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2 @setfilename rluser.info
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7 This file documents the end user interface to the GNU command line
8 editing feautres. It is to be an appendix to manuals for programs which
9 use these features. There is a document entitled "readline.texinfo"
10 which contains both end-user and programmer documentation for the GNU
13 Copyright (C) 1988 Free Software Foundation, Inc.
15 Authored by Brian Fox.
17 Permission is granted to process this file through Tex and print the
18 results, provided the printed document carries copying permission notice
19 identical to this one except for the removal of this paragraph (this
20 paragraph not being relevant to the printed manual).
22 Permission is granted to make and distribute verbatim copies of this manual
23 provided the copyright notice and this permission notice are preserved on
26 Permission is granted to copy and distribute modified versions of this
27 manual under the conditions for verbatim copying, provided also that the
28 GNU Copyright statement is available to the distributee, and provided that
29 the entire resulting derived work is distributed under the terms of a
30 permission notice identical to this one.
32 Permission is granted to copy and distribute translations of this manual
33 into another language, under the above conditions for modified versions.
36 @node Command Line Editing
37 @appendix Command Line Editing
39 This text describes GNU's command line editing interface.
42 * Introduction and Notation:: Notation used in this text.
43 * Readline Interaction:: The minimum set of commands for editing a line.
44 * Readline Init File:: Customizing Readline from a user's view.
47 @node Introduction and Notation
48 @section Introduction to Line Editing
50 The following paragraphs describe the notation we use to represent
53 The text @key{C-k} is read as `Control-K' and describes the character
54 produced when the Control key is depressed and the @key{k} key is struck.
56 The text @key{M-k} is read as `Meta-K' and describes the character
57 produced when the meta key (if you have one) is depressed, and the @key{k}
58 key is struck. If you do not have a meta key, the identical keystroke
59 can be generated by typing @key{ESC} @i{first}, and then typing @key{k}.
60 Either process is known as @dfn{metafying} the @key{k} key.
62 The text @key{M-C-k} is read as `Meta-Control-k' and describes the
63 character produced by @dfn{metafying} @key{C-k}.
65 In addition, several keys have their own names. Specifically,
66 @key{DEL}, @key{ESC}, @key{LFD}, @key{SPC}, @key{RET}, and @key{TAB} all
67 stand for themselves when seen in this text, or in an init file
68 (@pxref{Readline Init File}, for more info).
70 @node Readline Interaction
71 @section Readline Interaction
72 @cindex interaction, readline
74 Often during an interactive session you type in a long line of text,
75 only to notice that the first word on the line is misspelled. The
76 Readline library gives you a set of commands for manipulating the text
77 as you type it in, allowing you to just fix your typo, and not forcing
78 you to retype the majority of the line. Using these editing commands,
79 you move the cursor to the place that needs correction, and delete or
80 insert the text of the corrections. Then, when you are satisfied with
81 the line, you simply press @key{RETURN}. You do not have to be at the
82 end of the line to press @key{RETURN}; the entire line is accepted
83 regardless of the location of the cursor within the line.
86 * Readline Bare Essentials:: The least you need to know about Readline.
87 * Readline Movement Commands:: Moving about the input line.
88 * Readline Killing Commands:: How to delete text, and how to get it back!
89 * Readline Arguments:: Giving numeric arguments to commands.
92 @node Readline Bare Essentials
93 @subsection Readline Bare Essentials
95 In order to enter characters into the line, simply type them. The typed
96 character appears where the cursor was, and then the cursor moves one
97 space to the right. If you mistype a character, you can use @key{DEL} to
98 back up, and delete the mistyped character.
100 Sometimes you may miss typing a character that you wanted to type, and
101 not notice your error until you have typed several other characters. In
102 that case, you can type @key{C-b} to move the cursor to the left, and then
103 correct your mistake. Aftwerwards, you can move the cursor to the right
106 When you add text in the middle of a line, you will notice that characters
107 to the right of the cursor get `pushed over' to make room for the text
108 that you have inserted. Likewise, when you delete text behind the cursor,
109 characters to the right of the cursor get `pulled back' to fill in the
110 blank space created by the removal of the text. A list of the basic bare
111 essentials for editing the text of an input line follows.
115 Move back one character.
117 Move forward one character.
119 Delete the character to the left of the cursor.
121 Delete the character underneath the cursor.
122 @item @w{Printing characters}
123 Insert itself into the line at the cursor.
125 Undo the last thing that you did. You can undo all the way back to an
129 @node Readline Movement Commands
130 @subsection Readline Movement Commands
133 The above table describes the most basic possible keystrokes that you need
134 in order to do editing of the input line. For your convenience, many
135 other commands have been added in addition to @key{C-b}, @key{C-f},
136 @key{C-d}, and @key{DEL}. Here are some commands for moving more rapidly
141 Move to the start of the line.
143 Move to the end of the line.
147 Move backward a word.
149 Clear the screen, reprinting the current line at the top.
152 Notice how @key{C-f} moves forward a character, while @key{M-f} moves
153 forward a word. It is a loose convention that control keystrokes
154 operate on characters while meta keystrokes operate on words.
156 @node Readline Killing Commands
157 @subsection Readline Killing Commands
159 @dfn{Killing} text means to delete the text from the line, but to save
160 it away for later use, usually by @dfn{yanking} it back into the line.
161 If the description for a command says that it `kills' text, then you can
162 be sure that you can get the text back in a different (or the same)
165 Here is the list of commands for killing text.
169 Kill the text from the current cursor position to the end of the line.
172 Kill from the cursor to the end of the current word, or if between
173 words, to the end of the next word.
176 Kill from the cursor to the start of the previous word, or if between
177 words, to the start of the previous word.
180 Kill from the cursor to the previous whitespace. This is different than
181 @key{M-DEL} because the word boundaries differ.
185 And, here is how to @dfn{yank} the text back into the line. Yanking
190 Yank the most recently killed text back into the buffer at the cursor.
193 Rotate the kill-ring, and yank the new top. You can only do this if
194 the prior command is @key{C-y} or @key{M-y}.
197 When you use a kill command, the text is saved in a @dfn{kill-ring}.
198 Any number of consecutive kills save all of the killed text together, so
199 that when you yank it back, you get it in one clean sweep. The kill
200 ring is not line specific; the text that you killed on a previously
201 typed line is available to be yanked back later, when you are typing
204 @node Readline Arguments
205 @subsection Readline Arguments
207 You can pass numeric arguments to Readline commands. Sometimes the
208 argument acts as a repeat count, other times it is the @i{sign} of the
209 argument that is significant. If you pass a negative argument to a
210 command which normally acts in a forward direction, that command will
211 act in a backward direction. For example, to kill text back to the
212 start of the line, you might type @key{M--} @key{C-k}.
214 The general way to pass numeric arguments to a command is to type meta
215 digits before the command. If the first `digit' you type is a minus
216 sign (@key{-}), then the sign of the argument will be negative. Once
217 you have typed one meta digit to get the argument started, you can type
218 the remainder of the digits, and then the command. For example, to give
219 the @key{C-d} command an argument of 10, you could type @key{M-1 0 C-d}.
222 @node Readline Init File
223 @section Readline Init File
225 Although the Readline library comes with a set of Emacs-like
226 keybindings, it is possible that you would like to use a different set
227 of keybindings. You can customize programs that use Readline by putting
228 commands in an @dfn{init} file in your home directory. The name of this
229 file is @file{~/.inputrc}.
231 When a program which uses the Readline library starts up, the
232 @file{~/.inputrc} file is read, and the keybindings are set.
234 In addition, the @key{C-x C-r} command re-reads this init file, thus
235 incorporating any changes that you might have made to it.
238 * Readline Init Syntax:: Syntax for the commands in @file{~/.inputrc}.
239 * Readline Vi Mode:: Switching to @code{vi} mode in Readline.
242 @node Readline Init Syntax
243 @subsection Readline Init Syntax
245 There are only four constructs allowed in the @file{~/.inputrc}
249 @item Variable Settings
250 You can change the state of a few variables in Readline. You do this by
251 using the @code{set} command within the init file. Here is how you
252 would specify that you wish to use Vi line editing commands:
258 Right now, there are only a few variables which can be set; so few in
259 fact, that we just iterate them here:
265 The @code{editing-mode} variable controls which editing mode you are
266 using. By default, GNU Readline starts up in Emacs editing mode, where
267 the keystrokes are most similar to Emacs. This variable can either be
268 set to @code{emacs} or @code{vi}.
270 @item horizontal-scroll-mode
271 @vindex horizontal-scroll-mode
272 This variable can either be set to @code{On} or @code{Off}. Setting it
273 to @code{On} means that the text of the lines that you edit will scroll
274 horizontally on a single screen line when they are larger than the width
275 of the screen, instead of wrapping onto a new screen line. By default,
276 this variable is set to @code{Off}.
278 @item mark-modified-lines
279 @vindex mark-modified-lines
280 This variable when set to @code{On}, says to display an asterisk
281 (@samp{*}) at the starts of history lines which have been modified.
282 This variable is off by default.
284 @item prefer-visible-bell
285 @vindex prefer-visible-bell
286 If this variable is set to @code{On} it means to use a visible bell if
287 one is available, rather than simply ringing the terminal bell. By
288 default, the value is @code{Off}.
292 The syntax for controlling keybindings in the @file{~/.inputrc} file is
293 simple. First you have to know the @i{name} of the command that you
294 want to change. The following pages contain tables of the command name,
295 the default keybinding, and a short description of what the command
298 Once you know the name of the command, simply place the name of the key
299 you wish to bind the command to, a colon, and then the name of the
300 command on a line in the @file{~/.inputrc} file. The name of the key
301 can be expressed in different ways, depending on which is most
305 @item @w{@var{keyname}: @var{function-name} or @var{macro}}
306 @var{keyname} is the name of a key spelled out in English. For example:
308 Control-u: universal-argument
309 Meta-Rubout: backward-kill-word
310 Control-o: ">&output"
313 In the above example, @key{C-u} is bound to the function
314 @code{universal-argument}, and @key{C-o} is bound to run the macro
315 expressed on the right hand side (that is, to insert the text
316 @samp{>&output} into the line).
318 @item @w{"@var{keyseq}": @var{function-name} or @var{macro}}
319 @var{keyseq} differs from @var{keyname} above in that strings denoting
320 an entire key sequence can be specified. Simply place the key sequence
321 in double quotes. GNU Emacs style key escapes can be used, as in the
325 "\C-u": universal-argument
326 "\C-x\C-r": re-read-init-file
327 "\e[11~": "Function Key 1"
330 In the above example, @key{C-u} is bound to the function
331 @code{universal-argument} (just as it was in the first example),
332 @key{C-x C-r} is bound to the function @code{re-read-init-file}, and
333 @key{ESC [ 1 1 ~} is bound to insert the text @samp{Function Key 1}.
339 * Commands For Moving:: Moving about the line.
340 * Commands For History:: Getting at previous lines.
341 * Commands For Text:: Commands for changing text.
342 * Commands For Killing:: Commands for killing and yanking.
343 * Numeric Arguments:: Specifying numeric arguments, repeat counts.
344 * Commands For Completion:: Getting Readline to do the typing for you.
345 * Miscellaneous Commands:: Other miscillaneous commands.
348 @node Commands For Moving
349 @subsubsection Commands For Moving
351 @item beginning-of-line (@key{C-a})
352 Move to the start of the current line.
354 @item end-of-line (@key{C-e})
355 Move to the end of the line.
357 @item forward-char (@key{C-f})
358 Move forward a character.
360 @item backward-char (@key{C-b})
361 Move back a character.
363 @item forward-word (@key{M-f})
364 Move forward to the end of the next word.
366 @item backward-word (@key{M-b})
367 Move back to the start of this, or the previous, word.
369 @item clear-screen (@key{C-l})
370 Clear the screen leaving the current line at the top of the screen.
374 @node Commands For History
375 @subsubsection Commands For Manipulating The History
378 @item accept-line (Newline, Return)
379 Accept the line regardless of where the cursor is. If this line is
380 non-empty, add it to the history list. If this line was a history
381 line, then restore the history line to its original state.
383 @item previous-history (@key{C-p})
384 Move `up' through the history list.
386 @item next-history (@key{C-n})
387 Move `down' through the history list.
389 @item beginning-of-history (@key{M-<})
390 Move to the first line in the history.
392 @item end-of-history (@key{M->})
393 Move to the end of the input history, i.e., the line you are entering!
395 @item reverse-search-history (@key{C-r})
396 Search backward starting at the current line and moving `up' through
397 the history as necessary. This is an incremental search.
399 @item forward-search-history (@key{C-s})
400 Search forward starting at the current line and moving `down' through
401 the the history as neccessary.
405 @node Commands For Text
406 @subsubsection Commands For Changing Text
409 @item delete-char (@key{C-d})
410 Delete the character under the cursor. If the cursor is at the
411 beginning of the line, and there are no characters in the line, and
412 the last character typed was not @key{C-d}, then return EOF.
414 @item backward-delete-char (Rubout)
415 Delete the character behind the cursor. A numeric arg says to kill
416 the characters instead of deleting them.
418 @item quoted-insert (@key{C-q}, @key{C-v})
419 Add the next character that you type to the line verbatim. This is
420 how to insert things like @key{C-q} for example.
422 @item tab-insert (@key{M-TAB})
423 Insert a tab character.
425 @item self-insert (a, b, A, 1, !, ...)
428 @item transpose-chars (@key{C-t})
429 Drag the character before point forward over the character at point.
430 Point moves forward as well. If point is at the end of the line, then
431 transpose the two characters before point. Negative args don't work.
433 @item transpose-words (@key{M-t})
434 Drag the word behind the cursor past the word in front of the cursor
435 moving the cursor over that word as well.
437 @item upcase-word (@key{M-u})
438 Uppercase the current (or following) word. With a negative argument,
439 do the previous word, but do not move point.
441 @item downcase-word (@key{M-l})
442 Lowercase the current (or following) word. With a negative argument,
443 do the previous word, but do not move point.
445 @item capitalize-word (@key{M-c})
446 Uppercase the current (or following) word. With a negative argument,
447 do the previous word, but do not move point.
451 @node Commands For Killing
452 @subsubsection Killing And Yanking
456 @item kill-line (@key{C-k})
457 Kill the text from the current cursor position to the end of the line.
459 @item backward-kill-line ()
460 Kill backward to the beginning of the line. This is normally unbound.
462 @item kill-word (@key{M-d})
463 Kill from the cursor to the end of the current word, or if between
464 words, to the end of the next word.
466 @item backward-kill-word (@key{M-DEL})
467 Kill the word behind the cursor.
469 @item unix-line-discard (@key{C-u})
470 Do what @key{C-u} used to do in Unix line input. We save the killed text on
471 the kill-ring, though.
473 @item unix-word-rubout (@key{C-w})
474 Do what @key{C-w} used to do in Unix line input. The killed text is saved
475 on the kill-ring. This is different than backward-kill-word because
476 the word boundaries differ.
478 @item yank (@key{C-y})
479 Yank the top of the kill ring into the buffer at point.
481 @item yank-pop (@key{M-y})
482 Rotate the kill-ring, and yank the new top. You can only do this if
483 the prior command is yank or yank-pop.
486 @node Numeric Arguments
487 @subsubsection Specifying Numeric Arguments
490 @item digit-argument (@key{M-0}, @key{M-1}, ... @key{M--})
491 Add this digit to the argument already accumulating, or start a new
492 argument. @key{M--} starts a negative argument.
494 @item universal-argument ()
495 Do what @key{C-u} does in emacs. By default, this is not bound.
499 @node Commands For Completion
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.
515 @node Miscellaneous Commands
516 @subsubsection Some Miscellaneous Commands
519 @item re-read-init-file (@key{C-x} @key{C-r})
520 Read in the contents of your @file{~/.inputrc} file, and incorporate
521 any bindings found there.
523 @item abort (@key{C-g})
526 @item do-uppercase-version (@key{M-a}, @key{M-b}, ...)
527 Run the command that is bound to your uppercase brother.
529 @item prefix-meta (ESC)
530 Make the next character that you type be metafied. This is for people
531 without a meta key. Typing @key{ESC f} is equivalent to typing
534 @item undo (@key{C-_})
535 Incremental undo, separately remembered for each line.
537 @item revert-line (@key{M-r})
538 Undo all changes made to this line. This is like typing the `undo'
539 command enough times to get back to the beginning.
542 @node Readline Vi Mode
543 @subsection Readline Vi Mode
545 @cindex @code{vi} style command editing
546 @kindex toggle-editing-mode
547 While the Readline library does not have a full set of Vi editing
548 functions, it does contain enough to allow simple editing of the line.
550 In order to switch interactively between Emacs and Vi editing modes, use
551 the command @key{M-C-j} (toggle-editing-mode).
553 When you enter a line in Vi mode, you are already placed in `insertion'
554 mode, as if you had typed an `i'. Pressing @key{ESC} switches you into
555 `edit' mode, where you can edit the text of the line with the standard
556 Vi movement keys, move to previous history lines with `k', and following
557 lines with `j', and so forth.