2 This file documents the end user interface to the GNU command line
3 editing feautres. It is to be an appendix to manuals for programs which
4 use these features. There is a document entitled "readline.texinfo"
5 which contains both end-user and programmer documentation for the GNU
8 Copyright (C) 1988 Free Software Foundation, Inc.
10 Authored by Brian Fox.
12 Permission is granted to process this file through Tex and print the
13 results, provided the printed document carries copying permission notice
14 identical to this one except for the removal of this paragraph (this
15 paragraph not being relevant to the printed manual).
17 Permission is granted to make and distribute verbatim copies of this manual
18 provided the copyright notice and this permission notice are preserved on
21 Permission is granted to copy and distribute modified versions of this
22 manual under the conditions for verbatim copying, provided also that the
23 GNU Copyright statement is available to the distributee, and provided that
24 the entire resulting derived work is distributed under the terms of a
25 permission notice identical to this one.
27 Permission is granted to copy and distribute translations of this manual
28 into another language, under the above conditions for modified versions.
31 @node Command Line Editing
32 @appendix Command Line Editing
34 This text describes GNU's command line editing interface.
37 * Introduction and Notation:: Notation used in this text.
38 * Readline Interaction:: The minimum set of commands for editing a line.
39 * Readline Init File:: Customizing Readline from a user's view.
42 @node Introduction and Notation, Readline Interaction, Command Line Editing, Command Line Editing
43 @section Introduction to Line Editing
45 The following paragraphs describe the notation we use to represent
48 The text @key{C-k} is read as `Control-K' and describes the character
49 produced when the Control key is depressed and the @key{k} key is struck.
51 The text @key{M-k} is read as `Meta-K' and describes the character
52 produced when the meta key (if you have one) is depressed, and the @key{k}
53 key is struck. If you do not have a meta key, the identical keystroke
54 can be generated by typing @key{ESC} @i{first}, and then typing @key{k}.
55 Either process is known as @dfn{metafying} the @key{k} key.
57 The text @key{M-C-k} is read as `Meta-Control-k' and describes the
58 character produced by @dfn{metafying} @key{C-k}.
60 In addition, several keys have their own names. Specifically,
61 @key{DEL}, @key{ESC}, @key{LFD}, @key{SPC}, @key{RET}, and @key{TAB} all
62 stand for themselves when seen in this text, or in an init file
63 (@pxref{Readline Init File}, for more info).
65 @node Readline Interaction, Readline Init File, Introduction and Notation, Command Line Editing
66 @section Readline Interaction
67 @cindex interaction, readline
69 Often during an interactive session you type in a long line of text,
70 only to notice that the first word on the line is misspelled. The
71 Readline library gives you a set of commands for manipulating the text
72 as you type it in, allowing you to just fix your typo, and not forcing
73 you to retype the majority of the line. Using these editing commands,
74 you move the cursor to the place that needs correction, and delete or
75 insert the text of the corrections. Then, when you are satisfied with
76 the line, you simply press @key{RET}. You do not have to be at the
77 end of the line to press @key{RET}; the entire line is accepted
78 regardless of the location of the cursor within the line.
81 * Readline Bare Essentials:: The least you need to know about Readline.
82 * Readline Movement Commands:: Moving about the input line.
83 * Readline Killing Commands:: How to delete text, and how to get it back!
84 * Readline Arguments:: Giving numeric arguments to commands.
87 @node Readline Bare Essentials, Readline Movement Commands, Readline Interaction, Readline Interaction
88 @subsection Readline Bare Essentials
90 In order to enter characters into the line, simply type them. The typed
91 character appears where the cursor was, and then the cursor moves one
92 space to the right. If you mistype a character, you can use @key{DEL} to
93 back up, and delete the mistyped character.
95 Sometimes you may miss typing a character that you wanted to type, and
96 not notice your error until you have typed several other characters. In
97 that case, you can type @key{C-b} to move the cursor to the left, and then
98 correct your mistake. Aftwerwards, you can move the cursor to the right
101 When you add text in the middle of a line, you will notice that characters
102 to the right of the cursor get `pushed over' to make room for the text
103 that you have inserted. Likewise, when you delete text behind the cursor,
104 characters to the right of the cursor get `pulled back' to fill in the
105 blank space created by the removal of the text. A list of the basic bare
106 essentials for editing the text of an input line follows.
110 Move back one character.
112 Move forward one character.
114 Delete the character to the left of the cursor.
116 Delete the character underneath the cursor.
117 @item @w{Printing characters}
118 Insert itself into the line at the cursor.
120 Undo the last thing that you did. You can undo all the way back to an
124 @node Readline Movement Commands, Readline Killing Commands, Readline Bare Essentials, Readline Interaction
125 @subsection Readline Movement Commands
127 The above table describes the most basic possible keystrokes that you need
128 in order to do editing of the input line. For your convenience, many
129 other commands have been added in addition to @key{C-b}, @key{C-f},
130 @key{C-d}, and @key{DEL}. Here are some commands for moving more rapidly
135 Move to the start of the line.
137 Move to the end of the line.
141 Move backward a word.
143 Clear the screen, reprinting the current line at the top.
146 Notice how @key{C-f} moves forward a character, while @key{M-f} moves
147 forward a word. It is a loose convention that control keystrokes
148 operate on characters while meta keystrokes operate on words.
150 @node Readline Killing Commands, Readline Arguments, Readline Movement Commands, Readline Interaction
151 @subsection Readline Killing Commands
153 @dfn{Killing} text means to delete the text from the line, but to save
154 it away for later use, usually by @dfn{yanking} it back into the line.
155 If the description for a command says that it `kills' text, then you can
156 be sure that you can get the text back in a different (or the same)
159 Here is the list of commands for killing text.
163 Kill the text from the current cursor position to the end of the line.
166 Kill from the cursor to the end of the current word, or if between
167 words, to the end of the next word.
170 Kill from the cursor to the start of the previous word, or if between
171 words, to the start of the previous word.
174 Kill from the cursor to the previous whitespace. This is different than
175 @key{M-DEL} because the word boundaries differ.
179 And, here is how to @dfn{yank} the text back into the line.
183 Yank the most recently killed text back into the buffer at the cursor.
186 Rotate the kill-ring, and yank the new top. You can only do this if
187 the prior command is @key{C-y} or @key{M-y}.
190 When you use a kill command, the text is saved in a @dfn{kill-ring}.
191 Any number of consecutive kills save all of the killed text together, so
192 that when you yank it back, you get it in one clean sweep. The kill
193 ring is not line specific; the text that you killed on a previously
194 typed line is available to be yanked back later, when you are typing
197 @node Readline Arguments,, Readline Killing Commands, Readline Interaction
198 @subsection Readline Arguments
200 You can pass numeric arguments to Readline commands. Sometimes the
201 argument acts as a repeat count, other times it is the @i{sign} of the
202 argument that is significant. If you pass a negative argument to a
203 command which normally acts in a forward direction, that command will
204 act in a backward direction. For example, to kill text back to the
205 start of the line, you might type @key{M--} @key{C-k}.
207 The general way to pass numeric arguments to a command is to type meta
208 digits before the command. If the first `digit' you type is a minus
209 sign (@key{-}), then the sign of the argument will be negative. Once
210 you have typed one meta digit to get the argument started, you can type
211 the remainder of the digits, and then the command. For example, to give
212 the @key{C-d} command an argument of 10, you could type @key{M-1 0 C-d}.
215 @node Readline Init File,, Readline Interaction, Command Line Editing
216 @section Readline Init File
218 Although the Readline library comes with a set of @sc{gnu} Emacs-like
219 keybindings, it is possible that you would like to use a different set
220 of keybindings. You can customize programs that use Readline by putting
221 commands in an @dfn{init} file in your home directory. The name of this
222 file is @file{~/.inputrc}.
224 When a program which uses the Readline library starts up, the
225 @file{~/.inputrc} file is read, and the keybindings are set.
227 In addition, the @key{C-x C-r} command re-reads this init file, thus
228 incorporating any changes that you might have made to it.
231 * Readline Init Syntax:: Syntax for the commands in @file{~/.inputrc}.
232 * Readline vi Mode:: Switching to @code{vi} mode in Readline.
235 @node Readline Init Syntax, Readline vi Mode, Readline Init File, Readline Init File
236 @subsection Readline Init Syntax
238 There are only four constructs allowed in the @file{~/.inputrc}
242 @item Variable Settings
243 You can change the state of a few variables in Readline. You do this by
244 using the @code{set} command within the init file. Here is how you
245 would specify that you wish to use @code{vi} line editing commands:
251 Right now, there are only a few variables which can be set; so few in
252 fact, that we just iterate them here:
258 The @code{editing-mode} variable controls which editing mode you are
259 using. By default, @sc{gnu} Readline starts up in Emacs editing mode, where
260 the keystrokes are most similar to Emacs. This variable can either be
261 set to @code{emacs} or @code{vi}.
263 @item horizontal-scroll-mode
264 @vindex horizontal-scroll-mode
265 This variable can either be set to @code{On} or @code{Off}. Setting it
266 to @code{On} means that the text of the lines that you edit will scroll
267 horizontally on a single screen line when they are larger than the width
268 of the screen, instead of wrapping onto a new screen line. By default,
269 this variable is set to @code{Off}.
271 @item mark-modified-lines
272 @vindex mark-modified-lines
273 This variable when set to @code{On}, says to display an asterisk
274 (@samp{*}) at the starts of history lines which have been modified.
275 This variable is off by default.
277 @item prefer-visible-bell
278 @vindex prefer-visible-bell
279 If this variable is set to @code{On} it means to use a visible bell if
280 one is available, rather than simply ringing the terminal bell. By
281 default, the value is @code{Off}.
285 The syntax for controlling keybindings in the @file{~/.inputrc} file is
286 simple. First you have to know the @i{name} of the command that you
287 want to change. The following pages contain tables of the command name,
288 the default keybinding, and a short description of what the command
291 Once you know the name of the command, simply place the name of the key
292 you wish to bind the command to, a colon, and then the name of the
293 command on a line in the @file{~/.inputrc} file. The name of the key
294 can be expressed in different ways, depending on which is most
298 @item @w{@var{keyname}: @var{function-name} or @var{macro}}
299 @var{keyname} is the name of a key spelled out in English. For example:
301 Control-u: universal-argument
302 Meta-Rubout: backward-kill-word
303 Control-o: ">&output"
306 In the above example, @key{C-u} is bound to the function
307 @code{universal-argument}, and @key{C-o} is bound to run the macro
308 expressed on the right hand side (that is, to insert the text
309 @samp{>&output} into the line).
311 @item @w{"@var{keyseq}": @var{function-name} or @var{macro}}
312 @var{keyseq} differs from @var{keyname} above in that strings denoting
313 an entire key sequence can be specified. Simply place the key sequence
314 in double quotes. @sc{gnu} Emacs style key escapes can be used, as in the
318 "\C-u": universal-argument
319 "\C-x\C-r": re-read-init-file
320 "\e[11~": "Function Key 1"
323 In the above example, @key{C-u} is bound to the function
324 @code{universal-argument} (just as it was in the first example),
325 @key{C-x C-r} is bound to the function @code{re-read-init-file}, and
326 @key{ESC [ 1 1 ~} is bound to insert the text @samp{Function Key 1}.
332 * Commands For Moving:: Moving about the line.
333 * Commands For History:: Getting at previous lines.
334 * Commands For Text:: Commands for changing text.
335 * Commands For Killing:: Commands for killing and yanking.
336 * Numeric Arguments:: Specifying numeric arguments, repeat counts.
337 * Commands For Completion:: Getting Readline to do the typing for you.
338 * Miscellaneous Commands:: Other miscillaneous commands.
342 @node Commands For Moving, Commands For History, Readline Init Syntax, Readline Init Syntax
343 @subsubsection Commands For Moving
346 @item beginning-of-line (@key{C-a})
347 Move to the start of the current line.
349 @item end-of-line (@key{C-e})
350 Move to the end of the line.
352 @item forward-char (@key{C-f})
353 Move forward a character.
355 @item backward-char (@key{C-b})
356 Move back a character.
358 @item forward-word (@key{M-f})
359 Move forward to the end of the next word.
361 @item backward-word (@key{M-b})
362 Move back to the start of this, or the previous, word.
364 @item clear-screen (@key{C-l})
365 Clear the screen leaving the current line at the top of the screen.
370 @node Commands For History, Commands For Text, Commands For Moving, Readline Init Syntax
371 @subsubsection Commands For Manipulating The History
374 @item accept-line (Newline, Return)
375 Accept the line regardless of where the cursor is. If this line is
376 non-empty, add it to the history list. If this line was a history
377 line, then restore the history line to its original state.
379 @item previous-history (@key{C-p})
380 Move `up' through the history list.
382 @item next-history (@key{C-n})
383 Move `down' through the history list.
385 @item beginning-of-history (@key{M-<})
386 Move to the first line in the history.
388 @item end-of-history (@key{M->})
389 Move to the end of the input history, i.e., the line you are entering.
391 @item reverse-search-history (@key{C-r})
392 Search backward starting at the current line and moving `up' through
393 the history as necessary. This is an incremental search.
395 @item forward-search-history (@key{C-s})
396 Search forward starting at the current line and moving `down' through
397 the the history as necessary.
402 @node Commands For Text, Commands For Killing, Commands For History, Readline Init Syntax
403 @subsubsection Commands For Changing Text
406 @item delete-char (@key{C-d})
407 Delete the character under the cursor. If the cursor is at the
408 beginning of the line, and there are no characters in the line, and
409 the last character typed was not @key{C-d}, then return EOF.
411 @item backward-delete-char (Rubout)
412 Delete the character behind the cursor. A numeric argument says to kill
413 the characters instead of deleting them.
415 @item quoted-insert (@key{C-q}, @key{C-v})
416 Add the next character that you type to the line verbatim. This is
417 how to insert things like @key{C-q} for example.
419 @item tab-insert (@key{M-TAB})
420 Insert a tab character.
422 @item self-insert (a, b, A, 1, !, ...)
425 @item transpose-chars (@key{C-t})
426 Drag the character before point forward over the character at point.
427 Point moves forward as well. If point is at the end of the line, then
428 transpose the two characters before point. Negative arguments don't work.
430 @item transpose-words (@key{M-t})
431 Drag the word behind the cursor past the word in front of the cursor
432 moving the cursor over that word as well.
434 @item upcase-word (@key{M-u})
435 Uppercase all letters in the current (or following) word. With a
436 negative argument, do the previous word, but do not move point.
438 @item downcase-word (@key{M-l})
439 Lowercase all letters in the current (or following) word. With a
440 negative argument, do the previous word, but do not move point.
442 @item capitalize-word (@key{M-c})
443 Uppercase the first letter in the current (or following) word. With a
444 negative argument, do the previous word, but do not move point.
449 @node Commands For Killing, Numeric Arguments, Commands For Text, Readline Init Syntax
450 @subsubsection Killing And Yanking
453 @item kill-line (@key{C-k})
454 Kill the text from the current cursor position to the end of the line.
456 @item backward-kill-line ()
457 Kill backward to the beginning of the line. This is normally unbound.
459 @item kill-word (@key{M-d})
460 Kill from the cursor to the end of the current word, or if between
461 words, to the end of the next word.
463 @item backward-kill-word (@key{M-DEL})
464 Kill the word behind the cursor.
466 @item unix-line-discard (@key{C-u})
467 Kill the whole line the way @key{C-u} used to in Unix line input.
468 The killed text is saved on the kill-ring.
470 @item unix-word-rubout (@key{C-w})
471 Kill the word the way @key{C-w} used to in Unix line input.
472 The killed text is saved on the kill-ring. This is different than
473 backward-kill-word because the word boundaries differ.
475 @item yank (@key{C-y})
476 Yank the top of the kill ring into the buffer at point.
478 @item yank-pop (@key{M-y})
479 Rotate the kill-ring, and yank the new top. You can only do this if
480 the prior command is yank or yank-pop.
484 @node Numeric Arguments, Commands For Completion, Commands For Killing, Readline Init Syntax
485 @subsubsection Specifying Numeric Arguments
489 @item digit-argument (@key{M-0}, @key{M-1}, ... @key{M--})
490 Add this digit to the argument already accumulating, or start a new
491 argument. @key{M--} starts a negative argument.
493 @item universal-argument ()
494 Do what @key{C-u} does in @sc{gnu} Emacs. By default, this is not bound.
499 @node Commands For Completion, Miscellaneous Commands, Numeric Arguments, Readline Init Syntax
500 @subsubsection Letting Readline Type For You
504 Attempt to do completion on the text before point. This is
505 implementation defined. Generally, if you are typing a filename
506 argument, you can do filename completion; if you are typing a command,
507 you can do command completion, if you are typing in a symbol to GDB, you
508 can do symbol name completion, if you are typing in a variable to Bash,
509 you can do variable name completion.
511 @item possible-completions (M-?)
512 List the possible completions of the text before point.
516 @node Miscellaneous Commands,, Commands For Completion, Readline Init Syntax
517 @subsubsection Some Miscellaneous Commands
521 @item re-read-init-file (@key{C-x} @key{C-r})
522 Read in the contents of your @file{~/.inputrc} file, and incorporate
523 any bindings found there.
525 @item abort (@key{C-g})
526 Stop running the current editing command.
529 @c I have no idea what this means, and can't figure it out by
530 @c experiment, and can't find it in the readline source.
531 @c doc@cygnus.com, 20may1993.
532 @item do-uppercase-version (@key{M-a}, @key{M-b}, ...)
533 Run the command that is bound to your uppercase brother.
536 @item prefix-meta (ESC)
537 Make the next character that you type be metafied. This is for people
538 without a meta key. Typing @key{ESC f} is equivalent to typing
541 @item undo (@key{C-_})
542 Incremental undo, separately remembered for each line.
544 @item revert-line (@key{M-r})
545 Undo all changes made to this line. This is like typing the `undo'
546 command enough times to get back to the beginning.
550 @node Readline vi Mode,, Readline Init Syntax, Readline Init File
551 @subsection Readline @code{vi} Mode
553 @cindex @code{vi} style command editing
554 @kindex toggle-editing-mode
555 While the Readline library does not have a full set of @code{vi} editing
556 functions, it does contain enough to allow simple editing of the line.
558 In order to switch interactively between @sc{gnu} Emacs and @code{vi}
559 editing modes, use the command @key{M-C-j} (toggle-editing-mode).
561 When you enter a line in @code{vi} mode, you are already placed in `insertion'
562 mode, as if you had typed an `i'. Pressing @key{ESC} switches you into
563 `edit' mode, where you can edit the text of the line with the standard
564 @code{vi} movement keys, move to previous history lines with `k', and following
565 lines with `j', and so forth.