . . . . . . . . . . . . . . . . . . 269
C-\ (Shell mode). . . . . . . . . . . . . . . . . 405
C-a (C mode) . . . . . . . . . . . . . . . . . . . . 267
C-a (Log Edit mode) . . . . . . . . . . . . . 299
C-a (Message mode) . . . . . . . . . . . . . 373
C-a (Outline mode) . . . . . . . . . . . . . . 227
C-a (SGML mode) . . . . . . . . . . . . . . . 236
C-a (Shell mode). . . . . . . . . . . . . . . . . 404
C-b (Help mode) . . . . . . . . . . . . . . . . . . 43
C-b (Message mode) . . . . . . . . . . . . . 372
C-b (Outline mode) . . . . . . . . . . . . . . 226
C-b (SGML mode) . . . . . . . . . . . . . . . 236
C-b (Shell mode). . . . . . . . . . . . . . . . . 405
C-b (TEX mode) . . . . . . . . . . . . . . . . . 234
C-c (C mode) . . . . . . . . . . . . . . . . . . . . 260
C-c (customization buffer) . . . . . . . 438
C-c (Edit Abbrevs) . . . . . . . . . . . . . . 325
C-c (Edit Tab Stops) . . . . . . . . . . . . 211
C-c (Message mode) . . . . . . . . . . . . . 371
C-c (Outline mode) . . . . . . . . . . . . . . 227
C-c (Shell mode). . . . . . . . . . . . . . . . . 404
C-c (TEX mode) . . . . . . . . . . . . . . . . . 235
C-d (C Mode) . . . . . . . . . . . . . . . . . . . . 267
C-d (GUD) . . . . . . . . . . . . . . . . . . . . . . 279
C-d (Log Edit mode) . . . . . . . . . . . . . 299
C-d (Org Mode) . . . . . . . . . . . . . . . . . 230
C-d (Outline mode) . . . . . . . . . . . . . . 227
C-d (SGML mode) . . . . . . . . . . . . . . . 236
C-DEL (C Mode) . . . . . . . . . . . . . . . . . . 267
C-DELETE (C Mode). . . . . . . . . . . . . . . 267
C-e (C mode) . . . . . . . . . . . . . . . . . . . . 269
C-e (LaTEX mode) . . . . . . . . . . . . . . . 233
C-e (Org mode). . . . . . . . . . . . . . . . . . 230
C-e (Outline mode) . . . . . . . . . . . . . . 227
C-e (Shell mode). . . . . . . . . . . . . . . . . 405
C-f (GUD) . . . . . . . . . . . . . . . . . . . . . . 279
C-f (Log Edit mode) . . . . . . . . . . . . . 299
C-f (Outline mode) . . . . . . . . . . . . . . 226
C-f (SGML mode) . . . . . . . . . . . . . . . 236
C-f (Shell mode). . . . . . . . . . . . . . . . . 405
C-f (TEX mode) . . . . . . . . . . . . . . . . . 235
C-f C-b (Message mode) . . . . . . . . . 372
C-f C-c (Message mode) . . . . . . . . . 372
C-f C-f (Message mode) . . . . . . . . . 372

Key (Character) Index
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c
C-c

C-f
C-f
C-f
C-f
C-i
C-i
C-j
C-k
C-k
C-k
C-l
C-l
C-l
C-l
C-l
C-l
C-n
C-n
C-n
C-n
C-n
C-n
C-o
C-o
C-o
C-p
C-p
C-p
C-p
C-p
C-p
C-q
C-q
C-q
C-q
C-r
C-r
C-r
C-s
C-s
C-s
C-s
C-s
C-s
C-t
C-t
C-t
C-t
C-u
C-u
C-u
C-u

C-r (Message mode) . . . . . . . . .
C-s (Message mode) . . . . . . . . .
C-t (Message mode) . . . . . . . . .
C-w (Message mode) . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Term mode) . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Term mode) . . . . . . . . . . . . . . . .
(TEX mode) . . . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(Calendar mode) . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(TEX mode) . . . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . .
(SGML mode) . . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(LaTEX mode) . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(TEX mode) . . . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(Message mode) . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Term mode) . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(TEX mode) . . . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Message mode) . . . . . . . . . . . . .
(Org Mode) . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Org Mode) . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(SGML mode) . . . . . . . . . . . . . . .
(C mode) . . . . . . . . . . . . . . . . . . . .
(GUD) . . . . . . . . . . . . . . . . . . . . . .
(Outline mode) . . . . . . . . . . . . . .
(Shell mode). . . . . . . . . . . . . . . . .

582
372
372
372
372
279
227
411
227
411
234
267
349
278
227
407
234
266
279
226
378
236
408
233
227
405
266
279
226
378
408
234
254
373
227
411
279
405
234
269
278
371
230
227
405
279
230
227
236
266
279
226
404

C-c C-v (SGML mode) . . . . . . . . . . . . . . . 236
C-c C-v (TEX mode) . . . . . . . . . . . . . . . . . 234
C-c C-w (Message mode) . . . . . . . . . . . . . 374
C-c C-w (Shell mode). . . . . . . . . . . . . . . . . 404
C-c C-x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
C-c C-x (Shell mode). . . . . . . . . . . . . . . . . 407
C-c C-y (Message mode) . . . . . . . . . . . . . 373
C-c C-z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
C-c C-z (Shell mode). . . . . . . . . . . . . . . . . 405
C-c DEL (C Mode) . . . . . . . . . . . . . . . . . . . . 267
C-c DELETE (C Mode) . . . . . . . . . . . . . . . . . 267
C-c RET (Goto Address mode) . . . . . . . . 426
C-c RET (Shell mode). . . . . . . . . . . . . . . . . 408
C-c TAB (SGML mode) . . . . . . . . . . . . . . . 236
C-c TAB (TEX mode) . . . . . . . . . . . . . . . . . 235
C-d (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 379
C-d (Shell mode) . . . . . . . . . . . . . . . . . . . . . 404
C-Down-Mouse-1 . . . . . . . . . . . . . . . . . . . . . 158
C-e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-e (Calendar mode) . . . . . . . . . . . . . . . . . 347
C-f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-f (Calendar mode) . . . . . . . . . . . . . . . . . 346
C-g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
C-g (Incremental search) . . . . . . . . . . . . . . 93
C-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
C-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
C-h a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
C-h b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
C-h c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
C-h C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
C-h C-\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
C-h C-c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
C-h C-m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h C-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
C-h e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
C-h f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
C-h F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
C-h g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
C-h h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
C-h i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
C-h I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
C-h k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
C-h K . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Key (Character) Index
C-h l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
C-h L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
C-h m. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44, 205
C-h p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
C-h P . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
C-h S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44, 262
C-h t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
C-h v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
C-h w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
C-j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
C-j (and major modes) . . . . . . . . . . . . . . 204
C-j (indenting source code) . . . . . . . . . . 253
C-j (Lisp Interaction mode) . . . . . . . . . . 290
C-j (TEX mode) . . . . . . . . . . . . . . . . . . . . . 232
C-k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
C-k (Gnus Group mode) . . . . . . . . . . . . . 398
C-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
C-LEFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
C-M-% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
C-M-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
C-M-/ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
C-M-@ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49, 257
C-M-\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
C-M-a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
C-M-b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
C-M-c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424
C-M-d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
C-M-d (Dired) . . . . . . . . . . . . . . . . . . . . . . . . 340
C-M-e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
C-M-f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
C-M-f (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 388
C-M-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
C-M-h (C mode) . . . . . . . . . . . . . . . . . . . . . . 251
C-M-i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
C-M-i (customization buffer) . . . . . . . . . 436
C-M-j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
C-M-k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
C-M-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
C-M-l (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 387
C-M-l (Shell mode) . . . . . . . . . . . . . . . . . . 405
C-M-n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
C-M-n (Dired) . . . . . . . . . . . . . . . . . . . . . . . . 340
C-M-n (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 383
C-M-o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
C-M-p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
C-M-p (Dired) . . . . . . . . . . . . . . . . . . . . . . . . 340
C-M-p (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 383
C-M-q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
C-M-q (C mode) . . . . . . . . . . . . . . . . . . . . . . 254
C-M-r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
C-M-r (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 387
C-M-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

583
C-M-s (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 388
C-M-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
C-M-t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
C-M-t (Rmail) . . . . . . . . . . . . . . . . . . . . . . . 387
C-M-u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
C-M-u (Dired) . . . . . . . . . . . . . . . . . . . . . . . . 340
C-M-v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
C-M-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
C-M-w (Incremental search) . . . . . . . . . . . . 94
C-M-x (Emacs Lisp mode) . . . . . . . . . . . . 289
C-M-x (Lisp mode) . . . . . . . . . . . . . . . . . . . 290
C-M-x (Scheme mode) . . . . . . . . . . . . . . . . 291
C-M-y (Incremental search) . . . . . . . . . . . . 94
C-Mouse-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
C-Mouse-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
C-mouse-2 (mode line) . . . . . . . . . . . . . . . 169
C-Mouse-2 (mode line) . . . . . . . . . . . . . . . 160
C-Mouse-2 (scroll bar). . . . . . . . . . . . . . . . 160
C-Mouse-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
C-Mouse-3 (when menu bar is disabled)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
C-n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-n (Calendar mode) . . . . . . . . . . . . . . . . . 346
C-n (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 330
C-o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
C-o (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 332
C-o (Occur mode) . . . . . . . . . . . . . . . . . . . . 108
C-o (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 382
C-p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
C-p (Calendar mode) . . . . . . . . . . . . . . . . . 346
C-p (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 330
C-q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
C-r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
C-RIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
C-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
C-S-backspace . . . . . . . . . . . . . . . . . . . . . . . . 56
C-S-Mouse-3 (FFAP) . . . . . . . . . . . . . . . . 428
C-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
C-SPC C-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . 51
C-SPC C-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . 53
C-t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
C-t d (Image-Dired) . . . . . . . . . . . . . . . . . 343
C-TAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
C-u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
C-u C-/ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
C-u C-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
C-u C-x C-x . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
C-u C-x v = . . . . . . . . . . . . . . . . . . . . . . . . . . 301
C-u M-; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
C-u TAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
C-v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
C-v (Calendar mode) . . . . . . . . . . . . . . . . . 348

Key (Character) Index
C-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
C-w (Incremental search) . . . . . . . . . . . . . . 94
C-x # . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
C-x $ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
C-x ( . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
C-x ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
C-x + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
C-x ; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
C-x < . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
C-x =. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24, 181
C-x > . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
C-x [ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
C-x [ (Calendar mode) . . . . . . . . . . . . . . . 347
C-x [ (DocView mode) . . . . . . . . . . . . . . . 400
C-x ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
C-x ] (Calendar mode) . . . . . . . . . . . . . . . 347
C-x ] (DocView mode) . . . . . . . . . . . . . . . 400
C-x ^ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x ‘ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
C-x } . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
C-x 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
C-x 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
C-x 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
C-x 4 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
C-x 4 a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
C-x 4 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
C-x 4 b (Iswitchb mode) . . . . . . . . . . . . . 158
C-x 4 c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
C-x 4 C-o . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
C-x 4 C-o (Iswitchb mode) . . . . . . . . . . . 158
C-x 4 d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
C-x 4 f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
C-x 4 f (FFAP) . . . . . . . . . . . . . . . . . . . . . . 427
C-x 4 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
C-x 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
C-x 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
C-x 5 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
C-x 5 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
C-x 5 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
C-x 5 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
C-x 5 b (Iswitchb mode) . . . . . . . . . . . . . 158
C-x 5 d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
C-x 5 f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
C-x 5 f (FFAP) . . . . . . . . . . . . . . . . . . . . . . 427
C-x 5 m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
C-x 5 o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
C-x 5 r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

584
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x

6 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
6 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
6 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
6 d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
6 RET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
6 s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
8 RET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
a g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
a i g . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
a i l . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
a l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
b (Iswitchb mode) . . . . . . . . . . . . . . . 158
C-+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
C-- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
C-= . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
C-0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
C-a (GUD) . . . . . . . . . . . . . . . . . . . . . . 278
C-a C-j (GUD) . . . . . . . . . . . . . . . . . . 280
C-a C-w (GUD) . . . . . . . . . . . . . . . . . . 285
C-b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
C-c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
C-c (customization buffer) . . . . . . . 438
C-d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
C-e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
C-f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
C-f (FFAP) . . . . . . . . . . . . . . . . . . . . . 427
C-k b . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
C-k C-a . . . . . . . . . . . . . . . . . . . . . . . . . . 119
C-k C-c . . . . . . . . . . . . . . . . . . . . . . . . . . 119
C-k C-e . . . . . . . . . . . . . . . . . . . . . . . . . . 122
C-k C-f . . . . . . . . . . . . . . . . . . . . . . . . . . 119
C-k C-i . . . . . . . . . . . . . . . . . . . . . . . . . . 119
C-k C-k . . . . . . . . . . . . . . . . . . . . . . . . . . 118
C-k C-n . . . . . . . . . . . . . . . . . . . . . . . . . . 118
C-k C-p . . . . . . . . . . . . . . . . . . . . . . . . . . 118
C-k e . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
C-k l . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
C-k n . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
C-k r . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
C-k RET . . . . . . . . . . . . . . . . . . . . . . . . . . 122
C-k SPC . . . . . . . . . . . . . . . . . . . . . . . . . . 122
C-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
C-n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
C-o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
C-p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
C-q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
C-r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
C-r (FFAP) . . . . . . . . . . . . . . . . . . . . . 427
C-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
C-s (Custom Themes buffer) . . . . . 441

Key (Character) Index
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x
C-x

C-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
C-t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
C-u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
C-v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
C-v (FFAP) . . . . . . . . . . . . . . . . . . . . . 427
C-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
C-x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
C-z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
d (FFAP) . . . . . . . . . . . . . . . . . . . . . . . . 427
DEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
ESC ESC . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
LEFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
n n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
n p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
n w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
r + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
r b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
r c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
r d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
r f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
r i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
r j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
r k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
r l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
r m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
r n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
r N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
r o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
r r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
r s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
r SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
r t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
r w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
r y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
RET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
RET c . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
RET C-\ . . . . . . . . . . . . . . . . . . . . . . . . . . 187
RET f . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
RET F . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
RET k . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
RET p . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195

585
C-x RET r . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
C-x RET t . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
C-x RET x . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
C-x RET X . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
C-x RIGHT. . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
C-x s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
C-x SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
C-x TAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
C-x TAB (Enriched mode) . . . . . . . . . . . . . 240
C-x u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
C-x v + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
C-x v = . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
C-x v ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
C-x v d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
C-x v D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
C-x v g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
C-x v i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300
C-x v l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303
C-x v u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
C-x v v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
C-x w b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
C-x w h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
C-x w i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
C-x w l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
C-x w r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
C-x z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
C-y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
C-y (Incremental search) . . . . . . . . . . . . . . 94
C-z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
C-z (X windows) . . . . . . . . . . . . . . . . . . . . . 170

D
d (Calendar mode) . . . . . . . . . . . . . . . . . . . 359
d (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
D (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
D (GDB Breakpoints buffer) . . . . . . . . . . 283
D (GDB speedbar) . . . . . . . . . . . . . . . . . . . 285
d (GDB threads buffer) . . . . . . . . . . . . . . 283
d (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
DEL (and major modes) . . . . . . . . . . . . . . 204
DEL (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 330
DEL (DocView mode) . . . . . . . . . . . . . . . . . 400
DEL (Gnus Group mode) . . . . . . . . . . . . . 398
DEL (Gnus Summary mode) . . . . . . . . . . 399
DEL (programming modes) . . . . . . . . . . . 249
DEL (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 377
DEL (View mode) . . . . . . . . . . . . . . . . . . . . . . 75
DOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DOWN (minibuffer history) . . . . . . . . . . . . . . 34

Key (Character) Index

586

E
e (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
e (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
e (View mode) . . . . . . . . . . . . . . . . . . . . . . . . 75
END . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
ESC ESC ESC . . . . . . . . . . . . . . . . . . . . . . . . . . 469

F

i w (Calendar mode) . . . . . . . . . . . . . . . . . 362
i y (Calendar mode) . . . . . . . . . . . . . . . . . 362
INSERT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207

J
j (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
j (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378

f (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
f (GDB threads buffer) . . . . . . . . . . . . . . 283
f (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
F1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
F10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
F10 (MS-Windows) . . . . . . . . . . . . . . . . . . 539
F2 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F2 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F2 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F2 d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F2 RET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F2 s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
F3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
F4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

K

G

M

g
G
g
g
g
g
g
g

(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
char (Calendar mode) . . . . . . . . . . . . .
d (Calendar mode) . . . . . . . . . . . . . . . . .
D (Calendar mode) . . . . . . . . . . . . . . . . .
m (Calendar mode) . . . . . . . . . . . . . . . . .
w (Calendar mode) . . . . . . . . . . . . . . . . .

341
336
381
356
348
348
357
348

H
h (Calendar mode) . . . . . . . . . . . . . . . . . . . 351
H (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
h (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
HOME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

I
i
i
i
i
i
i
i

(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
a (Calendar mode) . . . . . . . . . . . . . . . . .
b (Calendar mode) . . . . . . . . . . . . . . . . .
c (Calendar mode) . . . . . . . . . . . . . . . . .
d (Calendar mode) . . . . . . . . . . . . . . . . .
m (Calendar mode) . . . . . . . . . . . . . . . . .

339
381
362
363
363
362
362

k (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
k (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383

L
l (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
L (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
l (GDB threads buffer) . . . . . . . . . . . . . . 283
l (Gnus Group mode) . . . . . . . . . . . . . . . . 398
L (Gnus Group mode) . . . . . . . . . . . . . . . . 398
l (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
LEFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

m (Calendar mode) . . . . . . . . . . . . . . . . . . . 359
M (Calendar mode) . . . . . . . . . . . . . . . . . . . 353
m (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
M (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
m (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
M-! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
M-$ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
M-$ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 340
M-% . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
M-% (Incremental search) . . . . . . . . . . . . . . 93
M-& . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
M-’ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
M-* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
M-, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
M-- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
M-- M-c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
M-- M-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
M-- M-u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
M-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
M-/ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
M-: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289
M-; . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
M-< . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-< (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-< (DocView mode) . . . . . . . . . . . . . . . . . 400
M- (Org Mode) . . . . . . . . . . . . . . . . 229

Key (Character) Index
M- (Org Mode) . . . . . . . . . . . . . . . . 229
M- (Org Mode) . . . . . . . . . . . . . . . 229
M- (Org Mode) . . . . . . . . . . . . . . . . . . 229
M-= . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
M-= (Calendar mode) . . . . . . . . . . . . . . . . . 349
M-= (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 339
M-> . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-> (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-> (DocView mode) . . . . . . . . . . . . . . . . . 400
M-? (Nroff mode) . . . . . . . . . . . . . . . . . . . . 237
M-? (Shell mode) . . . . . . . . . . . . . . . . . . . . . 404
M-@ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49, 215
M-^ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
M-‘ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
M-{ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
M-{ (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-{ (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 334
M-} . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
M-} (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-} (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 333
M-\ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
M-| . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
M-~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
M-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
M-a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
M-a (C mode). . . . . . . . . . . . . . . . . . . . . . . . . 266
M-a (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19, 214
M-c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
M-d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
M-DEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
M-DEL (Dired) . . . . . . . . . . . . . . . . . . . . . . . . 333
M-Drag-Mouse-1. . . . . . . . . . . . . . . . . . . . . . . 61
M-e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
M-e (C mode). . . . . . . . . . . . . . . . . . . . . . . . . 267
M-e (Calendar mode) . . . . . . . . . . . . . . . . . 347
M-e (Incremental search) . . . . . . . . . . . . . . 92
M-f . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18, 214
M-g g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-g M-g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-g M-n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
M-g n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
M-h . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
M-i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
M-j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
M-j b (Enriched mode) . . . . . . . . . . . . . . . 241
M-j c (Enriched mode) . . . . . . . . . . . . . . . 241
M-j l (Enriched mode) . . . . . . . . . . . . . . . 241
M-j r (Enriched mode) . . . . . . . . . . . . . . . 241
M-j u (Enriched mode) . . . . . . . . . . . . . . . 241
M-k . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
M-l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

587
M-LEFT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
M-m (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 385
M-Mouse-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
M-Mouse-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
M-Mouse-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
M-n (Incremental search) . . . . . . . . . . . . . . 92
M-n (Log Edit mode) . . . . . . . . . . . . . . . . . 300
M-n (Man mode) . . . . . . . . . . . . . . . . . . . . . 262
M-n (minibuffer history) . . . . . . . . . . . . . . . 34
M-n (Nroff mode) . . . . . . . . . . . . . . . . . . . . 237
M-n (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 378
M-n (Shell mode) . . . . . . . . . . . . . . . . . . . . . 407
M-o b (Enriched mode) . . . . . . . . . . . . . . . 239
M-o d (Enriched mode) . . . . . . . . . . . . . . . 239
M-o i (Enriched mode) . . . . . . . . . . . . . . . 239
M-o l (Enriched mode) . . . . . . . . . . . . . . . 239
M-o M-s (Text mode) . . . . . . . . . . . . . . . . . 220
M-o o (Enriched mode) . . . . . . . . . . . . . . . 239
M-o u (Enriched mode) . . . . . . . . . . . . . . . 239
M-p (Incremental search) . . . . . . . . . . . . . . 92
M-p (Log Edit mode) . . . . . . . . . . . . . . . . . 300
M-p (Man mode) . . . . . . . . . . . . . . . . . . . . . 262
M-p (minibuffer history) . . . . . . . . . . . . . . . 34
M-p (Nroff mode) . . . . . . . . . . . . . . . . . . . . 237
M-p (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 378
M-p (Shell mode) . . . . . . . . . . . . . . . . . . . . . 407
M-q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
M-q (C mode) . . . . . . . . . . . . . . . . . . . . . . . . 268
M-r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-r (Log Edit mode) . . . . . . . . . . . . . . . . . 300
M-r (minibuffer history) . . . . . . . . . . . . . . . 34
M-r (Shell mode) . . . . . . . . . . . . . . . . . . . . . 407
M-RIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
M-S (Enriched mode) . . . . . . . . . . . . . . . . . 241
M-s (Gnus Summary mode) . . . . . . . . . . 399
M-s (Log Edit mode) . . . . . . . . . . . . . . . . . 300
M-s (minibuffer history) . . . . . . . . . . . . . . . 34
M-s (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 378
M-s a C-s (Dired) . . . . . . . . . . . . . . . . . . . . 344
M-s a M-C-s (Dired) . . . . . . . . . . . . . . . . . . 344
M-s C-e (Incremental search) . . . . . . . . . . 94
M-s f C-s (Dired) . . . . . . . . . . . . . . . . . . . . 330
M-s f M-C-s (Dired) . . . . . . . . . . . . . . . . . . 330
M-s o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
M-s w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
M-SPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
M-t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
M-TAB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
M-TAB (customization buffer) . . . . . . . . . 436
M-TAB (Incremental search) . . . . . . . . . . . . 93
M-TAB (Text mode) . . . . . . . . . . . . . . . . . . . 224

Key (Character) Index

588

M-u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
M-v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
M-v (Calendar mode) . . . . . . . . . . . . . . . . . 348
M-w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
M-x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
M-y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
M-y (Incremental search) . . . . . . . . . . . . . . 94
M-z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Mouse-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Mouse-1 (mode line) . . . . . . . . . . . . . . . . . 169
Mouse-1 (on buttons) . . . . . . . . . . . . . . . . 167
Mouse-1 (scroll bar) . . . . . . . . . . . . . . . . . . 169
Mouse-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Mouse-2 (GDB Breakpoints buffer) . . . 283
Mouse-2 (mode line) . . . . . . . . . . . . . . . . . 169
Mouse-2 (on buttons) . . . . . . . . . . . . . . . . 167
Mouse-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
Mouse-3 (mode line) . . . . . . . . . . . . . . . . . 169

N
n (DocView mode) . . . . . . . . . . . . . . . . . . . 400
n (Gnus Group mode) . . . . . . . . . . . . . . . . 398
n (Gnus Summary mode). . . . . . . . . . . . . 399
n (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Q
q
q
q
Q
q
q
q

(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
(Gnus Group mode) . . . . . . . . . . . . . . . . 398
(Gnus Summary mode). . . . . . . . . . . . . 399
(Rmail summary) . . . . . . . . . . . . . . . . . . 389
(Rmail summary) . . . . . . . . . . . . . . . . . . 389
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
(VC Directory). . . . . . . . . . . . . . . . . . . . . 306
(View mode) . . . . . . . . . . . . . . . . . . . . . . . . 75

R
R (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335
r (GDB threads buffer) . . . . . . . . . . . . . . 284
r (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385
RET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
RET (completion in minibuffer) . . . . . . . . 31
RET (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 332
RET (GDB Breakpoints buffer) . . . . . . . 283
RET (GDB speedbar) . . . . . . . . . . . . . . . . . 285
RET (Help mode) . . . . . . . . . . . . . . . . . . . . . . 43
RET (Occur mode) . . . . . . . . . . . . . . . . . . . . 108
RET (Shell mode) . . . . . . . . . . . . . . . . . . . . . 404
RIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

S

p (Calendar mode) . . . . . . . . . . . . . . . . . . . 355
P (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
p (DocView mode) . . . . . . . . . . . . . . . . . . . 400
p (Gnus Group mode) . . . . . . . . . . . . . . . . 398
p (Gnus Summary mode). . . . . . . . . . . . . 399
p (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378
p d (Calendar mode) . . . . . . . . . . . . . . . . . 349
PageDown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
PageUp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
prior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

s (Calendar mode) . . . . . . . . . . . . . . . . . . . 359
S (Calendar mode) . . . . . . . . . . . . . . . . . . . 352
s (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
S (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
s (Gnus Summary mode). . . . . . . . . . . . . 399
s (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
s (View mode) . . . . . . . . . . . . . . . . . . . . . . . . 75
S-Mouse-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
S-Mouse-3 (FFAP) . . . . . . . . . . . . . . . . . . . 427
S-TAB (customization buffer) . . . . . . . . . 435
S-TAB (Help mode) . . . . . . . . . . . . . . . . . . . . 43
S-TAB (Org Mode) . . . . . . . . . . . . . . . . . . . 229
SPC (Calendar mode) . . . . . . . . . . . . . . . . . 349
SPC (completion) . . . . . . . . . . . . . . . . . . . . . . 30
SPC (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . 330
SPC (DocView mode) . . . . . . . . . . . . . . . . . 400
SPC (GDB Breakpoints buffer) . . . . . . . 283
SPC (Gnus Group mode) . . . . . . . . . . . . . 398
SPC (Gnus Summary mode) . . . . . . . . . . 399
SPC (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . 377
SPC (View mode) . . . . . . . . . . . . . . . . . . . . . . 75

Q

T

q (Calendar mode) . . . . . . . . . . . . . . . . . . . 349
q (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329

t (Calendar mode) . . . . . . . . . . . . . . 349, 350
t (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334

O
o
o
O
o
o

(Calendar mode) . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Occur mode) . . . . . . . . . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

348
332
336
108
382

P

Key (Character) Index
T (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
t (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
TAB (and major modes) . . . . . . . . . . . . . . 204
TAB (completion) . . . . . . . . . . . . . . . . . . 29, 30
TAB (customization buffer) . . . . . . . . . . . 435
TAB (GUD) . . . . . . . . . . . . . . . . . . . . . . . . . . 280
TAB (Help mode) . . . . . . . . . . . . . . . . . . . . . . 43
TAB (indentation) . . . . . . . . . . . . . . . . . . . . 210
TAB (Message mode) . . . . . . . . . . . . . . . . . 372
TAB (Org Mode). . . . . . . . . . . . . . . . . . . . . . 229
TAB (programming modes) . . . . . . . . . . . 252
TAB (Shell mode) . . . . . . . . . . . . . . . . . . . . . 404
TAB (Text mode) . . . . . . . . . . . . . . . . . . . . . 223

589
UP (minibuffer history) . . . . . . . . . . . . . . . . 34

V
v (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
v (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391

W
w (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344
w (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382

X
U
u (Calendar mode) . . . . . . . . . . . . . . . . . . . 351
u (Dired deletion) . . . . . . . . . . . . . . . . . . . . 330
u (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
U (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
u (Gnus Group mode) . . . . . . . . . . . . . . . . 398
u (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

x
x
X
x

(Calendar mode) . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
(Rmail) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

351
330
337
379

Z
Z (Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336

Command and Function Index

590

Command and Function Index
2
2C-associate-buffer . . . . . . . . . . . . . . . .
2C-dissociate. . . . . . . . . . . . . . . . . . . . . . .
2C-merge . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2C-newline . . . . . . . . . . . . . . . . . . . . . . . . . .
2C-split . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2C-two-columns . . . . . . . . . . . . . . . . . . . . .

247
247
247
247
247
247

5
5x5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428

A
abbrev-mode . . . . . . . . . . . . . . . . . . . . . . . . . 322
abbrev-prefix-mark . . . . . . . . . . . . . . . . . 324
abort-recursive-edit. . . . . . . . . . . . . . . 469
add-change-log-entry-other-window
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
add-change-log-entry-other-window, in
Diff mode . . . . . . . . . . . . . . . . . . . . . . . 142
add-dir-local-variable . . . . . . . . . . . . 451
add-file-local-variable . . . . . . . . . . . 448
add-file-local-variable-prop-line
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
add-global-abbrev . . . . . . . . . . . . . . . . . . 323
add-hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445
add-mode-abbrev . . . . . . . . . . . . . . . . . . . . 323
add-name-to-file . . . . . . . . . . . . . . . . . . . 143
add-untranslated-filesystem . . . . . . 537
animate-birthday-present . . . . . . . . . . 428
append-next-kill . . . . . . . . . . . . . . . . . . . . 59
append-to-buffer . . . . . . . . . . . . . . . . . . . . 61
append-to-file. . . . . . . . . . . . . . . . . . . . . . . 61
append-to-register . . . . . . . . . . . . . . . . . . 67
apply-macro-to-region-lines . . . . . . 117
appt-activate. . . . . . . . . . . . . . . . . . . . . . . 364
appt-add . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364
appt-delete . . . . . . . . . . . . . . . . . . . . . . . . . 364
apropos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
apropos-command . . . . . . . . . . . . . . . . . . . . . 41
apropos-documentation . . . . . . . . . . . . . . 42
apropos-value . . . . . . . . . . . . . . . . . . . . . . . . 42
apropos-variable . . . . . . . . . . . . . . . . . . . . 42
ask-user-about-lock . . . . . . . . . . . . . . . . 133
async-shell-command . . . . . . . . . . . . . . . . 402
auto-compression-mode . . . . . . . . . . . . . 144
auto-fill-mode . . . . . . . . . . . . . . . . . . . . . 218

auto-revert-mode . . . . . . . . . . . . . . . . . . . 135
auto-revert-tail-mode . . . . . . . . . . . . . 135
auto-save-mode . . . . . . . . . . . . . . . . . . . . . 137

B
back-to-indentation . . . . . . . . . . . . . . . . 210
backward-button . . . . . . . . . . . . . . . . . . . . . 43
backward-char . . . . . . . . . . . . . . . . . . . . . . . . 18
backward-delete-char-untabify . . . . 249
backward-kill-sentence . . . . . . . . . . . . 216
backward-kill-word . . . . . . . . . . . . . . . . . 215
backward-list. . . . . . . . . . . . . . . . . . . . . . . 258
backward-page. . . . . . . . . . . . . . . . . . . . . . . 217
backward-paragraph . . . . . . . . . . . . . . . . . 216
backward-sentence . . . . . . . . . . . . . . . . . . 215
backward-sexp. . . . . . . . . . . . . . . . . . . . . . . 256
backward-text-line . . . . . . . . . . . . . . . . . 237
backward-up-list . . . . . . . . . . . . . . . . . . . 258
backward-word . . . . . . . . . . . . . . . . . . . 19, 214
balance-windows . . . . . . . . . . . . . . . . . . . . 162
beginning-of-buffer . . . . . . . . . . . . . . . . . 19
beginning-of-defun . . . . . . . . . . . . . . . . . 251
beginning-of-visual-line . . . . . . . . . . . 89
bibtex-mode . . . . . . . . . . . . . . . . . . . . . . . . . 231
binary-overwrite-mode . . . . . . . . . . . . . 207
blackbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
blink-cursor-mode . . . . . . . . . . . . . . . . . . . 88
bookmark-delete . . . . . . . . . . . . . . . . . . . . . 69
bookmark-insert . . . . . . . . . . . . . . . . . . . . . 69
bookmark-insert-location . . . . . . . . . . . 69
bookmark-jump . . . . . . . . . . . . . . . . . . . . 68, 69
bookmark-load . . . . . . . . . . . . . . . . . . . . . . . . 69
bookmark-save . . . . . . . . . . . . . . . . . . . . . . . . 69
bookmark-set . . . . . . . . . . . . . . . . . . . . . 68, 69
bookmark-write. . . . . . . . . . . . . . . . . . . . . . . 69
browse-url . . . . . . . . . . . . . . . . . . . . . . 43, 426
browse-url-at-mouse . . . . . . . . . . . . . . . . 426
browse-url-at-point . . . . . . . . . . . . . . . . 426
bs-show . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
bubbles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
buffer-menu . . . . . . . . . . . . . . . . . . . . . . . . . 154
buffer-menu-other-window . . . . . . . . . . 154

C
c-backslash-region . . . . . . . . . . . . . . . . . 269
c-backward-conditional . . . . . . . . . . . . 266
c-beginning-of-defun. . . . . . . . . . . . . . . 266

Command and Function Index
c-beginning-of-statement . . . . . . . . . .
c-context-line-break. . . . . . . . . . . . . . .
c-electric-backspace. . . . . . . . . . . . . . .
c-end-of-defun . . . . . . . . . . . . . . . . . . . . .
c-end-of-statement . . . . . . . . . . . . . . . . .
c-fill-paragraph . . . . . . . . . . . . . . . . . . .
c-forward-conditional . . . . . . . . . . . . .
c-guess . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
c-guess-install . . . . . . . . . . . . . . . . . . . .
c-hungry-delete-backwards . . . . . . . . .
c-hungry-delete-forward . . . . . . . . . . .
c-indent-command . . . . . . . . . . . . . . 252,
c-indent-defun . . . . . . . . . . . . . . . . . . . . .
c-indent-exp . . . . . . . . . . . . . . . . . . . . . . . .
c-macro-expand . . . . . . . . . . . . . . . . . . . . .
c-mark-function . . . . . . . . . . . . . . . . . . . .
c-set-style . . . . . . . . . . . . . . . . . . . . . . . . .
c-show-syntactic-information . . . . .
c-toggle-auto-newline . . . . . . . . . . . . .
c-toggle-electric-state . . . . . . . . . . .
c-toggle-hungry-state . . . . . . . . . . . . .
c-up-conditional . . . . . . . . . . . . . . . . . . .
calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . .
calendar-astro-goto-day-number . . .
calendar-astro-print-day-number . .
calendar-backward-day . . . . . . . . . . . . .
calendar-backward-month . . . . . . . . . . .
calendar-backward-week . . . . . . . . . . . .
calendar-bahai-goto-date . . . . . . . . . .
calendar-bahai-print-date . . . . . . . . .
calendar-beginning-of-month . . . . . .
calendar-beginning-of-week . . . . . . . .
calendar-beginning-of-year . . . . . . . .
calendar-chinese-goto-date . . . . . . . .
calendar-chinese-print-date . . . . . .
calendar-coptic-goto-date . . . . . . . . .
calendar-coptic-print-date . . . . . . . .
calendar-count-days-region . . . . . . . .
calendar-cursor-holidays . . . . . . . . . .
calendar-end-of-month . . . . . . . . . . . . .
calendar-end-of-week. . . . . . . . . . . . . . .
calendar-end-of-year. . . . . . . . . . . . . . .
calendar-ethiopic-goto-date . . . . . .
calendar-ethiopic-print-date . . . . .
calendar-forward-day. . . . . . . . . . . . . . .
calendar-forward-month . . . . . . . . . . . .
calendar-forward-week . . . . . . . . . . . . .
calendar-forward-year . . . . . . . . . . . . .
calendar-french-goto-date . . . . . . . . .
calendar-french-print-date . . . . . . . .
calendar-goto-date . . . . . . . . . . . . . . . . .
calendar-goto-day-of-year . . . . . . . . .

591
266
268
249
266
267
268
266
256
256
267
267
254
254
254
269
251
255
269
267
267
268
266
346
356
355
346
347
346
356
355
347
347
347
356
355
356
355
349
351
347
347
347
356
355
346
347
346
347
356
355
348
348

calendar-goto-today . . . . . . . . . . . . . . . . 348
calendar-hebrew-goto-date . . . . . . . . . 356
calendar-hebrew-list-yahrzeits . . . 357
calendar-hebrew-print-date . . . . . . . . 355
calendar-islamic-goto-date . . . . . . . . 356
calendar-islamic-print-date . . . . . . 355
calendar-iso-goto-date . . . . . . . . . . . . 356
calendar-iso-goto-week . . . . . . . 348, 356
calendar-iso-print-date . . . . . . . . . . . 355
calendar-julian-goto-date . . . . . . . . . 356
calendar-julian-print-date . . . . . . . . 355
calendar-list-holidays . . . . . . . . . . . . 351
calendar-lunar-phases . . . . . . . . . . . . . 353
calendar-mark-holidays . . . . . . . . . . . . 351
calendar-mayan-goto-long-count-date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
calendar-mayan-next-calendar-rounddate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
calendar-mayan-next-haab-date . . . . 358
calendar-mayan-next-tzolkin-date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
calendar-mayan-previous-haab-date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
calendar-mayan-previous-tzolkin-date
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
calendar-mayan-print-date . . . . . . . . . 355
calendar-other-month. . . . . . . . . . . . . . . 348
calendar-persian-goto-date . . . . . . . . 356
calendar-persian-print-date . . . . . . 355
calendar-print-day-of-year . . . . . . . . 349
calendar-print-other-dates . . . . . . . . 355
calendar-redraw . . . . . . . . . . . . . . . . . . . . 349
calendar-scroll-left. . . . . . . . . . . . . . . 348
calendar-scroll-left-three-months
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
calendar-scroll-right . . . . . . . . . . . . . 348
calendar-scroll-right-three-months
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
calendar-set-date-style . . . . . . . . . . . 361
calendar-sunrise-sunset . . . . . . . . . . . 352
calendar-unmark . . . . . . . . . . . . . . . . . . . . 351
capitalize-word . . . . . . . . . . . . . . . . . . . . 223
cd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
center-line . . . . . . . . . . . . . . . . . . . . . . . . . 220
change-log-merge . . . . . . . . . . . . . . . . . . . 310
change-log-mode . . . . . . . . . . . . . . . . . . . . 310
check-parens . . . . . . . . . . . . . . . . . . . . . . . . 256
choose-completion . . . . . . . . . . . . . . . . . . . 31
clean-buffer-list . . . . . . . . . . . . . . . . . . 154
clear-rectangle . . . . . . . . . . . . . . . . . . . . . 64
clipboard-kill-region . . . . . . . . . . . . . . 60
clipboard-kill-ring-save . . . . . . . . . . . 60

Command and Function Index
clipboard-yank. . . . . . . . . . . . . . . . . . . . . . . 60
clone-indirect-buffer . . . . . . . . . . . . . 156
clone-indirect-buffer-other-window
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
column-number-mode . . . . . . . . . . . . . . . . . . 85
comint-bol-or-process-mark . . . . . . . . 404
comint-continue-subjob . . . . . . . . . . . . 405
comint-copy-old-input . . . . . . . . . . . . . 408
comint-delchar-or-maybe-eof . . . . . . 404
comint-delete-output. . . . . . . . . . . . . . . 405
comint-dynamic-list-filename... . . 404
comint-dynamic-list-input-ring . . . 407
comint-get-next-from-history . . . . . 407
comint-history-isearch-backwardregexp . . . . . . . . . . . . . . . . . . . . . . . . . . 407
comint-input-previous-argument . . . 407
comint-interrupt-subjob . . . . . . . . . . . 404
comint-kill-input . . . . . . . . . . . . . . . . . . 404
comint-magic-space . . . . . . . . . . . . . . . . . 409
comint-next-input . . . . . . . . . . . . . . . . . . 407
comint-next-prompt . . . . . . . . . . . . . . . . . 408
comint-previous-input . . . . . . . . . . . . . 407
comint-previous-prompt . . . . . . . . . . . . 408
comint-quit-subjob . . . . . . . . . . . . . . . . . 405
comint-run . . . . . . . . . . . . . . . . . . . . . . . . . . 406
comint-send-input . . . . . . . . . . . . . . . . . . 404
comint-show-maximum-output . . . . . . . . 405
comint-show-output . . . . . . . . . . . . . . . . . 405
comint-stop-subjob . . . . . . . . . . . . . . . . . 405
comint-strip-ctrl-m . . . . . . . . . . . . . . . . 405
comint-truncate-buffer . . . . . . . . . . . . 406
comint-write-output . . . . . . . . . . . . . . . . 405
comment-dwim . . . . . . . . . . . . . . . . . . . . . . . . 259
comment-indent-new-line . . . . . . . . . . . 260
comment-kill . . . . . . . . . . . . . . . . . . . . . . . . 260
comment-region . . . . . . . . . . . . . . . . . . . . . 260
comment-set-column . . . . . . . . . . . . . . . . . 261
compare-windows . . . . . . . . . . . . . . . . . . . . 140
compilation-next-error . . . . . . . . . . . . 274
compilation-next-file . . . . . . . . . . . . . 274
compilation-previous-error . . . . . . . . 274
compilation-previous-file . . . . . . . . . 274
compile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
compile-goto-error . . . . . . . . . . . . . . . . . 272
completion-at-point . . . . . . . . . . . 264, 404
compose-mail . . . . . . . . . . . . . . . . . . . . . . . . 367
compose-mail-other-frame . . . . . . . . . . 367
compose-mail-other-window . . . . . . . . . 367
copy-dir-locals-to-file-locals . . . 448
copy-dir-locals-to-file-locals-propline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
copy-directory . . . . . . . . . . . . . . . . . . . . . 143

592
copy-file . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
copy-file-locals-to-dir-locals . . . 451
copy-rectangle-to-register . . . . . . . . . 67
copy-to-buffer. . . . . . . . . . . . . . . . . . . . . . . 61
copy-to-register . . . . . . . . . . . . . . . . . . . . 67
count-lines-page . . . . . . . . . . . . . . . . . . . 218
count-text-lines . . . . . . . . . . . . . . . . . . . 237
count-words . . . . . . . . . . . . . . . . . . . . . . . . . . 24
count-words-region . . . . . . . . . . . . . . . . . . 24
cpp-highlight-buffer. . . . . . . . . . . . . . . 269
create-fontset-from-fontset-spec
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
crisp-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 425
cua-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Custom-save . . . . . . . . . . . . . . . . . . . . . . . . . 438
Custom-set . . . . . . . . . . . . . . . . . . . . . . . . . . 438
customize . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
customize-apropos . . . . . . . . . . . . . . . . . . 440
customize-browse . . . . . . . . . . . . . . . . . . . 435
customize-changed . . . . . . . . . . . . . . . . . . 441
customize-create-theme . . . . . . . . . . . . 442
customize-face . . . . . . . . . . . . . . . . . . . . . 440
customize-group . . . . . . . . . . . . . . . . . . . . 440
customize-option . . . . . . . . . . . . . . . . . . . 440
customize-saved . . . . . . . . . . . . . . . . . . . . 441
customize-themes . . . . . . . . . . . . . . . . . . . 441
customize-unsaved . . . . . . . . . . . . . . . . . . 441
cwarn-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 269

D
dabbrev-completion . . . . . . . . . . . . . . . . . 326
dabbrev-expand . . . . . . . . . . . . . . . . . . . . . 326
dbx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
debug_print . . . . . . . . . . . . . . . . . . . . . . . . . 479
decipher . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
default-value. . . . . . . . . . . . . . . . . . . . . . . 447
define-abbrevs . . . . . . . . . . . . . . . . . . . . . 326
define-global-abbrev. . . . . . . . . . . . . . . 323
define-key . . . . . . . . . . . . . . . . . . . . . . . . . . 456
define-mode-abbrev . . . . . . . . . . . . . . . . . 323
delete-backward-char . . . . . . . . . . . . . . . . 54
delete-blank-lines . . . . . . . . . . . . . . . . . . 22
delete-char . . . . . . . . . . . . . . . . . . . . . . . . . . 54
delete-dir-local-variable . . . . . . . . . 451
delete-file . . . . . . . . . . . . . . . . . . . . . . . . . 143
delete-file-local-variable . . . . . . . . 448
delete-file-local-variable-prop-line
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
delete-frame . . . . . . . . . . . . . . . . . . . . . . . . 170
delete-horizontal-space . . . . . . . . . . . . 55
delete-indentation . . . . . . . . . . . . . . . . . 211

Command and Function Index
delete-other-frames . . . . . . . . . . . . . . . . 170
delete-other-windows. . . . . . . . . . . . . . . 162
delete-rectangle . . . . . . . . . . . . . . . . . . . . 63
delete-selection-mode . . . . . . . . . . . . . . 50
delete-trailing-whitespace . . . . . . . . . 84
delete-whitespace-rectangle . . . . . . . . 64
delete-window. . . . . . . . . . . . . . . . . . . . . . . 162
describe-bindings . . . . . . . . . . . . . . . . . . . 44
describe-categories . . . . . . . . . . . . . . . . 102
describe-character-set . . . . . . . . . . . . 202
describe-coding-system . . . . . . . . . . . . 188
describe-copying . . . . . . . . . . . . . . . . . . . . 45
describe-distribution . . . . . . . . . . . . . . 45
describe-function . . . . . . . . . . . . . . . . . . . 40
describe-gnu-project . . . . . . . . . . . . . . . . 45
describe-input-method . . . . . . . . . . . . . 187
describe-key . . . . . . . . . . . . . . . . . . . . . . . . . 40
describe-key-briefly . . . . . . . . . . . . . . . . 40
describe-language-environment . . . . 184
describe-mode . . . . . . . . . . . . . . . . . . . 44, 205
describe-no-warranty . . . . . . . . . . . . . . . . 45
describe-package . . . . . . . . . . . . . . . 43, 430
describe-prefix-bindings . . . . . . . . . . . 45
describe-text-properties . . . . . . . . . . 239
describe-theme . . . . . . . . . . . . . . . . . . . . . 442
describe-variable . . . . . . . . . . . . . . . . . . . 41
desktop-change-dir . . . . . . . . . . . . . . . . . 423
desktop-clear. . . . . . . . . . . . . . . . . . . . . . . 423
desktop-revert . . . . . . . . . . . . . . . . . . . . . 423
desktop-save . . . . . . . . . . . . . . . . . . . . . . . . 423
diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
diary-anniversary . . . . . . . . . . . . . . . . . . 362
diary-block . . . . . . . . . . . . . . . . . . . . . . . . . 363
diary-cyclic . . . . . . . . . . . . . . . . . . . . . . . . 363
diary-float . . . . . . . . . . . . . . . . . . . . . . . . . 363
diary-insert-anniversary-entry . . . 362
diary-insert-block-entry . . . . . . . . . . 363
diary-insert-cyclic-entry . . . . . . . . . 363
diary-insert-entry . . . . . . . . . . . . . . . . . 362
diary-insert-monthly-entry . . . . . . . . 362
diary-insert-weekly-entry . . . . . . . . . 362
diary-insert-yearly-entry . . . . . . . . . 362
diary-mail-entries . . . . . . . . . . . . . . . . . 359
diary-mark-entries . . . . . . . . . . . . . . . . . 359
diary-show-all-entries . . . . . . . . . . . . 359
diary-view-entries . . . . . . . . . . . . . . . . . 359
diff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
diff-add-change-log-entries-otherwindow . . . . . . . . . . . . . . . . . . . . . . . . . . 142
diff-apply-hunk . . . . . . . . . . . . . . . . . . . . 142
diff-auto-refine-mode . . . . . . . . . . . . . 141
diff-backup . . . . . . . . . . . . . . . . . . . . . . . . . 140

593
diff-buffer-with-file . . . . . . . . . . . . . 140
diff-context->unified . . . . . . . . . . . . . 142
diff-ediff-patch . . . . . . . . . . . . . . . . . . . 142
diff-file-kill . . . . . . . . . . . . . . . . . . . . . 142
diff-file-next . . . . . . . . . . . . . . . . . . . . . 141
diff-file-prev . . . . . . . . . . . . . . . . . . . . . 141
diff-goto-source . . . . . . . . . . . . . . . . . . . 142
diff-hunk-kill . . . . . . . . . . . . . . . . . . . . . 142
diff-hunk-next . . . . . . . . . . . . . . . . . . . . . 141
diff-hunk-prev . . . . . . . . . . . . . . . . . . . . . 141
diff-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
diff-refine-hunk . . . . . . . . . . . . . . . . . . . 142
diff-restrict-view . . . . . . . . . . . . . . . . . 142
diff-reverse-direction . . . . . . . . . . . . 142
diff-split-hunk . . . . . . . . . . . . . . . . . . . . 142
diff-unified->context . . . . . . . . . . . . . 142
digit-argument. . . . . . . . . . . . . . . . . . . . . . . 25
dir-locals-set-class-variables . . . 451
dir-locals-set-directory-class . . . 451
dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
dired-at-point . . . . . . . . . . . . . . . . . . . . . 427
dired-backup-diff . . . . . . . . . . . . . . . . . . 339
dired-change-marks . . . . . . . . . . . . . . . . . 334
dired-clean-directory . . . . . . . . . . . . . 331
dired-compare-directories . . . . . . . . . 345
dired-copy-filename-as-kill . . . . . . 344
dired-create-directory . . . . . . . . . . . . 344
dired-diff . . . . . . . . . . . . . . . . . . . . . . . . . . 339
dired-display-file . . . . . . . . . . . . . . . . . 332
dired-do-byte-compile . . . . . . . . . . . . . 336
dired-do-chgrp . . . . . . . . . . . . . . . . . . . . . 336
dired-do-chmod . . . . . . . . . . . . . . . . . . . . . 336
dired-do-chown . . . . . . . . . . . . . . . . . . . . . 336
dired-do-compress . . . . . . . . . . . . . . . . . . 336
dired-do-copy. . . . . . . . . . . . . . . . . . . . . . . 335
dired-do-copy-regexp. . . . . . . . . . . . . . . 338
dired-do-delete . . . . . . . . . . . . . . . . . . . . 335
dired-do-flagged-delete . . . . . . . . . . . 330
dired-do-hardlink . . . . . . . . . . . . . . . . . . 335
dired-do-hardlink-regexp . . . . . . . . . . 338
dired-do-isearch . . . . . . . . . . . . . . . . . . . 344
dired-do-isearch-regexp . . . . . . . . . . . 344
dired-do-kill-lines . . . . . . . . . . . . . . . . 341
dired-do-load. . . . . . . . . . . . . . . . . . . . . . . 336
dired-do-print . . . . . . . . . . . . . . . . . . . . . 336
dired-do-query-replace-regexp . . . . 337
dired-do-redisplay . . . . . . . . . . . . . . . . . 341
dired-do-rename . . . . . . . . . . . . . . . . . . . . 335
dired-do-rename-regexp . . . . . . . . . . . . 338
dired-do-search . . . . . . . . . . . . . . . . . . . . 337
dired-do-shell-command . . . . . . . . . . . . 337
dired-do-symlink . . . . . . . . . . . . . . . . . . . 336

Command and Function Index
dired-do-symlink-regexp . . . . . . . . . . . 338
dired-do-touch . . . . . . . . . . . . . . . . . . . . . 336
dired-downcase . . . . . . . . . . . . . . . . . . . . . 338
dired-find-file . . . . . . . . . . . . . . . . . . . . 332
dired-find-file-other-window . . . . . 332
dired-flag-auto-save-files . . . . . . . . 331
dired-flag-backup-files . . . . . . . . . . . 331
dired-flag-file-deletion . . . . . . . . . . 330
dired-flag-files-regexp . . . . . . . . . . . 332
dired-flag-garbage-files . . . . . . . . . . 332
dired-goto-file . . . . . . . . . . . . . . . . . . . . 330
dired-hide-all . . . . . . . . . . . . . . . . . . . . . 340
dired-hide-subdir . . . . . . . . . . . . . . . . . . 340
dired-isearch-filenames . . . . . . . . . . . 330
dired-isearch-filenames-regexp . . . 330
dired-mark . . . . . . . . . . . . . . . . . . . . . . . . . . 333
dired-mark-directories . . . . . . . . . . . . 333
dired-mark-executables . . . . . . . . . . . . 333
dired-mark-files-containing-regexp
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
dired-mark-files-regexp . . . . . . . . . . . 334
dired-mark-subdir-files . . . . . . . . . . . 333
dired-mark-symlinks . . . . . . . . . . . . . . . . 333
dired-maybe-insert-subdir . . . . . . . . . 339
dired-mouse-find-file-other-window
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
dired-next-dirline . . . . . . . . . . . . . . . . . 340
dired-next-marked-file . . . . . . . . . . . . 333
dired-next-subdir . . . . . . . . . . . . . . . . . . 340
dired-other-frame . . . . . . . . . . . . . . . . . . 329
dired-other-window . . . . . . . . . . . . 161, 329
dired-prev-dirline . . . . . . . . . . . . . . . . . 340
dired-prev-marked-file . . . . . . . . . . . . 334
dired-prev-subdir . . . . . . . . . . . . . . . . . . 340
dired-sort-toggle-or-edit . . . . . . . . . 342
dired-toggle-marks . . . . . . . . . . . . . . . . . 334
dired-tree-down . . . . . . . . . . . . . . . . . . . . 340
dired-tree-up. . . . . . . . . . . . . . . . . . . . . . . 340
dired-undo . . . . . . . . . . . . . . . . . . . . . . . . . . 334
dired-unmark . . . . . . . . . . . . . . . . . . . . . . . . 333
dired-unmark-all-files . . . . . . . . . . . . 333
dired-unmark-all-marks . . . . . . . . . . . . 333
dired-unmark-backward . . . . . . . . . . . . . 333
dired-up-directory . . . . . . . . . . . . . . . . . 332
dired-upcase . . . . . . . . . . . . . . . . . . . . . . . . 338
dired-view-file . . . . . . . . . . . . . . . . . . . . 332
dirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
dirtrack-mode. . . . . . . . . . . . . . . . . . . . . . . 409
disable-command . . . . . . . . . . . . . . . . . . . . 461
disable-theme. . . . . . . . . . . . . . . . . . . . . . . 442
display-battery-mode . . . . . . . . . . . . . . . . 86
display-buffer . . . . . . . . . . . . . . . . . 161, 163

594
display-local-help . . . . . . . . . . . . . . . . . . 46
display-time . . . . . . . . . . . . . . . . . . . . . . . . . 86
dissociated-press . . . . . . . . . . . . . . . . . . 428
do-auto-save . . . . . . . . . . . . . . . . . . . . . . . . 137
doc-view-clear-cache. . . . . . . . . . . . . . . 401
doc-view-enlarge . . . . . . . . . . . . . . . . . . . 400
doc-view-first-page . . . . . . . . . . . . . . . . 400
doc-view-goto-page . . . . . . . . . . . . . . . . . 400
doc-view-kill-proc . . . . . . . . . . . . . . . . . 401
doc-view-kill-proc-and-buffer . . . . 401
doc-view-last-page . . . . . . . . . . . . . . . . . 400
doc-view-mode. . . . . . . . . . . . . . . . . . . . . . . 399
doc-view-next-page . . . . . . . . . . . . . . . . . 400
doc-view-previous-page . . . . . . . . . . . . 400
doc-view-reset-slice. . . . . . . . . . . . . . . 401
doc-view-scroll-down-or-previouspage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400
doc-view-scroll-up-or-next-page . . 400
doc-view-search . . . . . . . . . . . . . . . . . . . . 400
doc-view-search-backward . . . . . . . . . . 400
doc-view-set-slice . . . . . . . . . . . . . . . . . 400
doc-view-set-slice-using-mouse . . . 400
doc-view-show-tooltip . . . . . . . . . . . . . 400
doc-view-shrink . . . . . . . . . . . . . . . . . . . . 400
doc-view-toggle-display . . . . . . . . . . . 399
doctex-mode . . . . . . . . . . . . . . . . . . . . . . . . . 231
doctor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
down-list . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
downcase-region . . . . . . . . . . . . . . . . . . . . 223
downcase-word. . . . . . . . . . . . . . . . . . . . . . . 223
dunnet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428

E
edit-abbrevs . . . . . . . . . . . . . . . . . . . . . . . . 325
edit-kbd-macro . . . . . . . . . . . . . . . . . . . . . 122
edit-tab-stops . . . . . . . . . . . . . . . . . . . . . 211
edt-emulation-off . . . . . . . . . . . . . . . . . . 425
edt-emulation-on . . . . . . . . . . . . . . . . . . . 425
eldoc-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 263
electric-indent-mode. . . . . . . . . . . . . . . 213
electric-layout-mode. . . . . . . . . . . . . . . 266
electric-nroff-mode . . . . . . . . . . . . . . . . 237
electric-pair-mode . . . . . . . . . . . . . . . . . 258
emacs-lisp-mode . . . . . . . . . . . . . . . . . . . . 288
emacs-version. . . . . . . . . . . . . . . . . . . . . . . 475
enable-command . . . . . . . . . . . . . . . . . . . . . 461
enable-theme . . . . . . . . . . . . . . . . . . . . . . . . 442
end-of-buffer . . . . . . . . . . . . . . . . . . . . . . . . 19
end-of-defun . . . . . . . . . . . . . . . . . . . . . . . . 251
end-of-visual-line . . . . . . . . . . . . . . . . . . 89
enlarge-window . . . . . . . . . . . . . . . . . . . . . 162

Command and Function Index
enlarge-window-horizontally . . . . . . 162
enriched-mode. . . . . . . . . . . . . . . . . . . . . . . 238
epa-dired-do-decrypt. . . . . . . . . . . . . . . 336
epa-dired-do-encrypt. . . . . . . . . . . . . . . 336
epa-dired-do-sign . . . . . . . . . . . . . . . . . . 336
epa-dired-do-verify . . . . . . . . . . . . . . . . 336
eval-buffer . . . . . . . . . . . . . . . . . . . . . . . . . 289
eval-defun . . . . . . . . . . . . . . . . . . . . . . . . . . 289
eval-expression . . . . . . . . . . . . . . . . . . . . 289
eval-last-sexp . . . . . . . . . . . . . . . . . . . . . 289
eval-print-last-sexp. . . . . . . . . . . . . . . 290
eval-region . . . . . . . . . . . . . . . . . . . . . . . . . 289
exchange-point-and-mark . . . . . . . . . . . . 48
execute-extended-command . . . . . . . . . . . 37
exit-calendar. . . . . . . . . . . . . . . . . . . . . . . 349
exit-recursive-edit . . . . . . . . . . . . . . . . 424
expand-abbrev. . . . . . . . . . . . . . . . . . . . . . . 324
expand-region-abbrevs . . . . . . . . . . . . . 324

F
facemenu-remove-all . . . . . . . . . . . . . . . . 239
facemenu-remove-face-props . . . . . . . . 239
facemenu-set-background . . . . . . . . . . . 240
facemenu-set-bold . . . . . . . . . . . . . . . . . . 239
facemenu-set-bold-italic . . . . . . . . . . 239
facemenu-set-default. . . . . . . . . . . . . . . 239
facemenu-set-face . . . . . . . . . . . . . . . . . . 239
facemenu-set-foreground . . . . . . . . . . . 240
facemenu-set-italic . . . . . . . . . . . . . . . . 239
facemenu-set-underline . . . . . . . . . . . . 239
ff-find-related-file. . . . . . . . . . . . . . . 270
ffap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
ffap-menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
ffap-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
ffap-next . . . . . . . . . . . . . . . . . . . . . . . . . . . 427
file-cache-add-directory . . . . . . . . . . 147
file-cache-minibuffer-complete . . . 147
file-name-shadow-mode . . . . . . . . . . . . . . 27
filesets-add-buffer . . . . . . . . . . . . . . . . 148
filesets-init. . . . . . . . . . . . . . . . . . . . . . . 148
filesets-remove-buffer . . . . . . . . . . . . 148
fill-individual-paragraphs . . . . . . . . 221
fill-nonuniform-paragraphs . . . . . . . . 221
fill-paragraph . . . . . . . . . . . . . . . . . . . . . 219
fill-region . . . . . . . . . . . . . . . . . . . . . . . . . 219
fill-region-as-paragraph . . . . . . . . . . 219
find-alternate-file . . . . . . . . . . . . . . . . 126
find-dired . . . . . . . . . . . . . . . . . . . . . . . . . . 342
find-file . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
find-file-at-point . . . . . . . . . . . . . . . . . 427
find-file-literally . . . . . . . . . . . . . . . . 127

595
find-file-other-frame . . . . . . . . . . . . . 127
find-file-other-window . . . . . . . 127, 161
find-file-read-only . . . . . . . . . . . . . . . . 127
find-file-read-only-other-frame . . 170
find-grep . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
find-grep-dired . . . . . . . . . . . . . . . . . . . . 342
find-name-dired . . . . . . . . . . . . . . . . . . . . 342
find-tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318
find-tag-other-frame. . . . . . . . . . . . . . . 318
find-tag-other-window . . . . . . . . . 161, 318
find-tag-regexp . . . . . . . . . . . . . . . . . . . . 318
finder-by-keyword . . . . . . . . . . . . . . . . . . . 43
flush-lines . . . . . . . . . . . . . . . . . . . . . . . . . 107
flyspell-mode. . . . . . . . . . . . . . . . . . . . . . . 115
flyspell-prog-mode . . . . . . . . . . . . . . . . . 115
foldout-exit-fold . . . . . . . . . . . . . . . . . . 228
foldout-zoom-subtree. . . . . . . . . . . . . . . 228
follow-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 75
font-lock-add-keywords . . . . . . . . . . . . . 81
font-lock-mode. . . . . . . . . . . . . . . . . . . . . . . 80
font-lock-remove-keywords . . . . . . . . . . 81
format-decode-buffer. . . . . . . . . . . . . . . 238
fortune-to-signature. . . . . . . . . . . . . . . 375
forward-button. . . . . . . . . . . . . . . . . . . . . . . 43
forward-char . . . . . . . . . . . . . . . . . . . . . . . . . 18
forward-list . . . . . . . . . . . . . . . . . . . . . . . . 258
forward-page . . . . . . . . . . . . . . . . . . . . . . . . 217
forward-paragraph . . . . . . . . . . . . . . . . . . 216
forward-sentence . . . . . . . . . . . . . . . . . . . 215
forward-sexp . . . . . . . . . . . . . . . . . . . . . . . . 256
forward-text-line . . . . . . . . . . . . . . . . . . 237
forward-word . . . . . . . . . . . . . . . . . . . . 18, 214
frame-configuration-to-register . . . 67
fringe-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 83

G
gdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
gdb-delete-breakpoint . . . . . . . . . . . . . 283
gdb-display-disassembly-for-thread
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
gdb-display-locals-for-thread . . . . 283
gdb-display-registers-for-thread
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
gdb-display-stack-for-thread . . . . . 283
gdb-edit-value . . . . . . . . . . . . . . . . . . . . . 285
gdb-frames-select . . . . . . . . . . . . . . . . . . 284
gdb-goto-breakpoint . . . . . . . . . . . . . . . . 283
gdb-many-windows . . . . . . . . . . . . . . . . . . . 281
gdb-restore-windows . . . . . . . . . . . . . . . . 281
gdb-select-thread . . . . . . . . . . . . . . . . . . 283
gdb-toggle-breakpoint . . . . . . . . . . . . . 283

Command and Function Index
gdb-var-delete . . . . . . . . . . . . . . . . . . . . . 285
getenv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510
global-auto-revert-mode . . . . . . . . . . . 135
global-cwarn-mode . . . . . . . . . . . . . . . . . . 269
global-font-lock-mode . . . . . . . . . . . . . . 80
global-hl-line-mode . . . . . . . . . . . . . . . . . 88
global-set-key . . . . . . . . . . . . . . . . . . . . . 454
global-unset-key . . . . . . . . . . . . . . . . . . . 454
global-visual-line-mode . . . . . . . . . . . . 89
gnus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
gnus-group-exit . . . . . . . . . . . . . . . . . . . . 398
gnus-group-kill-group . . . . . . . . . . . . . 398
gnus-group-list-all-groups . . . . . . . . 398
gnus-group-list-groups . . . . . . . . . . . . 398
gnus-group-next-unread-group . . . . . 398,
399
gnus-group-prev-unread-group . . . . . 398,
399
gnus-group-read-group . . . . . . . . . 398, 399
gnus-group-unsubscribe-current-group
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
gnus-summary-isearch-article . . . . . 399
gnus-summary-next-unread-article
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 398, 399
gnus-summary-prev-page . . . . . . . . . . . . 399
gnus-summary-prev-unread-article
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 398, 399
gnus-summary-search-article-forward
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
gomoku . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
goto-address-at-point . . . . . . . . . . . . . 426
goto-address-mode . . . . . . . . . . . . . . . . . . 426
goto-char . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
goto-followup-to . . . . . . . . . . . . . . . . . . . 372
goto-line. . . . . . . . . . . . . . . . . . . . . . . . 19, 151
goto-reply-to. . . . . . . . . . . . . . . . . . . . . . . 372
gpm-mouse-mode . . . . . . . . . . . . . . . . . . . . . 179
grep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
grep-find . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
gud-cont . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-def . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
gud-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-finish . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-gdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
gud-gdb-complete-command . . . . . . . . . . 280
gud-jump . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
gud-next . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-print . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-refresh . . . . . . . . . . . . . . . . . . . . . . . . . 278
gud-remove . . . . . . . . . . . . . . . . . . . . . . . . . . 279
gud-step . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
gud-stepi . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

596
gud-tbreak . . . . . . . . . . . . . . . . . . . . . . . . . .
gud-tooltip-mode . . . . . . . . . . . . . . . . . . .
gud-until . . . . . . . . . . . . . . . . . . . . . . . . . . .
gud-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
gud-watch . . . . . . . . . . . . . . . . . . . . . . . . . . .

279
278
279
279
285

H
handwrite . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
hanoi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
help-command . . . . . . . . . . . . . . . . . . . . . . . . . 38
help-follow . . . . . . . . . . . . . . . . . . . . . . . . . . 43
help-for-help . . . . . . . . . . . . . . . . . . . . . . . . 38
help-go-back . . . . . . . . . . . . . . . . . . . . . . . . . 43
help-with-tutorial . . . . . . . . . . . . . . . . . . 17
hi-lock-find-patterns . . . . . . . . . . . . . . 82
hi-lock-mode . . . . . . . . . . . . . . . . . . . . . . . . . 81
hi-lock-write-interactive-patterns
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
hide-body . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
hide-entry . . . . . . . . . . . . . . . . . . . . . . . . . . 227
hide-ifdef-mode . . . . . . . . . . . . . . . . . . . . 269
hide-leaves . . . . . . . . . . . . . . . . . . . . . . . . . 227
hide-other . . . . . . . . . . . . . . . . . . . . . . . . . . 227
hide-sublevels . . . . . . . . . . . . . . . . . . . . . 227
hide-subtree . . . . . . . . . . . . . . . . . . . . . . . . 227
highlight-changes-mode . . . . . . . . . . . . . 81
highlight-lines-matching-regexp . . . 82
highlight-regexp . . . . . . . . . . . . . . . . . . . . 81
hl-line-mode . . . . . . . . . . . . . . . . . . . . . . . . . 88
holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
how-many . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
hs-hide-all . . . . . . . . . . . . . . . . . . . . . . . . . 263
hs-hide-block. . . . . . . . . . . . . . . . . . . . . . . 263
hs-hide-level. . . . . . . . . . . . . . . . . . . . . . . 263
hs-minor-mode. . . . . . . . . . . . . . . . . . . . . . . 263
hs-show-all . . . . . . . . . . . . . . . . . . . . . . . . . 263
hs-show-block. . . . . . . . . . . . . . . . . . . . . . . 263
hs-show-region . . . . . . . . . . . . . . . . . . . . . 263
html-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
htmlfontify-buffer . . . . . . . . . . . . . . . . . 417

I
icalendar-export-file,
icalendar-export-region . . . . . . . 365
icalendar-import-buffer . . . . . . . . . . . 365
icalendar-import-file . . . . . . . . . . . . . 365
icomplete-mode. . . . . . . . . . . . . . . . . . . . . . . 34
ielm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
image-dired-display-thumbs . . . . . . . . 343
image-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 148

Command and Function Index
image-toggle-animation . . . . . . . . . . . . 148
image-toggle-display. . . . . . . . . . . . . . . 148
imenu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
imenu-add-menubar-index . . . . . . . . . . . 251
increase-left-margin. . . . . . . . . . . . . . . 240
increment-register . . . . . . . . . . . . . . . . . . 68
indent-code-rigidly . . . . . . . . . . . . . . . . 253
indent-for-tab-command . . . . . . . 210, 252
indent-line-function. . . . . . . . . . . . . . . 252
indent-pp-sexp . . . . . . . . . . . . . . . . . . . . . 253
indent-region. . . . . . . . . . . . . . . . . . . . . . . 211
indent-relative . . . . . . . . . . . . . . . . . . . . 210
indent-rigidly . . . . . . . . . . . . . . . . . . . . . 211
info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Info-goto-emacs-command-node . . . . . . 41
Info-goto-emacs-key-command-node . . 40
info-lookup-file . . . . . . . . . . . . . . . . . . . 262
info-lookup-symbol . . . . . . . . . . . . . 44, 262
insert-abbrevs . . . . . . . . . . . . . . . . . . . . . 326
insert-file . . . . . . . . . . . . . . . . . . . . . . . . . 144
insert-file-literally . . . . . . . . . . . . . 144
insert-kbd-macro . . . . . . . . . . . . . . . . . . . 121
insert-register . . . . . . . . . . . . . . . . . . . . . 67
inverse-add-global-abbrev . . . . . . . . . 323
inverse-add-mode-abbrev . . . . . . . . . . . 323
isearch-backward . . . . . . . . . . . . . . . . . . . . 92
isearch-backward-regexp . . . . . . . . . . . . 96
isearch-del-char . . . . . . . . . . . . . . . . . . . . 94
isearch-forward . . . . . . . . . . . . . . . . . . . . . 91
isearch-forward-regexp . . . . . . . . . . . . . 96
isearch-forward-word . . . . . . . . . . . . . . . . 96
isearch-toggle-input-method . . . . . . . . 93
isearch-toggle-specified-inputmethod . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
isearch-yank-char . . . . . . . . . . . . . . . . . . . 94
isearch-yank-kill . . . . . . . . . . . . . . . . . . . 94
isearch-yank-line . . . . . . . . . . . . . . . . . . . 94
isearch-yank-pop . . . . . . . . . . . . . . . . . . . . 94
isearch-yank-word-or-char . . . . . . . . . . 94
iso-gtex2iso . . . . . . . . . . . . . . . . . . . . . . . . 235
iso-iso2gtex . . . . . . . . . . . . . . . . . . . . . . . . 235
iso-iso2tex . . . . . . . . . . . . . . . . . . . . . . . . . 235
iso-tex2iso . . . . . . . . . . . . . . . . . . . . . . . . . 235
ispell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
ispell-buffer. . . . . . . . . . . . . . . . . . . . . . . 113
ispell-change-dictionary . . . . . . . . . . 114
ispell-complete-word. . . . . . . . . . . . . . . 114
ispell-kill-ispell . . . . . . . . . . . . . . . . . 114
ispell-message . . . . . . . . . . . . . . . . . . . . . 373
ispell-region. . . . . . . . . . . . . . . . . . . . . . . 113
ispell-word . . . . . . . . . . . . . . . . . . . . . . . . . 113
iswitchb-mode. . . . . . . . . . . . . . . . . . . . . . . 158

597

J
jdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
jump-to-register . . . . . . . . . . . . . . . . . . . . 66
just-one-space. . . . . . . . . . . . . . . . . . . . . . . 55

K
kbd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455
kbd-macro-query . . . . . . . . . . . . . . . . . . . . 120
keep-lines . . . . . . . . . . . . . . . . . . . . . . . . . . 107
keyboard-escape-quit. . . . . . . . . . . . . . . 469
keyboard-quit. . . . . . . . . . . . . . . . . . . . . . . 468
kill-all-abbrevs . . . . . . . . . . . . . . . . . . . 323
kill-buffer . . . . . . . . . . . . . . . . . . . . . . . . . 153
kill-buffer-and-window . . . . . . . . . . . . 162
kill-compilation . . . . . . . . . . . . . . . . . . . 272
kill-emacs . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
kill-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
kill-local-variable . . . . . . . . . . . . . . . . 447
kill-matching-buffers . . . . . . . . . . . . . 153
kill-rectangle. . . . . . . . . . . . . . . . . . . . . . . 63
kill-region . . . . . . . . . . . . . . . . . . . . . . . . . . 56
kill-ring-save. . . . . . . . . . . . . . . . . . . . . . . 56
kill-sentence. . . . . . . . . . . . . . . . . . . . . . . 215
kill-sexp . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
kill-some-buffers . . . . . . . . . . . . . . . . . . 153
kill-whole-line . . . . . . . . . . . . . . . . . . . . . 56
kill-word . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
kmacro-add-counter . . . . . . . . . . . . . . . . . 119
kmacro-bind-to-key . . . . . . . . . . . . . . . . . 121
kmacro-cycle-ring-next . . . . . . . . . . . . 118
kmacro-cycle-ring-previous . . . . . . . . 118
kmacro-edit-lossage . . . . . . . . . . . . . . . . 122
kmacro-edit-macro . . . . . . . . . . . . . . . . . . 122
kmacro-end-and-call-macro . . . . . . . . . 116
kmacro-end-macro . . . . . . . . . . . . . . . . . . . 117
kmacro-end-or-call-macro . . . . . . . . . . 116
kmacro-end-or-call-macro-repeat . . 118
kmacro-insert-counter . . . . . . . . . . . . . 119
kmacro-name-last-macro . . . . . . . . . . . . 121
kmacro-set-counter . . . . . . . . . . . . . . . . . 119
kmacro-set-format . . . . . . . . . . . . . . . . . . 119
kmacro-start-macro . . . . . . . . . . . . . . . . . 117
kmacro-start-macro-or-insert-counter
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
kmacro-step-edit-macro . . . . . . . . . . . . 122

L
landmark . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
latex-electric-env-pair-mode . . . . . 233

Command and Function Index

598

latex-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 231
left-char . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
left-word . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
lgrep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
line-number-mode . . . . . . . . . . . . . . . . . . . . 85
linum-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 206
lisp-eval-defun . . . . . . . . . . . . . . . . . . . . 290
lisp-interaction-mode . . . . . . . . . . . . . 290
list-abbrevs . . . . . . . . . . . . . . . . . . . . . . . . 325
list-bookmarks. . . . . . . . . . . . . . . . . . . . . . . 68
list-buffers . . . . . . . . . . . . . . . . . . . . . . . . 152
list-character-sets . . . . . . . . . . . . . . . . 202
list-charset-chars . . . . . . . . . . . . . . . . . 202
list-coding-systems . . . . . . . . . . . . . . . . 189
list-colors-display . . . . . . . . . . . . . . . . . 76
list-command-history . . . . . . . . . . . . . . . . 35
list-directory . . . . . . . . . . . . . . . . . . . . . 139
list-faces-display . . . . . . . . . . . . . . . . . . 75
list-holidays. . . . . . . . . . . . . . . . . . . . . . . 352
list-input-methods . . . . . . . . . . . . . . . . . 188
list-matching-lines . . . . . . . . . . . . . . . . 107
list-packages. . . . . . . . . . . . . . . . . . . . . . . 430
list-tags . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
load-file . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
load-library . . . . . . . . . . . . . . . . . . . . . . . . 288
load-theme . . . . . . . . . . . . . . . . . . . . . . . . . . 442
local-set-key. . . . . . . . . . . . . . . . . . . . . . . 454
local-unset-key . . . . . . . . . . . . . . . . . . . . 454
locate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
locate-with-filter . . . . . . . . . . . . . . . . . 342
log-edit-done. . . . . . . . . . . . . . . . . . . . . . . 299
log-edit-insert-changelog . . . . . . . . . 299
log-edit-show-diff . . . . . . . . . . . . . . . . . 299
log-edit-show-files . . . . . . . . . . . . . . . . 299
log-view-toggle-entry-display . . . . 303
lpr-buffer . . . . . . . . . . . . . . . . . . . . . . . . . . 417
lpr-region . . . . . . . . . . . . . . . . . . . . . . . . . . 417
lunar-phases . . . . . . . . . . . . . . . . . . . . . . . . 353

M
mail-abbrev-insert-alias . . . . . . . . . .
mail-add-attachment . . . . . . . . . . . . . . . .
mail-fill-yanked-message . . . . . . . . . .
mail-other-window . . . . . . . . . . . . . . . . . .
mail-text . . . . . . . . . . . . . . . . . . . . . . . . . . .
make-frame-command . . . . . . . . . . . . . . . . .
make-frame-on-display . . . . . . . . . . . . .
make-indirect-buffer. . . . . . . . . . . . . . .
make-local-variable . . . . . . . . . . . . . . . .

370
373
373
161
372
169
175
156
446

make-symbolic-link . . . . . . . . . . . . . . . . . 143
make-variable-buffer-local . . . . . . . . 446
manual-entry . . . . . . . . . . . . . . . . . . . . . . . . 262
mark-defun . . . . . . . . . . . . . . . . . . . . . . . . . . 251
mark-page . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
mark-paragraph . . . . . . . . . . . . . . . . . . . . . 216
mark-sexp. . . . . . . . . . . . . . . . . . . . . . . . 49, 257
mark-whole-buffer . . . . . . . . . . . . . . . . . . . 49
mark-word. . . . . . . . . . . . . . . . . . . . . . . . 49, 215
menu-bar-mode. . . . . . . . . . . . . . . . . . . . . . . 176
menu-bar-open . . . . . . . . . . . . . . . . . . . . . . . . 10
message-goto-bcc . . . . . . . . . . . . . . . . . . . 372
message-goto-cc . . . . . . . . . . . . . . . . . . . . 372
message-goto-fcc . . . . . . . . . . . . . . . . . . . 372
message-goto-subject. . . . . . . . . . . . . . . 372
message-goto-to . . . . . . . . . . . . . . . . . . . . 372
message-insert-signature . . . . . . . . . . 374
message-send . . . . . . . . . . . . . . . . . . . . . . . . 371
message-send-and-exit . . . . . . . . . . . . . 371
message-tab . . . . . . . . . . . . . . . . . . . . . . . . . 372
message-yank-original . . . . . . . . . . . . . 373
message-yank-prefix . . . . . . . . . . . . . . . . 373
minibuffer-complete . . . . . . . . . . . . . . . . . 30
minibuffer-complete-and-exit . . . . . . 31
minibuffer-complete-word . . . . . . . . . . . 30
minibuffer-inactive-mode . . . . . . . . . . . 29
mml-attach-file . . . . . . . . . . . . . . . . . . . . 373
mode, Glasses . . . . . . . . . . . . . . . . . . . . . . . 264
mode, Org. . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
mode, thumbs . . . . . . . . . . . . . . . . . . . . . . . . 148
morse-region . . . . . . . . . . . . . . . . . . . . . . . . 428
mouse-avoidance-mode. . . . . . . . . . . . . . . 179
mouse-buffer-menu . . . . . . . . . . . . . . . . . . 158
mouse-choose-completion . . . . . . . . . . . . 30
mouse-save-then-kill. . . . . . . . . . . . . . . 166
mouse-secondary-save-then-kill . . . . 61
mouse-set-point . . . . . . . . . . . . . . . . . . . . 165
mouse-set-region . . . . . . . . . . . . . . . . . . . 166
mouse-set-secondary . . . . . . . . . . . . . . . . . 61
mouse-start-secondary . . . . . . . . . . . . . . 61
mouse-wheel-mode . . . . . . . . . . . . . . . . . . . 167
mouse-yank-at-click . . . . . . . . . . . . . . . . 166
mouse-yank-primary . . . . . . . . . . . . . . . . . 166
mouse-yank-secondary . . . . . . . . . . . . . . . . 61
move-beginning-of-line . . . . . . . . . . . . . 18
move-end-of-line . . . . . . . . . . . . . . . . . . . . 18
move-to-window-line-top-bottom . . . . 19
mpuz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
msb-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
multi-occur . . . . . . . . . . . . . . . . . . . . . . . . . 107
multi-occur-in-matching-buffers . . 107

Command and Function Index

N
narrow-to-defun . . . . . . . . . . . . . . . . . . . . . 74
narrow-to-page. . . . . . . . . . . . . . . . . . . . . . . 74
narrow-to-region . . . . . . . . . . . . . . . . . . . . 74
nato-region . . . . . . . . . . . . . . . . . . . . . . . . . 428
negative-argument . . . . . . . . . . . . . . . . . . . 25
newline-and-indent . . . . . . . . . . . . 210, 253
next-buffer . . . . . . . . . . . . . . . . . . . . . . . . . 151
next-completion . . . . . . . . . . . . . . . . . . . . . 31
next-error . . . . . . . . . . . . . . . . . . . . . . . . . . 273
next-error-follow-minor-mode . . . . . 274
next-file . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
next-history-element . . . . . . . . . . . . . . . . 34
next-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
next-logical-line . . . . . . . . . . . . . . . . . . . 89
next-matching-history-element . . . . . 34
normal-erase-is-backspace-mode . . . 470
normal-mode . . . . . . . . . . . . . . . . . . . . . . . . . 209
not-modified . . . . . . . . . . . . . . . . . . . . . . . . 129
nroff-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 237
number-to-register . . . . . . . . . . . . . . . . . . 68
nxml-mode . . . . . . . . . . . . . . . . . . . . . . 214, 236

O
occur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
open-dribble-file . . . . . . . . . . . . . . . . . . 477
open-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
open-rectangle. . . . . . . . . . . . . . . . . . . . . . . 64
open-termscript . . . . . . . . . . . . . . . . . . . . 477
Org mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
org-agenda . . . . . . . . . . . . . . . . . . . . . . . . . . 230
org-agenda-file-to-front . . . . . . . . . . 230
org-cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
org-deadline . . . . . . . . . . . . . . . . . . . . . . . . 230
org-export . . . . . . . . . . . . . . . . . . . . . . . . . . 230
org-metadown . . . . . . . . . . . . . . . . . . . . . . . . 229
org-metaleft . . . . . . . . . . . . . . . . . . . . . . . . 229
org-metaright. . . . . . . . . . . . . . . . . . . . . . . 229
org-metaup . . . . . . . . . . . . . . . . . . . . . . . . . . 229
org-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
org-schedule . . . . . . . . . . . . . . . . . . . . . . . . 230
org-shifttab . . . . . . . . . . . . . . . . . . . . . . . . 229
org-todo . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
other-frame . . . . . . . . . . . . . . . . . . . . . . . . . 170
other-window . . . . . . . . . . . . . . . . . . . . . . . . 160
outline-backward-same-level . . . . . . 226
outline-forward-same-level . . . . . . . . 226
outline-minor-mode . . . . . . . . . . . . . . . . . 224
outline-mode . . . . . . . . . . . . . . . . . . . . . . . . 224
outline-next-visible-heading . . . . . 226

599
outline-previous-visible-heading
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
outline-up-heading . . . . . . . . . . . . . . . . . 226
overwrite-mode . . . . . . . . . . . . . . . . . . . . . 207

P
package-initialize . . . . . . . . . . . . . . . . . 432
package-install . . . . . . . . . . . . . . . . . . . . 431
package-install-file. . . . . . . . . . . . . . . 432
paragraph-indent-minor-mode . . . . . . 224
paragraph-indent-text-mode . . . . . . . . 224
partial completion . . . . . . . . . . . . . . . . . . 32
pdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
perldb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
plain-tex-mode . . . . . . . . . . . . . . . . . . . . . 231
point-to-register . . . . . . . . . . . . . . . . . . . 66
pong . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
pop-global-mark . . . . . . . . . . . . . . . . . . . . . 51
pop-tag-mark . . . . . . . . . . . . . . . . . . . . . . . . 318
pr-interface . . . . . . . . . . . . . . . . . . . . . . . . 420
prefer-coding-system. . . . . . . . . . . . . . . 190
prepend-to-buffer . . . . . . . . . . . . . . . . . . . 61
prepend-to-register . . . . . . . . . . . . . . . . . 67
previous-buffer . . . . . . . . . . . . . . . . . . . . 151
previous-completion . . . . . . . . . . . . . . . . . 31
previous-history-element . . . . . . . . . . . 34
previous-line . . . . . . . . . . . . . . . . . . . . . . . . 18
previous-logical-line . . . . . . . . . . . . . . 89
previous-matching-history-element
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
print-buffer . . . . . . . . . . . . . . . . . . . . . . . . 417
print-buffer (MS-DOS) . . . . . . . . . . . . 542
print-region . . . . . . . . . . . . . . . . . . . . . . . . 417
print-region (MS-DOS) . . . . . . . . . . . . 542
ps-despool . . . . . . . . . . . . . . . . . . . . . . . . . . 418
ps-print-buffer . . . . . . . . . . . . . . . . . . . . 418
ps-print-buffer (MS-DOS) . . . . . . . . . 542
ps-print-buffer-with-faces . . . . . . . . 418
ps-print-region . . . . . . . . . . . . . . . . . . . . 418
ps-print-region-with-faces . . . . . . . . 418
ps-spool-buffer . . . . . . . . . . . . . . . . . . . . 418
ps-spool-buffer (MS-DOS) . . . . . . . . . 542
ps-spool-buffer-with-faces . . . . . . . . 418
ps-spool-region . . . . . . . . . . . . . . . . . . . . 418
ps-spool-region-with-faces . . . . . . . . 418
pwd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

Q
quail-set-keyboard-layout . . . . . . . . . 188
quail-show-key . . . . . . . . . . . . . . . . . . . . . 188

Command and Function Index
query-replace. . . . . . . . . . . . . . . . . . . . . . . 106
query-replace-regexp. . . . . . . . . . . . . . . 106
quietly-read-abbrev-file . . . . . . . . . . 326
quit-window . . . . . . . . . . . . . . . . . . . . 306, 329
quoted-insert . . . . . . . . . . . . . . . . . . . . . . . . 17

R
re-search-backward . . . . . . . . . . . . . . . . . . 97
re-search-forward . . . . . . . . . . . . . . . . . . . 97
read-abbrev-file . . . . . . . . . . . . . . . . . . . 326
recenter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
recenter-top-bottom . . . . . . . . . . . . . . . . . 71
recentf-edit-list . . . . . . . . . . . . . . . . . . 148
recentf-mode . . . . . . . . . . . . . . . . . . . . . . . . 148
recentf-save-list . . . . . . . . . . . . . . . . . . 148
recode-file-name . . . . . . . . . . . . . . . . . . . 196
recode-region. . . . . . . . . . . . . . . . . . . . . . . 194
recompile . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
recover-file . . . . . . . . . . . . . . . . . . . . . . . . 137
recover-session . . . . . . . . . . . . . . . . . . . . 138
rectangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
remove-hook . . . . . . . . . . . . . . . . . . . . . . . . . 446
remove-untranslated-filesystem . . . 537
rename-buffer. . . . . . . . . . . . . . . . . . . . . . . 153
rename-file . . . . . . . . . . . . . . . . . . . . . . . . . 143
rename-uniquely . . . . . . . . . . . . . . . . . . . . 153
repeat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
repeat-complex-command . . . . . . . . . . . . . 35
replace-regexp . . . . . . . . . . . . . . . . . . . . . 104
replace-string . . . . . . . . . . . . . . . . . . . . . 104
report-emacs-bug . . . . . . . . . . . . . . . . . . . 475
reposition-window . . . . . . . . . . . . . . . . . . . 72
reveal-mode . . . . . . . . . . . . . . . . . . . . . . . . . 227
revert-buffer. . . . . . . . . . . . . . . . . . . . . . . 135
revert-buffer (Dired) . . . . . . . . . . . . . . . 341
revert-buffer-with-coding-system
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
rgrep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
right-char . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
right-word . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
rmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
rmail-add-label . . . . . . . . . . . . . . . . . . . . 383
rmail-beginning-of-message . . . . . . . . 377
rmail-bury . . . . . . . . . . . . . . . . . . . . . . . . . . 376
rmail-continue . . . . . . . . . . . . . . . . . . . . . 386
rmail-delete-backward . . . . . . . . . . . . . 379
rmail-delete-forward. . . . . . . . . . . . . . . 379
rmail-edit-current-message . . . . . . . . 393
rmail-end-of-message. . . . . . . . . . . . . . . 377
rmail-epa-decrypt . . . . . . . . . . . . . . . . . . 392
rmail-expunge. . . . . . . . . . . . . . . . . . . . . . . 379

600
rmail-expunge-and-save . . . . . . . . . . . .
rmail-first-message . . . . . . . . . . . . . . . .
rmail-forward. . . . . . . . . . . . . . . . . . . . . . .
rmail-get-new-mail . . . . . . . . . . . . . . . . .
rmail-input . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-kill-label . . . . . . . . . . . . . . . . . . .
rmail-last-message . . . . . . . . . . . . . . . . .
rmail-mail . . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-mime . . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-mime-next-item. . . . . . . . . . . . . . .
rmail-mime-previous-item . . . . . . . . . .
rmail-mime-toggle-hidden . . . . . . . . . .
rmail-mode . . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-next-labeled-message . . . . . . . .
rmail-next-message . . . . . . . . . . . . . . . . .
rmail-next-same-subject . . . . . . . . . . .
rmail-next-undeleted-message . . . . .
rmail-output . . . . . . . . . . . . . . . . . . . . . . . .
rmail-output-as-seen. . . . . . . . . . . . . . .
rmail-output-body-to-file . . . . . . . . .
rmail-previous-labeled-message . . .
rmail-previous-message . . . . . . . . . . . .
rmail-previous-same-subject . . . . . .
rmail-previous-undeleted-message
.................................
rmail-quit . . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-redecode-body . . . . . . . . . . . . . . . .
rmail-reply . . . . . . . . . . . . . . . . . . . . . . . . .
rmail-resend . . . . . . . . . . . . . . . . . . . . . . . .
rmail-retry-failure . . . . . . . . . . . . . . . .
rmail-search . . . . . . . . . . . . . . . . . . . . . . . .
rmail-show-message . . . . . . . . . . . . . . . . .
rmail-sort-by-author. . . . . . . . . . . . . . .
rmail-sort-by-correspondent . . . . . .
rmail-sort-by-date . . . . . . . . . . . . . . . . .
rmail-sort-by-labels. . . . . . . . . . . . . . .
rmail-sort-by-lines . . . . . . . . . . . . . . . .
rmail-sort-by-recipient . . . . . . . . . . .
rmail-sort-by-subject . . . . . . . . . . . . .
rmail-summary. . . . . . . . . . . . . . . . . . . . . . .
rmail-summary-bury . . . . . . . . . . . . . . . . .
rmail-summary-by-labels . . . . . . . . . . .
rmail-summary-by-recipients . . . . . .
rmail-summary-by-regexp . . . . . . . . . . .
rmail-summary-by-senders . . . . . . . . . .
rmail-summary-by-topic . . . . . . . . . . . .
rmail-summary-quit . . . . . . . . . . . . . . . . .
rmail-summary-undelete-many . . . . . .
rmail-summary-wipe . . . . . . . . . . . . . . . . .
rmail-toggle-header . . . . . . . . . . . . . . . .
rmail-undelete-previous-message . .
rot13-other-window . . . . . . . . . . . . . . . . .

376
378
386
381
381
383
378
386
391
391
391
391
376
383
378
378
378
382
382
382
383
378
378
378
376
392
385
386
385
378
378
390
390
390
390
390
390
390
387
389
387
387
388
388
387
389
388
389
391
379
393

Command and Function Index
run-lisp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
run-scheme . . . . . . . . . . . . . . . . . . . . . . . . . . 291

S
save-buffer . . . . . . . . . . . . . . . . . . . . . . . . . 128
save-buffers-kill-terminal . . . . . . . . . 15
save-some-buffers . . . . . . . . . . . . . . . . . . 128
scheme-mode . . . . . . . . . . . . . . . . . . . . . . . . . 291
scroll-all-mode . . . . . . . . . . . . . . . . . . . . 425
scroll-bar-mode . . . . . . . . . . . . . . . . . . . . 176
scroll-down-command . . . . . . . . . . . . . . . . . 70
scroll-down-line . . . . . . . . . . . . . . . . . . . . 71
scroll-left . . . . . . . . . . . . . . . . . . . . . . . . . . 73
scroll-other-window . . . . . . . . . . . . . . . . 161
scroll-right . . . . . . . . . . . . . . . . . . . . . . . . . 73
scroll-up-command . . . . . . . . . . . . . . . . . . . 70
scroll-up-line. . . . . . . . . . . . . . . . . . . . . . . 71
sdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
search-backward . . . . . . . . . . . . . . . . . . . . . 95
search-forward. . . . . . . . . . . . . . . . . . . . . . . 95
select-frame-by-name. . . . . . . . . . . . . . . 179
send-invisible . . . . . . . . . . . . . . . . . . . . . 405
serial-term . . . . . . . . . . . . . . . . . . . . . . . . . 412
server-edit . . . . . . . . . . . . . . . . . . . . . . . . . 413
server-eval-at . . . . . . . . . . . . . . . . . . . . . 413
server-start . . . . . . . . . . . . . . . . . . . . . . . . 412
set-buffer-file-coding-system . . . . 193
set-buffer-process-coding-system
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
set-face-background . . . . . . . . . . . . . . . . . 76
set-face-foreground . . . . . . . . . . . . . . . . . 76
set-file-modes . . . . . . . . . . . . . . . . . . . . . 144
set-file-name-coding-system . . . . . . 195
set-fill-column . . . . . . . . . . . . . . . . . . . . 220
set-fill-prefix . . . . . . . . . . . . . . . . . . . . 221
set-fontset-font . . . . . . . . . . . . . . . . . . . 199
set-frame-name . . . . . . . . . . . . . . . . . . . . . 179
set-fringe-style . . . . . . . . . . . . . . . . . . . . 83
set-goal-column . . . . . . . . . . . . . . . . . . . . . 20
set-input-method . . . . . . . . . . . . . . . . . . . 187
set-justification-center . . . . . . . . . . 241
set-justification-full . . . . . . . . . . . . 241
set-justification-left . . . . . . . . . . . . 241
set-justification-none . . . . . . . . . . . . 241
set-justification-right . . . . . . . . . . . 241
set-keyboard-coding-system . . . . . . . . 196
set-language-environment . . . . . . . . . . 183
set-left-margin . . . . . . . . . . . . . . . . . . . . 240
set-locale-environment . . . . . . . . . . . . 184
set-mark-command . . . . . . . . . . . . . . . . . . . . 48

601
set-next-selection-coding-system
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
set-right-margin . . . . . . . . . . . . . . . . . . . 240
set-selection-coding-system . . . . . . 194
set-selective-display . . . . . . . . . . . . . . 85
set-terminal-coding-system . . . . . . . . 196
set-variable . . . . . . . . . . . . . . . . . . . . . . . . 444
set-visited-file-name . . . . . . . . . . . . . 129
setenv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510
setq-default . . . . . . . . . . . . . . . . . . . . . . . . 447
sgml-attributes . . . . . . . . . . . . . . . . . . . . 236
sgml-close-tag . . . . . . . . . . . . . . . . . . . . . 236
sgml-delete-tag . . . . . . . . . . . . . . . . . . . . 236
sgml-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
sgml-name-8bit-mode . . . . . . . . . . . . . . . . 236
sgml-name-char . . . . . . . . . . . . . . . . . . . . . 236
sgml-skip-tag-backward . . . . . . . . . . . . 236
sgml-skip-tag-forward . . . . . . . . . . . . . 236
sgml-tag . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
sgml-tag-help. . . . . . . . . . . . . . . . . . . . . . . 236
sgml-tags-invisible . . . . . . . . . . . . . . . . 236
sgml-validate. . . . . . . . . . . . . . . . . . . . . . . 236
shadow-initialize . . . . . . . . . . . . . . . . . . 134
shell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
shell-backward-command . . . . . . . . . . . . 405
shell-command. . . . . . . . . . . . . . . . . . . . . . . 402
shell-command-on-region . . . . . . . . . . . 402
shell-forward-command . . . . . . . . . . . . . 405
shell-pushd-dextract. . . . . . . . . . . . . . . 410
shell-pushd-dunique . . . . . . . . . . . . . . . . 410
shell-pushd-tohome . . . . . . . . . . . . . . . . . 410
show-all . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
show-branches. . . . . . . . . . . . . . . . . . . . . . . 227
show-children. . . . . . . . . . . . . . . . . . . . . . . 227
show-entry . . . . . . . . . . . . . . . . . . . . . . . . . . 227
show-paren-mode . . . . . . . . . . . . . . . . . . . . 258
show-subtree . . . . . . . . . . . . . . . . . . . . . . . . 227
shrink-window-horizontally . . . . . . . . 162
shrink-window-if-larger-than-buffer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
size-indication-mode . . . . . . . . . . . . . . . . 85
slitex-mode . . . . . . . . . . . . . . . . . . . . . . . . . 231
smerge-mode . . . . . . . . . . . . . . . . . . . . . . . . . 141
snake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
solitaire . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
sort-columns . . . . . . . . . . . . . . . . . . . . . . . . 422
sort-fields . . . . . . . . . . . . . . . . . . . . . . . . . 420
sort-lines . . . . . . . . . . . . . . . . . . . . . . . . . . 420
sort-numeric-fields . . . . . . . . . . . . . . . . 420
sort-pages . . . . . . . . . . . . . . . . . . . . . . . . . . 420
sort-paragraphs . . . . . . . . . . . . . . . . . . . . 420
split-line . . . . . . . . . . . . . . . . . . . . . . . . . . 210

Command and Function Index

602

split-window-below . . . . . . . . . . . . . . . . . 159
split-window-right . . . . . . . . . . . . . . . . . 160
spook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
standard-display-8bit . . . . . . . . . . . . . 201
string-insert-rectangle . . . . . . . . . . . . 64
string-rectangle . . . . . . . . . . . . . . . . . . . . 64
substitute-key-definition . . . . . . . . . 464
subword-mode . . . . . . . . . . . . . . . . . . . . . . . . 268
sunrise-sunset . . . . . . . . . . . . . . . . . . . . . 352
suspend-frame . . . . . . . . . . . . . . . . . . . 15, 170
switch-to-buffer . . . . . . . . . . . . . . . . . . . 151
switch-to-buffer-other-frame . . . . . 151
switch-to-buffer-other-window. . . . 151,
161
switch-to-completions . . . . . . . . . . . . . . 30

T
tab-to-tab-stop . . . . . . . . . . . . . . . . . . . .
tabify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
table-backward-cell . . . . . . . . . . . . . . . .
table-capture. . . . . . . . . . . . . . . . . . . . . . .
table-fixed-width-mode . . . . . . . . . . . .
table-forward-cell . . . . . . . . . . . . . . . . .
table-generate-source . . . . . . . . . . . . .
table-heighten-cell . . . . . . . . . . . . . . . .
table-insert . . . . . . . . . . . . . . . . . . . . . . . .
table-insert-column . . . . . . . . . . . . . . . .
table-insert-row . . . . . . . . . . . . . . . . . . .
table-insert-sequence . . . . . . . . . . . . .
table-justify. . . . . . . . . . . . . . . . . . . . . . .
table-narrow-cell . . . . . . . . . . . . . . . . . .
table-query-dimension . . . . . . . . . . . . .
table-recognize . . . . . . . . . . . . . . . . . . . .
table-recognize-cell. . . . . . . . . . . . . . .
table-recognize-region . . . . . . . . . . . .
table-recognize-table . . . . . . . . . . . . .
table-release. . . . . . . . . . . . . . . . . . . . . . .
table-shorten-cell . . . . . . . . . . . . . . . . .
table-span-cell . . . . . . . . . . . . . . . . . . . .
table-split-cell . . . . . . . . . . . . . . . . . . .
table-split-cell-horizontally . . . .
table-split-cell-vertically . . . . . .
table-unrecognize . . . . . . . . . . . . . . . . . .
table-unrecognize-cell . . . . . . . . . . . .
table-unrecognize-region . . . . . . . . . .
table-unrecognize-table . . . . . . . . . . .
table-widen-cell . . . . . . . . . . . . . . . . . . .
tags-apropos . . . . . . . . . . . . . . . . . . . . . . . .
tags-loop-continue . . . . . . . . . . . . . . . . .
tags-query-replace . . . . . . . . . . . . . . . . .
tags-search . . . . . . . . . . . . . . . . . . . . . . . . .

210
212
244
245
242
244
246
244
243
245
245
246
244
244
246
243
243
243
243
245
244
244
244
244
244
243
243
243
243
244
320
319
319
319

term . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
term-char-mode . . . . . . . . . . . . . . . . . . . . . 411
term-line-mode . . . . . . . . . . . . . . . . . . . . . 411
term-pager-toggle . . . . . . . . . . . . . . . . . . 411
tetris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
tex-bibtex-file . . . . . . . . . . . . . . . . . . . . 235
tex-buffer . . . . . . . . . . . . . . . . . . . . . . . . . . 234
tex-close-latex-block . . . . . . . . . . . . . 233
tex-compile . . . . . . . . . . . . . . . . . . . . . . . . . 235
tex-file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
tex-insert-braces . . . . . . . . . . . . . . . . . . 232
tex-insert-quote . . . . . . . . . . . . . . . . . . . 232
tex-kill-job . . . . . . . . . . . . . . . . . . . . . . . . 234
tex-latex-block . . . . . . . . . . . . . . . . . . . . 233
tex-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
tex-print . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
tex-recenter-output-buffer . . . . . . . . 234
tex-region . . . . . . . . . . . . . . . . . . . . . . . . . . 234
tex-terminate-paragraph . . . . . . . . . . . 232
tex-validate-region . . . . . . . . . . . . . . . . 232
tex-view . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234
text-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
text-scale-adjust . . . . . . . . . . . . . . . . . . . 79
text-scale-decrease . . . . . . . . . . . . . . . . . 79
text-scale-increase . . . . . . . . . . . . . . . . . 79
text-scale-mode . . . . . . . . . . . . . . . . . . . . . 79
text-scale-set. . . . . . . . . . . . . . . . . . . . . . . 79
thumbs-mode . . . . . . . . . . . . . . . . . . . . . . . . . 148
time-stamp . . . . . . . . . . . . . . . . . . . . . . . . . . 135
timeclock-change . . . . . . . . . . . . . . . . . . . 366
timeclock-in . . . . . . . . . . . . . . . . . . . . . . . . 366
timeclock-modeline-display . . . . . . . . 366
timeclock-out. . . . . . . . . . . . . . . . . . . . . . . 366
timeclock-reread-log. . . . . . . . . . . . . . . 366
timeclock-when-to-leave . . . . . . . . . . . 366
timeclock-workday-remaining . . . . . . 366
tmm-menubar . . . . . . . . . . . . . . . . . . . . . . . . . . 10
toggle-debug-on-error . . . . . . . . . . . . . 478
toggle-enable-multibyte-characters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
toggle-gdb-all-registers . . . . . . . . . . 284
toggle-input-method . . . . . . . . . . . . . . . . 187
toggle-read-only . . . . . . . . . . . . . . . . . . . 152
toggle-scroll-bar . . . . . . . . . . . . . . . . . . 176
toggle-truncate-lines . . . . . . . . . . . . . . 89
tool-bar-mode. . . . . . . . . . . . . . . . . . . . . . . 177
tooltip-mode . . . . . . . . . . . . . . . . . . . . . . . . 178
top-level . . . . . . . . . . . . . . . . . . . . . . . . . . . 469
tpu-edt-on . . . . . . . . . . . . . . . . . . . . . . . . . . 425
transient-mark-mode . . . . . . . . . . . . . . . . . 52
transpose-chars . . . . . . . . . . . . . . . . . . . . 111
transpose-lines . . . . . . . . . . . . . . . . . . . . 112

Command and Function Index
transpose-sexps . . . . . . . . . . . . . . . . . . . . 257
transpose-words . . . . . . . . . . . . . . . . . . . . 112
tty-suppress-bold-inverse-defaultcolors . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

U
ucs-insert . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
uncomment-region . . . . . . . . . . . . . . . . . . . 260
undigestify-rmail-message . . . . . . . . . 393
undo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
undo-only . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
unexpand-abbrev . . . . . . . . . . . . . . . . . . . . 324
unforward-rmail-message . . . . . . . . . . . 386
unhighlight-regexp . . . . . . . . . . . . . . . . . . 82
universal-argument . . . . . . . . . . . . . . . . . . 25
universal-coding-system-argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
unmorse-region . . . . . . . . . . . . . . . . . . . . . 428
untabify . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
up-list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
upcase-region. . . . . . . . . . . . . . . . . . . . . . . 223
upcase-word . . . . . . . . . . . . . . . . . . . . . . . . . 223

V
vc-annotate . . . . . . . . . . . . . . . . . . . . . . . . . 301
vc-diff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
vc-dir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
vc-dir-mark . . . . . . . . . . . . . . . . . . . . . . . . . 306
vc-dir-mark-all-files . . . . . . . . . . . . . 306
vc-next-action . . . . . . . . . . . . . . . . . . . . . 297
vc-print-log . . . . . . . . . . . . . . . . . . . . . . . . 303
vc-print-root-log . . . . . . . . . . . . . . . . . . 303
vc-pull . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
vc-register . . . . . . . . . . . . . . . . . . . . . . . . . 300
vc-revert . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
vc-revision-other-window . . . . . . . . . . 301
vc-root-diff . . . . . . . . . . . . . . . . . . . . . . . . 301
vi-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
view-buffer . . . . . . . . . . . . . . . . . . . . . . . . . . 75
view-echo-area-messages . . . . . . . . . . . . 44
view-emacs-debugging . . . . . . . . . . . . . . . . 45
view-emacs-FAQ. . . . . . . . . . . . . . . . . . . . . . . 45
view-emacs-news . . . . . . . . . . . . . . . . . . . . . 45
view-emacs-problems . . . . . . . . . . . . . . . . . 45
view-emacs-todo . . . . . . . . . . . . . . . . . . . . . 45
View-exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
view-external-packages . . . . . . . . . . . . . 45
view-file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
view-hello-file . . . . . . . . . . . . . . . . . . . . 181

603
view-lossage . . . . . . . . . . . . . . . . . . . . . . . . . 44
view-order-manuals . . . . . . . . . . . . . . . . . . 45
View-quit . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
view-register . . . . . . . . . . . . . . . . . . . . . . . . 66
vip-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
viper-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 425
visit-tags-table . . . . . . . . . . . . . . . . . . . 317
visual-line-mode . . . . . . . . . . . . . . . . . . . . 89

W
wdired-change-to-wdired-mode . . . . . 343
wdired-finish-edit . . . . . . . . . . . . . . . . . 343
what-cursor-position . . . . . . . . . . . 24, 181
what-line . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
what-page . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
where-is . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
which-function-mode . . . . . . . . . . . . . . . . 252
whitespace-mode . . . . . . . . . . . . . . . . . . . . . 84
widen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
widget-backward . . . . . . . . . . . . . . . . . . . . 435
widget-complete . . . . . . . . . . . . . . . . . . . . 436
widget-forward . . . . . . . . . . . . . . . . . . . . . 435
windmove-default-keybindings . . . . . 164
windmove-right . . . . . . . . . . . . . . . . . . . . . 164
window-configuration-to-register . . 67
winner-mode . . . . . . . . . . . . . . . . . . . . . . . . . 164
woman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
word-search-backward . . . . . . . . . . . . . . . . 96
word-search-forward . . . . . . . . . . . . . . . . . 96
wordstar-mode. . . . . . . . . . . . . . . . . . . . . . . 426
write-abbrev-file . . . . . . . . . . . . . . . . . . 325
write-file . . . . . . . . . . . . . . . . . . . . . . . . . . 129
write-region . . . . . . . . . . . . . . . . . . . . . . . . 144

X
xdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

Y
yank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
yank-pop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
yank-rectangle. . . . . . . . . . . . . . . . . . . . . . . 64

Z
zap-to-char . . . . . . . . . . . . . . . . . . . . . . . . . . 56
zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
zrgrep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275

Variable Index

604

Variable Index
A
abbrev-all-caps . . . . . . . . . . . . . . . . . . . . 323
abbrev-file-name . . . . . . . . . . . . . . . . . . . 326
adaptive-fill-first-line-regexp . . 222
adaptive-fill-function . . . . . . . . . . . . 222
adaptive-fill-mode . . . . . . . . . . . . . . . . . 222
adaptive-fill-regexp. . . . . . . . . . . . . . . 222
add-log-always-start-new-record . . 310
add-log-keep-changes-together . . . . 310
ange-ftp-default-user . . . . . . . . . . . . . 146
ange-ftp-gateway-host . . . . . . . . . . . . . 146
ange-ftp-generate-anonymous-password
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
ange-ftp-make-backup-files . . . . . . . . 146
ange-ftp-smart-gateway . . . . . . . . . . . . 146
appt-audible . . . . . . . . . . . . . . . . . . . . . . . . 364
appt-delete-window-function . . . . . . 364
appt-disp-window-function . . . . . . . . . 364
appt-display-diary . . . . . . . . . . . . . . . . . 364
appt-display-duration . . . . . . . . . . . . . 364
appt-display-format . . . . . . . . . . . . . . . . 364
appt-display-mode-line . . . . . . . . . . . . 364
appt-message-warning-time . . . . . . . . . 364
appt-warning-time-regexp . . . . . . . . . . 364
apropos-do-all. . . . . . . . . . . . . . . . . . . . . . . 42
apropos-documentation-sort-by-scores
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
apropos-sort-by-scores . . . . . . . . . . . . . 42
auto-coding-alist . . . . . . . . . . . . . . . . . . 191
auto-coding-functions . . . . . . . . . . . . . 191
auto-coding-regexp-alist . . . . . . . . . . 191
auto-compression-mode . . . . . . . . . . . . . 144
auto-hscroll-mode . . . . . . . . . . . . . . . . . . . 73
auto-mode-alist . . . . . . . . . . . . . . . . . . . . 207
auto-mode-case-fold . . . . . . . . . . . . . . . . 209
auto-revert-check-vc-info . . . . . . . . . 296
auto-revert-interval. . . . . . . . . . . . . . . 135
auto-save-default . . . . . . . . . . . . . . . . . . 137
auto-save-file-name-transforms . . . 136
auto-save-interval . . . . . . . . . . . . . . . . . 137
auto-save-list-file-prefix . . . . . . . . 138
auto-save-timeout . . . . . . . . . . . . . . . . . . 137
auto-save-visited-file-name . . . . . . 137

B
backup-by-copying . . . . . . . . . . . . . . . . . . 132
backup-by-copying-when-linked . . . . 132

backup-by-copying-when-mismatch . . 132
backup-by-copying-when-privilegedmismatch . . . . . . . . . . . . . . . . . . . . . . . . 132
backup-directory-alist . . . . . . . . . . . . 131
backup-enable-predicate . . . . . . . . . . . 130
battery-mode-line-format . . . . . . . . . . . 86
bdf-directory-list . . . . . . . . . . . . . . . . . 420
bidi-display-reordering . . . . . . . . . . . 203
bidi-paragraph-direction . . . . . . . . . . 203
blink-cursor-alist . . . . . . . . . . . . . . . . . . 88
blink-matching-delay. . . . . . . . . . . . . . . 258
blink-matching-paren. . . . . . . . . . . . . . . 258
blink-matching-paren-distance . . . . 258
bookmark-save-flag . . . . . . . . . . . . . . . . . . 69
bookmark-search-size . . . . . . . . . . . . . . . . 69
browse-url-browser-function . . . . . . 426
browse-url-mailto-function . . . . . . . . 426
buffer-file-coding-system . . . . . . . . . 192
buffer-read-only . . . . . . . . . . . . . . . . . . . 152

C
c-default-style . . . . . . . . . . . . . . . . . . . . 255
c-hungry-delete-key . . . . . . . . . . . . . . . . 268
c-mode-hook . . . . . . . . . . . . . . . . . . . . . . . . . 249
c-tab-always-indent . . . . . . . . . . . . . . . . 254
cal-html-css-default. . . . . . . . . . . . . . . 349
calendar-date-style . . . . . . . . . . . . . . . . 361
calendar-daylight-savings-ends . . . 365
calendar-daylight-savings-ends-time
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
calendar-daylight-savings-starts
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
calendar-daylight-time-offset . . . . 366
calendar-daylight-time-zone-name
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
calendar-latitude . . . . . . . . . . . . . . . . . . 352
calendar-location-name . . . . . . . . . . . . 352
calendar-longitude . . . . . . . . . . . . . . . . . 352
calendar-mark-diary-entries-flag
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
calendar-mark-holidays-flag . . . . . . 351
calendar-remove-frame-by-deleting
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
calendar-standard-time-zone-name
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
calendar-time-zone . . . . . . . . . . . . . . . . . 353
calendar-view-diary-initially-flag
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

Variable Index
calendar-view-holidays-initiallyflag . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
calendar-week-start-day . . . . . . . . . . . 347
case-fold-search . . . . . . . . . . . . . . . . . . . 103
case-replace . . . . . . . . . . . . . . . . . . . . . . . . 105
change-log-version-info-enabled . . 310
change-log-version-number-regexplist . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
change-major-mode-with-file-name
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
clone-indirect-buffer-hook . . . . . . . . 157
coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
colon-double-space . . . . . . . . . . . . . . . . . 220
comint-completion-addsuffix . . . . . . 410
comint-completion-autolist . . . . . . . . 410
comint-completion-fignore . . . . . . . . . 404
comint-completion-recexact . . . . . . . . 410
comint-input-autoexpand . . . . . . . . . . . 409
comint-input-ignoredups . . . . . . . . . . . 410
comint-move-point-for-output . . . . . 409
comint-prompt-read-only . . . . . . . . . . . 410
comint-scroll-show-maximum-output
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
comint-scroll-to-bottom-on-input
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
comint-use-prompt-regexp . . . . . . . . . . 406
command-history . . . . . . . . . . . . . . . . . . . . . 36
command-line-args . . . . . . . . . . . . . . . . . . 505
comment-column . . . . . . . . . . . . . . . . . . . . . 261
comment-end . . . . . . . . . . . . . . . . . . . . . . . . . 261
comment-indent-function . . . . . . . . . . . 261
comment-multi-line . . . . . . . . . . . . . . . . . 260
comment-padding . . . . . . . . . . . . . . . . . . . . 261
comment-start. . . . . . . . . . . . . . . . . . . . . . . 261
comment-start-skip . . . . . . . . . . . . . . . . . 261
compare-ignore-case . . . . . . . . . . . . . . . . 140
compare-ignore-whitespace . . . . . . . . . 140
compilation-auto-jump-to-first-error
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
compilation-context-lines . . . . . . . . . 273
compilation-environment . . . . . . . . . . . 272
compilation-error-regexp-alist . . . 273
compilation-scroll-output . . . . . . . . . 271
compilation-skip-threshold . . . . . . . . 273
compile-command . . . . . . . . . . . . . . . . . . . . 271
completion-auto-help . . . . . . . . . . . . . . . . 33
completion-category-overrides . . . . . 33
completion-cycle-threshold . . . . . . . . . 33
completion-ignored-extensions . . . . . 33
completion-styles . . . . . . . . . . . . . . . . . . . 32
confirm-kill-emacs . . . . . . . . . . . . . . . . . . 15

605
confirm-nonexistent-file-or-buffer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
crisp-override-meta-x . . . . . . . . . . . . . 425
ctl-arrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
ctl-x-4-map . . . . . . . . . . . . . . . . . . . . . . . . . 453
ctl-x-map . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
cua-enable-cua-keys . . . . . . . . . . . . . . . . . 64
cua-mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
current-input-method. . . . . . . . . . . . . . . 187
current-language-environment . . . . . 183
cursor-in-non-selected-windows . . . . 88
cursor-type . . . . . . . . . . . . . . . . . . . . . . . . . . 88
custom-buffer-done-kill . . . . . . . . . . . 438
custom-enabled-themes . . . . . . . . . . . . . 442
custom-file . . . . . . . . . . . . . . . . . . . . . . . . . 438
custom-safe-themes . . . . . . . . . . . . . . . . . 441
custom-search-field . . . . . . . . . . . . . . . . 435
custom-theme-directory . . . . . . . 441, 442
custom-theme-load-path . . . . . . . . . . . . 441

D
dabbrev-abbrev-char-regexp . . . . . . . . 327
dabbrev-abbrev-skip-leading-regexp
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
dabbrev-case-fold-search . . . . . . . . . . 327
dabbrev-case-replace. . . . . . . . . . . . . . . 327
dabbrev-check-all-buffers . . . . . . . . . 326
dabbrev-ignored-buffer-regexps . . . 326
dabbrev-limit. . . . . . . . . . . . . . . . . . . . . . . 326
dbx-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280
debug-on-event . . . . . . . . . . . . . . . . . . . . . 478
debug-on-quit. . . . . . . . . . . . . . . . . . . . . . . 478
default-directory . . . . . . . . . . . . . . . . . . 124
default-input-method. . . . . . . . . . . . . . . 187
default-justification . . . . . . . . . . . . . 241
delete-active-region . . . . . . . . . . . . . . . . 50
delete-auto-save-files . . . . . . . . . . . . 137
delete-by-moving-to-trash . . . . 143, 331
delete-old-versions . . . . . . . . . . . . . . . . 131
desktop-clear-preserve-buffersregexp . . . . . . . . . . . . . . . . . . . . . . . . . . 423
desktop-globals-to-clear . . . . . . . . . . 423
desktop-path . . . . . . . . . . . . . . . . . . . . . . . . 423
desktop-restore-eager . . . . . . . . . . . . . 423
desktop-save-mode . . . . . . . . . . . . . . . . . . 423
diary-file . . . . . . . . . . . . . . . . . . . . . . . . . . 360
diary-mail-days . . . . . . . . . . . . . . . . . . . . 359
diary-nonmarking-symbol . . . . . . . . . . . 360
diary-outlook-formats . . . . . . . . . . . . . 364
diff-switches. . . . . . . . . . . . . . . . . . . . . . . 140
diff-update-on-the-fly . . . . . . . . . . . . 141

Variable Index
directory-abbrev-alist . . . . . . . . . . . . 139
directory-free-space-args . . . . . . . . . 140
directory-free-space-program . . . . . 140
dired-auto-revert-buffer . . . . . . . . . . 341
dired-chown-program . . . . . . . . . . . . . . . . 336
dired-copy-preserve-time . . . . . . . . . . 335
dired-dwim-target . . . . . . . . . . . . . . . . . . 335
dired-garbage-files-regexp . . . . . . . . 332
dired-isearch-filenames . . . . . . . . . . . 330
dired-kept-versions . . . . . . . . . . . . . . . . 331
dired-listing-switches . . . . . . . . . . . . 329
dired-recursive-copies . . . . . . . . . . . . 335
dired-recursive-deletes . . . . . . . . . . . 331
dired-use-ls-dired . . . . . . . . . . . . . . . . . 329
dirtrack-list. . . . . . . . . . . . . . . . . . . . . . . 409
display-battery-mode . . . . . . . . . . . . . . . . 86
display-buffer-reuse-frames . . . . . . 163
display-hourglass . . . . . . . . . . . . . . . . . . . 90
display-time-24hr-format . . . . . . . . . . . 86
display-time-mail-directory . . . . . . . . 86
display-time-mail-face . . . . . . . . . . . . . 86
display-time-mail-file . . . . . . . . . . . . . 86
display-time-use-mail-icon . . . . . . . . . 86
dnd-open-file-other-window . . . . . . . . 176
doc-view-cache-directory . . . . . . . . . . 401
doc-view-continuous . . . . . . . . . . . . . . . . 400
doc-view-resolution . . . . . . . . . . . . . . . . 400
double-click-fuzz . . . . . . . . . . . . . . . . . . 460
double-click-time . . . . . . . . . . . . . . . . . . 460

E
echo-keystrokes . . . . . . . . . . . . . . . . . . . . . 90
emacs-lisp-mode-hook. . . . . . . . . . . . . . . 249
enable-local-eval . . . . . . . . . . . . . . . . . . 450
enable-local-variables . . . . . . . . . . . . 450
enable-multibyte-characters . . . . . . 183
enable-recursive-minibuffers . . . . . . 29
enriched-translations . . . . . . . . . . . . . 238
eol-mnemonic-dos . . . . . . . . . . . . . . . . . . . . 87
eol-mnemonic-mac . . . . . . . . . . . . . . . . . . . . 87
eol-mnemonic-undecided . . . . . . . . . . . . . 87
eol-mnemonic-unix . . . . . . . . . . . . . . . . . . . 87
esc-map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
eval-expression-debug-on-error . . . 289
eval-expression-print-length . . . . . 289
eval-expression-print-level . . . . . . 289
exec-path . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
exit-language-environment-hook . . . 185
explicit-shell-file-name . . . . . . . . . . 403

606

F
ff-related-file-alist . . . . . . . . . . . . . 270
file-coding-system-alist . . . . . . . . . . 190
file-name-buffer-file-type-alist
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
file-name-coding-system . . . . . . . . . . . 195
fill-column . . . . . . . . . . . . . . . . . . . . . . . . . 220
fill-nobreak-predicate . . . . . . . . . . . . 220
fill-prefix . . . . . . . . . . . . . . . . . . . . . . . . . 221
find-file-existing-other-name . . . . 138
find-file-hook . . . . . . . . . . . . . . . . . . . . . 127
find-file-not-found-functions . . . . 127
find-file-run-dired . . . . . . . . . . . . . . . . 126
find-file-suppress-same-filewarnings . . . . . . . . . . . . . . . . . . . . . . . . 138
find-file-visit-truename . . . . . . . . . . 138
find-file-wildcards . . . . . . . . . . . . . . . . 126
find-ls-option . . . . . . . . . . . . . . . . . . . . . 342
find-tag-marker-ring-length . . . . . . 318
focus-follows-mouse . . . . . . . . . . . . . . . . 170
foldout-mouse-modifiers . . . . . . . . . . . 229
font-lock-beginning-of-syntaxfunction . . . . . . . . . . . . . . . . . . . . . . . . . 80
font-lock-maximum-decoration . . . . . . 80
font-slant-table (MS-Windows). . . . 544
font-weight-table (MS-Windows) . . 544

G
gdb-delete-out-of-scope . . . . . . . . . . . 285
gdb-gud-control-all-threads . . . . . . 286
gdb-many-windows . . . . . . . . . . . . . . . . . . . 281
gdb-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280
gdb-non-stop-setting. . . . . . . . . . . . . . . 286
gdb-show-changed-values . . . . . . . . . . . 285
gdb-show-threads-by-default . . . . . . 283
gdb-speedbar-auto-raise . . . . . . . . . . . 285
gdb-stopped-hooks . . . . . . . . . . . . . . . . . . 286
gdb-switch-reasons . . . . . . . . . . . . . . . . . 286
gdb-switch-when-another-stopped . . 286
gdb-thread-buffer-addresses . . . . . . 283
gdb-thread-buffer-arguments . . . . . . 283
gdb-thread-buffer-locations . . . . . . 283
gdb-thread-buffer-verbose-names . . 283
gdb-use-colon-colon-notation . . . . . 285
global-cwarn-mode . . . . . . . . . . . . . . . . . . 269
global-font-lock-mode . . . . . . . . . . . . . . 80
global-mark-ring-max . . . . . . . . . . . . . . . . 51
grep-find-ignored-directories . . . . 276
grep-regexp-alist . . . . . . . . . . . . . . . . . . 273
gud-gdb-command-name. . . . . . . . . . . . . . . 281
gud-tooltip-echo-area . . . . . . . . . . . . . 278

Variable Index
gud-xdb-directories . . . . . . . . . . . . . . . . 277

H
help-at-pt-display-when-idle . . . . . . 46
help-map . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
hi-lock-exclude-modes . . . . . . . . . . . . . . 82
hi-lock-file-patterns-policy . . . . . . 82
hide-ifdef-shadow . . . . . . . . . . . . . . . . . . 269
highlight-nonselected-windows . . . . . 47
history-delete-duplicates . . . . . . . . . . 35
history-length. . . . . . . . . . . . . . . . . . . . . . . 35
hourglass-delay . . . . . . . . . . . . . . . . . . . . . 90
hs-hide-comments-when-hiding-all
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
hs-isearch-open . . . . . . . . . . . . . . . . . . . . 263
hs-special-modes-alist . . . . . . . . . . . . 263
hscroll-margin. . . . . . . . . . . . . . . . . . . . . . . 73
hscroll-step . . . . . . . . . . . . . . . . . . . . . . . . . 73

I
image-dired-external-viewer . . . . . . 343
imenu-auto-rescan . . . . . . . . . . . . . . . . . . 252
imenu-sort-function . . . . . . . . . . . . . . . . 252
indent-tabs-mode . . . . . . . . . . . . . . . . . . . 212
indicate-buffer-boundaries . . . . . . . . . 83
indicate-empty-lines . . . . . . . . . . . . . . . . 84
inferior-lisp-program . . . . . . . . . . . . . 290
inhibit-eol-conversion . . . . . . . . . . . . 191
inhibit-iso-escape-detection . . . . . 191
inhibit-startup-buffer-menu . . . . . . 505
inhibit-startup-screen . . . . . . . . . 14, 508
initial-environment . . . . . . . . . . . . . . . . 510
initial-scratch-message . . . . . . . . . . . 290
input-method-highlight-flag . . . . . . 186
input-method-verbose-flag . . . . . . . . . 186
insert-default-directory . . . . . . 28, 124
interpreter-mode-alist . . . . . . . . . . . . 208
isearch-allow-scroll . . . . . . . . . . . . . . . . 94
isearch-lazy-highlight . . . . . . . . . . . . . 92
isearch-mode-map . . . . . . . . . . . . . . . . . . . . 94
isearch-resume-in-command-history
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
ispell-complete-word-dict . . . . . . . . . 115
ispell-dictionary . . . . . . . . . . . . . . . . . . 114
ispell-local-dictionary . . . . . . . . . . . 114
ispell-personal-dictionary . . . . . . . . 114

J
jdb-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280

607

K
kept-new-versions . . . . . . . . . . . . . . . . . . 131
kept-old-versions . . . . . . . . . . . . . . . . . . 131
keyboard-coding-system . . . . . . . . . . . . 196
kill-buffer-hook . . . . . . . . . . . . . . . . . . . 154
kill-do-not-save-duplicates . . . . . . . . 57
kill-read-only-ok . . . . . . . . . . . . . . . . . . . 56
kill-ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
kill-ring-max . . . . . . . . . . . . . . . . . . . . . . . . 57
kill-whole-line . . . . . . . . . . . . . . . . . . . . . 56
kmacro-ring-max . . . . . . . . . . . . . . . . . . . . 118

L
large-file-warning-threshold . . . . . 126
latex-block-names . . . . . . . . . . . . . . . . . . 233
latex-mode-hook . . . . . . . . . . . . . . . . . . . . 235
latex-run-command . . . . . . . . . . . . . . . . . . 234
latin1-display . . . . . . . . . . . . . . . . . . . . . 200
line-move-visual . . . . . . . . . . . . . . . . . . . . 20
line-number-display-limit . . . . . . . . . . 86
line-number-display-limit-width . . . 86
lisp-body-indent . . . . . . . . . . . . . . . . . . . 254
lisp-indent-offset . . . . . . . . . . . . . . . . . 254
lisp-interaction-mode-hook . . . . . . . . 249
lisp-mode-hook . . . . . . . . . . . . . . . . . . . . . 249
list-colors-sort . . . . . . . . . . . . . . . . . . . . 76
list-directory-brief-switches . . . . 139
list-directory-verbose-switches . . 139
load-dangerous-libraries . . . . . . . . . . 288
load-path . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
locale-charset-language-names . . . . 184
locale-coding-system. . . . . . . . . . . . . . . 195
locale-language-names . . . . . . . . . . . . . 184
locale-preferred-coding-systems . . 184
locate-command . . . . . . . . . . . . . . . . . . . . . 342
lpr-add-switches . . . . . . . . . . . . . . . . . . . 417
lpr-command (MS-DOS) . . . . . . . . . . . . . . 542
lpr-commands . . . . . . . . . . . . . . . . . . . . . . . . 417
lpr-headers-switches. . . . . . . . . . . . . . . 417
lpr-headers-switches (MS-DOS) . . . 542
lpr-printer-switch . . . . . . . . . . . . . . . . . 417
lpr-switches . . . . . . . . . . . . . . . . . . . . . . . . 417
lpr-switches (MS-DOS) . . . . . . . . . . . . 542

M
magic-fallback-mode-alist . . . . . . . . .
magic-mode-alist . . . . . . . . . . . . . . . . . . .
mail-citation-hook . . . . . . . . . . . . . . . . .
mail-default-headers. . . . . . . . . . . . . . .

209
208
373
369

Variable Index
mail-dont-reply-to-names . . . . . . . . . . 385
mail-from-style . . . . . . . . . . . . . . . . . . . . 368
mail-mode-hook . . . . . . . . . . . . . . . . . . . . . 374
mail-personal-alias-file . . . . . . . . . . 370
mail-setup-hook . . . . . . . . . . . . . . . . . . . . 374
mail-signature . . . . . . . . . . . . . . . . . . . . . 374
mail-signature-file . . . . . . . . . . . . . . . . 374
mail-user-agent . . . . . . . . . . . . . . . . . . . . 375
major-mode . . . . . . . . . . . . . . . . . . . . . . . . . . 204
make-backup-file-name-function . . . 131
make-backup-files . . . . . . . . . . . . . . . . . . 130
make-pointer-invisible . . . . . . . . . 90, 178
Man-switches . . . . . . . . . . . . . . . . . . . . . . . . 262
mark-even-if-inactive . . . . . . . . . . . . . . 50
mark-ring-max . . . . . . . . . . . . . . . . . . . . . . . . 51
max-mini-window-height . . . . . . . . . . . . . 29
menu-bar-mode. . . . . . . . . . . . . . . . . . . . . . . 176
message-kill-buffer-on-exit . . . . . . 371
message-log-max. . . . . . . . . . . . . . . . . . . . . . . 7
message-send-hook . . . . . . . . . . . . . . . . . . 371
midnight-hook. . . . . . . . . . . . . . . . . . . . . . . 154
midnight-mode. . . . . . . . . . . . . . . . . . . . . . . 154
minibuffer-local-completion-map . . 454
minibuffer-local-filenamecompletion-map . . . . . . . . . . . . . . . . . 454
minibuffer-local-filename-mustmatch-map . . . . . . . . . . . . . . . . . . . . . . . 454
minibuffer-local-map. . . . . . . . . . . . . . . 454
minibuffer-local-must-match-map . . 454
minibuffer-local-ns-map . . . . . . . . . . . 454
minibuffer-prompt-properties . . . . . . 78
mode-line-in-non-selected-windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
mode-require-final-newline . . . . . . . . 132
mode-specific-map . . . . . . . . . . . . . . . . . . 453
mouse-1-click-in-non-selectedwindows . . . . . . . . . . . . . . . . . . . . . . . . . 168
mouse-autoselect-window . . . . . . . . . . . 161
mouse-avoidance-mode. . . . . . . . . . . . . . . 178
mouse-drag-copy-region . . . . . . . . . . . . 166
mouse-highlight . . . . . . . . . . . . . . . . . . . . 167
mouse-scroll-min-lines . . . . . . . . . . . . 166
mouse-wheel-follow-mouse . . . . . . . . . . 167
mouse-wheel-progressive-speed . . . . 167
mouse-wheel-scroll-amount . . . . . . . . . 167
mouse-yank-at-point . . . . . . . . . . . . . . . . 166

N
next-error-highlight. . . . . . . . . . . . . . . 273
next-line-add-newlines . . . . . . . . . . . . . 20
next-screen-context-lines . . . . . . . . . . 70

608
nobreak-char-display . . . . . . . . . . . . . . . . 87
normal-erase-is-backspace . . . . . . . . . 470
nroff-mode-hook . . . . . . . . . . . . . . . . . . . . 237
ns-pop-up-frames . . . . . . . . . . . . . . . . . . . 532
ns-standard-fontset-spec . . . . . . . . . . 198

O
open-paren-in-column-0-is-defunstart . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
org-agenda-files . . . . . . . . . . . . . . . . . . . 230
org-publish-project-alist . . . . . . . . . 230
org-todo-keywords . . . . . . . . . . . . . . . . . . 230
outline-level. . . . . . . . . . . . . . . . . . . . . . . 226
outline-minor-mode-prefix . . . . . . . . . 224
outline-mode-hook . . . . . . . . . . . . . . . . . . 224
outline-regexp . . . . . . . . . . . . . . . . . . . . . 225
overflow-newline-into-fringe . . . . . . 83
overline-margin . . . . . . . . . . . . . . . . . . . . . 90

P
package-archives . . . . . . . . . . . . . . . . . . . 431
package-directory-list . . . . . . . . . . . . 433
package-enable-at-startup . . . . . . . . . 432
package-load-list . . . . . . . . . . . . . . . . . . 432
package-user-dir . . . . . . . . . . . . . . . . . . . 432
page-delimiter . . . . . . . . . . . . . . . . . . . . . 218
paragraph-separate . . . . . . . . . . . . . . . . . 217
paragraph-start . . . . . . . . . . . . . . . . . . . . 217
pdb-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280
perldb-mode-hook . . . . . . . . . . . . . . . . . . . 280
plain-tex-mode-hook . . . . . . . . . . . . . . . . 235
pop-up-frames. . . . . . . . . . . . . . . . . . . . . . . 164
print-region-function (MS-DOS) . . 542
printer-name . . . . . . . . . . . . . . . . . . . . . . . . 417
printer-name, (MS-DOS/MS-Windows)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541
prog-mode-hook . . . . . . . . . . . . . . . . . . . . . 205
ps-font-family . . . . . . . . . . . . . . . . . . . . . 419
ps-font-info-database . . . . . . . . . . . . . 419
ps-font-size . . . . . . . . . . . . . . . . . . . . . . . . 419
ps-landscape-mode . . . . . . . . . . . . . . . . . . 419
ps-lpr-command . . . . . . . . . . . . . . . . . . . . . 419
ps-lpr-command (MS-DOS) . . . . . . . . . . 542
ps-lpr-switches . . . . . . . . . . . . . . . . . . . . 419
ps-lpr-switches (MS-DOS) . . . . . . . . . 542
ps-multibyte-buffer . . . . . . . . . . . . . . . . 419
ps-number-of-columns. . . . . . . . . . . . . . . 419
ps-page-dimensions-database . . . . . . 419
ps-paper-type. . . . . . . . . . . . . . . . . . . . . . . 419
ps-print-color-p . . . . . . . . . . . . . . . . . . . 419

Variable Index
ps-print-header . . . . . . . . . . . . . . . . . . . .
ps-printer-name . . . . . . . . . . . . . . . . . . . .
ps-printer-name (MS-DOS) . . . . . . . . .
ps-use-face-background . . . . . . . . . . . .

609
419
419
542
419

R
read-buffer-completion-ignore-case
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
read-file-name-completion-ignorecase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
read-mail-command . . . . . . . . . . . . . . . . . . 375
read-quoted-char-radix . . . . . . . . . . . . . 17
recenter-positions . . . . . . . . . . . . . . . . . . 71
recenter-redisplay . . . . . . . . . . . . . . . . . . 72
recentf-mode . . . . . . . . . . . . . . . . . . . . . . . . 148
require-final-newline . . . . . . . . . . . . . 132
resize-mini-windows . . . . . . . . . . . . . . . . . 28
revert-without-query. . . . . . . . . . . . . . . 135
rmail-automatic-folder-directives
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382
rmail-decode-mime-charset . . . . . . . . . 191
rmail-delete-after-output . . . . . . . . . 382
rmail-delete-message-hook . . . . . . . . . 379
rmail-displayed-headers . . . . . . . . . . . 391
rmail-edit-mode-hook. . . . . . . . . . . . . . . 393
rmail-enable-mime . . . . . . . . . . . . . . . . . . 391
rmail-enable-mime-composing . . . . . . 386
rmail-file-coding-system . . . . . . . . . . 191
rmail-file-name . . . . . . . . . . . . . . . . . . . . 376
rmail-highlighted-headers . . . . . . . . . 391
rmail-ignored-headers . . . . . . . . . . . . . 391
rmail-inbox-list . . . . . . . . . . . . . . . . . . . 381
rmail-mail-new-frame. . . . . . . . . . . . . . . 386
rmail-mode-hook . . . . . . . . . . . . . . . . . . . . 376
rmail-movemail-flags. . . . . . . . . . . . . . . 395
rmail-movemail-program . . . . . . . . . . . . 395
rmail-movemail-search-path . . . . . . . . 395
rmail-nonignored-headers . . . . . . . . . . 391
rmail-output-file-alist . . . . . . . . . . . 382
rmail-preserve-inbox. . . . . . . . . . . . . . . 380
rmail-primary-inbox-list . . . . . . . . . . 379
rmail-redisplay-summary . . . . . . . . . . . 389
rmail-remote-password . . . . . . . . . . . . . 395
rmail-remote-password-required . . . 395
rmail-retry-ignored-headers . . . . . . 385
rmail-secondary-file-directory . . . 381
rmail-secondary-file-regexp . . . . . . 381
rmail-summary-line-count-flag . . . . 388
rmail-summary-window-size . . . . . . . . . 388

S
safe-local-eval-forms . . . . . . . . . . . . . 450
safe-local-variable-values . . . . . . . . 450
same-window-buffer-names . . . . . . . . . . 163
same-window-regexps . . . . . . . . . . . . . . . . 163
save-abbrevs . . . . . . . . . . . . . . . . . . . . . . . . 326
save-interprogram-paste-before-kill
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
scheme-mode-hook . . . . . . . . . . . . . . . . . . . 249
scroll-all-mode . . . . . . . . . . . . . . . . . . . . 164
scroll-bar-mode . . . . . . . . . . . . . . . . . . . . 176
scroll-bar-width . . . . . . . . . . . . . . . . . . . 176
scroll-conservatively . . . . . . . . . . . . . . 72
scroll-down . . . . . . . . . . . . . . . . . . . . . . . . . . 71
scroll-down-aggressively . . . . . . . . . . . 72
scroll-error-top-bottom . . . . . . . . . . . . 70
scroll-margin . . . . . . . . . . . . . . . . . . . . . . . . 73
scroll-preserve-screen-position . . . 71
scroll-step . . . . . . . . . . . . . . . . . . . . . . . . . . 72
scroll-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
scroll-up-aggressively . . . . . . . . . . . . . 72
sdb-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280
search-whitespace-regexp . . . . . . . . . . . 97
select-active-regions . . . . . . . . . . . . . . 60
selective-display-ellipses . . . . . . . . . 85
send-mail-function . . . . . . . . . . . . . . . . . 371
sendmail-coding-system . . . . . . . 193, 371
sentence-end . . . . . . . . . . . . . . . . . . . . . . . . 216
sentence-end-double-space . . . . . . . . . 216
sentence-end-without-period . . . . . . 216
server-host . . . . . . . . . . . . . . . . . . . . . . . . . 415
server-kill-new-buffers . . . . . . . . . . . 414
server-name . . . . . . . . . . . . . . . . . . . . . . . . . 413
server-port . . . . . . . . . . . . . . . . . . . . . . . . . 415
server-temp-file-regexp . . . . . . . . . . . 414
server-use-tcp . . . . . . . . . . . . . . . . . . . . . 415
server-window. . . . . . . . . . . . . . . . . . . . . . . 414
set-language-environment-hook . . . . 184
set-mark-command-repeat-pop . . . . . . . . 51
sgml-xml-mode. . . . . . . . . . . . . . . . . . . . . . . 237
shell-cd-regexp . . . . . . . . . . . . . . . . . . . . 409
shell-command-default-error-buffer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402
shell-command-regexp. . . . . . . . . . . . . . . 405
shell-completion-execonly . . . . . . . . . 410
shell-completion-fignore . . . . . . . . . . 404
shell-file-name . . . . . . . . . . . . . . . . . . . . 402
shell-input-ring-file-name . . . . . . . . 408
shell-popd-regexp . . . . . . . . . . . . . . . . . . 409
shell-prompt-pattern. . . . . . . . . . . . . . . 406
shell-pushd-regexp . . . . . . . . . . . . . . . . . 409
show-trailing-whitespace . . . . . . . . . . . 84

Variable Index
slitex-mode-hook . . . . . . . . . . . . . . . . . . . 235
small-temporary-file-directory . . . 130
sort-fold-case . . . . . . . . . . . . . . . . . . . . . 422
sort-numeric-base . . . . . . . . . . . . . . . . . . 420
split-height-threshold . . . . . . . . . . . . 164
split-width-threshold . . . . . . . . . . . . . 164
split-window-keep-point . . . . . . . . . . . 160
standard-fontset-spec . . . . . . . . . . . . . 198
standard-indent . . . . . . . . . . . . . . . . . . . . 240
suggest-key-bindings . . . . . . . . . . . . . . . . 37

T
tab-always-indent . . . . . . . . . . . . . . . . . . 212
tab-stop-list. . . . . . . . . . . . . . . . . . . . . . . 211
tab-width. . . . . . . . . . . . . . . . . . . . . . . . 87, 212
table-cell-horizontal-chars . . . . . . 242
table-cell-intersection-char . . . . . 242
table-cell-vertical-char . . . . . . . . . . 242
table-detect-cell-alignment . . . . . . 244
tags-apropos-additional-actions . . 320
tags-apropos-verbose. . . . . . . . . . . . . . . 320
tags-case-fold-search . . . . . . . . . . . . . 319
tags-file-name . . . . . . . . . . . . . . . . . . . . . 317
tags-table-list . . . . . . . . . . . . . . . . . . . . 317
tags-tag-face. . . . . . . . . . . . . . . . . . . . . . . 320
temporary-file-directory . . . . . . . . . . 130
term-file-prefix . . . . . . . . . . . . . . . . . . . 466
term-setup-hook . . . . . . . . . . . . . . . . . . . . 466
tex-bibtex-command . . . . . . . . . . . . . . . . . 235
tex-default-mode . . . . . . . . . . . . . . . . . . . 231
tex-directory. . . . . . . . . . . . . . . . . . . . . . . 234
tex-dvi-print-command . . . . . . . . . . . . . 234
tex-dvi-view-command. . . . . . . . . . . . . . . 234
tex-main-file. . . . . . . . . . . . . . . . . . . . . . . 235
tex-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 235
tex-run-command . . . . . . . . . . . . . . . . . . . . 234
tex-shell-hook . . . . . . . . . . . . . . . . . . . . . 235
tex-start-commands . . . . . . . . . . . . . . . . . 235
tex-start-options . . . . . . . . . . . . . . . . . . 235
text-mode-hook . . . . . . . . . . . . . . . . . 205, 224
timeclock-ask-before-exiting . . . . . 366
timeclock-file . . . . . . . . . . . . . . . . . . . . . 366
timeclock-modeline-display . . . . . . . . 366
tool-bar-mode. . . . . . . . . . . . . . . . . . . . . . . 177
tool-bar-style . . . . . . . . . . . . . . . . . . . . . 177
tooltip-delay. . . . . . . . . . . . . . . . . . . . . . . 178
track-eol . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
truncate-lines. . . . . . . . . . . . . . . . . . . . . . . 89
truncate-partial-width-windows. . . . 89,
160

610

U
underline-minimum-offset . . . . . . . . . . . 90
undo-limit . . . . . . . . . . . . . . . . . . . . . . . . . . 111
undo-outer-limit . . . . . . . . . . . . . . . . . . . 111
undo-strong-limit . . . . . . . . . . . . . . . . . . 111
unibyte-display-via-languageenvironment . . . . . . . . . . . . . . . . . . . . 200
uniquify-buffer-name-style . . . . . . . . 157
use-dialog-box . . . . . . . . . . . . . . . . . . . . . 177
use-file-dialog . . . . . . . . . . . . . . . . . . . . 177
user-full-name . . . . . . . . . . . . . . . . . . . . . 368
user-mail-address . . . . . . . . . . . . . 368, 463
user-mail-address, initialization . . . . 510

V
vc-diff-switches . . . . . . . . . . . . . . . . . . . 301
vc-directory-exclusion-list . . . . . . 305
vc-log-mode-hook . . . . . . . . . . . . . . . . . . . 299
vc-log-show-limit . . . . . . . . . . . . . . . . . . 304
vc-make-backup-files. . . . . . . . . . . . . . . 130
vc-revert-show-diff . . . . . . . . . . . . . . . . 304
version-control . . . . . . . . . . . . . . . . . . . . 130
visible-bell . . . . . . . . . . . . . . . . . . . . . . . . . 90
visible-cursor. . . . . . . . . . . . . . . . . . . . . . . 88

W
w32-apps-modifier . . . . . . . . . . . . . . . . . . 539
w32-charset-info-alist . . . . . . . . . . . . 544
w32-get-true-file-attributes . . . . . 538
w32-lwindow-modifier. . . . . . . . . . . . . . . 540
w32-mouse-button-tolerance . . . . . . . . 540
w32-pass-alt-to-system . . . . . . . . . . . . 540
w32-pass-extra-mouse-buttons-tosystem . . . . . . . . . . . . . . . . . . . . . . . . . . 540
w32-quote-process-args . . . . . . . . . . . . 541
w32-rwindow-modifier. . . . . . . . . . . . . . . 540
w32-scroll-lock-modifier . . . . . . . . . . 540
w32-standard-fontset-spec . . . . . . . . . 198
w32-swap-mouse-buttons . . . . . . . . . . . . 540
w32-use-visible-system-caret . . . . . 545
which-func-modes . . . . . . . . . . . . . . . . . . . 252
whitespace-line-column . . . . . . . . . . . . . 84
whitespace-style . . . . . . . . . . . . . . . . . . . . 84
window-min-height . . . . . . . . . . . . . . . . . . 162
window-min-width . . . . . . . . . . . . . . . . . . . 162
write-region-inhibit-fsync . . . . . . . . 132

X
x-gtk-file-dialog-help-text . . . . . . 177

Variable Index
x-gtk-show-hidden-files . . . . . . . . . . . 177
x-gtk-use-system-tooltips . . . . . . . . . 178
x-mouse-click-focus-ignore-position
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
x-select-enable-clipboard . . . . . . . . . . 60
x-select-enable-clipboard-manager
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
x-select-enable-primary . . . . . . . . . . . . 60

611
x-select-request-type . . . . . . . . . . . . . 195
x-stretch-cursor . . . . . . . . . . . . . . . . . . . . 88
x-underline-at-descent-line . . . . . . . . 90
xdb-mode-hook. . . . . . . . . . . . . . . . . . . . . . . 280

Y
yank-pop-change-selection . . . . . . . . . . 60

Concept Index

612

Concept Index
$

8

$ in file names . . . . . . . . . . . . . . . . . . . . . . . 125

8-bit display . . . . . . . . . . . . . . . . . . . . . . . . . 201
8-bit input . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

(
( in leftmost column . . . . . . . . . . . . . . . . . 250

*
‘*Messages*’ buffer. . . . . . . . . . . . . . . . . . . . . 7

–/—/.-./.../. . . . . . . . . . . . . . . . . . . . . . . . . . 428

.
‘.dir-locals.el’ file. . . . . . . . . . . . . . . . .
.emacs file . . . . . . . . . . . . . . . . . . . . . . . . . . .
‘.mailrc’ file . . . . . . . . . . . . . . . . . . . . . . . . .
‘.newsrc’ file . . . . . . . . . . . . . . . . . . . . . . . . .
‘.timelog’ file . . . . . . . . . . . . . . . . . . . . . . .

450
461
370
397
366

/
// in file name . . . . . . . . . . . . . . . . . . . . . . . . 27

?
‘?’ in display . . . . . . . . . . . . . . . . . . . . . . . . . 181

‘_emacs’ init file, MS-Windows . . . . . . . 539

~
~/.emacs file . . . . . . . . . . . . . . . . . . . . . . . . .
‘~/.emacs.d/gtkrc’ file . . . . . . . . . . . . . .
‘~/.gtkrc-2.0’ file . . . . . . . . . . . . . . . . . . .
‘~/.Xdefaults’ file . . . . . . . . . . . . . . . . . . .
‘~/.Xresources’ file . . . . . . . . . . . . . . . . . .

461
523
523
521
521

7
7z . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

A
abbrev file . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Abbrev mode . . . . . . . . . . . . . . . . . . . . . . . . 322
abbrevs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
abnormal hook . . . . . . . . . . . . . . . . . . . . . . . 445
aborting recursive edit . . . . . . . . . . . . . . . 469
accented characters . . . . . . . . . . . . . . . . . . 200
accessible portion . . . . . . . . . . . . . . . . . . . . . 74
accumulating scattered text . . . . . . . . . . . 61
action options (command line) . . . . . . . 505
active region . . . . . . . . . . . . . . . . . . . . . . . . . . 47
adaptive filling . . . . . . . . . . . . . . . . . . . . . . . 222
Adding to the kill ring in Dired. . . . . . . 344
addpm, MS-Windows installation program
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514
adjust buffer face height . . . . . . . . . . . . . . . 79
aggressive scrolling . . . . . . . . . . . . . . . . . . . . 72
alarm clock . . . . . . . . . . . . . . . . . . . . . . . . . . 364
alignment for comments . . . . . . . . . . . . . . 259
Alt key invokes menu (Windows) . . . . . 540
ALTERNATE_EDITOR environment variable
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414
ange-ftp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
animate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
animated images . . . . . . . . . . . . . . . . . . . . . 148
anonymous FTP . . . . . . . . . . . . . . . . . . . . . 146
appending kills in the ring . . . . . . . . . . . . . 58
appointment notification . . . . . . . . . . . . . 364
apropos . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
apropos search results, order by score . . 42
arc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Arch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Archive mode . . . . . . . . . . . . . . . . . . . . . . . . 145
arguments (command line) . . . . . . . . . . . 505
arguments to commands. . . . . . . . . . . . . . . 25
arrow keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
ASCII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
ASCII art . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
Asm mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
assembler mode . . . . . . . . . . . . . . . . . . . . . . 270
astronomical day numbers . . . . . . . . . . . . 354
attached frame (of speedbar) . . . . . . . . . 174
attribute (Rmail) . . . . . . . . . . . . . . . . . . . . 383

Concept Index
attributes of mode line, changing . . . . . . 86
Auto Compression mode . . . . . . . . . . . . . 144
Auto Fill mode . . . . . . . . . . . . . . . . . . . . . . 218
Auto Save mode . . . . . . . . . . . . . . . . . . . . . 136
Auto-Revert mode . . . . . . . . . . . . . . . . . . . 135
auto-save for remote files . . . . . . . . . . . . . 136
autoload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
autoload Lisp libraries . . . . . . . . . . . . . . . 464
avoiding mouse in the way of your typing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
AWK mode . . . . . . . . . . . . . . . . . . . . . . . . . . 266

B
back end (version control) . . . . . . . . . . . . 293
back reference, in regexp . . . . . . . . . . . . . 101
back reference, in regexp replacement
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
background color . . . . . . . . . . . . . . . . . . . . . . 75
background color, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515
background mode, on xterm . . . . . . . . . . 512
background syntax highlighting . . . . . . . . 81
BACKSPACE vs DEL . . . . . . . . . . . . . . . 470
backtrace for bug reports . . . . . . . . . . . . . 479
backup file . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
backup, and user-id . . . . . . . . . . . . . . . . . . 132
backups for remote files . . . . . . . . . . . . . . 146
Bahá’ı́ calendar . . . . . . . . . . . . . . . . . . . . . . 355
balanced expression . . . . . . . . . . . . . . . . . . 256
balloon help. . . . . . . . . . . . . . . . . . . . . . . . . . . 46
base buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
base direction of paragraphs . . . . . . . . . . 203
batch mode . . . . . . . . . . . . . . . . . . . . . . . . . . 507
Bazaar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
bidirectional editing . . . . . . . . . . . . . . . . . . 202
binary files, on MS-DOS/MS-Windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537
binding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
binding keyboard macros . . . . . . . . . . . . . 121
binding keys . . . . . . . . . . . . . . . . . . . . . . . . . 454
blank lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
blank lines in programs . . . . . . . . . . . . . . 260
blinking cursor . . . . . . . . . . . . . . . . . . . . . . . . 88
blinking cursor disable, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 520
body lines (Outline mode) . . . . . . . . . . . 225
bookmarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
border color, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515
borders (X Window System) . . . . . . . . . 518
boredom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428

613
brace in column zero and fontification . . 80
braces, moving across . . . . . . . . . . . . . . . . 257
branch (version control) . . . . . . . . . . . . . . 307
Brief emulation . . . . . . . . . . . . . . . . . . . . . . 425
Browse-URL . . . . . . . . . . . . . . . . . . . . . . . . . 426
buffer definitions index . . . . . . . . . . . . . . . 251
buffer list, customizable . . . . . . . . . . . . . . 158
buffer menu . . . . . . . . . . . . . . . . . . . . . 154, 158
buffer size display . . . . . . . . . . . . . . . . . . . . . 85
buffer size, maximum . . . . . . . . . . . . . . . . 150
buffer-local hooks . . . . . . . . . . . . . . . . . . . . 446
buffers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
bug tracker . . . . . . . . . . . . . . . . . . . . . . . . . . 473
bugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473
building programs . . . . . . . . . . . . . . . . . . . . 271
built-in package . . . . . . . . . . . . . . . . . . . . . . 430
button down events . . . . . . . . . . . . . . . . . . 459
buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
buttons (customization buffer) . . . . . . . 435
buttons at buffer position . . . . . . . . . . . . 239
bypassing init and ‘default.el’ file . . 508
byte code . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
byte-compiling several files (in Dired)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
bzr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293

C
C editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
C mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
C++ class browser, tags . . . . . . . . . . . . . . . 311
C++ mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
C- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
C-c C-c (Log Edit mode) . . . . . . . . . . . . . 299
cache of file names . . . . . . . . . . . . . . . . . . . 147
calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
calendar and HTML . . . . . . . . . . . . . . . . . 349
calendar and LaTEX . . . . . . . . . . . . . . . . . 350
calendar, first day of week . . . . . . . . . . . . 347
call Lisp functions, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 506
camel case . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
capitalizing words . . . . . . . . . . . . . . . . . . . . 223
case conversion. . . . . . . . . . . . . . . . . . . . . . . 223
case in completion . . . . . . . . . . . . . . . . . . . . 33
case-sensitivity and completion . . . . . . . . 33
case-sensitivity and tags search . . . . . . . 319
categories of characters . . . . . . . . . . . . . . . 102
cells, for text-based tables . . . . . . . . . . . . 242
Celtic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
centering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
centralized version control . . . . . . . . . . . . 295

Concept Index
change buffers . . . . . . . . . . . . . . . . . . . . . . . 150
change Emacs directory . . . . . . . . . . . . . . 507
change log . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Change Log mode . . . . . . . . . . . . . . . . . . . . 310
changes, undoing . . . . . . . . . . . . . . . . . . . . . 110
changeset-based version control . . . . . . . 295
changing file group (in Dired) . . . . . . . . 336
changing file owner (in Dired) . . . . . . . . 336
changing file permissions (in Dired) . . 336
changing file time (in Dired) . . . . . . . . . 336
character set (keyboard). . . . . . . . . . . . . . . 11
character set of character at point . . . . 181
character syntax . . . . . . . . . . . . . . . . . . . . . 463
characters (in text) . . . . . . . . . . . . . . . . . . . . 87
characters in a certain charset . . . . . . . . 202
characters which belong to a specific
language . . . . . . . . . . . . . . . . . . . . . . . . 102
characters with no font glyphs . . . . . . . . . 87
characters, inserting by name or
code-point . . . . . . . . . . . . . . . . . . . . . . . . 17
charsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
checking out files . . . . . . . . . . . . . . . . . . . . . 294
checking spelling . . . . . . . . . . . . . . . . . . . . . 112
checking syntax . . . . . . . . . . . . . . . . . . . . . . 276
Chinese . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Chinese calendar . . . . . . . . . . . . . . . . . . . . . 355
choosing a major mode . . . . . . . . . . . . . . . 207
choosing a minor mode . . . . . . . . . . . . . . . 207
ciphers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
citing mail . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
class browser, C++ . . . . . . . . . . . . . . . . . . . 311
click events . . . . . . . . . . . . . . . . . . . . . . . . . . 459
client frame . . . . . . . . . . . . . . . . . . . . . . . . . . 414
client-side fonts . . . . . . . . . . . . . . . . . . . . . . 173
clipboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
clipboard manager . . . . . . . . . . . . . . . . . . . . 60
coding systems . . . . . . . . . . . . . . . . . . . . . . . 188
collision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
color emulation on black-and-white
printers . . . . . . . . . . . . . . . . . . . . . . . . . 419
color name . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
color of window, from command line . . 515
color scheme . . . . . . . . . . . . . . . . . . . . . . . . . 441
Column Number mode . . . . . . . . . . . . . . . . 85
columns (and rectangles) . . . . . . . . . . . . . . 63
columns (indentation) . . . . . . . . . . . . . . . . 210
columns, splitting . . . . . . . . . . . . . . . . . . . . 247
Comint mode . . . . . . . . . . . . . . . . . . . . . . . . 406
comint-highlight-input face . . . . . . . . 403
comint-highlight-prompt face. . . . . . . 403
command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
command history. . . . . . . . . . . . . . . . . . . . . . 35

614
command line arguments . . . . . . . . . . . . . 505
comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258
comments on customized settings . . . . . 438
Common Lisp . . . . . . . . . . . . . . . . . . . . . . . . 290
compare files (in Dired) . . . . . . . . . . . . . . 339
comparing 3 files (diff3) . . . . . . . . . . . . . 141
comparing files . . . . . . . . . . . . . . . . . . . . . . . 140
compilation buffer, keeping point at end
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
compilation errors . . . . . . . . . . . . . . . . . . . . 271
Compilation mode . . . . . . . . . . . . . . . . . . . 272
complete key . . . . . . . . . . . . . . . . . . . . . . . . . . 11
completion . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
completion (Lisp symbols) . . . . . . . . . . . 264
completion (symbol names) . . . . . . 264, 320
completion alternative . . . . . . . . . . . . . . . . . 29
completion list . . . . . . . . . . . . . . . . . . . . . . . . 30
completion style . . . . . . . . . . . . . . . . . . . . . . . 32
compose character . . . . . . . . . . . . . . . . . . . 201
compressing files (in Dired) . . . . . . . . . . 336
compression . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Conf mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
confirming in the minibuffer . . . . . . . . . . . 31
conflicts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
connecting to remote host . . . . . . . . . . . . 411
continuation line . . . . . . . . . . . . . . . . . . . . . . 23
contributing to Emacs. . . . . . . . . . . . . . . . 483
Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
control character . . . . . . . . . . . . . . . . . . . . . . 11
control characters on display . . . . . . . . . . 87
converting text to upper or lower case
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Coptic calendar . . . . . . . . . . . . . . . . . . . . . . 354
copy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
copying files . . . . . . . . . . . . . . . . . . . . . . . . . 143
copying files (in Dired) . . . . . . . . . . . . . . . 335
copying text . . . . . . . . . . . . . . . . . . . . . . . . . . 57
CORBA IDL mode . . . . . . . . . . . . . . . . . . 266
correcting spelling. . . . . . . . . . . . . . . . . . . . 112
CPerl mode . . . . . . . . . . . . . . . . . . . . . . . . . . 249
crashes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
create a text-based table . . . . . . . . . . . . . 243
creating files . . . . . . . . . . . . . . . . . . . . . . . . . 126
creating frames . . . . . . . . . . . . . . . . . . . . . . 169
CRiSP mode . . . . . . . . . . . . . . . . . . . . . . . . . 425
cryptanalysis . . . . . . . . . . . . . . . . . . . . . . . . . 428
CSSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
CUA key bindings. . . . . . . . . . . . . . . . . . . . . 64
current buffer . . . . . . . . . . . . . . . . . . . . . . . . 150
current function name in mode line . . . 252
cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Concept Index
cursor color, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516
cursor face . . . . . . . . . . . . . . . . . . . . . . . . 76, 88
cursor in non-selected windows . . . . . . . . 88
cursor location . . . . . . . . . . . . . . . . . . . . . . . . 24
cursor location, on MS-DOS . . . . . . . . . . 536
cursor motion . . . . . . . . . . . . . . . . . . . . . . . . . 18
cursor, blinking . . . . . . . . . . . . . . . . . . . . . . . 88
custom themes . . . . . . . . . . . . . . . . . . . . . . . 441
custom themes, creating . . . . . . . . . . . . . . 442
customizable variable . . . . . . . . . . . . . . . . 434
customization . . . . . . . . . . . . . . . . . . . . . . . . 434
customization buffer . . . . . . . . . . . . . . . . . 434
customization groups . . . . . . . . . . . . . . . . . 434
customization of menu face. . . . . . . . . . . . . 79
customizing faces . . . . . . . . . . . . . . . . . . . . 439
customizing Lisp indentation . . . . . . . . . 254
customizing variables. . . . . . . . . . . . . . . . . 436
cut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
cut and paste . . . . . . . . . . . . . . . . . . . . . . . . 560
cutting text . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
CVS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
CWarn mode . . . . . . . . . . . . . . . . . . . . . . . . 269
Cyrillic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Czech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

D
daemon, Emacs . . . . . . . . . . . . . . . . . . . . . . 412
day of year. . . . . . . . . . . . . . . . . . . . . . . . . . . 349
daylight saving time. . . . . . . . . . . . . . . . . . 365
DBX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
dead character . . . . . . . . . . . . . . . . . . . . . . . 201
debbugs package . . . . . . . . . . . . . . . . . . . . . 473
debuggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
debugging Emacs, tricks and techniques
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480
decentralized version control . . . . . . . . . 295
decoding mail messages (Rmail) . . . . . . 392
decoding non-ASCII keyboard input on X
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
decrease buffer face height . . . . . . . . . . . . . 79
decrypting files (in Dired) . . . . . . . . . . . . 336
default argument . . . . . . . . . . . . . . . . . . . . . . 27
default directory . . . . . . . . . . . . . . . . . 27, 124
default face . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
default file name . . . . . . . . . . . . . . . . . . . . . 124
default-frame-alist . . . . . . . . . . . . . . . . . . . 175
‘default.el’ file, not loading . . . . . . . . . 508
‘default.el’, the default init file . . . . . 461
defining keyboard macros . . . . . . . . . . . . 116
defuns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

615
DEL vs BACKSPACE . . . . . . . . . . . . . . . 470
Delete Selection mode . . . . . . . . . . . . . . . . . 50
deleting auto-save files . . . . . . . . . . . . . . . 331
deleting blank lines. . . . . . . . . . . . . . . . . . . . 22
deleting characters and lines . . . . . . . . . . . 20
deleting files (in Dired) . . . . . . . . . . . . . . . 330
deleting rows and column in text-based
tables . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
deleting some backup files . . . . . . . . . . . . 332
deletion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
deletion (of files) . . . . . . . . . . . . . . . . . . . . . 143
deletion (Rmail) . . . . . . . . . . . . . . . . . . . . . 378
Delphi mode . . . . . . . . . . . . . . . . . . . . . . . . . 249
desktop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
desktop shortcut, MS-Windows . . . . . . . 535
Devanagari . . . . . . . . . . . . . . . . . . . . . . . . . . 180
device for Emacs terminal I/O . . . . . . . 507
dialog boxes . . . . . . . . . . . . . . . . . . . . . . . . . 177
diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
diary file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360
Diff Auto-Refine mode . . . . . . . . . . . . . . . 141
Diff mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
digest message . . . . . . . . . . . . . . . . . . . . . . . 393
directional window selection . . . . . . . . . . 164
directories in buffer names . . . . . . . . . . . 157
directory header lines . . . . . . . . . . . . . . . . 340
directory listing . . . . . . . . . . . . . . . . . . . . . . 139
directory name abbreviation . . . . . . . . . . 139
directory tracking . . . . . . . . . . . . . . . . . . . . 409
directory where Emacs starts on
MS-Windows . . . . . . . . . . . . . . . . . . . . 535
directory-local variables . . . . . . . . . . . . . . 450
Dired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Dired and version control . . . . . . . . . . . . 345
Dired sorting. . . . . . . . . . . . . . . . . . . . . . . . . 342
Dired, and MS-Windows/MS-DOS . . . 538
Dirtrack mode . . . . . . . . . . . . . . . . . . . . . . . 409
disable window system . . . . . . . . . . . . . . . 507
disabled command . . . . . . . . . . . . . . . . . . . 460
disabling remote files . . . . . . . . . . . . . . . . . 146
DISPLAY environment variable . . . . . . . . 514
display for Emacs frame . . . . . . . . . . . . . . 507
display name (X Window System) . . . . 514
display of buffer size . . . . . . . . . . . . . . . . . . 85
display of line number . . . . . . . . . . . . . . . . . 85
distributed version control. . . . . . . . . . . . 295
DNS mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
doc-view-minor-mode . . . . . . . . . . . . . . . . 399
DocTEX mode . . . . . . . . . . . . . . . . . . . . . . . 231
document viewer (DocView). . . . . . . . . . 399
documentation string . . . . . . . . . . . . . . . . . . 40
DocView mode . . . . . . . . . . . . . . . . . . . . . . . 399

Concept Index
DOS applications, running from Emacs
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540
DOS-style end-of-line display . . . . . . . . . 191
DOS-to-Unix conversion of files . . . . . . 537
double clicks . . . . . . . . . . . . . . . . . . . . . . . . . 459
double slash in file name . . . . . . . . . . . . . . 27
down events . . . . . . . . . . . . . . . . . . . . . . . . . 459
downcase file names . . . . . . . . . . . . . . . . . . 338
drag and drop . . . . . . . . . . . . . . . . . . . . . . . 176
drag and drop, Dired . . . . . . . . . . . . . . . . . 345
drag events . . . . . . . . . . . . . . . . . . . . . . . . . . 459
drastic changes. . . . . . . . . . . . . . . . . . . . . . . 135
dribble file . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
DSSSL mode. . . . . . . . . . . . . . . . . . . . . . . . . 249
Dutch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
DVI file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399

E
Ebrowse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
echo area. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
echo area message . . . . . . . . . . . . . . . . . . . . . . 7
echoing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
EDE (Emacs Development Environment)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Edebug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478
editable fields (customization buffer) . . 435
editing binary files . . . . . . . . . . . . . . . . . . . 422
editing level, recursive . . . . . . . . . . . . . . . . 424
EDITOR environment variable . . . . . . . . . 412
EDT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Eldoc mode . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Electric Indent mode . . . . . . . . . . . . . . . . . 213
Electric Pair mode . . . . . . . . . . . . . . . . . . . 258
Eliza . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Emacs as a server . . . . . . . . . . . . . . . . . . . . 412
Emacs Development Environment . . . . 320
EMACS environment variable . . . . . . . . . . 403
Emacs icon, a gnu. . . . . . . . . . . . . . . . . . . . 519
Emacs initialization file . . . . . . . . . . . . . . 461
Emacs Lisp mode . . . . . . . . . . . . . . . . . . . . 288
Emacs Lisp package . . . . . . . . . . . . . . . . . . 430
Emacs Lisp package archive . . . . . . . . . . 430
emacs-internal, coding system . . . . . . 190
EMACS_SERVER_FILE environment variable
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
emacsclient . . . . . . . . . . . . . . . . . . . . . . . . . . 412
emacsclient invocation . . . . . . . . . . . . . . 413
emacsclient options . . . . . . . . . . . . . . . . . 414
emacsclient, on MS-Windows . . . . . . . . . 536
emacsclient.exe . . . . . . . . . . . . . . . . . . . . . . 535
emacsclientw.exe . . . . . . . . . . . . . . . . . . . . . 535

616
email . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
emulating other editors. . . . . . . . . . . . . . . 425
emulation of Brief . . . . . . . . . . . . . . . . . . . . 425
encoding of characters. . . . . . . . . . . . . . . . 180
encrypted mails (reading in Rmail) . . . 392
encrypting files (in Dired) . . . . . . . . . . . . 336
end-of-line convention, mode-line
indication . . . . . . . . . . . . . . . . . . . . . . . . . 8
end-of-line conversion . . . . . . . . . . . . . . . . 189
end-of-line conversion on
MS-DOS/MS-Windows . . . . . . . . . . 536
Enriched mode . . . . . . . . . . . . . . . . . . . . . . . 237
enriched text . . . . . . . . . . . . . . . . . . . . . . . . . 237
entering Emacs. . . . . . . . . . . . . . . . . . . . . . . . 14
environment variables . . . . . . . . . . . . . . . . 509
environment variables for subshells . . . 403
environment variables in file names . . . 125
erasing characters and lines. . . . . . . . . . . . 20
error log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
error message . . . . . . . . . . . . . . . . . . . . . . . . . . 7
errors in init file . . . . . . . . . . . . . . . . . . . . . 509
ESC replacing META key . . . . . . . . . . . . . 11
escape sequences in files . . . . . . . . . . . . . . 191
ESHELL environment variable . . . . . . . . . 403
etags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
etags program . . . . . . . . . . . . . . . . . . . . . . . 314
Ethiopic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Ethiopic calendar . . . . . . . . . . . . . . . . . . . . 354
Euro sign . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
European character sets . . . . . . . . . . . . . . 200
evaluate expression, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 506
exiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
exiting recursive edit . . . . . . . . . . . . . . . . . 424
expanding subdirectories in Dired . . . . 339
expansion (of abbrevs) . . . . . . . . . . . . . . . 322
expansion of C macros . . . . . . . . . . . . . . . 269
expansion of environment variables . . . 125
expression . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
expunging (Rmail) . . . . . . . . . . . . . . . . . . . 378

F
face at point . . . . . . . . . . . . . . . . . . . . . . . . . 181
face colors, setting . . . . . . . . . . . . . . . . . . . . 76
faces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
faces for highlighting query replace . . . 106
faces for highlighting search matches. . . 91
faces, customizing . . . . . . . . . . . . . . . . . . . . 439
failed merges . . . . . . . . . . . . . . . . . . . . . . . . . 141
Feedmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
FFAP minor mode . . . . . . . . . . . . . . . . . . . 427

Concept Index
file
file
file
file
file
file
file
file
file
file
file
file

archives . . . . . . . . . . . . . . . . . . . . . . . . . . 144
comparison (in Dired) . . . . . . . . . . . . 339
database (locate) . . . . . . . . . . . . . . . . . 342
dates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
directory . . . . . . . . . . . . . . . . . . . . . . . . . 139
local variables . . . . . . . . . . . . . . . . . . . . 447
management . . . . . . . . . . . . . . . . . . . . . 329
modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
name caching. . . . . . . . . . . . . . . . . . . . . 147
names . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
names on MS-Windows . . . . . . . . . . . 538
names with non-ASCII characters
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
file names, quote special characters . . . 146
file ownership, and backup . . . . . . . . . . . 132
file permissions. . . . . . . . . . . . . . . . . . . . . . . 144
file selection dialog . . . . . . . . . . . . . . . . . . . 127
file selection dialog, how to disable . . . 177
file shadows . . . . . . . . . . . . . . . . . . . . . . . . . . 134
file truenames . . . . . . . . . . . . . . . . . . . . . . . . 138
file version in change log entries . . . . . . 310
file, warning when size is large. . . . . . . . 126
file-based version control . . . . . . . . . . . . . 295
file-name completion, on MS-Windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538
files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
files, visiting and saving . . . . . . . . . . . . . . 125
filesets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
filesets, VC . . . . . . . . . . . . . . . . . . . . . . . . . . 296
fill prefix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
filling text . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
find . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
find and Dired . . . . . . . . . . . . . . . . . . . . . . 342
find Info manual by its file name . . . . . . 44
finder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
finding file at point . . . . . . . . . . . . . . . . . . 427
finding files containing regexp matches (in
Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . 334
finding strings within text . . . . . . . . . . . . . 91
firewall, and accessing remote files . . . . 146
fixing incorrectly decoded mail messages
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 392
flagging files (in Dired) . . . . . . . . . . . . . . . 330
flagging many files for deletion (in Dired)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Flyspell mode . . . . . . . . . . . . . . . . . . . . . . . . 115
folding editing . . . . . . . . . . . . . . . . . . . . . . . 228
Follow mode . . . . . . . . . . . . . . . . . . . . . . . . . . 75
font antialiasing (MS Windows) . . . . . . 544
font backend selection (MS-Windows)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543
Font Lock mode . . . . . . . . . . . . . . . . . . . . . . . 80

617
font name (X Window System) . . . . . . . 515
font of character at point . . . . . . . . . . . . . 181
font properties (MS Windows gdi
backend) . . . . . . . . . . . . . . . . . . . . . . . . 544
font properties (MS Windows) . . . . . . . 544
font scripts (MS Windows) . . . . . . . . . . . 544
font specification (MS Windows) . . . . . 543
font Unicode subranges (MS Windows)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544
fontconfig . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
fonts and faces . . . . . . . . . . . . . . . . . . . . . . . 439
fonts for PostScript printing . . . . . . . . . . 419
fonts for various scripts . . . . . . . . . . . . . . 197
fontsets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
fontsets, modifying . . . . . . . . . . . . . . . . . . . 199
foreground color, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515
formfeed character . . . . . . . . . . . . . . . . . . . 217
fortune cookies . . . . . . . . . . . . . . . . . . . . . . . 375
forwarding a message . . . . . . . . . . . . . . . . 386
frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
frame size, specifying default . . . . . . . . . 175
frame title, command-line argument . . 519
frames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
French Revolutionary calendar . . . . . . . 354
fringe face . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
fringes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
fringes, and continuation lines . . . . . . . . . 23
fringes, and unused line indication . . . . . 84
fringes, for debugging . . . . . . . . . . . . . . . . 282
FTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
fullheight, command-line argument . . . 517
fullscreen, command-line argument . . . 517
fullwidth, command-line argument . . . 517
function key . . . . . . . . . . . . . . . . . . . . . . . . . 452
function, move to beginning or end . . . 251

G
gateway, and remote file access with
ange-ftp . . . . . . . . . . . . . . . . . . . . . . . . 146
GDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
GDB User Interface layout . . . . . . . . . . . 281
geometry of Emacs window. . . . . . . . . . . 517
geometry, command-line argument . . . 517
German . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
getting help with keys . . . . . . . . . . . . . . . . . 22
Ghostscript, use for PostScript printing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543
git . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Glasses mode . . . . . . . . . . . . . . . . . . . . . . . . 264

Concept Index
Global Auto-Revert mode . . . . . . . . . . . . 135
global keymap . . . . . . . . . . . . . . . . . . . . . . . 452
global mark . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
global mark ring . . . . . . . . . . . . . . . . . . . . . . 51
global substitution . . . . . . . . . . . . . . . . . . . 103
glyphless characters . . . . . . . . . . . . . . . . . . . 87
GNU Arch . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Gnus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
GNUstep . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531
Go Moku . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Goto Address mode . . . . . . . . . . . . . . . . . . 426
graphic characters . . . . . . . . . . . . . . . . . . . . . 17
Greek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Gregorian calendar . . . . . . . . . . . . . . . . . . . 353
growing minibuffer . . . . . . . . . . . . . . . . . . . . 28
GTK font pattern . . . . . . . . . . . . . . . . . . . . 172
GTK styles . . . . . . . . . . . . . . . . . . . . . . . . . . 526
GTK widget classes . . . . . . . . . . . . . . . . . . 525
GTK widget names . . . . . . . . . . . . . . . . . . 525
GTK+ resources. . . . . . . . . . . . . . . . . . . . . . 523
GUD interaction buffer . . . . . . . . . . . . . . . 277
GUD library . . . . . . . . . . . . . . . . . . . . . . . . . 276
GUD Tooltip mode . . . . . . . . . . . . . . . . . . 278
gzip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

H
handwriting . . . . . . . . . . . . . . . . . . . . . . . . . . 418
hard links (creation) . . . . . . . . . . . . . . . . . 143
hard links (in Dired) . . . . . . . . . . . . . . . . . 335
hard links (visiting) . . . . . . . . . . . . . . . . . . 138
hard newline . . . . . . . . . . . . . . . . . . . . . . . . . 238
hardcopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
header (TEX mode) . . . . . . . . . . . . . . . . . . 234
header line (Dired) . . . . . . . . . . . . . . . . . . . 340
headers (of mail message) . . . . . . . . . . . . 368
heading lines (Outline mode) . . . . . . . . . 225
Hebrew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Hebrew calendar . . . . . . . . . . . . . . . . . . . . . 354
height of minibuffer . . . . . . . . . . . . . . . . . . . 28
help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
help text, in GTK+ file chooser . . . . . . . 177
help, viewing web pages . . . . . . . . . . . . . . . 43
hex editing. . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Hexl mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
hg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Hi Lock mode . . . . . . . . . . . . . . . . . . . . . . . . . 81
hidden files, in GTK+ file chooser . . . . 177
Hide-ifdef mode . . . . . . . . . . . . . . . . . . . . . . 269
Hideshow mode . . . . . . . . . . . . . . . . . . . . . . 263
hiding subdirectories (Dired) . . . . . . . . . 340
Highlight Changes mode . . . . . . . . . . . . . . 81

618
highlight current line . . . . . . . . . . . . . . . . . . 88
highlighting by matching . . . . . . . . . . . . . . 81
highlighting lines of text. . . . . . . . . . . . . . . 82
highlighting matching parentheses . . . . 258
highlighting region . . . . . . . . . . . . . . . . . . . . 52
Hindi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
history of commands . . . . . . . . . . . . . . . . . . 35
history of minibuffer input . . . . . . . . . . . . 34
history reference . . . . . . . . . . . . . . . . . . . . . 408
holidays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
HOME directory on MS-Windows . . . . . . 538
home directory shorthand . . . . . . . . . . . . . 28
hook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445
horizontal scrolling . . . . . . . . . . . . . . . . . . . . 73
hourglass pointer display . . . . . . . . . . . . . . 90
HTML mode . . . . . . . . . . . . . . . . . . . . . . . . . 236
hungry deletion (C Mode) . . . . . . . . . . . . 267
hunk, diff . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
hyperlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
hyperlinks . . . . . . . . . . . . . . . . . . . . . . . . . . . 167

I
iCalendar support . . . . . . . . . . . . . . . . . . . . 365
Icomplete mode . . . . . . . . . . . . . . . . . . . . . . . 34
Icon mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
iconifying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
icons (X Window System) . . . . . . . . . . . . 519
icons, toolbar . . . . . . . . . . . . . . . . . . . . . . . . 177
IDL mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
ignored file names, in completion . . . . . . 33
image animation . . . . . . . . . . . . . . . . . . . . . 148
image-dired . . . . . . . . . . . . . . . . . . . . . . . . . . 343
image-dired mode . . . . . . . . . . . . . . . . . . . . 343
ImageMagick support . . . . . . . . . . . . . . . . 148
images, viewing . . . . . . . . . . . . . . . . . . . . . . 148
IMAP mailboxes . . . . . . . . . . . . . . . . . . . . . 395
in-situ subdirectory (Dired) . . . . . . . . . . 339
inbox file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
incorrect fontification . . . . . . . . . . . . . . . . . 80
increase buffer face height . . . . . . . . . . . . . 79
incremental search . . . . . . . . . . . . . . . . . . . . 91
incremental search, input method
interference . . . . . . . . . . . . . . . . . . . . . . 186
indentation . . . . . . . . . . . . . . . . . . . . . . . . . . 210
indentation for comments . . . . . . . . . . . . 259
indentation for programs . . . . . . . . . . . . . 252
index of buffer definitions . . . . . . . . . . . . 251
indirect buffer. . . . . . . . . . . . . . . . . . . . . . . . 156
indirect buffers and outlines . . . . . . . . . . 228
inferior process . . . . . . . . . . . . . . . . . . . . . . . 271
Info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Concept Index

619

init file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
init file ‘.emacs’ on MS-Windows . . . . . 539
init file, and non-ASCII characters . . . . 183
init file, not loading . . . . . . . . . . . . . . . . . . 508
initial options (command line) . . . . . . . . 505
initial-frame-alist. . . . . . . . . . . . . . . . . . . . . 175
input event . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
input methods . . . . . . . . . . . . . . . . . . . . . . . 185
input methods, X . . . . . . . . . . . . . . . . . . . . 523
input with the keyboard . . . . . . . . . . . . . . . 11
insert file contents, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 506
insert Unicode character. . . . . . . . . . . . . . . 17
inserted subdirectory (Dired) . . . . . . . . . 339
inserting blank lines . . . . . . . . . . . . . . . . . . . 22
inserting matching parentheses . . . . . . . 258
inserting rows and columns in text-based
tables . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
insertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
INSIDE_EMACS environment variable . . 403
Integrated development environment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
interactive highlighting . . . . . . . . . . . . . . . . 81
internal border width, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 518
international characters in ‘.emacs’ . . . 466
international files from DOS/Windows
systems . . . . . . . . . . . . . . . . . . . . . . . . . 188
international scripts . . . . . . . . . . . . . . . . . . 180
Intlfonts for PostScript printing . . . . . . 419
Intlfonts package, installation . . . . . . . . 197
invisible lines . . . . . . . . . . . . . . . . . . . . . . . . 224
invocation (command line arguments)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
invoking Emacs from Windows Explorer
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535
IPA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
isearch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Islamic calendar. . . . . . . . . . . . . . . . . . . . . . 354
ISO commercial calendar . . . . . . . . . . . . . 354
ISO Latin character sets . . . . . . . . . . . . . 200
iso-ascii library . . . . . . . . . . . . . . . . . . . . 201
iso-transl library . . . . . . . . . . . . . . . . . . . 201
ispell program . . . . . . . . . . . . . . . . . . . . . . 114
Iswitchb mode . . . . . . . . . . . . . . . . . . . . . . . 158

J
Japanese . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
jar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Java class archives . . . . . . . . . . . . . . . . . . .
Java mode . . . . . . . . . . . . . . . . . . . . . . . . . . .

180
145
145
266

Javascript mode. . . . . . . . . . . . . . . . . . . . . . 249
JDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Julian calendar . . . . . . . . . . . . . . . . . . . . . . 354
Julian day numbers . . . . . . . . . . . . . . . . . . 354
just-in-time (JIT) font-lock . . . . . . . . . . . . 81
justification . . . . . . . . . . . . . . . . . . . . . . . . . . 219
justification in text-based tables . . . . . . 244

K
Kerberos POP authentication . . . . . . . . 396
key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
key bindings . . . . . . . . . . . . . . . . . . . . . . . . . 452
key rebinding, permanent . . . . . . . . . . . . 461
key rebinding, this session . . . . . . . . . . . . 454
key sequence . . . . . . . . . . . . . . . . . . . . . . . . . . 11
keyboard input . . . . . . . . . . . . . . . . . . . . . . . . 11
keyboard macro . . . . . . . . . . . . . . . . . . . . . . 116
keyboard shortcuts . . . . . . . . . . . . . . . . . . . 568
keyboard, MS-Windows . . . . . . . . . . . . . . 539
keymap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452
keypad. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458
keys stolen by window manager . . . . . . . 11
kill DOS application . . . . . . . . . . . . . . . . . 541
kill ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
killing buffers . . . . . . . . . . . . . . . . . . . . . . . . 153
killing characters and lines . . . . . . . . . . . . 20
killing Emacs . . . . . . . . . . . . . . . . . . . . . . . . . 15
killing expressions . . . . . . . . . . . . . . . . . . . . 257
killing rectangular areas of text . . . . . . . . 63
killing text . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Korean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180

L
label (Rmail) . . . . . . . . . . . . . . . . . . . . . . . . 383
landmark game . . . . . . . . . . . . . . . . . . . . . . 428
language environments . . . . . . . . . . . . . . . 183
Lao . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
LaTEX mode . . . . . . . . . . . . . . . . . . . . . . . . . 231
Latin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Latin-1 TEX encoding . . . . . . . . . . . . . . . . 235
lazy search highlighting . . . . . . . . . . . . . . . 92
leaving Emacs . . . . . . . . . . . . . . . . . . . . . . . . . 15
libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287
Life . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
line endings . . . . . . . . . . . . . . . . . . . . . . . . . . 189
line number commands . . . . . . . . . . . . . . . . 24
line number display . . . . . . . . . . . . . . . . . . . 85
line spacing . . . . . . . . . . . . . . . . . . . . . . . . . . 523
line spacing, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520

Concept Index
line truncation, and fringes . . . . . . . . 23, 89
line wrapping . . . . . . . . . . . . . . . . . . . . . . . . . 23
lines, highlighting . . . . . . . . . . . . . . . . . . . . . 82
links . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
links (customization buffer) . . . . . . . . . . 435
Linum mode . . . . . . . . . . . . . . . . . . . . . . . . . 206
Lisp character syntax . . . . . . . . . . . . . . . . 463
Lisp editing . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Lisp files byte-compiled by XEmacs . . 288
Lisp files, and multibyte operation. . . . 183
Lisp mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Lisp object syntax . . . . . . . . . . . . . . . . . . . 463
Lisp string syntax . . . . . . . . . . . . . . . . . . . . 462
Lisp symbol completion . . . . . . . . . . . . . . 264
lisp-indent-function property . . . . . 254
list commands . . . . . . . . . . . . . . . . . . . . . . . 257
listing current buffers . . . . . . . . . . . . . . . . 152
listing system fonts. . . . . . . . . . . . . . . . . . . 173
load init file of another user . . . . . . . . . . 509
load path for Emacs Lisp . . . . . . . . . . . . . 288
loading Lisp code . . . . . . . . . . . . . . . . . . . . 287
loading Lisp libraries automatically . . . 464
loading Lisp libraries, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 506
loading several files (in Dired) . . . . . . . . 336
local keymap . . . . . . . . . . . . . . . . . . . . . . . . . 453
local variables . . . . . . . . . . . . . . . . . . . . . . . . 446
local variables in files . . . . . . . . . . . . . . . . 447
local variables, for all files in a directory
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450
locale, date format . . . . . . . . . . . . . . . . . . . 135
locales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184
location of point . . . . . . . . . . . . . . . . . . . . . . 24
locking files . . . . . . . . . . . . . . . . . . . . . . . . . . 133
locking-based version . . . . . . . . . . . . . . . . . 294
locus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Log Edit mode . . . . . . . . . . . . . . . . . . . . . . . 299
log File, types of . . . . . . . . . . . . . . . . . . . . . 295
logging keystrokes . . . . . . . . . . . . . . . . . . . . 477
logical order . . . . . . . . . . . . . . . . . . . . . . . . . 202
looking for a subject in documentation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
lpr usage under MS-DOS . . . . . . . . . . . . . 542
LRM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
ls emulation . . . . . . . . . . . . . . . . . . . . . . . . . 538
lzh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

M
M- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
M4 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Mac OS X . . . . . . . . . . . . . . . . . . . . . . . . . . . 531

620
Macintosh . . . . . . . . . . . . . . . . . . . . . . . . . . . 531
Macintosh end-of-line conversion . . . . . 189
Macintosh key bindings . . . . . . . . . . . . . . 425
macro expansion in C . . . . . . . . . . . . . . . . 269
mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
mail (on mode line) . . . . . . . . . . . . . . . . . . . 86
mail aliases . . . . . . . . . . . . . . . . . . . . . . . . . . 370
MAIL environment variable. . . . . . . . . . . . 379
Mail mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
mail signature . . . . . . . . . . . . . . . . . . . . . . . 374
mail-composition methods . . . . . . . . . . . . 375
Mailclient . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
MAILHOST environment variable . . . . . . . 395
mailrc file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
main border width, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 518
major modes . . . . . . . . . . . . . . . . . . . . . . . . . 204
make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Makefile mode . . . . . . . . . . . . . . . . . . . . . . . 249
man page . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
man pages, and local file variables . . . . 448
manipulating paragraphs . . . . . . . . . . . . . 216
manipulating sentences . . . . . . . . . . . . . . . 215
manipulating text . . . . . . . . . . . . . . . . . . . . 214
manual pages, on MS-DOS/MS-Windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262
manuals, on-line. . . . . . . . . . . . . . . . . . . . . . . 44
Marathi. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
mark. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
mark rectangle . . . . . . . . . . . . . . . . . . . . . . . . 63
mark ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
marking executable files (in Dired) . . . 333
marking many files (in Dired) . . . . . . . . 333
marking sections of text . . . . . . . . . . . . . . . 49
marking subdirectories (in Dired) . . . . 333
marking symbolic links (in Dired) . . . . 333
matching parentheses . . . . . . . . . . . . . . . . 258
matching parenthesis and braces, moving
to . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
maximized, command-line argument . . 517
maximum buffer size exceeded, error
message . . . . . . . . . . . . . . . . . . . . . . . . . 126
Mayan calendar . . . . . . . . . . . . . . . . . . . . . . 354
Mayan calendar round . . . . . . . . . . . . . . . 358
Mayan haab calendar . . . . . . . . . . . . . . . . 358
Mayan long count . . . . . . . . . . . . . . . . . . . . 357
Mayan tzolkin calendar . . . . . . . . . . . . . . 357
memory full . . . . . . . . . . . . . . . . . . . . . . . . . . 471
menu bar. . . . . . . . . . . . . . . . . . . . . . . . . 10, 523
menu bar access using keyboard
(MS-Windows) . . . . . . . . . . . . . . . . . . 539
menu bar appearance . . . . . . . . . . . . . . . . . 79

Concept Index
Menu Bar mode . . . . . . . . . . . . . . . . . . . . . . 176
menu face, no effect if customized . . . . . . 79
Mercurial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
merges, failed . . . . . . . . . . . . . . . . . . . . . . . . 141
merging changes . . . . . . . . . . . . . . . . . . . . . 308
merging-based version . . . . . . . . . . . . . . . . 294
message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Message mode . . . . . . . . . . . . . . . . . . . . . . . 370
Message mode for sending mail . . . . . . . 375
message number . . . . . . . . . . . . . . . . . . . . . 376
messages saved from echo area . . . . . . . . . . 7
Meta. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Meta commands and words . . . . . . . . . . 214
Metafont mode . . . . . . . . . . . . . . . . . . . . . . 249
MH mail interface . . . . . . . . . . . . . . . . . . . . 375
Microsoft Office file . . . . . . . . . . . . . . . . . . 399
Microsoft Windows . . . . . . . . . . . . . . . . . . 535
Midnight mode . . . . . . . . . . . . . . . . . . . . . . 154
MIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
MIME messages (Rmail) . . . . . . . . . . . . . 391
minibuffer . . . . . . . . . . . . . . . . . . . . . . . . . . 8, 27
minibuffer confirmation . . . . . . . . . . . . . . . 31
minibuffer history . . . . . . . . . . . . . . . . . . . . . 34
minibuffer history, searching . . . . . . . . . . . 95
minibuffer keymaps . . . . . . . . . . . . . . . . . . 454
minibuffer-prompt face. . . . . . . . . . . . . . . 78
minimizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
minimizing a frame at startup . . . . . . . . 519
minor mode keymap . . . . . . . . . . . . . . . . . 453
minor modes . . . . . . . . . . . . . . . . . . . . . . . . . 205
mistakes, correcting . . . . . . . . . . . . . . . . . . 110
mode commands for minor modes . . . . 206
mode hook . . . . . . . . . . . . . . . . . . . . . . 205, 249
mode line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
mode line, 3D appearance . . . . . . . . . . . . . 86
mode line, mouse . . . . . . . . . . . . . . . . . . . . 169
mode, Abbrev. . . . . . . . . . . . . . . . . . . . . . . . 322
mode, archive . . . . . . . . . . . . . . . . . . . . . . . . 145
mode, Auto Compression . . . . . . . . . . . . . 144
mode, Auto Fill . . . . . . . . . . . . . . . . . . . . . . 218
mode, Auto Save . . . . . . . . . . . . . . . . . . . . . 136
mode, Auto-Revert . . . . . . . . . . . . . . . . . . . 135
mode, AWK . . . . . . . . . . . . . . . . . . . . . . . . . 266
mode, C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
mode, C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
mode, Column Number . . . . . . . . . . . . . . . 85
mode, Comint . . . . . . . . . . . . . . . . . . . . . . . 406
mode, Compilation . . . . . . . . . . . . . . . . . . . 272
mode, CORBA IDL . . . . . . . . . . . . . . . . . . 266
mode, CRiSP . . . . . . . . . . . . . . . . . . . . . . . . 425
mode, Delete Selection . . . . . . . . . . . . . . . . 50
mode, Diff Auto-Refine. . . . . . . . . . . . . . . 141

621
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,
mode,

Dirtrack . . . . . . . . . . . . . . . . . . . . . . . 409
DocTEX . . . . . . . . . . . . . . . . . . . . . . . 231
DocView . . . . . . . . . . . . . . . . . . . . . . 399
Electric Indent . . . . . . . . . . . . . . . . 213
Emacs Lisp . . . . . . . . . . . . . . . . . . . 288
Enriched . . . . . . . . . . . . . . . . . . . . . . 237
Flyspell . . . . . . . . . . . . . . . . . . . . . . . 115
Follow . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Font Lock . . . . . . . . . . . . . . . . . . . . . . 80
Global Auto-Revert . . . . . . . . . . . 135
Goto Address . . . . . . . . . . . . . . . . . 426
GUD Tooltip . . . . . . . . . . . . . . . . . . 278
Hexl . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Hideshow . . . . . . . . . . . . . . . . . . . . . 263
HTML . . . . . . . . . . . . . . . . . . . . . . . . 236
Iswitchb . . . . . . . . . . . . . . . . . . . . . . . 158
Java . . . . . . . . . . . . . . . . . . . . . . . . . . 266
LaTEX . . . . . . . . . . . . . . . . . . . . . . . . 231
Lisp . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Log Edit . . . . . . . . . . . . . . . . . . . . . . 299
Mail . . . . . . . . . . . . . . . . . . . . . . . . . . 375
major . . . . . . . . . . . . . . . . . . . . . . . . . 204
Menu Bar . . . . . . . . . . . . . . . . . . . . . 176
Message . . . . . . . . . . . . . . . . . . . . . . . 370
minor . . . . . . . . . . . . . . . . . . . . . . . . . 205
Mouse Wheel. . . . . . . . . . . . . . . . . . 167
MSB . . . . . . . . . . . . . . . . . . . . . . . . . . 158
nXML . . . . . . . . . . . . . . . . . . . . 214, 236
Objective C . . . . . . . . . . . . . . . . . . . 266
Occur . . . . . . . . . . . . . . . . . . . . . . . . . 107
Occur Edit . . . . . . . . . . . . . . . . . . . . 108
Outline . . . . . . . . . . . . . . . . . . . . . . . 224
Overwrite . . . . . . . . . . . . . . . . . . . . . 207
Paragraph-Indent Text . . . . . . . . 224
Pike. . . . . . . . . . . . . . . . . . . . . . . . . . . 266
Scheme . . . . . . . . . . . . . . . . . . . . . . . 291
Scroll Bar . . . . . . . . . . . . . . . . . . . . . 176
Scroll-all . . . . . . . . . . . . . . . . . . . . . . 164
Semantic . . . . . . . . . . . . . . . . . . . . . . 265
SGML . . . . . . . . . . . . . . . . . . . . . . . . 236
Shell . . . . . . . . . . . . . . . . . . . . . . . . . . 403
SliTEX . . . . . . . . . . . . . . . . . . . . . . . . 231
tar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Term . . . . . . . . . . . . . . . . . . . . . . . . . . 411
TEX . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
Text . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Tool Bar . . . . . . . . . . . . . . . . . . . . . . 177
Transient Mark . . . . . . . . . . . . . . . . . 52
View . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Whitespace . . . . . . . . . . . . . . . . . . . . . 84
Winner . . . . . . . . . . . . . . . . . . . . . . . 164
XML . . . . . . . . . . . . . . . . . . . . . . . . . . 214

Concept Index
modes for programming languages . . . . 249
modification dates . . . . . . . . . . . . . . . . . . . 135
modified (buffer) . . . . . . . . . . . . . . . . . . . . . 126
modifier keys . . . . . . . . . . . . . . . . . . . . . 11, 456
Modula2 mode . . . . . . . . . . . . . . . . . . . . . . . 249
moon, phases of . . . . . . . . . . . . . . . . . . . . . . 353
Morse code . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Motif key bindings . . . . . . . . . . . . . . . . . . . 425
mouse avoidance . . . . . . . . . . . . . . . . . . . . . 178
mouse button events . . . . . . . . . . . . . . . . . 459
mouse buttons (what they do). . . . . . . . 165
mouse on mode line . . . . . . . . . . . . . . . . . . 169
mouse pointer . . . . . . . . . . . . . . . . . . . . . . . . . 90
mouse pointer color, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 516
mouse support . . . . . . . . . . . . . . . . . . . . . . . 179
mouse wheel . . . . . . . . . . . . . . . . . . . . . . . . . 167
Mouse Wheel minor mode . . . . . . . . . . . . 167
mouse, and MS-Windows. . . . . . . . . . . . . 540
mouse, dragging . . . . . . . . . . . . . . . . . . . . . 166
mouse, selecting text using . . . . . . . . . . . 165
move to beginning or end of function
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
movemail . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
movemail program . . . . . . . . . . . . . . . . . . . 393
movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
moving files (in Dired) . . . . . . . . . . . . . . . 335
moving inside the calendar . . . . . . . . . . . 346
moving point . . . . . . . . . . . . . . . . . . . . . . . . . . 18
moving text . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
moving the cursor . . . . . . . . . . . . . . . . . . . . . 18
MS-DOS end-of-line conversion . . . . . . . 189
MS-Windows keyboard shortcuts . . . . . 539
MS-Windows, and primary selection . . . 61
MS-Windows, Emacs peculiarities . . . . 535
MSB mode. . . . . . . . . . . . . . . . . . . . . . . . . . . 158
MULE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
multibyte characters . . . . . . . . . . . . . . . . . 180
multibyte operation, and Lisp files. . . . 183
multiple displays . . . . . . . . . . . . . . . . . . . . . 175
multiple views of outline . . . . . . . . . . . . . 228
multiple windows in Emacs . . . . . . . . . . . 159
multiple-file search and replace . . . . . . . 318
Multipurpose Internet Mail Extensions
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Multithreaded debugging in GDB . . . . 286

N
narrowing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
narrowing, and line number display . . . . 86

622
‘net use’, and printing on MS-Windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542
networked printers (MS-Windows) . . . . 542
newline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
newlines, hard and soft . . . . . . . . . . . . . . . 238
newsreader . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
Next Error Follow mode. . . . . . . . . . . . . . 274
NFS and quitting . . . . . . . . . . . . . . . . . . . . 469
nil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571
no-conversion, coding system . . . . . . . 189
non-ASCII characters in ‘.emacs’ . . . . . 466
non-ASCII keys, binding . . . . . . . . . . . . . . 466
non-breaking hyphen . . . . . . . . . . . . . . . . . . 87
non-breaking space . . . . . . . . . . . . . . . . . . . . 87
non-greedy regexp matching . . . . . . . . . . . 98
non-integral number of lines in a window
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
non-selected windows, mode line
appearance . . . . . . . . . . . . . . . . . . . . . . . 86
Non-stop debugging in GDB . . . . . . . . . 286
nonincremental search . . . . . . . . . . . . . . . . . 95
normal hook . . . . . . . . . . . . . . . . . . . . . . . . . 445
nroff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
NSA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
numeric arguments . . . . . . . . . . . . . . . . . . . . 25
nXML mode . . . . . . . . . . . . . . . . . . . . 214, 236

O
Objective C mode . . . . . . . . . . . . . . . . . . . . 266
Occur Edit mode. . . . . . . . . . . . . . . . . . . . . 108
Occur mode. . . . . . . . . . . . . . . . . . . . . . . . . . 107
octal escapes . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Octave mode . . . . . . . . . . . . . . . . . . . . . . . . . 249
on-line manuals . . . . . . . . . . . . . . . . . . . . . . . 44
open file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
open-parenthesis in leftmost column . . 250
OpenDocument file . . . . . . . . . . . . . . . . . . 399
operating on files in Dired . . . . . . . . . . . . 335
operations on a marked region . . . . . . . . . 50
options (command line) . . . . . . . . . . . . . . 505
Org agenda . . . . . . . . . . . . . . . . . . . . . . . . . . 230
Org exporting . . . . . . . . . . . . . . . . . . . . . . . . 230
organizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
other editors . . . . . . . . . . . . . . . . . . . . . . . . . 425
out of memory . . . . . . . . . . . . . . . . . . . . . . . 471
Outline mode . . . . . . . . . . . . . . . . . . . . . . . . 224
outline with multiple views . . . . . . . . . . . 228
overlays at character position. . . . . . . . . 239
override character terminal color support
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516
Overwrite mode . . . . . . . . . . . . . . . . . . . . . . 207

Concept Index

P
Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430
Package archive . . . . . . . . . . . . . . . . . . . . . . 430
package directory . . . . . . . . . . . . . . . . . . . . 432
package file . . . . . . . . . . . . . . . . . . . . . . . . . . 432
package menu . . . . . . . . . . . . . . . . . . . . . . . . 430
package requirements . . . . . . . . . . . . . . . . 431
pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
paging in Term mode . . . . . . . . . . . . . . . . 411
paragraph, base direction . . . . . . . . . . . . 203
Paragraph-Indent Text mode . . . . . . . . . 224
paragraphs . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
parentheses, displaying matches . . . . . . 258
parentheses, moving across . . . . . . . . . . . 257
parenthesis in column zero and
fontification . . . . . . . . . . . . . . . . . . . . . . 80
parenthetical groupings . . . . . . . . . . . . . . 257
paste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
pasting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
patches, editing . . . . . . . . . . . . . . . . . . . . . . 141
patches, sending . . . . . . . . . . . . . . . . . . . . . 481
PC key bindings . . . . . . . . . . . . . . . . . . . . . 425
PC selection . . . . . . . . . . . . . . . . . . . . . . . . . 425
PDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
PDF file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
per-buffer variables. . . . . . . . . . . . . . . . . . . 446
per-directory local variables . . . . . . . . . . 450
Perl mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Perldb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
Persian calendar . . . . . . . . . . . . . . . . . . . . . 354
phases of the moon . . . . . . . . . . . . . . . . . . 353
Pike mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
planner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
point location . . . . . . . . . . . . . . . . . . . . . . . . . 24
point location, on MS-DOS. . . . . . . . . . . 536
Polish. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Pong game . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
POP mailboxes . . . . . . . . . . . . . . . . . . . . . . 395
position and size of Emacs frame . . . . . 517
PostScript file . . . . . . . . . . . . . . . . . . . . . . . . 399
PostScript mode . . . . . . . . . . . . . . . . . . . . . 249
prefix arguments . . . . . . . . . . . . . . . . . . . . . . 25
prefix key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
preprocessor highlighting . . . . . . . . . . . . . 269
pretty-printer . . . . . . . . . . . . . . . . . . . . . . . . 252
primary Rmail file . . . . . . . . . . . . . . . . . . . 376
primary selection . . . . . . . . . . . . . . . . . . 48, 60
printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
printing character . . . . . . . . . . . . . . . . . . . . . 87
printing files (in Dired) . . . . . . . . . . . . . . . 336
Printing package . . . . . . . . . . . . . . . . . . . . . 420

623
Prog mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 446
program building . . . . . . . . . . . . . . . . . . . . 271
program editing . . . . . . . . . . . . . . . . . 249, 446
Prolog mode . . . . . . . . . . . . . . . . . . . . . . . . . 249
prompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
prompt, shell . . . . . . . . . . . . . . . . . . . . . . . . 406
PS file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
puzzles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Python mode . . . . . . . . . . . . . . . . . . . . . . . . 249

Q
query replace . . . . . . . . . . . . . . . . . . . . . . . . 106
quitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 468
quitting (in search) . . . . . . . . . . . . . . . . . . . . 93
quitting Emacs . . . . . . . . . . . . . . . . . . . . . . . . 15
quoting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
quoting file names. . . . . . . . . . . . . . . . . . . . 146

R
rar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
raw-text, coding system . . . . . . . . . . . . . 189
RCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
read-only buffer . . . . . . . . . . . . . . . . . . . . . . 152
read-only text, killing . . . . . . . . . . . . . . . . . 56
reading mail . . . . . . . . . . . . . . . . . . . . . . . . . 376
rebinding keys, permanently . . . . . . . . . . 461
rebinding major mode keys . . . . . . . . . . . 455
rebinding mouse buttons . . . . . . . . . . . . . 459
rebinding non-ASCII keys . . . . . . . . . . . . 466
rectangle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
rectangle highlighting . . . . . . . . . . . . . . . . . 65
recursive copying . . . . . . . . . . . . . . . . . . . . . 335
recursive deletion . . . . . . . . . . . . . . . . . . . . 331
recursive editing level . . . . . . . . . . . . . . . . 424
recycle bin . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
redefining keys, this session . . . . . . . . . . 454
redo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
refreshing displayed files . . . . . . . . . . . . . . 341
regexp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
regexp search . . . . . . . . . . . . . . . . . . . . . . . . . 96
region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
region highlighting . . . . . . . . . . . . . . . . . . . . 52
registered file . . . . . . . . . . . . . . . . . . . . . . . . 293
registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
registry, setting environment variables
(MS-Windows) . . . . . . . . . . . . . . . . . . 514
registry, setting resources (MS-Windows)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
regular expression . . . . . . . . . . . . . . . . . . . . . 97
related files . . . . . . . . . . . . . . . . . . . . . . . . . . 270

Concept Index
reload files . . . . . . . . . . . . . . . . . . . . . . . . . . . 423
remember editing session . . . . . . . . . . . . . 423
remote file access . . . . . . . . . . . . . . . . . . . . 145
remote host . . . . . . . . . . . . . . . . . . . . . . . . . . 411
remote host, debugging on . . . . . . . . . . . 277
remove indentation . . . . . . . . . . . . . . . . . . . 211
renaming files . . . . . . . . . . . . . . . . . . . . . . . . 143
renaming files (in Dired) . . . . . . . . . . . . . 335
repeating a command . . . . . . . . . . . . . . . . . 26
replacement . . . . . . . . . . . . . . . . . . . . . . . . . . 103
reply to a message . . . . . . . . . . . . . . . . . . . 385
reporting bugs . . . . . . . . . . . . . . . . . . . . . . . 475
repository . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
reread a file . . . . . . . . . . . . . . . . . . . . . . . . . . 135
resizing minibuffer . . . . . . . . . . . . . . . . . . . . 28
resolving conflicts . . . . . . . . . . . . . . . . . . . . 309
resource files for GTK . . . . . . . . . . . . . . . . 523
resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
restore session . . . . . . . . . . . . . . . . . . . . . . . 423
restriction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
retrying a failed message . . . . . . . . . . . . . 385
reverse order in POP inboxes . . . . . . . . . 396
reverse video, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516
revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
revision ID . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
revision ID in version control . . . . . . . . . 298
RGB triplet . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
right-to-left text . . . . . . . . . . . . . . . . . . . . . 202
risky variable . . . . . . . . . . . . . . . . . . . . . . . . 450
RLM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Rlogin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
Rmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376
Rmail file sorting . . . . . . . . . . . . . . . . . . . . 390
Romanian . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
rot13 code . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
Ruby mode . . . . . . . . . . . . . . . . . . . . . . . . . . 249
runemacs.exe . . . . . . . . . . . . . . . . . . . . . . . . 535
running a hook . . . . . . . . . . . . . . . . . . . . . . 445
running Lisp functions . . . . . . . . . . . . . . . 271

S
saved echo area messages . . . . . . . . . . . . . . . 7
saving a setting . . . . . . . . . . . . . . . . . . . . . . 437
saving file name in a register . . . . . . . . . . 68
saving files . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
saving keyboard macros . . . . . . . . . . . . . . 121
saving number in a register . . . . . . . . . . . . 68
saving position in a register . . . . . . . . . . . 66
saving rectangle in a register . . . . . . . . . . 67
saving sessions . . . . . . . . . . . . . . . . . . . . . . . 423

624
saving text in a register . . . . . . . . . . . . . . . 66
saving window configuration in a register
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
SCCS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
Scheme mode . . . . . . . . . . . . . . . . . . . . . . . . 291
screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
screen reader software, MS-Windows
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545
script mode . . . . . . . . . . . . . . . . . . . . . . . . . . 508
Scroll Bar mode . . . . . . . . . . . . . . . . . . . . . . 176
Scroll-all mode . . . . . . . . . . . . . . . . . . . . . . . 164
scroll-command property . . . . . . . . . . . . . 71
scrolling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
scrolling all windows . . . . . . . . . . . . . . . . . 425
scrolling in the calendar . . . . . . . . . . . . . . 348
scrolling windows together . . . . . . . . . . . 164
SDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
search and replace in multiple files . . . 318
search and replace in multiple files (in
Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
search for a regular expression . . . . . . . . . 96
search multiple files (in Dired) . . . . . . . 337
search ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
search-and-replace commands . . . . . . . . 103
searching. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
searching Dired buffers . . . . . . . . . . . . . . . 330
searching documentation efficiently . . . . 38
searching in Rmail . . . . . . . . . . . . . . . . . . . 378
searching multiple files via Dired . . . . . 344
secondary selection . . . . . . . . . . . . . . . . . . . . 61
sections of manual pages . . . . . . . . . . . . . 262
select all . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
selected buffer . . . . . . . . . . . . . . . . . . . . . . . 150
selected window . . . . . . . . . . . . . . . . . . . . . . 159
selecting buffers in other windows . . . . 161
selection, primary . . . . . . . . . . . . . . . . . . . . . 60
selective display . . . . . . . . . . . . . . . . . . . . . . . 85
selective undo . . . . . . . . . . . . . . . . . . . . . . . . 111
self-documentation . . . . . . . . . . . . . . . . . . . . 38
Semantic mode . . . . . . . . . . . . . . . . . . . . . . 265
Semantic package . . . . . . . . . . . . . . . . . . . . 265
sending mail . . . . . . . . . . . . . . . . . . . . . . . . . 367
sending patches for GNU Emacs. . . . . . 481
Sendmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
sentences . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
server file . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
server, using Emacs as . . . . . . . . . . . . . . . 412
server-side fonts . . . . . . . . . . . . . . . . . . . . . . 173
set buffer face height . . . . . . . . . . . . . . . . . . 79
setting a mark . . . . . . . . . . . . . . . . . . . . . . . . 47
setting variables. . . . . . . . . . . . . . . . . . . . . . 443
settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434

Concept Index
settings, how to save . . . . . . . . . . . . . . . . . 437
sexp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
SGML mode . . . . . . . . . . . . . . . . . . . . . . . . . 236
shadow files . . . . . . . . . . . . . . . . . . . . . . . . . . 134
shell commands . . . . . . . . . . . . . . . . . . . . . . 401
shell commands, Dired . . . . . . . . . . . . . . . 337
SHELL environment variable . . . . . . . . . . 403
Shell mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
shell scripts, and local file variables . . . 448
Shell-script mode . . . . . . . . . . . . . . . . . . . . 249
shelves in version control . . . . . . . . . . . . . 307
shift-selection. . . . . . . . . . . . . . . . . . . . . . 48, 52
Show Paren mode . . . . . . . . . . . . . . . . . . . . 258
showing hidden subdirectories (Dired)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
shy group, in regexp . . . . . . . . . . . . . . . . . 101
signing files (in Dired) . . . . . . . . . . . . . . . 336
Simula mode . . . . . . . . . . . . . . . . . . . . . . . . . 249
simulation of middle mouse button . . . 540
simultaneous editing . . . . . . . . . . . . . . . . . 133
site init file . . . . . . . . . . . . . . . . . . . . . . . . . . 461
‘site-start.el’ file, not loading . . . . . 508
‘site-start.el’, the site startup file
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
size of file, warning when visiting . . . . . 126
size of minibuffer . . . . . . . . . . . . . . . . . . . . . . 28
slashes repeated in file name. . . . . . . . . . . 27
SliTEX mode . . . . . . . . . . . . . . . . . . . . . . . . . 231
Slovak . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Slovenian . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
slow display during scrolling . . . . . . . . . . . 80
Smerge mode . . . . . . . . . . . . . . . . . . . . . . . . 141
SMTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
Snake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
soft hyphen . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
soft newline . . . . . . . . . . . . . . . . . . . . . . . . . . 238
solitaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
sorting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420
sorting Dired buffer . . . . . . . . . . . . . . . . . . 342
sorting Rmail file . . . . . . . . . . . . . . . . . . . . 390
Spanish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
specific version control system . . . . . . . . 298
specify default font from the command
line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515
specify end-of-line conversion . . . . . . . . . 193
specifying fullscreen for Emacs frame
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517
speedbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
spell-checking the active region . . . . . . . 113
spelling, checking and correcting . . . . . 112
splash screen . . . . . . . . . . . . . . . . . . . . . . . . . 508
splitting columns . . . . . . . . . . . . . . . . . . . . . 247

625
splitting table cells . . . . . . . . . . . . . . . . . . . 244
standard colors on a character terminal
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516
standard fontset . . . . . . . . . . . . . . . . . . . . . 198
start directory, MS-Windows . . . . . . . . . 535
start iconified, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519
starting Emacs . . . . . . . . . . . . . . . . . . . . . . . . 14
starting Emacs on MS-Windows . . . . . . 535
startup (command line arguments) . . . 505
startup (init file) . . . . . . . . . . . . . . . . . . . . . 461
startup fontset . . . . . . . . . . . . . . . . . . . . . . . 198
startup message . . . . . . . . . . . . . . . . . . . . . . 508
startup screen . . . . . . . . . . . . . . . . . . . . . . . . . 14
stashes in version control . . . . . . . . . . . . . 307
string substitution . . . . . . . . . . . . . . . . . . . 103
string syntax . . . . . . . . . . . . . . . . . . . . . . . . . 462
style (for indentation) . . . . . . . . . . . . . . . . 255
subdirectories in Dired . . . . . . . . . . . . . . . 339
subprocesses on MS-Windows . . . . . . . . 540
subscribe groups . . . . . . . . . . . . . . . . . . . . . 398
subshell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
subtree (Outline mode) . . . . . . . . . . . . . . 227
Subversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
summary (Rmail) . . . . . . . . . . . . . . . . . . . . 386
summing time intervals . . . . . . . . . . . . . . 366
sunrise and sunset . . . . . . . . . . . . . . . . . . . 352
suspending . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
suspicious constructions in C, C++ . . . . 269
SVN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
switch buffers . . . . . . . . . . . . . . . . . . . . . . . . 150
switches (command line) . . . . . . . . . . . . . 505
symbolic links (creation in Dired) . . . . 336
symbolic links (creation) . . . . . . . . . . . . . 143
symbolic links (visiting) . . . . . . . . . . . . . . 138
synchronizing windows . . . . . . . . . . . . . . . . 75
syntax highlighting and coloring . . . . . . . 80
syntax of regexps. . . . . . . . . . . . . . . . . . . . . . 97
system-wide packages . . . . . . . . . . . . . . . . 433

T
t. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
tab stops . . . . . . . . . . . . . . . . . . . . . . . . . . . .
table creation . . . . . . . . . . . . . . . . . . . . . . . .
table dimensions . . . . . . . . . . . . . . . . . . . . .
table for HTML and LaTeX . . . . . . . . . .
table mode. . . . . . . . . . . . . . . . . . . . . . . . . . .
table recognition . . . . . . . . . . . . . . . . . . . . .
table to text . . . . . . . . . . . . . . . . . . . . . . . . .
tabs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
tags and tag tables . . . . . . . . . . . . . . . . . . .

571
211
243
246
246
241
243
245
210
311

Concept Index
tags, C++ . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
tags-based completion . . . . . . . . . . . . . . . . 264
Tar mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Tcl mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Telnet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
TERM environment variable. . . . . . . . . . . . 477
Term mode . . . . . . . . . . . . . . . . . . . . . . . . . . 411
terminal emulators, mouse support . . . 179
terminal, serial . . . . . . . . . . . . . . . . . . . . . . . 412
termscript file . . . . . . . . . . . . . . . . . . . . . . . . 477
Tetris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
TEX encoding . . . . . . . . . . . . . . . . . . . . . . . . 235
TEX mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
TEXEDIT environment variable . . . . . . . . 412
TEXINPUTS environment variable . . . . . . 234
text. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
text and binary files on
MS-DOS/MS-Windows . . . . . . . . . . 536
text buttons . . . . . . . . . . . . . . . . . . . . . . . . . 167
text colors, from command line . . . . . . . 515
text cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Text mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
text properties at point . . . . . . . . . . . . . . 181
text properties of characters . . . . . . . . . . 239
text terminal. . . . . . . . . . . . . . . . . . . . . . . . . 179
text to table . . . . . . . . . . . . . . . . . . . . . . . . . 245
text-based tables . . . . . . . . . . . . . . . . . . . . . 241
text-based tables, splitting cells . . . . . . 244
text/enriched MIME format . . . . . . . . . . 237
Thai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Tibetan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
time (on mode line) . . . . . . . . . . . . . . . . . . . 86
time intervals, summing . . . . . . . . . . . . . . 366
time stamps . . . . . . . . . . . . . . . . . . . . . . . . . 135
timeclock . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
TLS encryption (Rmail) . . . . . . . . . . . . . . 396
TODO item. . . . . . . . . . . . . . . . . . . . . . . . . . 230
toggling marks (in Dired) . . . . . . . . . . . . 334
tool bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523
Tool Bar mode . . . . . . . . . . . . . . . . . . . . . . . 177
Tool Bar position . . . . . . . . . . . . . . . . . . . . 177
Tool Bar style. . . . . . . . . . . . . . . . . . . . . . . . 177
tooltips . . . . . . . . . . . . . . . . . . . . . . . . . . 46, 178
top level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
tower of Hanoi . . . . . . . . . . . . . . . . . . . . . . . 428
TPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
trailing whitespace . . . . . . . . . . . . . . . . . . . . 84
Tramp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Transient Mark mode . . . . . . . . . . . . . . . . . 52
transposition of expressions . . . . . . . . . . 257
trash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
triple clicks . . . . . . . . . . . . . . . . . . . . . . . . . . 459

626
truenames of files . . . . . . . . . . . . . . . . . . . . 138
truncation . . . . . . . . . . . . . . . . . . . . . . . . . 23, 89
Turkish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
turn multibyte support on or off . . . . . . 182
two directories (in Dired) . . . . . . . . . . . . 335
two-column editing . . . . . . . . . . . . . . . . . . . 247
types of log file . . . . . . . . . . . . . . . . . . . . . . 295
typos, fixing . . . . . . . . . . . . . . . . . . . . . . . . . 110

U
unbalanced parentheses and quotes . . . 256
uncompression . . . . . . . . . . . . . . . . . . . . . . . 144
undecided, coding system . . . . . . . . . . . . 189
undeletion (Rmail) . . . . . . . . . . . . . . . . . . . 379
undigestify . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
undisplayable characters . . . . . . . . . . . . . 181
undo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
undo limit . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
undoing window configuration changes
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Unibyte operation . . . . . . . . . . . . . . . . . . . . 200
unibyte operation, and Lisp files . . . . . . 183
Unicode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
Unicode characters, inserting . . . . . . . . . . 17
unique buffer names . . . . . . . . . . . . . . . . . . 157
unmarking files (in Dired) . . . . . . . . . . . . 333
unsubscribe groups . . . . . . . . . . . . . . . . . . . 398
untranslated file system . . . . . . . . . . . . . . 537
unused lines . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
unzip archives. . . . . . . . . . . . . . . . . . . . . . . . 145
upcase file names . . . . . . . . . . . . . . . . . . . . 338
updating Dired buffer . . . . . . . . . . . . . . . . 341
URL, viewing in help. . . . . . . . . . . . . . . . . . 43
URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
URLs, activating . . . . . . . . . . . . . . . . . . . . . 426
use-hard-newlines . . . . . . . . . . . . . . . . . . . . 238
Usenet news . . . . . . . . . . . . . . . . . . . . . . . . . 397
user name for remote file access . . . . . . 146
user option . . . . . . . . . . . . . . . . . . . . . . . . . . 434
user options, changing. . . . . . . . . . . . . . . . 436
UTF-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183

V
variable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
variables, changing . . . . . . . . . . . . . . . . . . .
VC Directory buffer . . . . . . . . . . . . . . . . . .
VC filesets . . . . . . . . . . . . . . . . . . . . . . . . . . .
VC mode line indicator . . . . . . . . . . . . . .
verifying digital signatures on files (in
Dired) . . . . . . . . . . . . . . . . . . . . . . . . . . .

443
436
304
296
296
336

Concept Index
version control . . . . . . . . . . . . . . . . . . . . . . . 292
version control log . . . . . . . . . . . . . . . . . . . 295
version control status . . . . . . . . . . . . . . . . 296
VERSION_CONTROL environment variable
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
vertical scroll bars, command-line
argument . . . . . . . . . . . . . . . . . . . . . . . . 520
VHDL mode . . . . . . . . . . . . . . . . . . . . . . . . . 249
vi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Vietnamese . . . . . . . . . . . . . . . . . . . . . . . . . . 180
View mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
viewing web pages in help . . . . . . . . . . . . . 43
views of an outline . . . . . . . . . . . . . . . . . . . 228
visiting files . . . . . . . . . . . . . . . . . . . . . . . . . . 125
visiting files, command-line argument
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505
Visual Line mode . . . . . . . . . . . . . . . . . . . . . 89
visual order . . . . . . . . . . . . . . . . . . . . . . . . . . 202

W
Watching expressions in GDB . . . . . . . . 285
wdired mode . . . . . . . . . . . . . . . . . . . . . . . . . 343
Web . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426
web pages, viewing in help . . . . . . . . . . . . 43
weeks, which day they start on . . . . . . . 347
whitespace character . . . . . . . . . . . . . . . . . 210
Whitespace mode . . . . . . . . . . . . . . . . . . . . . 84
whitespace, trailing . . . . . . . . . . . . . . . . . . . 84
wide block cursor . . . . . . . . . . . . . . . . . . . . . 88
widening . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
widgets at buffer position . . . . . . . . . . . . 239
width and height of Emacs frame . . . . . 517
width of the scroll bar. . . . . . . . . . . . . . . . 176
wildcard characters in file names . . . . . 126
Windmove package . . . . . . . . . . . . . . . . . . . 164
window configuration changes, undoing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
window manager, keys stolen by . . . . . . . 11
windows in Emacs . . . . . . . . . . . . . . . . . . . 159
Windows system menu . . . . . . . . . . . . . . . 540

627
windows, synchronizing. . . . . . . . . . . . . . . . 75
Winner mode . . . . . . . . . . . . . . . . . . . . . . . . 164
word processing . . . . . . . . . . . . . . . . . . . . . . 237
word search . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
word wrap. . . . . . . . . . . . . . . . . . . . . . . . . 23, 89
words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
words, case conversion . . . . . . . . . . . . . . . 223
WordStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
work file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
working tree . . . . . . . . . . . . . . . . . . . . . . . . . 294
World Wide Web . . . . . . . . . . . . . . . . . . . . 426
wrapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
WYSIWYG . . . . . . . . . . . . . . . . . . . . . . . . . . 237

X
X cutting and pasting . . . . . . . . . . . . . . . . . 60
X defaults file . . . . . . . . . . . . . . . . . . . . . . . . 171
X input methods . . . . . . . . . . . . . . . . . . . . . 523
X Logical Font Description . . . . . . . . . . . 172
X resources . . . . . . . . . . . . . . . . . . . . . . . . . . 521
X resources file. . . . . . . . . . . . . . . . . . . . . . . 171
X selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
XDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276
XIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523
XLFD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
XML schema. . . . . . . . . . . . . . . . . . . . . . . . . 236
xterm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

Y
yahrzeits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
yanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
yanking previous kills . . . . . . . . . . . . . . . . . 58

Z
zip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Zmacs mode . . . . . . . . . . . . . . . . . . . . . . . . . . 52
zoo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145



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