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1 | @ignore |
2 | ||
3 | This file documents the end user interface to the GNU command line | |
4 | editing feautres. It is to be an appendix to manuals for programs which | |
5 | use these features. There is a document entitled "readline.texinfo" | |
6 | which contains both end-user and programmer documentation for the GNU | |
7 | Readline Library. | |
8 | ||
9 | Copyright (C) 1988 Free Software Foundation, Inc. | |
10 | ||
11 | Authored by Brian Fox. | |
12 | ||
13 | Permission is granted to process this file through Tex and print the | |
14 | results, provided the printed document carries copying permission notice | |
15 | identical to this one except for the removal of this paragraph (this | |
16 | paragraph not being relevant to the printed manual). | |
17 | ||
18 | Permission is granted to make and distribute verbatim copies of this manual | |
19 | provided the copyright notice and this permission notice are preserved on | |
20 | all copies. | |
21 | ||
22 | Permission is granted to copy and distribute modified versions of this | |
23 | manual under the conditions for verbatim copying, provided also that the | |
24 | GNU Copyright statement is available to the distributee, and provided that | |
25 | the entire resulting derived work is distributed under the terms of a | |
26 | permission notice identical to this one. | |
27 | ||
28 | Permission is granted to copy and distribute translations of this manual | |
29 | into another language, under the above conditions for modified versions. | |
30 | @end ignore | |
31 | ||
32 | @appendix Command Line Editing | |
33 | @node Command Line Editing, , , Top | |
34 | ||
35 | This appendix describes GNU's command line editing interface. | |
36 | ||
37 | @menu | |
38 | * Introduction and Notation:: Notation used in this appendix. | |
39 | * Basic Line Editing:: The minimum set of commands for editing a line. | |
40 | * Movement Commands:: Commands for moving the cursor about the line. | |
41 | * Cutting and Pasting:: Deletion and copying of text sections. | |
42 | * Transposition:: Exchanging two characters or words. | |
43 | * Completion:: Expansion of a partially typed word into | |
44 | the full text. | |
45 | @end menu | |
46 | ||
47 | @node Readline Introduction, Readline Interaction, Readline Top, Readline Top | |
48 | @section Introduction to Line Editing | |
49 | ||
50 | Many programs read input from the user one line at a time. The GNU | |
51 | Readline library provides Emacs style command line editing, and | |
52 | interfaces directly with the GNU History library. @inforef{Top, History, | |
53 | history.info}, for more information. | |
54 | ||
55 | Readline uses a single initialization file, (@file{~/.inputrc}) which | |
56 | means that any program which uses Readline will present your customized | |
57 | version of Readline. @xref{Readline Init File} for details. | |
58 | ||
59 | In this section of the manual, we use a special syntax to describe | |
60 | keystrokes. | |
61 | ||
62 | The text @key{C-k} is read as `Control-K' and describes the character | |
63 | produced when the Control key is depressed and the @key{k} key is struck. | |
64 | ||
65 | The text @key{M-k} is read as `Meta-K' and describes the character | |
66 | produced when the meta key (if you have one) is depressed, and the @key{k} | |
67 | key is struck. If you do not have a meta key, the identical keystroke | |
68 | can be generated by typing @key{ESC} @i{first}, and then typing @key{k}. | |
69 | Either process is known as @dfn{metafying} the @key{k} key. | |
70 | ||
71 | The text @key{M-C-k} is read as `Meta-Control-k' and describes the | |
72 | character produced by @dfn{metafying} @key{C-k}. | |
73 | ||
74 | In addition, several keys have their own names. Specifically, | |
75 | @key{RUBOUT}, @key{DEL}, @key{ESC}, @key{NEWLINE}, @key{SPACE}, | |
76 | @key{RETURN}, @key{LFD}, and @key{TAB} all stand for themselves when | |
77 | seen in this text, or in an init file (@pxref{Readline Init File}, for | |
78 | more info). | |
79 | ||
80 | @node Readline Interaction, Readline Init File, Readline Introduction, Readline Top | |
81 | @section Readline Interaction | |
82 | @cindex interaction, readline | |
83 | ||
84 | Often during an interactive session you will type in a long line of | |
85 | text, only to notice that the first word on the line is misspelled. The | |
86 | Readline library gives you a set of commands for manipulating the text | |
87 | as you type it in, allowing you to just fix your typo, and not forcing | |
88 | you to retype the majority of the line. Using these editing commands, | |
89 | you move the cursor to the place that needs correction, and delete or | |
90 | insert the text of the corrections. Then, when you are satisfied with | |
91 | the line, you simply press @key{RETURN}. You do not have to be at the | |
92 | end of the line to press @key{RETURN}; the entire line will be accepted | |
93 | in any case. | |
94 | ||
95 | @menu | |
96 | * Readline Bare Essentials:: The least you need to know about Readline. | |
97 | * Readline Movement Commands:: Moving about the input line. | |
98 | * Readline Killing Commands:: How to delete text, and how to get it back! | |
99 | * Readline Arguments:: Giving numeric arguments to commands. | |
100 | @end menu | |
101 | ||
102 | @node Readline Bare Essentials, Readline Movement Commands, Readline Interaction, Readline Interaction | |
103 | @subsection Readline Bare Essentials | |
104 | ||
105 | As you type text into the line, you will notice that characters to the | |
106 | right of the cursor get `pushed over' to make room for the characters | |
107 | that you are typing. Likewise, when you delete a character behind the | |
108 | cursor, characters to the right of the cursor get `pulled back' to fill | |
109 | in the blank space created by the removal of the character. There is no | |
110 | `overwrite mode' provided by Readline; all characters are inserted. | |
111 | ||
112 | Here are the basic bare essentials for editing the text of an input line. | |
113 | ||
114 | @table @key | |
115 | @item C-b | |
116 | Move back one character. | |
117 | @item C-f | |
118 | Move forward one character. | |
119 | @item C-d | |
120 | Delete the character underneath the cursor. | |
121 | @item DEL | |
122 | Delete the character to the left of the cursor. | |
123 | @item printing character | |
124 | Insert itself into the line at the cursor. | |
125 | @item C-_ | |
126 | Undo the last thing that you did. You can undo all the way back to an | |
127 | empty line. | |
128 | @end table | |
129 | ||
130 | @node Readline Movement Commands, Readline Killing Commands, Readline Bare Essentials, Readline Interaction | |
131 | @subsection Readline Movement Commands | |
132 | ||
133 | The above table described the most basic possible keystrokes that you | |
134 | would need in order to do editing of the input line. For your | |
135 | convenience, many other commands have been added in addition to | |
136 | @key{C-b}, @key{C-f}, @key{C-d}, and @key{DEL}. Here are some | |
137 | commands for moving more rapidly about the line. | |
138 | ||
139 | @table @key | |
140 | @item C-a | |
141 | Move to the start of the line. | |
142 | @item C-e | |
143 | Move to the end of the line. | |
144 | @item M-f | |
145 | Move forward a word. | |
146 | @item M-b | |
147 | Move backward a word. | |
148 | @item C-l | |
149 | Clear the screen, reprinting the current line at the top. | |
150 | @end table | |
151 | ||
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. | |
155 | ||
156 | @node Readline Killing Commands, Readline Arguments, Readline Movement Commands, Readline Interaction | |
157 | @subsection Readline Killing Commands | |
158 | ||
159 | Now that we know how to move about the line, we might be interested in | |
160 | performing more sophisticated operations, such as moving a word from the | |
161 | front of the line to the end, or removing a mistyped argument to a | |
162 | command. | |
163 | ||
164 | @dfn{Killing} text means to delete the text from the line, but to save | |
165 | it away for later use, usually by @dfn{yanking} it back into the line. | |
166 | If the description for a command says that it `kills' text, then you can | |
167 | be sure that you can get the text back in a different (or the same) | |
168 | place later. | |
169 | ||
170 | Here is the list of commands for killing text. | |
171 | ||
172 | @table @key | |
173 | @item C-k | |
174 | Kill the text from the current cursor position to the end of the line. | |
175 | ||
176 | @item M-d | |
177 | Kill from the cursor to the end of the current word, or if between | |
178 | words, to the end of the next word. | |
179 | ||
180 | @item M-DEL | |
181 | Kill from the cursor to the start of the current word, or if between | |
182 | words, to the start of the previous word. | |
183 | ||
184 | @item C-w | |
185 | Kill from the cursor to the previous whitespace. This is different than | |
186 | @key{M-DEL} because the word boundaries differ. | |
187 | ||
188 | @end table | |
189 | ||
190 | And, here is how to @dfn{yank} the text back into the line. | |
191 | ||
192 | @table @key | |
193 | @item C-y | |
194 | Yank the most recently killed text back into the buffer at the cursor. | |
195 | ||
196 | @item M-y | |
197 | Rotate the kill-ring, and yank the new top. You can only do this if | |
198 | the prior command is @key{C-y} or @key{M-y}. | |
199 | @end table | |
200 | ||
201 | When you use a kill command, the text is saved in a @dfn{kill-ring}. | |
202 | Any number of consecutive kills save all of the killed text together, so | |
203 | that when you yank it back, you get it in one clean sweep. The kill | |
204 | ring is not line specific; the text that you killed on a previously | |
205 | typed line is available to be yanked back later, when you are typing | |
206 | another line. | |
207 | ||
208 | @node Readline Arguments, , Readline Killing Commands, Readline Interaction | |
209 | @subsection Readline Arguments | |
210 | ||
211 | You can pass numeric arguments to Readline commands. Sometimes the | |
212 | argument acts as a repeat count, other times it is the @i{sign} of the | |
213 | argument that is significant. If you pass a negative argument to a | |
214 | command which normally acts in a forward direction, that command will | |
215 | act in a backward direction. For example, to kill text back to the | |
216 | start of the line, you might type @key{M--} @key{C-k}. | |
217 | ||
218 | The general way to pass numeric arguments to a command is to type meta | |
219 | digits before the command. If the first `digit' you type is a minus | |
220 | sign (@key{-}), then the sign of the argument will be negative. Once | |
221 | you have typed one meta digit to get the argument started, you can type | |
222 | the remainder of the digits, and then the command. For example, to give | |
223 | the @key{C-d} command an argument of 10, you could type @key{M-1 0 C-d}. | |
224 | ||
225 | ||
226 | @node Readline Init File, , Readline Interaction, Readline Top | |
227 | @section Readline Init File | |
228 | ||
229 | Although the Readline library comes with a set of Emacs-like | |
230 | keybindings, it is possible that you would like to use a different set | |
231 | of keybindings. You can customize programs that use Readline by putting | |
232 | commands in an @dfn{init} file in your home directory. The name of this | |
233 | file is @file{~/.inputrc}. | |
234 | ||
235 | When a program which uses the Readline library starts up, the | |
236 | @file{~/.inputrc} file is read, and the keybindings are set. | |
237 | ||
238 | @menu | |
239 | * Readline Init Syntax:: Syntax for the commands in @file{~/.inputrc}. | |
240 | * Readline Vi Mode:: Switching to @code{vi} mode in Readline. | |
241 | @end menu | |
242 | ||
243 | @node Readline Init Syntax, Readline Vi Mode, Readline Init File, Readline Init File | |
244 | @subsection Readline Init Syntax | |
245 | ||
246 | You can start up with a vi-like editing mode by placing | |
247 | ||
248 | @example | |
249 | @code{set editing-mode vi} | |
250 | @end example | |
251 | ||
252 | in your @file{~/.inputrc} file. | |
253 | ||
254 | You can have Readline use a single line for display, scrolling the input | |
255 | between the two edges of the screen by placing | |
256 | ||
257 | @example | |
258 | @code{set horizontal-scroll-mode On} | |
259 | @end example | |
260 | ||
261 | in your @file{~/.inputrc} file. | |
262 | ||
263 | The syntax for controlling keybindings in the @file{~/.inputrc} file is | |
264 | simple. First you have to know the @i{name} of the command that you | |
265 | want to change. The following pages contain tables of the command name, the | |
266 | default keybinding, and a short description of what the command does. | |
267 | ||
268 | Once you know the name of the command, simply place the name of the key | |
269 | you wish to bind the command to, a colon, and then the name of the | |
270 | command on a line in the @file{~/.inputrc} file. Here is an example: | |
271 | ||
272 | @example | |
273 | # This is a comment line. | |
274 | Meta-Rubout: backward-kill-word | |
275 | Control-u: universal-argument | |
276 | @end example | |
277 | ||
278 | @menu | |
279 | * Commands For Moving:: Moving about the line. | |
280 | * Commands For History:: Getting at previous lines. | |
281 | * Commands For Text:: Commands for changing text. | |
282 | * Commands For Killing:: Commands for killing and yanking. | |
283 | * Numeric Arguments:: Specifying numeric arguments, repeat counts. | |
284 | * Commands For Completion:: Getting Readline to do the typing for you. | |
285 | * Miscellaneous Commands:: Other miscillaneous commands. | |
286 | @end menu | |
287 | ||
288 | @node Commands For Moving, Commands For History, Readline Init Syntax, Readline Init Syntax | |
289 | @subsubsection Commands For Moving | |
290 | @table @code | |
291 | @item beginning-of-line (C-a) | |
292 | Move to the start of the current line. | |
293 | ||
294 | @item end-of-line (C-e) | |
295 | Move to the end of the line. | |
296 | ||
297 | @item forward-char (C-f) | |
298 | Move forward a character. | |
299 | ||
300 | @item backward-char (C-b) | |
301 | Move back a character. | |
302 | ||
303 | @item forward-word (M-f) | |
304 | Move forward to the end of the next word. | |
305 | ||
306 | @item backward-word (M-b) | |
307 | Move back to the start of this, or the previous, word. | |
308 | ||
309 | @item clear-screen (C-l) | |
310 | Clear the screen leaving the current line at the top of the screen. | |
311 | ||
312 | @end table | |
313 | ||
314 | @node Commands For History, Commands For Text, Commands For Moving, Readline Init Syntax | |
315 | @subsubsection Commands For Manipulating The History | |
316 | ||
317 | @table @code | |
318 | @item accept-line (Newline, Return) | |
319 | Accept the line regardless of where the cursor is. If this line is | |
320 | non-empty, add it too the history list. If this line was a history | |
321 | line, then restore the history line to its original state. | |
322 | ||
323 | @item previous-history (C-p) | |
324 | Move `up' through the history list. | |
325 | ||
326 | @item next-history (C-n) | |
327 | Move `down' through the history list. | |
328 | ||
329 | @item beginning-of-history (M-<) | |
330 | Move to the first line in the history. | |
331 | ||
332 | @item end-of-history (M->) | |
333 | Move to the end of the input history, i.e., the line you are entering! | |
334 | ||
335 | @item reverse-search-history (C-r) | |
336 | Search backward starting at the current line and moving `up' through | |
337 | the history as necessary. This is an incremental search. | |
338 | ||
339 | @item forward-search-history (C-s) | |
340 | Search forward starting at the current line and moving `down' through | |
341 | the the history as neccessary. | |
342 | ||
343 | @end table | |
344 | ||
345 | @node Commands For Text, Commands For Killing, Commands For History, Readline Init Syntax | |
346 | @subsubsection Commands For Changing Text | |
347 | ||
348 | @table @code | |
349 | @item delete-char (C-d) | |
350 | Delete the character under the cursor. If the cursor is at the | |
351 | beginning of the line, and there are no characters in the line, and | |
352 | the last character typed was not C-d, then return EOF. | |
353 | ||
354 | @item backward-delete-char (Rubout) | |
355 | Delete the character behind the cursor. A numeric arg says to kill | |
356 | the characters instead of deleting them. | |
357 | ||
358 | @item quoted-insert (C-q, C-v) | |
359 | Add the next character that you type to the line verbatim. This is | |
360 | how to insert things like C-q for example. | |
361 | ||
362 | @item tab-insert (M-TAB) | |
363 | Insert a tab character. | |
364 | ||
365 | @item self-insert (a, b, A, 1, !, ...) | |
366 | Insert yourself. | |
367 | ||
368 | @item transpose-chars (C-t) | |
369 | Drag the character before point forward over the character at point. | |
370 | Point moves forward as well. If point is at the end of the line, then | |
371 | transpose the two characters before point. Negative args don't work. | |
372 | ||
373 | @item transpose-words (M-t) | |
374 | Drag the word behind the cursor past the word in front of the cursor | |
375 | moving the cursor over that word as well. | |
376 | ||
377 | @item upcase-word (M-u) | |
378 | Uppercase the current (or following) word. With a negative argument, | |
379 | do the previous word, but do not move point. | |
380 | ||
381 | @item downcase-word (M-l) | |
382 | Lowercase the current (or following) word. With a negative argument, | |
383 | do the previous word, but do not move point. | |
384 | ||
385 | @item capitalize-word (M-c) | |
386 | Uppercase the current (or following) word. With a negative argument, | |
387 | do the previous word, but do not move point. | |
388 | ||
389 | @end table | |
390 | ||
391 | @node Commands For Killing, Numeric Arguments, Commands For Text, Readline Init Syntax | |
392 | @subsubsection Killing And Yanking | |
393 | ||
394 | @table @code | |
395 | ||
396 | @item kill-line (C-k) | |
397 | Kill the text from the current cursor position to the end of the line. | |
398 | ||
399 | @item backward-kill-line () | |
400 | Kill backward to the beginning of the line. This is normally unbound. | |
401 | ||
402 | @item kill-word (M-d) | |
403 | Kill from the cursor to the end of the current word, or if between | |
404 | words, to the end of the next word. | |
405 | ||
406 | @item backward-kill-word (M-DEL) | |
407 | Kill the word behind the cursor. | |
408 | ||
409 | @item unix-line-discard (C-u) | |
410 | Do what C-u used to do in Unix line input. We save the killed text on | |
411 | the kill-ring, though. | |
412 | ||
413 | @item unix-word-rubout (C-w) | |
414 | Do what C-w used to do in Unix line input. The killed text is saved | |
415 | on the kill-ring. This is different than backward-kill-word because | |
416 | the word boundaries differ. | |
417 | ||
418 | @item yank (C-y) | |
419 | Yank the top of the kill ring into the buffer at point. | |
420 | ||
421 | @item yank-pop (M-y) | |
422 | Rotate the kill-ring, and yank the new top. You can only do this if | |
423 | the prior command is yank or yank-pop. | |
424 | @end table | |
425 | ||
426 | @node Numeric Arguments, Commands For Completion, Commands For Killing, Readline Init Syntax | |
427 | @subsubsection Specifying Numeric Arguments | |
428 | @table @code | |
429 | ||
430 | @item digit-argument (M-0, M-1, ... M--) | |
431 | Add this digit to the argument already accumulating, or start a new | |
432 | argument. M-- starts a negative argument. | |
433 | ||
434 | @item universal-argument () | |
435 | Do what C-u does in emacs. By default, this is not bound. | |
436 | @end table | |
437 | ||
438 | ||
439 | @node Commands For Completion, Miscellaneous Commands, Numeric Arguments, Readline Init Syntax | |
440 | @subsubsection Letting Readline Type For You | |
441 | ||
442 | @table @code | |
443 | @item complete (TAB) | |
444 | Attempt to do completion on the text before point. This is | |
445 | implementation defined. Generally, if you are typing a filename | |
446 | argument, you can do filename completion; if you are typing a command, | |
447 | you can do command completion, if you are typing in a symbol to GDB, you | |
448 | can do symbol name completion, if you are typing in a variable to Bash, | |
449 | you can do variable name completion... | |
450 | ||
451 | @item possible-completions (M-?) | |
452 | List the possible completions of the text before point. | |
453 | @end table | |
454 | ||
455 | @node Miscellaneous Commands, , Commands For Completion, Readline Init Syntax | |
456 | @subsubsection Some Miscellaneous Commands | |
457 | @table @code | |
458 | ||
459 | @item abort (C-g) | |
460 | Ding! Stops things. | |
461 | ||
462 | @item do-uppercase-version (M-a, M-b, ...) | |
463 | Run the command that is bound to your uppercase brother. | |
464 | ||
465 | @item prefix-meta (ESC) | |
466 | Make the next character that you type be metafied. This is for | |
467 | people without a meta key. @key{ESC-f} is equivalent to @key{M-f}. | |
468 | ||
469 | @item undo (C-_) | |
470 | Incremental undo, separately remembered for each line. | |
471 | ||
472 | @item revert-line (M-r) | |
473 | Undo all changes made to this line. This is like typing the `undo' | |
474 | command enough times to get back to the beginning. | |
475 | @end table | |
476 | ||
477 | @node Readline Vi Mode, , Readline Init Syntax, Readline Init File | |
478 | @subsection Readline Vi Mode | |
479 | ||
480 | While the Readline library does not have a full set of Vi editing | |
481 | functions, it does contain enough to allow simple editing of the line. | |
482 | ||
483 | In order to switch interactively between Emacs and Vi editing modes, use | |
484 | the command M-C-j (toggle-editing-mode). | |
485 | ||
486 | When you enter a line in Vi mode, you are already placed in `insertion' | |
487 | mode, as if you had typed an `i'. Pressing @key{ESC} switches you into | |
488 | `edit' mode, where you can edit the text of the line with the standard | |
489 | Vi movement keys, move to previous history lines with `k', and following | |
490 | lines with `j', and so forth. | |
491 | ||
492 | ||
493 | ||
494 |