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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 @chapter 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 The act of @dfn{cutting} text means to delete the text from the line, and
160 to save away the deleted text for later use, just as if you had cut the
161 text out of the line with a pair of scissors. There is a
163 @dfn{Killing} text means to delete the text from the line, but to save
164 it away for later use, usually by @dfn{yanking} it back into the line.
165 If the description for a command says that it `kills' text, then you can
166 be sure that you can get the text back in a different (or the same)
169 Here is the list of commands for killing text.
173 Kill the text from the current cursor position to the end of the line.
176 Kill from the cursor to the end of the current word, or if between
177 words, to the end of the next word.
180 Kill fromthe cursor the start of the previous word, or if between words, to the start of the previous word.
183 Kill from the cursor to the previous whitespace. This is different than
184 @key{M-DEL} because the word boundaries differ.
188 And, here is how to @dfn{yank} the text back into the line. Yanking
193 Yank the most recently killed text back into the buffer at the cursor.
196 Rotate the kill-ring, and yank the new top. You can only do this if
197 the prior command is @key{C-y} or @key{M-y}.
200 When you use a kill command, the text is saved in a @dfn{kill-ring}.
201 Any number of consecutive kills save all of the killed text together, so
202 that when you yank it back, you get it in one clean sweep. The kill
203 ring is not line specific; the text that you killed on a previously
204 typed line is available to be yanked back later, when you are typing
207 @node Readline Arguments
208 @subsection Readline Arguments
210 You can pass numeric arguments to Readline commands. Sometimes the
211 argument acts as a repeat count, other times it is the @i{sign} of the
212 argument that is significant. If you pass a negative argument to a
213 command which normally acts in a forward direction, that command will
214 act in a backward direction. For example, to kill text back to the
215 start of the line, you might type @key{M--} @key{C-k}.
217 The general way to pass numeric arguments to a command is to type meta
218 digits before the command. If the first `digit' you type is a minus
219 sign (@key{-}), then the sign of the argument will be negative. Once
220 you have typed one meta digit to get the argument started, you can type
221 the remainder of the digits, and then the command. For example, to give
222 the @key{C-d} command an argument of 10, you could type @key{M-1 0 C-d}.
225 @node Readline Init File
226 @section Readline Init File
228 Although the Readline library comes with a set of Emacs-like
229 keybindings, it is possible that you would like to use a different set
230 of keybindings. You can customize programs that use Readline by putting
231 commands in an @dfn{init} file in your home directory. The name of this
232 file is @file{~/.inputrc}.
234 When a program which uses the Readline library starts up, the
235 @file{~/.inputrc} file is read, and the keybindings are set.
237 In addition, the @code{C-x C-r} command re-reads this init file, thus
238 incorporating any changes that you might have made to it.
241 * Readline Init Syntax:: Syntax for the commands in @file{~/.inputrc}.
242 * Readline Vi Mode:: Switching to @code{vi} mode in Readline.
245 @node Readline Init Syntax
246 @subsection Readline Init Syntax
248 There are only four constructs allowed in the @file{~/.inputrc}
252 @item Variable Settings
253 You can change the state of a few variables in Readline. You do this by
254 using the @code{set} command within the init file. Here is how you
255 would specify that you wish to use Vi line editing commands:
261 Right now, there are only a few variables which can be set; so few in
262 fact, that we just iterate them here:
268 The @code{editing-mode} variable controls which editing mode you are
269 using. By default, GNU Readline starts up in Emacs editing mode, where
270 the keystrokes are most similar to Emacs. This variable can either be
271 set to @code{emacs} or @code{vi}.
273 @item horizontal-scroll-mode
274 @vindex horizontal-scroll-mode
275 This variable can either be set to @code{On} or @code{Off}. Setting it
276 to @code{On} means that the text of the lines that you edit will scroll
277 horizontally on a single screen line when they are larger than the width
278 of the screen, instead of wrapping onto a new screen line. By default,
279 this variable is set to @code{Off}.
281 @item mark-modified-lines
282 @vindex mark-modified-lines
283 This variable when set to @code{On}, says to display an asterisk
284 (@samp{*}) at the starts of history lines which have been modified.
285 This variable is off by default.
287 @item prefer-visible-bell
288 @vindex prefer-visible-bell
289 If this variable is set to @code{On} it means to use a visible bell if
290 one is available, rather than simply ringing the terminal bell. By
291 default, the value is @code{Off}.
295 The syntax for controlling keybindings in the @file{~/.inputrc} file is
296 simple. First you have to know the @i{name} of the command that you
297 want to change. The following pages contain tables of the command name,
298 the default keybinding, and a short description of what the command
301 Once you know the name of the command, simply place the name of the key
302 you wish to bind the command to, a colon, and then the name of the
303 command on a line in the @file{~/.inputrc} file. The name of the key
304 can be expressed in different ways, depending on which is most
308 @item @w{@var{keyname}: @var{function-name} or @var{macro}}
309 @var{keyname} is the name of a key spelled out in English. For example:
311 Control-u: universal-argument
312 Meta-Rubout: backward-kill-word
313 Control-o: ">&output"
316 In the above example, @samp{C-u} is bound to the function
317 @code{universal-argument}, and @samp{C-o} is bound to run the macro
318 expressed on the right hand side (that is, to insert the text
319 @samp{>&output} into the line).
321 @item @w{"@var{keyseq}": @var{function-name} or @var{macro}}
322 @var{keyseq} differs from @var{keyname} above in that strings denoting
323 an entire key sequence can be specified. Simply place the key sequence
324 in double quotes. GNU Emacs style key escapes can be used, as in the
328 "\C-u": universal-argument
329 "\C-x\C-r": re-read-init-file
330 "\e[11~": "Function Key 1"
333 In the above example, @samp{C-u} is bound to the function
334 @code{universal-argument} (just as it was in the first example),
335 @samp{C-x C-r} is bound to the function @code{re-read-init-file}, and
336 @samp{ESC [ 1 1 ~} is bound to insert the text @samp{Function Key 1}.
342 * Commands For Moving:: Moving about the line.
343 * Commands For History:: Getting at previous lines.
344 * Commands For Text:: Commands for changing text.
345 * Commands For Killing:: Commands for killing and yanking.
346 * Numeric Arguments:: Specifying numeric arguments, repeat counts.
347 * Commands For Completion:: Getting Readline to do the typing for you.
348 * Miscellaneous Commands:: Other miscillaneous commands.
351 @node Commands For Moving
352 @subsubsection Commands For Moving
354 @item beginning-of-line (C-a)
355 Move to the start of the current line.
357 @item end-of-line (C-e)
358 Move to the end of the line.
360 @item forward-char (C-f)
361 Move forward a character.
363 @item backward-char (C-b)
364 Move back a character.
366 @item forward-word (M-f)
367 Move forward to the end of the next word.
369 @item backward-word (M-b)
370 Move back to the start of this, or the previous, word.
372 @item clear-screen (C-l)
373 Clear the screen leaving the current line at the top of the screen.
377 @node Commands For History
378 @subsubsection Commands For Manipulating The History
381 @item accept-line (Newline, Return)
382 Accept the line regardless of where the cursor is. If this line is
383 non-empty, add it to the history list. If this line was a history
384 line, then restore the history line to its original state.
386 @item previous-history (C-p)
387 Move `up' through the history list.
389 @item next-history (C-n)
390 Move `down' through the history list.
392 @item beginning-of-history (M-<)
393 Move to the first line in the history.
395 @item end-of-history (M->)
396 Move to the end of the input history, i.e., the line you are entering!
398 @item reverse-search-history (C-r)
399 Search backward starting at the current line and moving `up' through
400 the history as necessary. This is an incremental search.
402 @item forward-search-history (C-s)
403 Search forward starting at the current line and moving `down' through
404 the the history as neccessary.
408 @node Commands For Text
409 @subsubsection Commands For Changing Text
412 @item delete-char (C-d)
413 Delete the character under the cursor. If the cursor is at the
414 beginning of the line, and there are no characters in the line, and
415 the last character typed was not C-d, then return EOF.
417 @item backward-delete-char (Rubout)
418 Delete the character behind the cursor. A numeric arg says to kill
419 the characters instead of deleting them.
421 @item quoted-insert (C-q, C-v)
422 Add the next character that you type to the line verbatim. This is
423 how to insert things like C-q for example.
425 @item tab-insert (M-TAB)
426 Insert a tab character.
428 @item self-insert (a, b, A, 1, !, ...)
431 @item transpose-chars (C-t)
432 Drag the character before point forward over the character at point.
433 Point moves forward as well. If point is at the end of the line, then
434 transpose the two characters before point. Negative args don't work.
436 @item transpose-words (M-t)
437 Drag the word behind the cursor past the word in front of the cursor
438 moving the cursor over that word as well.
440 @item upcase-word (M-u)
441 Uppercase the current (or following) word. With a negative argument,
442 do the previous word, but do not move point.
444 @item downcase-word (M-l)
445 Lowercase the current (or following) word. With a negative argument,
446 do the previous word, but do not move point.
448 @item capitalize-word (M-c)
449 Uppercase the current (or following) word. With a negative argument,
450 do the previous word, but do not move point.
454 @node Commands For Killing
455 @subsubsection Killing And Yanking
459 @item kill-line (C-k)
460 Kill the text from the current cursor position to the end of the line.
462 @item backward-kill-line ()
463 Kill backward to the beginning of the line. This is normally unbound.
465 @item kill-word (M-d)
466 Kill from the cursor to the end of the current word, or if between
467 words, to the end of the next word.
469 @item backward-kill-word (M-DEL)
470 Kill the word behind the cursor.
472 @item unix-line-discard (C-u)
473 Do what C-u used to do in Unix line input. We save the killed text on
474 the kill-ring, though.
476 @item unix-word-rubout (C-w)
477 Do what C-w used to do in Unix line input. The killed text is saved
478 on the kill-ring. This is different than backward-kill-word because
479 the word boundaries differ.
482 Yank the top of the kill ring into the buffer at point.
485 Rotate the kill-ring, and yank the new top. You can only do this if
486 the prior command is yank or yank-pop.
489 @node Numeric Arguments
490 @subsubsection Specifying Numeric Arguments
493 @item digit-argument (M-0, M-1, ... M--)
494 Add this digit to the argument already accumulating, or start a new
495 argument. M-- starts a negative argument.
497 @item universal-argument ()
498 Do what C-u does in emacs. By default, this is not bound.
502 @node Commands For Completion
503 @subsubsection Letting Readline Type For You
507 Attempt to do completion on the text before point. This is
508 implementation defined. Generally, if you are typing a filename
509 argument, you can do filename completion; if you are typing a command,
510 you can do command completion, if you are typing in a symbol to GDB, you
511 can do symbol name completion, if you are typing in a variable to Bash,
512 you can do variable name completion...
514 @item possible-completions (M-?)
515 List the possible completions of the text before point.
518 @node Miscellaneous Commands
519 @subsubsection Some Miscellaneous Commands
522 @item re-read-init-file (C-x C-r)
523 Read in the contents of your @file{~/.inputrc} file, and incorporate
524 any bindings found there.
529 @item do-uppercase-version (M-a, M-b, ...)
530 Run the command that is bound to your uppercase brother.
532 @item prefix-meta (ESC)
533 Make the next character that you type be metafied. This is for people
534 without a meta key. Typing @samp{ESC f} is equivalent to typing
538 Incremental undo, separately remembered for each line.
540 @item revert-line (M-r)
541 Undo all changes made to this line. This is like typing the `undo'
542 command enough times to get back to the beginning.
545 @node Readline Vi Mode
546 @subsection Readline Vi Mode
548 While the Readline library does not have a full set of Vi editing
549 functions, it does contain enough to allow simple editing of the line.
551 In order to switch interactively between Emacs and Vi editing modes, use
552 the command M-C-j (toggle-editing-mode).
554 When you enter a line in Vi mode, you are already placed in `insertion'
555 mode, as if you had typed an `i'. Pressing @key{ESC} switches you into
556 `edit' mode, where you can edit the text of the line with the standard
557 Vi movement keys, move to previous history lines with `k', and following
558 lines with `j', and so forth.