1READLINE(3) Library Functions Manual READLINE(3)
2
6 readline - get a line from a user with editing
7
9 #include <stdio.h>
10 #include <readline/readline.h>
11 #include <readline/history.h>
12 char *
14 readline (const char *prompt);
15
17 Readline is Copyright (C) 1989-2020 Free Software Foundation, Inc.
18
20 readline will read a line from the terminal and return it, using prompt
21 as a prompt. If prompt is NULL or the empty string, no prompt is is‐
22 sued. The line returned is allocated with malloc(3); the caller must
23 free it when finished. The line returned has the final newline re‐
24 moved, so only the text of the line remains.
25 readline offers editing capabilities while the user is entering the
27 line. By default, the line editing commands are similar to those of
28 emacs. A vi-style line editing interface is also available.
29 This manual page describes only the most basic use of readline. Much
31 more functionality is available; see The GNU Readline Library and The
32 GNU History Library for additional information.
33
35 readline returns the text of the line read. A blank line returns the
36 empty string. If EOF is encountered while reading a line, and the line
37 is empty, NULL is returned. If an EOF is read with a non-empty line,
38 it is treated as a newline.
39
41 An Emacs-style notation is used to denote keystrokes. Control keys are
42 denoted by C-key, e.g., C-n means Control-N. Similarly, meta keys are
43 denoted by M-key, so M-x means Meta-X. (On keyboards without a meta
44 key, M-x means ESC x, i.e., press the Escape key then the x key. This
45 makes ESC the meta prefix. The combination M-C-x means ESC-Control-x,
46 or press the Escape key then hold the Control key while pressing the x
47 key.)
48 Readline commands may be given numeric arguments, which normally act as
50 a repeat count. Sometimes, however, it is the sign of the argument
51 that is significant. Passing a negative argument to a command that
52 acts in the forward direction (e.g., kill-line) causes that command to
53 act in a backward direction. Commands whose behavior with arguments
54 deviates from this are noted below.
55 When a command is described as killing text, the text deleted is saved
57 for possible future retrieval (yanking). The killed text is saved in a
58 kill ring. Consecutive kills cause the text to be accumulated into one
59 unit, which can be yanked all at once. Commands which do not kill text
60 separate the chunks of text on the kill ring.
61
63 Readline is customized by putting commands in an initialization file
64 (the inputrc file). The name of this file is taken from the value of
65 the INPUTRC environment variable. If that variable is unset, the de‐
66 fault is ~/.inputrc. If that file does not exist or cannot be read,
67 the ultimate default is /etc/inputrc. When a program which uses the
68 readline library starts up, the init file is read, and the key bindings
69 and variables are set. There are only a few basic constructs allowed
70 in the readline init file. Blank lines are ignored. Lines beginning
71 with a # are comments. Lines beginning with a $ indicate conditional
72 constructs. Other lines denote key bindings and variable settings.
73 Each program using this library may add its own commands and bindings.
74 For example, placing
76 M-Control-u: universal-argument
78 or
79 C-Meta-u: universal-argument
80 into the inputrc would make M-C-u execute the readline command univer‐
82 sal-argument.
83 The following symbolic character names are recognized while processing
85 key bindings: DEL, ESC, ESCAPE, LFD, NEWLINE, RET, RETURN, RUBOUT,
86 SPACE, SPC, and TAB.
87 In addition to command names, readline allows keys to be bound to a
89 string that is inserted when the key is pressed (a macro).
90 Key Bindings
92 The syntax for controlling key bindings in the inputrc file is simple.
93 All that is required is the name of the command or the text of a macro
94 and a key sequence to which it should be bound. The name may be speci‐
95 fied in one of two ways: as a symbolic key name, possibly with Meta- or
96 Control- prefixes, or as a key sequence. The name and key sequence are
97 separated by a colon. There can be no whitespace between the name and
98 the colon.
99 When using the form keyname:function-name or macro, keyname is the name
101 of a key spelled out in English. For example:
102 Control-u: universal-argument
104 Meta-Rubout: backward-kill-word
105 Control-o: "> output"
106 In the above example, C-u is bound to the function universal-argument,
108 M-DEL is bound to the function backward-kill-word, and C-o is bound to
109 run the macro expressed on the right hand side (that is, to insert the
110 text ``> output'' into the line).
111 In the second form, "keyseq":function-name or macro, keyseq differs
113 from keyname above in that strings denoting an entire key sequence may
114 be specified by placing the sequence within double quotes. Some GNU
115 Emacs style key escapes can be used, as in the following example, but
116 the symbolic character names are not recognized.
117 "\C-u": universal-argument
119 "\C-x\C-r": re-read-init-file
120 "\e[11~": "Function Key 1"
121 In this example, C-u is again bound to the function universal-argument.
123 C-x C-r is bound to the function re-read-init-file, and ESC [ 1 1 ~ is
124 bound to insert the text ``Function Key 1''.
125 The full set of GNU Emacs style escape sequences available when speci‐
127 fying key sequences is
128 \C- control prefix
129 \M- meta prefix
130 \e an escape character
131 \\ backslash
132 \" literal ", a double quote
133 \' literal ', a single quote
134 In addition to the GNU Emacs style escape sequences, a second set of
136 backslash escapes is available:
137 \a alert (bell)
138 \b backspace
139 \d delete
140 \f form feed
141 \n newline
142 \r carriage return
143 \t horizontal tab
144 \v vertical tab
145 \nnn the eight-bit character whose value is the octal value
146 nnn (one to three digits)
147 \xHH the eight-bit character whose value is the hexadecimal
148 value HH (one or two hex digits)
149 When entering the text of a macro, single or double quotes should be
151 used to indicate a macro definition. Unquoted text is assumed to be a
152 function name. In the macro body, the backslash escapes described
153 above are expanded. Backslash will quote any other character in the
154 macro text, including " and '.
155 Bash allows the current readline key bindings to be displayed or modi‐
157 fied with the bind builtin command. The editing mode may be switched
158 during interactive use by using the -o option to the set builtin com‐
159 mand. Other programs using this library provide similar mechanisms.
160 The inputrc file may be edited and re-read if a program does not pro‐
161 vide any other means to incorporate new bindings.
162 Variables
164 Readline has variables that can be used to further customize its behav‐
165 ior. A variable may be set in the inputrc file with a statement of the
166 form
167 set variable-name value
169 Except where noted, readline variables can take the values On or Off
171 (without regard to case). Unrecognized variable names are ignored.
172 When a variable value is read, empty or null values, "on" (case-insen‐
173 sitive), and "1" are equivalent to On. All other values are equivalent
174 to Off. The variables and their default values are:
175 bell-style (audible)
177 Controls what happens when readline wants to ring the terminal
178 bell. If set to none, readline never rings the bell. If set to
179 visible, readline uses a visible bell if one is available. If
180 set to audible, readline attempts to ring the terminal's bell.
181 bind-tty-special-chars (On)
182 If set to On (the default), readline attempts to bind the con‐
183 trol characters treated specially by the kernel's terminal
184 driver to their readline equivalents.
185 blink-matching-paren (Off)
186 If set to On, readline attempts to briefly move the cursor to an
187 opening parenthesis when a closing parenthesis is inserted.
188 colored-completion-prefix (Off)
189 If set to On, when listing completions, readline displays the
190 common prefix of the set of possible completions using a differ‐
191 ent color. The color definitions are taken from the value of
192 the LS_COLORS environment variable.
193 colored-stats (Off)
194 If set to On, readline displays possible completions using dif‐
195 ferent colors to indicate their file type. The color defini‐
196 tions are taken from the value of the LS_COLORS environment
197 variable.
198 comment-begin (``#'')
199 The string that is inserted in vi mode when the insert-comment
200 command is executed. This command is bound to M-# in emacs mode
201 and to # in vi command mode.
202 completion-display-width (-1)
203 The number of screen columns used to display possible matches
204 when performing completion. The value is ignored if it is less
205 than 0 or greater than the terminal screen width. A value of 0
206 will cause matches to be displayed one per line. The default
207 value is -1.
208 completion-ignore-case (Off)
209 If set to On, readline performs filename matching and completion
210 in a case-insensitive fashion.
211 completion-map-case (Off)
212 If set to On, and completion-ignore-case is enabled, readline
213 treats hyphens (-) and underscores (_) as equivalent when per‐
214 forming case-insensitive filename matching and completion.
215 completion-prefix-display-length (0)
216 The length in characters of the common prefix of a list of pos‐
217 sible completions that is displayed without modification. When
218 set to a value greater than zero, common prefixes longer than
219 this value are replaced with an ellipsis when displaying possi‐
220 ble completions.
221 completion-query-items (100)
222 This determines when the user is queried about viewing the num‐
223 ber of possible completions generated by the possible-comple‐
224 tions command. It may be set to any integer value greater than
225 or equal to zero. If the number of possible completions is
226 greater than or equal to the value of this variable, readline
227 will ask whether or not the user wishes to view them; otherwise
228 they are simply listed on the terminal. A negative value causes
229 readline to never ask.
230 convert-meta (On)
231 If set to On, readline will convert characters with the eighth
232 bit set to an ASCII key sequence by stripping the eighth bit and
233 prefixing it with an escape character (in effect, using escape
234 as the meta prefix). The default is On, but readline will set
235 it to Off if the locale contains eight-bit characters.
236 disable-completion (Off)
237 If set to On, readline will inhibit word completion. Completion
238 characters will be inserted into the line as if they had been
239 mapped to self-insert.
240 echo-control-characters (On)
241 When set to On, on operating systems that indicate they support
242 it, readline echoes a character corresponding to a signal gener‐
243 ated from the keyboard.
244 editing-mode (emacs)
245 Controls whether readline begins with a set of key bindings sim‐
246 ilar to Emacs or vi. editing-mode can be set to either emacs or
247 vi.
248 emacs-mode-string (@)
249 If the show-mode-in-prompt variable is enabled, this string is
250 displayed immediately before the last line of the primary prompt
251 when emacs editing mode is active. The value is expanded like a
252 key binding, so the standard set of meta- and control prefixes
253 and backslash escape sequences is available. Use the \1 and \2
254 escapes to begin and end sequences of non-printing characters,
255 which can be used to embed a terminal control sequence into the
256 mode string.
257 enable-bracketed-paste (On)
258 When set to On, readline will configure the terminal in a way
259 that will enable it to insert each paste into the editing buffer
260 as a single string of characters, instead of treating each char‐
261 acter as if it had been read from the keyboard. This can pre‐
262 vent pasted characters from being interpreted as editing com‐
263 mands.
264 enable-keypad (Off)
265 When set to On, readline will try to enable the application key‐
266 pad when it is called. Some systems need this to enable the ar‐
267 row keys.
268 enable-meta-key (On)
269 When set to On, readline will try to enable any meta modifier
270 key the terminal claims to support when it is called. On many
271 terminals, the meta key is used to send eight-bit characters.
272 expand-tilde (Off)
273 If set to On, tilde expansion is performed when readline at‐
274 tempts word completion.
275 history-preserve-point (Off)
276 If set to On, the history code attempts to place point at the
277 same location on each history line retrieved with previous-his‐
278 tory or next-history.
279 history-size (unset)
280 Set the maximum number of history entries saved in the history
281 list. If set to zero, any existing history entries are deleted
282 and no new entries are saved. If set to a value less than zero,
283 the number of history entries is not limited. By default, the
284 number of history entries is not limited. If an attempt is made
285 to set history-size to a non-numeric value, the maximum number
286 of history entries will be set to 500.
287 horizontal-scroll-mode (Off)
288 When set to On, makes readline use a single line for display,
289 scrolling the input horizontally on a single screen line when it
290 becomes longer than the screen width rather than wrapping to a
291 new line. This setting is automatically enabled for terminals
292 of height 1.
293 input-meta (Off)
294 If set to On, readline will enable eight-bit input (that is, it
295 will not clear the eighth bit in the characters it reads), re‐
296 gardless of what the terminal claims it can support. The name
297 meta-flag is a synonym for this variable. The default is Off,
298 but readline will set it to On if the locale contains eight-bit
299 characters.
300 isearch-terminators (``C-[ C-J'')
301 The string of characters that should terminate an incremental
302 search without subsequently executing the character as a com‐
303 mand. If this variable has not been given a value, the charac‐
304 ters ESC and C-J will terminate an incremental search.
305 keymap (emacs)
306 Set the current readline keymap. The set of legal keymap names
307 is emacs, emacs-standard, emacs-meta, emacs-ctlx, vi, vi-move,
308 vi-command, and vi-insert. vi is equivalent to vi-command;
309 emacs is equivalent to emacs-standard. The default value is
310 emacs. The value of editing-mode also affects the default
311 keymap.
312 keyseq-timeout (500)
313 Specifies the duration readline will wait for a character when
314 reading an ambiguous key sequence (one that can form a complete
315 key sequence using the input read so far, or can take additional
316 input to complete a longer key sequence). If no input is re‐
317 ceived within the timeout, readline will use the shorter but
318 complete key sequence. The value is specified in milliseconds,
319 so a value of 1000 means that readline will wait one second for
320 additional input. If this variable is set to a value less than
321 or equal to zero, or to a non-numeric value, readline will wait
322 until another key is pressed to decide which key sequence to
323 complete.
324 mark-directories (On)
325 If set to On, completed directory names have a slash appended.
326 mark-modified-lines (Off)
327 If set to On, history lines that have been modified are dis‐
328 played with a preceding asterisk (*).
329 mark-symlinked-directories (Off)
330 If set to On, completed names which are symbolic links to direc‐
331 tories have a slash appended (subject to the value of mark-di‐
332 rectories).
333 match-hidden-files (On)
334 This variable, when set to On, causes readline to match files
335 whose names begin with a `.' (hidden files) when performing
336 filename completion. If set to Off, the leading `.' must be
337 supplied by the user in the filename to be completed.
338 menu-complete-display-prefix (Off)
339 If set to On, menu completion displays the common prefix of the
340 list of possible completions (which may be empty) before cycling
341 through the list.
342 output-meta (Off)
343 If set to On, readline will display characters with the eighth
344 bit set directly rather than as a meta-prefixed escape sequence.
345 The default is Off, but readline will set it to On if the locale
346 contains eight-bit characters.
347 page-completions (On)
348 If set to On, readline uses an internal more-like pager to dis‐
349 play a screenful of possible completions at a time.
350 print-completions-horizontally (Off)
351 If set to On, readline will display completions with matches
352 sorted horizontally in alphabetical order, rather than down the
353 screen.
354 revert-all-at-newline (Off)
355 If set to On, readline will undo all changes to history lines
356 before returning when accept-line is executed. By default, his‐
357 tory lines may be modified and retain individual undo lists
358 across calls to readline.
359 show-all-if-ambiguous (Off)
360 This alters the default behavior of the completion functions.
361 If set to On, words which have more than one possible completion
362 cause the matches to be listed immediately instead of ringing
363 the bell.
364 show-all-if-unmodified (Off)
365 This alters the default behavior of the completion functions in
366 a fashion similar to show-all-if-ambiguous. If set to On, words
367 which have more than one possible completion without any possi‐
368 ble partial completion (the possible completions don't share a
369 common prefix) cause the matches to be listed immediately in‐
370 stead of ringing the bell.
371 show-mode-in-prompt (Off)
372 If set to On, add a string to the beginning of the prompt indi‐
373 cating the editing mode: emacs, vi command, or vi insertion.
374 The mode strings are user-settable (e.g., emacs-mode-string).
375 skip-completed-text (Off)
376 If set to On, this alters the default completion behavior when
377 inserting a single match into the line. It's only active when
378 performing completion in the middle of a word. If enabled,
379 readline does not insert characters from the completion that
380 match characters after point in the word being completed, so
381 portions of the word following the cursor are not duplicated.
382 vi-cmd-mode-string ((cmd))
383 If the show-mode-in-prompt variable is enabled, this string is
384 displayed immediately before the last line of the primary prompt
385 when vi editing mode is active and in command mode. The value
386 is expanded like a key binding, so the standard set of meta- and
387 control prefixes and backslash escape sequences is available.
388 Use the \1 and \2 escapes to begin and end sequences of non-
389 printing characters, which can be used to embed a terminal con‐
390 trol sequence into the mode string.
391 vi-ins-mode-string ((ins))
392 If the show-mode-in-prompt variable is enabled, this string is
393 displayed immediately before the last line of the primary prompt
394 when vi editing mode is active and in insertion mode. The value
395 is expanded like a key binding, so the standard set of meta- and
396 control prefixes and backslash escape sequences is available.
397 Use the \1 and \2 escapes to begin and end sequences of non-
398 printing characters, which can be used to embed a terminal con‐
399 trol sequence into the mode string.
400 visible-stats (Off)
401 If set to On, a character denoting a file's type as reported by
402 stat(2) is appended to the filename when listing possible com‐
403 pletions.
404 Conditional Constructs
406 Readline implements a facility similar in spirit to the conditional
407 compilation features of the C preprocessor which allows key bindings
408 and variable settings to be performed as the result of tests. There
409 are four parser directives used.
410 $if The $if construct allows bindings to be made based on the edit‐
412 ing mode, the terminal being used, or the application using
413 readline. The text of the test, after any comparison operator,
414 extends to the end of the line; unless otherwise noted, no char‐
415 acters are required to isolate it.
416 mode The mode= form of the $if directive is used to test
418 whether readline is in emacs or vi mode. This may be
419 used in conjunction with the set keymap command, for in‐
420 stance, to set bindings in the emacs-standard and emacs-
421 ctlx keymaps only if readline is starting out in emacs
422 mode.
423 term The term= form may be used to include terminal-specific
425 key bindings, perhaps to bind the key sequences output by
426 the terminal's function keys. The word on the right side
427 of the = is tested against the full name of the terminal
428 and the portion of the terminal name before the first -.
429 This allows sun to match both sun and sun-cmd, for in‐
430 stance.
431 version
433 The version test may be used to perform comparisons
434 against specific readline versions. The version expands
435 to the current readline version. The set of comparison
436 operators includes =, (and ==), !=, <=, >=, <, and >.
437 The version number supplied on the right side of the op‐
438 erator consists of a major version number, an optional
439 decimal point, and an optional minor version (e.g., 7.1).
440 If the minor version is omitted, it is assumed to be 0.
441 The operator may be separated from the string version and
442 from the version number argument by whitespace.
443 application
445 The application construct is used to include application-
446 specific settings. Each program using the readline li‐
447 brary sets the application name, and an initialization
448 file can test for a particular value. This could be used
449 to bind key sequences to functions useful for a specific
450 program. For instance, the following command adds a key
451 sequence that quotes the current or previous word in
452 bash:
453 $if Bash
455 # Quote the current or previous word
456 "\C-xq": "\eb\"\ef\""
457 $endif
458 variable
460 The variable construct provides simple equality tests for
461 readline variables and values. The permitted comparison
462 operators are =, ==, and !=. The variable name must be
463 separated from the comparison operator by whitespace; the
464 operator may be separated from the value on the right
465 hand side by whitespace. Both string and boolean vari‐
466 ables may be tested. Boolean variables must be tested
467 against the values on and off.
468 $endif This command, as seen in the previous example, terminates an $if
470 command.
471 $else Commands in this branch of the $if directive are executed if the
473 test fails.
474 $include
476 This directive takes a single filename as an argument and reads
477 commands and bindings from that file. For example, the follow‐
478 ing directive would read /etc/inputrc:
479 $include /etc/inputrc
481
483 Readline provides commands for searching through the command history
484 for lines containing a specified string. There are two search modes:
485 incremental and non-incremental.
486 Incremental searches begin before the user has finished typing the
488 search string. As each character of the search string is typed, read‐
489 line displays the next entry from the history matching the string typed
490 so far. An incremental search requires only as many characters as
491 needed to find the desired history entry. To search backward in the
492 history for a particular string, type C-r. Typing C-s searches forward
493 through the history. The characters present in the value of the
494 isearch-terminators variable are used to terminate an incremental
495 search. If that variable has not been assigned a value the Escape and
496 C-J characters will terminate an incremental search. C-G will abort an
497 incremental search and restore the original line. When the search is
498 terminated, the history entry containing the search string becomes the
499 current line.
500 To find other matching entries in the history list, type C-s or C-r as
502 appropriate. This will search backward or forward in the history for
503 the next line matching the search string typed so far. Any other key
504 sequence bound to a readline command will terminate the search and exe‐
505 cute that command. For instance, a newline will terminate the search
506 and accept the line, thereby executing the command from the history
507 list. A movement command will terminate the search, make the last line
508 found the current line, and begin editing.
509 Non-incremental searches read the entire search string before starting
511 to search for matching history lines. The search string may be typed
512 by the user or be part of the contents of the current line.
513
515 The following is a list of the names of the commands and the default
516 key sequences to which they are bound. Command names without an accom‐
517 panying key sequence are unbound by default.
518 In the following descriptions, point refers to the current cursor posi‐
520 tion, and mark refers to a cursor position saved by the set-mark com‐
521 mand. The text between the point and mark is referred to as the re‐
522 gion.
523 Commands for Moving
525 beginning-of-line (C-a)
526 Move to the start of the current line.
527 end-of-line (C-e)
528 Move to the end of the line.
529 forward-char (C-f)
530 Move forward a character.
531 backward-char (C-b)
532 Move back a character.
533 forward-word (M-f)
534 Move forward to the end of the next word. Words are composed of
535 alphanumeric characters (letters and digits).
536 backward-word (M-b)
537 Move back to the start of the current or previous word. Words
538 are composed of alphanumeric characters (letters and digits).
539 previous-screen-line
540 Attempt to move point to the same physical screen column on the
541 previous physical screen line. This will not have the desired
542 effect if the current Readline line does not take up more than
543 one physical line or if point is not greater than the length of
544 the prompt plus the screen width.
545 next-screen-line
546 Attempt to move point to the same physical screen column on the
547 next physical screen line. This will not have the desired effect
548 if the current Readline line does not take up more than one
549 physical line or if the length of the current Readline line is
550 not greater than the length of the prompt plus the screen width.
551 clear-display (M-C-l)
552 Clear the screen and, if possible, the terminal's scrollback
553 buffer, then redraw the current line, leaving the current line
554 at the top of the screen.
555 clear-screen (C-l)
556 Clear the screen, then redraw the current line, leaving the cur‐
557 rent line at the top of the screen. With an argument, refresh
558 the current line without clearing the screen.
559 redraw-current-line
560 Refresh the current line.
561 Commands for Manipulating the History
563 accept-line (Newline, Return)
564 Accept the line regardless of where the cursor is. If this line
565 is non-empty, it may be added to the history list for future re‐
566 call with add_history(). If the line is a modified history
567 line, the history line is restored to its original state.
568 previous-history (C-p)
569 Fetch the previous command from the history list, moving back in
570 the list.
571 next-history (C-n)
572 Fetch the next command from the history list, moving forward in
573 the list.
574 beginning-of-history (M-<)
575 Move to the first line in the history.
576 end-of-history (M->)
577 Move to the end of the input history, i.e., the line currently
578 being entered.
579 reverse-search-history (C-r)
580 Search backward starting at the current line and moving `up'
581 through the history as necessary. This is an incremental
582 search.
583 forward-search-history (C-s)
584 Search forward starting at the current line and moving `down'
585 through the history as necessary. This is an incremental
586 search.
587 non-incremental-reverse-search-history (M-p)
588 Search backward through the history starting at the current line
589 using a non-incremental search for a string supplied by the
590 user.
591 non-incremental-forward-search-history (M-n)
592 Search forward through the history using a non-incremental
593 search for a string supplied by the user.
594 history-search-backward
595 Search backward through the history for the string of characters
596 between the start of the current line and the current cursor po‐
597 sition (the point). The search string must match at the begin‐
598 ning of a history line. This is a non-incremental search.
599 history-search-forward
600 Search forward through the history for the string of characters
601 between the start of the current line and the point. The search
602 string must match at the beginning of a history line. This is a
603 non-incremental search.
604 history-substring-search-backward
605 Search backward through the history for the string of characters
606 between the start of the current line and the current cursor po‐
607 sition (the point). The search string may match anywhere in a
608 history line. This is a non-incremental search.
609 history-substring-search-forward
610 Search forward through the history for the string of characters
611 between the start of the current line and the point. The search
612 string may match anywhere in a history line. This is a non-in‐
613 cremental search.
614 yank-nth-arg (M-C-y)
615 Insert the first argument to the previous command (usually the
616 second word on the previous line) at point. With an argument n,
617 insert the nth word from the previous command (the words in the
618 previous command begin with word 0). A negative argument in‐
619 serts the nth word from the end of the previous command. Once
620 the argument n is computed, the argument is extracted as if the
621 "!n" history expansion had been specified.
622 yank-last-arg (M-., M-_)
623 Insert the last argument to the previous command (the last word
624 of the previous history entry). With a numeric argument, behave
625 exactly like yank-nth-arg. Successive calls to yank-last-arg
626 move back through the history list, inserting the last word (or
627 the word specified by the argument to the first call) of each
628 line in turn. Any numeric argument supplied to these successive
629 calls determines the direction to move through the history. A
630 negative argument switches the direction through the history
631 (back or forward). The history expansion facilities are used to
632 extract the last argument, as if the "!$" history expansion had
633 been specified.
634 operate-and-get-next (C-o)
635 Accept the current line for return to the calling application as
636 if a newline had been entered, and fetch the next line relative
637 to the current line from the history for editing. A numeric ar‐
638 gument, if supplied, specifies the history entry to use instead
639 of the current line.
640 Commands for Changing Text
642 end-of-file (usually C-d)
643 The character indicating end-of-file as set, for example, by
644 ``stty''. If this character is read when there are no charac‐
645 ters on the line, and point is at the beginning of the line,
646 Readline interprets it as the end of input and returns EOF.
647 delete-char (C-d)
648 Delete the character at point. If this function is bound to the
649 same character as the tty EOF character, as C-d commonly is, see
650 above for the effects.
651 backward-delete-char (Rubout)
652 Delete the character behind the cursor. When given a numeric
653 argument, save the deleted text on the kill ring.
654 forward-backward-delete-char
655 Delete the character under the cursor, unless the cursor is at
656 the end of the line, in which case the character behind the cur‐
657 sor is deleted.
658 quoted-insert (C-q, C-v)
659 Add the next character that you type to the line verbatim. This
660 is how to insert characters like C-q, for example.
661 tab-insert (M-TAB)
662 Insert a tab character.
663 self-insert (a, b, A, 1, !, ...)
664 Insert the character typed.
665 transpose-chars (C-t)
666 Drag the character before point forward over the character at
667 point, moving point forward as well. If point is at the end of
668 the line, then this transposes the two characters before point.
669 Negative arguments have no effect.
670 transpose-words (M-t)
671 Drag the word before point past the word after point, moving
672 point over that word as well. If point is at the end of the
673 line, this transposes the last two words on the line.
674 upcase-word (M-u)
675 Uppercase the current (or following) word. With a negative ar‐
676 gument, uppercase the previous word, but do not move point.
677 downcase-word (M-l)
678 Lowercase the current (or following) word. With a negative ar‐
679 gument, lowercase the previous word, but do not move point.
680 capitalize-word (M-c)
681 Capitalize the current (or following) word. With a negative ar‐
682 gument, capitalize the previous word, but do not move point.
683 overwrite-mode
684 Toggle overwrite mode. With an explicit positive numeric argu‐
685 ment, switches to overwrite mode. With an explicit non-positive
686 numeric argument, switches to insert mode. This command affects
687 only emacs mode; vi mode does overwrite differently. Each call
688 to readline() starts in insert mode. In overwrite mode, charac‐
689 ters bound to self-insert replace the text at point rather than
690 pushing the text to the right. Characters bound to back‐
691 ward-delete-char replace the character before point with a
692 space. By default, this command is unbound.
693 Killing and Yanking
695 kill-line (C-k)
696 Kill the text from point to the end of the line.
697 backward-kill-line (C-x Rubout)
698 Kill backward to the beginning of the line.
699 unix-line-discard (C-u)
700 Kill backward from point to the beginning of the line. The
701 killed text is saved on the kill-ring.
702 kill-whole-line
703 Kill all characters on the current line, no matter where point
704 is.
705 kill-word (M-d)
706 Kill from point the end of the current word, or if between
707 words, to the end of the next word. Word boundaries are the
708 same as those used by forward-word.
709 backward-kill-word (M-Rubout)
710 Kill the word behind point. Word boundaries are the same as
711 those used by backward-word.
712 unix-word-rubout (C-w)
713 Kill the word behind point, using white space as a word bound‐
714 ary. The killed text is saved on the kill-ring.
715 unix-filename-rubout
716 Kill the word behind point, using white space and the slash
717 character as the word boundaries. The killed text is saved on
718 the kill-ring.
719 delete-horizontal-space (M-\)
720 Delete all spaces and tabs around point.
721 kill-region
722 Kill the text between the point and mark (saved cursor posi‐
723 tion). This text is referred to as the region.
724 copy-region-as-kill
725 Copy the text in the region to the kill buffer.
726 copy-backward-word
727 Copy the word before point to the kill buffer. The word bound‐
728 aries are the same as backward-word.
729 copy-forward-word
730 Copy the word following point to the kill buffer. The word
731 boundaries are the same as forward-word.
732 yank (C-y)
733 Yank the top of the kill ring into the buffer at point.
734 yank-pop (M-y)
735 Rotate the kill ring, and yank the new top. Only works follow‐
736 ing yank or yank-pop.
737 Numeric Arguments
739 digit-argument (M-0, M-1, ..., M--)
740 Add this digit to the argument already accumulating, or start a
741 new argument. M-- starts a negative argument.
742 universal-argument
743 This is another way to specify an argument. If this command is
744 followed by one or more digits, optionally with a leading minus
745 sign, those digits define the argument. If the command is fol‐
746 lowed by digits, executing universal-argument again ends the nu‐
747 meric argument, but is otherwise ignored. As a special case, if
748 this command is immediately followed by a character that is nei‐
749 ther a digit or minus sign, the argument count for the next com‐
750 mand is multiplied by four. The argument count is initially
751 one, so executing this function the first time makes the argu‐
752 ment count four, a second time makes the argument count sixteen,
753 and so on.
754 Completing
756 complete (TAB)
757 Attempt to perform completion on the text before point. The ac‐
758 tual completion performed is application-specific. Bash, for
759 instance, attempts completion treating the text as a variable
760 (if the text begins with $), username (if the text begins with
761 ~), hostname (if the text begins with @), or command (including
762 aliases and functions) in turn. If none of these produces a
763 match, filename completion is attempted. Gdb, on the other
764 hand, allows completion of program functions and variables, and
765 only attempts filename completion under certain circumstances.
766 possible-completions (M-?)
767 List the possible completions of the text before point. When
768 displaying completions, readline sets the number of columns used
769 for display to the value of completion-display-width, the value
770 of the environment variable COLUMNS, or the screen width, in
771 that order.
772 insert-completions (M-*)
773 Insert all completions of the text before point that would have
774 been generated by possible-completions.
775 menu-complete
776 Similar to complete, but replaces the word to be completed with
777 a single match from the list of possible completions. Repeated
778 execution of menu-complete steps through the list of possible
779 completions, inserting each match in turn. At the end of the
780 list of completions, the bell is rung (subject to the setting of
781 bell-style) and the original text is restored. An argument of n
782 moves n positions forward in the list of matches; a negative ar‐
783 gument may be used to move backward through the list. This com‐
784 mand is intended to be bound to TAB, but is unbound by default.
785 menu-complete-backward
786 Identical to menu-complete, but moves backward through the list
787 of possible completions, as if menu-complete had been given a
788 negative argument. This command is unbound by default.
789 delete-char-or-list
790 Deletes the character under the cursor if not at the beginning
791 or end of the line (like delete-char). If at the end of the
792 line, behaves identically to possible-completions.
793 Keyboard Macros
795 start-kbd-macro (C-x ()
796 Begin saving the characters typed into the current keyboard
797 macro.
798 end-kbd-macro (C-x ))
799 Stop saving the characters typed into the current keyboard macro
800 and store the definition.
801 call-last-kbd-macro (C-x e)
802 Re-execute the last keyboard macro defined, by making the char‐
803 acters in the macro appear as if typed at the keyboard.
804 print-last-kbd-macro ()
805 Print the last keyboard macro defined in a format suitable for
806 the inputrc file.
807 Miscellaneous
809 re-read-init-file (C-x C-r)
810 Read in the contents of the inputrc file, and incorporate any
811 bindings or variable assignments found there.
812 abort (C-g)
813 Abort the current editing command and ring the terminal's bell
814 (subject to the setting of bell-style).
815 do-lowercase-version (M-A, M-B, M-x, ...)
816 If the metafied character x is uppercase, run the command that
817 is bound to the corresponding metafied lowercase character. The
818 behavior is undefined if x is already lowercase.
819 prefix-meta (ESC)
820 Metafy the next character typed. ESC f is equivalent to Meta-f.
821 undo (C-_, C-x C-u)
822 Incremental undo, separately remembered for each line.
823 revert-line (M-r)
824 Undo all changes made to this line. This is like executing the
825 undo command enough times to return the line to its initial
826 state.
827 tilde-expand (M-&)
828 Perform tilde expansion on the current word.
829 set-mark (C-@, M-<space>)
830 Set the mark to the point. If a numeric argument is supplied,
831 the mark is set to that position.
832 exchange-point-and-mark (C-x C-x)
833 Swap the point with the mark. The current cursor position is
834 set to the saved position, and the old cursor position is saved
835 as the mark.
836 character-search (C-])
837 A character is read and point is moved to the next occurrence of
838 that character. A negative count searches for previous occur‐
839 rences.
840 character-search-backward (M-C-])
841 A character is read and point is moved to the previous occur‐
842 rence of that character. A negative count searches for subse‐
843 quent occurrences.
844 skip-csi-sequence
845 Read enough characters to consume a multi-key sequence such as
846 those defined for keys like Home and End. Such sequences begin
847 with a Control Sequence Indicator (CSI), usually ESC-[. If this
848 sequence is bound to "\[", keys producing such sequences will
849 have no effect unless explicitly bound to a readline command,
850 instead of inserting stray characters into the editing buffer.
851 This is unbound by default, but usually bound to ESC-[.
852 insert-comment (M-#)
853 Without a numeric argument, the value of the readline com‐
854 ment-begin variable is inserted at the beginning of the current
855 line. If a numeric argument is supplied, this command acts as a
856 toggle: if the characters at the beginning of the line do not
857 match the value of comment-begin, the value is inserted, other‐
858 wise the characters in comment-begin are deleted from the begin‐
859 ning of the line. In either case, the line is accepted as if a
860 newline had been typed. The default value of comment-begin
861 makes the current line a shell comment. If a numeric argument
862 causes the comment character to be removed, the line will be ex‐
863 ecuted by the shell.
864 dump-functions
865 Print all of the functions and their key bindings to the read‐
866 line output stream. If a numeric argument is supplied, the out‐
867 put is formatted in such a way that it can be made part of an
868 inputrc file.
869 dump-variables
870 Print all of the settable variables and their values to the
871 readline output stream. If a numeric argument is supplied, the
872 output is formatted in such a way that it can be made part of an
873 inputrc file.
874 dump-macros
875 Print all of the readline key sequences bound to macros and the
876 strings they output. If a numeric argument is supplied, the
877 output is formatted in such a way that it can be made part of an
878 inputrc file.
879 emacs-editing-mode (C-e)
880 When in vi command mode, this causes a switch to emacs editing
881 mode.
882 vi-editing-mode (M-C-j)
883 When in emacs editing mode, this causes a switch to vi editing
884 mode.
885
887 The following is a list of the default emacs and vi bindings. Charac‐
888 ters with the eighth bit set are written as M-<character>, and are re‐
889 ferred to as metafied characters. The printable ASCII characters not
890 mentioned in the list of emacs standard bindings are bound to the
891 self-insert function, which just inserts the given character into the
892 input line. In vi insertion mode, all characters not specifically men‐
893 tioned are bound to self-insert. Characters assigned to signal genera‐
894 tion by stty(1) or the terminal driver, such as C-Z or C-C, retain that
895 function. Upper and lower case metafied characters are bound to the
896 same function in the emacs mode meta keymap. The remaining characters
897 are unbound, which causes readline to ring the bell (subject to the
898 setting of the bell-style variable).
899 Emacs Mode
901 Emacs Standard bindings
902 "C-@" set-mark
904 "C-A" beginning-of-line
905 "C-B" backward-char
906 "C-D" delete-char
907 "C-E" end-of-line
908 "C-F" forward-char
909 "C-G" abort
910 "C-H" backward-delete-char
911 "C-I" complete
912 "C-J" accept-line
913 "C-K" kill-line
914 "C-L" clear-screen
915 "C-M" accept-line
916 "C-N" next-history
917 "C-P" previous-history
918 "C-Q" quoted-insert
919 "C-R" reverse-search-history
920 "C-S" forward-search-history
921 "C-T" transpose-chars
922 "C-U" unix-line-discard
923 "C-V" quoted-insert
924 "C-W" unix-word-rubout
925 "C-Y" yank
926 "C-]" character-search
927 "C-_" undo
928 " " to "/" self-insert
929 "0" to "9" self-insert
930 ":" to "~" self-insert
931 "C-?" backward-delete-char
932 Emacs Meta bindings
934 "M-C-G" abort
936 "M-C-H" backward-kill-word
937 "M-C-I" tab-insert
938 "M-C-J" vi-editing-mode
939 "M-C-L" clear-display
940 "M-C-M" vi-editing-mode
941 "M-C-R" revert-line
942 "M-C-Y" yank-nth-arg
943 "M-C-[" complete
944 "M-C-]" character-search-backward
945 "M-space" set-mark
946 "M-#" insert-comment
947 "M-&" tilde-expand
948 "M-*" insert-completions
949 "M--" digit-argument
950 "M-." yank-last-arg
951 "M-0" digit-argument
952 "M-1" digit-argument
953 "M-2" digit-argument
954 "M-3" digit-argument
955 "M-4" digit-argument
956 "M-5" digit-argument
957 "M-6" digit-argument
958 "M-7" digit-argument
959 "M-8" digit-argument
960 "M-9" digit-argument
961 "M-<" beginning-of-history
962 "M-=" possible-completions
963 "M->" end-of-history
964 "M-?" possible-completions
965 "M-B" backward-word
966 "M-C" capitalize-word
967 "M-D" kill-word
968 "M-F" forward-word
969 "M-L" downcase-word
970 "M-N" non-incremental-forward-search-history
971 "M-P" non-incremental-reverse-search-history
972 "M-R" revert-line
973 "M-T" transpose-words
974 "M-U" upcase-word
975 "M-Y" yank-pop
976 "M-\" delete-horizontal-space
977 "M-~" tilde-expand
978 "M-C-?" backward-kill-word
979 "M-_" yank-last-arg
980 Emacs Control-X bindings
982 "C-XC-G" abort
984 "C-XC-R" re-read-init-file
985 "C-XC-U" undo
986 "C-XC-X" exchange-point-and-mark
987 "C-X(" start-kbd-macro
988 "C-X)" end-kbd-macro
989 "C-XE" call-last-kbd-macro
990 "C-XC-?" backward-kill-line
991 VI Mode bindings
994 VI Insert Mode functions
995 "C-D" vi-eof-maybe
997 "C-H" backward-delete-char
998 "C-I" complete
999 "C-J" accept-line
1000 "C-M" accept-line
1001 "C-R" reverse-search-history
1002 "C-S" forward-search-history
1003 "C-T" transpose-chars
1004 "C-U" unix-line-discard
1005 "C-V" quoted-insert
1006 "C-W" unix-word-rubout
1007 "C-Y" yank
1008 "C-[" vi-movement-mode
1009 "C-_" undo
1010 " " to "~" self-insert
1011 "C-?" backward-delete-char
1012 VI Command Mode functions
1014 "C-D" vi-eof-maybe
1016 "C-E" emacs-editing-mode
1017 "C-G" abort
1018 "C-H" backward-char
1019 "C-J" accept-line
1020 "C-K" kill-line
1021 "C-L" clear-screen
1022 "C-M" accept-line
1023 "C-N" next-history
1024 "C-P" previous-history
1025 "C-Q" quoted-insert
1026 "C-R" reverse-search-history
1027 "C-S" forward-search-history
1028 "C-T" transpose-chars
1029 "C-U" unix-line-discard
1030 "C-V" quoted-insert
1031 "C-W" unix-word-rubout
1032 "C-Y" yank
1033 "C-_" vi-undo
1034 " " forward-char
1035 "#" insert-comment
1036 "$" end-of-line
1037 "%" vi-match
1038 "&" vi-tilde-expand
1039 "*" vi-complete
1040 "+" next-history
1041 "," vi-char-search
1042 "-" previous-history
1043 "." vi-redo
1044 "/" vi-search
1045 "0" beginning-of-line
1046 "1" to "9" vi-arg-digit
1047 ";" vi-char-search
1048 "=" vi-complete
1049 "?" vi-search
1050 "A" vi-append-eol
1051 "B" vi-prev-word
1052 "C" vi-change-to
1053 "D" vi-delete-to
1054 "E" vi-end-word
1055 "F" vi-char-search
1056 "G" vi-fetch-history
1057 "I" vi-insert-beg
1058 "N" vi-search-again
1059 "P" vi-put
1060 "R" vi-replace
1061 "S" vi-subst
1062 "T" vi-char-search
1063 "U" revert-line
1064 "W" vi-next-word
1065 "X" backward-delete-char
1066 "Y" vi-yank-to
1067 "\" vi-complete
1068 "^" vi-first-print
1069 "_" vi-yank-arg
1070 "`" vi-goto-mark
1071 "a" vi-append-mode
1072 "b" vi-prev-word
1073 "c" vi-change-to
1074 "d" vi-delete-to
1075 "e" vi-end-word
1076 "f" vi-char-search
1077 "h" backward-char
1078 "i" vi-insertion-mode
1079 "j" next-history
1080 "k" prev-history
1081 "l" forward-char
1082 "m" vi-set-mark
1083 "n" vi-search-again
1084 "p" vi-put
1085 "r" vi-change-char
1086 "s" vi-subst
1087 "t" vi-char-search
1088 "u" vi-undo
1089 "w" vi-next-word
1090 "x" vi-delete
1091 "y" vi-yank-to
1092 "|" vi-column
1093 "~" vi-change-case
1094
1096 The Gnu Readline Library, Brian Fox and Chet Ramey
1097 The Gnu History Library, Brian Fox and Chet Ramey
1098 bash(1)
1099
1101 ~/.inputrc
1102 Individual readline initialization file
1103
1105 Brian Fox, Free Software Foundation
1106 bfox@gnu.org
1107 Chet Ramey, Case Western Reserve University
1109 chet.ramey@case.edu
1110
1112 If you find a bug in readline, you should report it. But first, you
1113 should make sure that it really is a bug, and that it appears in the
1114 latest version of the readline library that you have.
1115 Once you have determined that a bug actually exists, mail a bug report
1117 to bug-readline@gnu.org. If you have a fix, you are welcome to mail
1118 that as well! Suggestions and `philosophical' bug reports may be
1119 mailed to bug-readline@gnu.org or posted to the Usenet newsgroup
1120 gnu.bash.bug.
1121 Comments and bug reports concerning this manual page should be directed
1123 to chet.ramey@case.edu.
1124
1126 It's too big and too slow.
1127GNU Readline 8.1 2020 October 29 READLINE(3)