rluser.texi revision 136644
1@comment %**start of header (This is for running Texinfo on a region.) 2@setfilename rluser.info 3@comment %**end of header (This is for running Texinfo on a region.) 4@setchapternewpage odd 5 6@ignore 7This file documents the end user interface to the GNU command line 8editing features. It is to be an appendix to manuals for programs which 9use these features. There is a document entitled "readline.texinfo" 10which contains both end-user and programmer documentation for the 11GNU Readline Library. 12 13Copyright (C) 1988-2004 Free Software Foundation, Inc. 14 15Authored by Brian Fox and Chet Ramey. 16 17Permission is granted to process this file through Tex and print the 18results, provided the printed document carries copying permission notice 19identical to this one except for the removal of this paragraph (this 20paragraph not being relevant to the printed manual). 21 22Permission is granted to make and distribute verbatim copies of this manual 23provided the copyright notice and this permission notice are preserved on 24all copies. 25 26Permission is granted to copy and distribute modified versions of this 27manual under the conditions for verbatim copying, provided also that the 28GNU Copyright statement is available to the distributee, and provided that 29the entire resulting derived work is distributed under the terms of a 30permission notice identical to this one. 31 32Permission is granted to copy and distribute translations of this manual 33into another language, under the above conditions for modified versions. 34@end ignore 35 36@comment If you are including this manual as an appendix, then set the 37@comment variable readline-appendix. 38 39@ifclear BashFeatures 40@defcodeindex bt 41@end ifclear 42 43@node Command Line Editing 44@chapter Command Line Editing 45 46This chapter describes the basic features of the @sc{gnu} 47command line editing interface. 48@ifset BashFeatures 49Command line editing is provided by the Readline library, which is 50used by several different programs, including Bash. 51@end ifset 52 53@menu 54* Introduction and Notation:: Notation used in this text. 55* Readline Interaction:: The minimum set of commands for editing a line. 56* Readline Init File:: Customizing Readline from a user's view. 57* Bindable Readline Commands:: A description of most of the Readline commands 58 available for binding 59* Readline vi Mode:: A short description of how to make Readline 60 behave like the vi editor. 61@ifset BashFeatures 62* Programmable Completion:: How to specify the possible completions for 63 a specific command. 64* Programmable Completion Builtins:: Builtin commands to specify how to 65 complete arguments for a particular command. 66@end ifset 67@end menu 68 69@node Introduction and Notation 70@section Introduction to Line Editing 71 72The following paragraphs describe the notation used to represent 73keystrokes. 74 75The text @kbd{C-k} is read as `Control-K' and describes the character 76produced when the @key{k} key is pressed while the Control key 77is depressed. 78 79The text @kbd{M-k} is read as `Meta-K' and describes the character 80produced when the Meta key (if you have one) is depressed, and the @key{k} 81key is pressed. 82The Meta key is labeled @key{ALT} on many keyboards. 83On keyboards with two keys labeled @key{ALT} (usually to either side of 84the space bar), the @key{ALT} on the left side is generally set to 85work as a Meta key. 86The @key{ALT} key on the right may also be configured to work as a 87Meta key or may be configured as some other modifier, such as a 88Compose key for typing accented characters. 89 90If you do not have a Meta or @key{ALT} key, or another key working as 91a Meta key, the identical keystroke can be generated by typing @key{ESC} 92@emph{first}, and then typing @key{k}. 93Either process is known as @dfn{metafying} the @key{k} key. 94 95The text @kbd{M-C-k} is read as `Meta-Control-k' and describes the 96character produced by @dfn{metafying} @kbd{C-k}. 97 98In addition, several keys have their own names. Specifically, 99@key{DEL}, @key{ESC}, @key{LFD}, @key{SPC}, @key{RET}, and @key{TAB} all 100stand for themselves when seen in this text, or in an init file 101(@pxref{Readline Init File}). 102If your keyboard lacks a @key{LFD} key, typing @key{C-j} will 103produce the desired character. 104The @key{RET} key may be labeled @key{Return} or @key{Enter} on 105some keyboards. 106 107@node Readline Interaction 108@section Readline Interaction 109@cindex interaction, readline 110 111Often during an interactive session you type in a long line of text, 112only to notice that the first word on the line is misspelled. The 113Readline library gives you a set of commands for manipulating the text 114as you type it in, allowing you to just fix your typo, and not forcing 115you to retype the majority of the line. Using these editing commands, 116you move the cursor to the place that needs correction, and delete or 117insert the text of the corrections. Then, when you are satisfied with 118the line, you simply press @key{RET}. You do not have to be at the 119end of the line to press @key{RET}; the entire line is accepted 120regardless of the location of the cursor within the line. 121 122@menu 123* Readline Bare Essentials:: The least you need to know about Readline. 124* Readline Movement Commands:: Moving about the input line. 125* Readline Killing Commands:: How to delete text, and how to get it back! 126* Readline Arguments:: Giving numeric arguments to commands. 127* Searching:: Searching through previous lines. 128@end menu 129 130@node Readline Bare Essentials 131@subsection Readline Bare Essentials 132@cindex notation, readline 133@cindex command editing 134@cindex editing command lines 135 136In order to enter characters into the line, simply type them. The typed 137character appears where the cursor was, and then the cursor moves one 138space to the right. If you mistype a character, you can use your 139erase character to back up and delete the mistyped character. 140 141Sometimes you may mistype a character, and 142not notice the error until you have typed several other characters. In 143that case, you can type @kbd{C-b} to move the cursor to the left, and then 144correct your mistake. Afterwards, you can move the cursor to the right 145with @kbd{C-f}. 146 147When you add text in the middle of a line, you will notice that characters 148to the right of the cursor are `pushed over' to make room for the text 149that you have inserted. Likewise, when you delete text behind the cursor, 150characters to the right of the cursor are `pulled back' to fill in the 151blank space created by the removal of the text. A list of the bare 152essentials for editing the text of an input line follows. 153 154@table @asis 155@item @kbd{C-b} 156Move back one character. 157@item @kbd{C-f} 158Move forward one character. 159@item @key{DEL} or @key{Backspace} 160Delete the character to the left of the cursor. 161@item @kbd{C-d} 162Delete the character underneath the cursor. 163@item @w{Printing characters} 164Insert the character into the line at the cursor. 165@item @kbd{C-_} or @kbd{C-x C-u} 166Undo the last editing command. You can undo all the way back to an 167empty line. 168@end table 169 170@noindent 171(Depending on your configuration, the @key{Backspace} key be set to 172delete the character to the left of the cursor and the @key{DEL} key set 173to delete the character underneath the cursor, like @kbd{C-d}, rather 174than the character to the left of the cursor.) 175 176@node Readline Movement Commands 177@subsection Readline Movement Commands 178 179 180The above table describes the most basic keystrokes that you need 181in order to do editing of the input line. For your convenience, many 182other commands have been added in addition to @kbd{C-b}, @kbd{C-f}, 183@kbd{C-d}, and @key{DEL}. Here are some commands for moving more rapidly 184about the line. 185 186@table @kbd 187@item C-a 188Move to the start of the line. 189@item C-e 190Move to the end of the line. 191@item M-f 192Move forward a word, where a word is composed of letters and digits. 193@item M-b 194Move backward a word. 195@item C-l 196Clear the screen, reprinting the current line at the top. 197@end table 198 199Notice how @kbd{C-f} moves forward a character, while @kbd{M-f} moves 200forward a word. It is a loose convention that control keystrokes 201operate on characters while meta keystrokes operate on words. 202 203@node Readline Killing Commands 204@subsection Readline Killing Commands 205 206@cindex killing text 207@cindex yanking text 208 209@dfn{Killing} text means to delete the text from the line, but to save 210it away for later use, usually by @dfn{yanking} (re-inserting) 211it back into the line. 212(`Cut' and `paste' are more recent jargon for `kill' and `yank'.) 213 214If the description for a command says that it `kills' text, then you can 215be sure that you can get the text back in a different (or the same) 216place later. 217 218When you use a kill command, the text is saved in a @dfn{kill-ring}. 219Any number of consecutive kills save all of the killed text together, so 220that when you yank it back, you get it all. The kill 221ring is not line specific; the text that you killed on a previously 222typed line is available to be yanked back later, when you are typing 223another line. 224@cindex kill ring 225 226Here is the list of commands for killing text. 227 228@table @kbd 229@item C-k 230Kill the text from the current cursor position to the end of the line. 231 232@item M-d 233Kill from the cursor to the end of the current word, or, if between 234words, to the end of the next word. 235Word boundaries are the same as those used by @kbd{M-f}. 236 237@item M-@key{DEL} 238Kill from the cursor the start of the current word, or, if between 239words, to the start of the previous word. 240Word boundaries are the same as those used by @kbd{M-b}. 241 242@item C-w 243Kill from the cursor to the previous whitespace. This is different than 244@kbd{M-@key{DEL}} because the word boundaries differ. 245 246@end table 247 248Here is how to @dfn{yank} the text back into the line. Yanking 249means to copy the most-recently-killed text from the kill buffer. 250 251@table @kbd 252@item C-y 253Yank the most recently killed text back into the buffer at the cursor. 254 255@item M-y 256Rotate the kill-ring, and yank the new top. You can only do this if 257the prior command is @kbd{C-y} or @kbd{M-y}. 258@end table 259 260@node Readline Arguments 261@subsection Readline Arguments 262 263You can pass numeric arguments to Readline commands. Sometimes the 264argument acts as a repeat count, other times it is the @i{sign} of the 265argument that is significant. If you pass a negative argument to a 266command which normally acts in a forward direction, that command will 267act in a backward direction. For example, to kill text back to the 268start of the line, you might type @samp{M-- C-k}. 269 270The general way to pass numeric arguments to a command is to type meta 271digits before the command. If the first `digit' typed is a minus 272sign (@samp{-}), then the sign of the argument will be negative. Once 273you have typed one meta digit to get the argument started, you can type 274the remainder of the digits, and then the command. For example, to give 275the @kbd{C-d} command an argument of 10, you could type @samp{M-1 0 C-d}, 276which will delete the next ten characters on the input line. 277 278@node Searching 279@subsection Searching for Commands in the History 280 281Readline provides commands for searching through the command history 282@ifset BashFeatures 283(@pxref{Bash History Facilities}) 284@end ifset 285for lines containing a specified string. 286There are two search modes: @dfn{incremental} and @dfn{non-incremental}. 287 288Incremental searches begin before the user has finished typing the 289search string. 290As each character of the search string is typed, Readline displays 291the next entry from the history matching the string typed so far. 292An incremental search requires only as many characters as needed to 293find the desired history entry. 294To search backward in the history for a particular string, type 295@kbd{C-r}. Typing @kbd{C-s} searches forward through the history. 296The characters present in the value of the @code{isearch-terminators} variable 297are used to terminate an incremental search. 298If that variable has not been assigned a value, the @key{ESC} and 299@kbd{C-J} characters will terminate an incremental search. 300@kbd{C-g} will abort an incremental search and restore the original line. 301When the search is terminated, the history entry containing the 302search string becomes the current line. 303 304To find other matching entries in the history list, type @kbd{C-r} or 305@kbd{C-s} as appropriate. 306This will search backward or forward in the history for the next 307entry matching the search string typed so far. 308Any other key sequence bound to a Readline command will terminate 309the search and execute that command. 310For instance, a @key{RET} will terminate the search and accept 311the line, thereby executing the command from the history list. 312A movement command will terminate the search, make the last line found 313the current line, and begin editing. 314 315Readline remembers the last incremental search string. If two 316@kbd{C-r}s are typed without any intervening characters defining a new 317search string, any remembered search string is used. 318 319Non-incremental searches read the entire search string before starting 320to search for matching history lines. The search string may be 321typed by the user or be part of the contents of the current line. 322 323@node Readline Init File 324@section Readline Init File 325@cindex initialization file, readline 326 327Although the Readline library comes with a set of Emacs-like 328keybindings installed by default, it is possible to use a different set 329of keybindings. 330Any user can customize programs that use Readline by putting 331commands in an @dfn{inputrc} file, conventionally in his home directory. 332The name of this 333@ifset BashFeatures 334file is taken from the value of the shell variable @env{INPUTRC}. If 335@end ifset 336@ifclear BashFeatures 337file is taken from the value of the environment variable @env{INPUTRC}. If 338@end ifclear 339that variable is unset, the default is @file{~/.inputrc}. 340 341When a program which uses the Readline library starts up, the 342init file is read, and the key bindings are set. 343 344In addition, the @code{C-x C-r} command re-reads this init file, thus 345incorporating any changes that you might have made to it. 346 347@menu 348* Readline Init File Syntax:: Syntax for the commands in the inputrc file. 349 350* Conditional Init Constructs:: Conditional key bindings in the inputrc file. 351 352* Sample Init File:: An example inputrc file. 353@end menu 354 355@node Readline Init File Syntax 356@subsection Readline Init File Syntax 357 358There are only a few basic constructs allowed in the 359Readline init file. Blank lines are ignored. 360Lines beginning with a @samp{#} are comments. 361Lines beginning with a @samp{$} indicate conditional 362constructs (@pxref{Conditional Init Constructs}). Other lines 363denote variable settings and key bindings. 364 365@table @asis 366@item Variable Settings 367You can modify the run-time behavior of Readline by 368altering the values of variables in Readline 369using the @code{set} command within the init file. 370The syntax is simple: 371 372@example 373set @var{variable} @var{value} 374@end example 375 376@noindent 377Here, for example, is how to 378change from the default Emacs-like key binding to use 379@code{vi} line editing commands: 380 381@example 382set editing-mode vi 383@end example 384 385Variable names and values, where appropriate, are recognized without regard 386to case. 387 388@ifset BashFeatures 389The @w{@code{bind -V}} command lists the current Readline variable names 390and values. @xref{Bash Builtins}. 391@end ifset 392 393A great deal of run-time behavior is changeable with the following 394variables. 395 396@cindex variables, readline 397@table @code 398 399@item bell-style 400@vindex bell-style 401Controls what happens when Readline wants to ring the terminal bell. 402If set to @samp{none}, Readline never rings the bell. If set to 403@samp{visible}, Readline uses a visible bell if one is available. 404If set to @samp{audible} (the default), Readline attempts to ring 405the terminal's bell. 406 407@item comment-begin 408@vindex comment-begin 409The string to insert at the beginning of the line when the 410@code{insert-comment} command is executed. The default value 411is @code{"#"}. 412 413@item completion-ignore-case 414If set to @samp{on}, Readline performs filename matching and completion 415in a case-insensitive fashion. 416The default value is @samp{off}. 417 418@item completion-query-items 419@vindex completion-query-items 420The number of possible completions that determines when the user is 421asked whether the list of possibilities should be displayed. 422If the number of possible completions is greater than this value, 423Readline will ask the user whether or not he wishes to view 424them; otherwise, they are simply listed. 425This variable must be set to an integer value greater than or equal to 0. 426The default limit is @code{100}. 427 428@item convert-meta 429@vindex convert-meta 430If set to @samp{on}, Readline will convert characters with the 431eighth bit set to an @sc{ascii} key sequence by stripping the eighth 432bit and prefixing an @key{ESC} character, converting them to a 433meta-prefixed key sequence. The default value is @samp{on}. 434 435@item disable-completion 436@vindex disable-completion 437If set to @samp{On}, Readline will inhibit word completion. 438Completion characters will be inserted into the line as if they had 439been mapped to @code{self-insert}. The default is @samp{off}. 440 441@item editing-mode 442@vindex editing-mode 443The @code{editing-mode} variable controls which default set of 444key bindings is used. By default, Readline starts up in Emacs editing 445mode, where the keystrokes are most similar to Emacs. This variable can be 446set to either @samp{emacs} or @samp{vi}. 447 448@item enable-keypad 449@vindex enable-keypad 450When set to @samp{on}, Readline will try to enable the application 451keypad when it is called. Some systems need this to enable the 452arrow keys. The default is @samp{off}. 453 454@item expand-tilde 455@vindex expand-tilde 456If set to @samp{on}, tilde expansion is performed when Readline 457attempts word completion. The default is @samp{off}. 458 459@vindex history-preserve-point 460If set to @samp{on}, the history code attempts to place point at the 461same location on each history line retrieved with @code{previous-history} 462or @code{next-history}. 463 464@item horizontal-scroll-mode 465@vindex horizontal-scroll-mode 466This variable can be set to either @samp{on} or @samp{off}. Setting it 467to @samp{on} means that the text of the lines being edited will scroll 468horizontally on a single screen line when they are longer than the width 469of the screen, instead of wrapping onto a new screen line. By default, 470this variable is set to @samp{off}. 471 472@item input-meta 473@vindex input-meta 474@vindex meta-flag 475If set to @samp{on}, Readline will enable eight-bit input (it 476will not clear the eighth bit in the characters it reads), 477regardless of what the terminal claims it can support. The 478default value is @samp{off}. The name @code{meta-flag} is a 479synonym for this variable. 480 481@item isearch-terminators 482@vindex isearch-terminators 483The string of characters that should terminate an incremental search without 484subsequently executing the character as a command (@pxref{Searching}). 485If this variable has not been given a value, the characters @key{ESC} and 486@kbd{C-J} will terminate an incremental search. 487 488@item keymap 489@vindex keymap 490Sets Readline's idea of the current keymap for key binding commands. 491Acceptable @code{keymap} names are 492@code{emacs}, 493@code{emacs-standard}, 494@code{emacs-meta}, 495@code{emacs-ctlx}, 496@code{vi}, 497@code{vi-move}, 498@code{vi-command}, and 499@code{vi-insert}. 500@code{vi} is equivalent to @code{vi-command}; @code{emacs} is 501equivalent to @code{emacs-standard}. The default value is @code{emacs}. 502The value of the @code{editing-mode} variable also affects the 503default keymap. 504 505@item mark-directories 506If set to @samp{on}, completed directory names have a slash 507appended. The default is @samp{on}. 508 509@item mark-modified-lines 510@vindex mark-modified-lines 511This variable, when set to @samp{on}, causes Readline to display an 512asterisk (@samp{*}) at the start of history lines which have been modified. 513This variable is @samp{off} by default. 514 515@item mark-symlinked-directories 516@vindex mark-symlinked-directories 517If set to @samp{on}, completed names which are symbolic links 518to directories have a slash appended (subject to the value of 519@code{mark-directories}). 520The default is @samp{off}. 521 522@item match-hidden-files 523@vindex match-hidden-files 524This variable, when set to @samp{on}, causes Readline to match files whose 525names begin with a @samp{.} (hidden files) when performing filename 526completion, unless the leading @samp{.} is 527supplied by the user in the filename to be completed. 528This variable is @samp{on} by default. 529 530@item output-meta 531@vindex output-meta 532If set to @samp{on}, Readline will display characters with the 533eighth bit set directly rather than as a meta-prefixed escape 534sequence. The default is @samp{off}. 535 536@item page-completions 537@vindex page-completions 538If set to @samp{on}, Readline uses an internal @code{more}-like pager 539to display a screenful of possible completions at a time. 540This variable is @samp{on} by default. 541 542@item print-completions-horizontally 543If set to @samp{on}, Readline will display completions with matches 544sorted horizontally in alphabetical order, rather than down the screen. 545The default is @samp{off}. 546 547@item show-all-if-ambiguous 548@vindex show-all-if-ambiguous 549This alters the default behavior of the completion functions. If 550set to @samp{on}, 551words which have more than one possible completion cause the 552matches to be listed immediately instead of ringing the bell. 553The default value is @samp{off}. 554 555@item show-all-if-unmodified 556@vindex show-all-if-unmodified 557This alters the default behavior of the completion functions in 558a fashion similar to @var{show-all-if-ambiguous}. 559If set to @samp{on}, 560words which have more than one possible completion without any 561possible partial completion (the possible completions don't share 562a common prefix) cause the matches to be listed immediately instead 563of ringing the bell. 564The default value is @samp{off}. 565 566@item visible-stats 567@vindex visible-stats 568If set to @samp{on}, a character denoting a file's type 569is appended to the filename when listing possible 570completions. The default is @samp{off}. 571 572@end table 573 574@item Key Bindings 575The syntax for controlling key bindings in the init file is 576simple. First you need to find the name of the command that you 577want to change. The following sections contain tables of the command 578name, the default keybinding, if any, and a short description of what 579the command does. 580 581Once you know the name of the command, simply place on a line 582in the init file the name of the key 583you wish to bind the command to, a colon, and then the name of the 584command. The name of the key 585can be expressed in different ways, depending on what you find most 586comfortable. 587 588In addition to command names, readline allows keys to be bound 589to a string that is inserted when the key is pressed (a @var{macro}). 590 591@ifset BashFeatures 592The @w{@code{bind -p}} command displays Readline function names and 593bindings in a format that can put directly into an initialization file. 594@xref{Bash Builtins}. 595@end ifset 596 597@table @asis 598@item @w{@var{keyname}: @var{function-name} or @var{macro}} 599@var{keyname} is the name of a key spelled out in English. For example: 600@example 601Control-u: universal-argument 602Meta-Rubout: backward-kill-word 603Control-o: "> output" 604@end example 605 606In the above example, @kbd{C-u} is bound to the function 607@code{universal-argument}, 608@kbd{M-DEL} is bound to the function @code{backward-kill-word}, and 609@kbd{C-o} is bound to run the macro 610expressed on the right hand side (that is, to insert the text 611@samp{> output} into the line). 612 613A number of symbolic character names are recognized while 614processing this key binding syntax: 615@var{DEL}, 616@var{ESC}, 617@var{ESCAPE}, 618@var{LFD}, 619@var{NEWLINE}, 620@var{RET}, 621@var{RETURN}, 622@var{RUBOUT}, 623@var{SPACE}, 624@var{SPC}, 625and 626@var{TAB}. 627 628@item @w{"@var{keyseq}": @var{function-name} or @var{macro}} 629@var{keyseq} differs from @var{keyname} above in that strings 630denoting an entire key sequence can be specified, by placing 631the key sequence in double quotes. Some @sc{gnu} Emacs style key 632escapes can be used, as in the following example, but the 633special character names are not recognized. 634 635@example 636"\C-u": universal-argument 637"\C-x\C-r": re-read-init-file 638"\e[11~": "Function Key 1" 639@end example 640 641In the above example, @kbd{C-u} is again bound to the function 642@code{universal-argument} (just as it was in the first example), 643@samp{@kbd{C-x} @kbd{C-r}} is bound to the function @code{re-read-init-file}, 644and @samp{@key{ESC} @key{[} @key{1} @key{1} @key{~}} is bound to insert 645the text @samp{Function Key 1}. 646 647@end table 648 649The following @sc{gnu} Emacs style escape sequences are available when 650specifying key sequences: 651 652@table @code 653@item @kbd{\C-} 654control prefix 655@item @kbd{\M-} 656meta prefix 657@item @kbd{\e} 658an escape character 659@item @kbd{\\} 660backslash 661@item @kbd{\"} 662@key{"}, a double quotation mark 663@item @kbd{\'} 664@key{'}, a single quote or apostrophe 665@end table 666 667In addition to the @sc{gnu} Emacs style escape sequences, a second 668set of backslash escapes is available: 669 670@table @code 671@item \a 672alert (bell) 673@item \b 674backspace 675@item \d 676delete 677@item \f 678form feed 679@item \n 680newline 681@item \r 682carriage return 683@item \t 684horizontal tab 685@item \v 686vertical tab 687@item \@var{nnn} 688the eight-bit character whose value is the octal value @var{nnn} 689(one to three digits) 690@item \x@var{HH} 691the eight-bit character whose value is the hexadecimal value @var{HH} 692(one or two hex digits) 693@end table 694 695When entering the text of a macro, single or double quotes must 696be used to indicate a macro definition. 697Unquoted text is assumed to be a function name. 698In the macro body, the backslash escapes described above are expanded. 699Backslash will quote any other character in the macro text, 700including @samp{"} and @samp{'}. 701For example, the following binding will make @samp{@kbd{C-x} \} 702insert a single @samp{\} into the line: 703@example 704"\C-x\\": "\\" 705@end example 706 707@end table 708 709@node Conditional Init Constructs 710@subsection Conditional Init Constructs 711 712Readline implements a facility similar in spirit to the conditional 713compilation features of the C preprocessor which allows key 714bindings and variable settings to be performed as the result 715of tests. There are four parser directives used. 716 717@table @code 718@item $if 719The @code{$if} construct allows bindings to be made based on the 720editing mode, the terminal being used, or the application using 721Readline. The text of the test extends to the end of the line; 722no characters are required to isolate it. 723 724@table @code 725@item mode 726The @code{mode=} form of the @code{$if} directive is used to test 727whether Readline is in @code{emacs} or @code{vi} mode. 728This may be used in conjunction 729with the @samp{set keymap} command, for instance, to set bindings in 730the @code{emacs-standard} and @code{emacs-ctlx} keymaps only if 731Readline is starting out in @code{emacs} mode. 732 733@item term 734The @code{term=} form may be used to include terminal-specific 735key bindings, perhaps to bind the key sequences output by the 736terminal's function keys. The word on the right side of the 737@samp{=} is tested against both the full name of the terminal and 738the portion of the terminal name before the first @samp{-}. This 739allows @code{sun} to match both @code{sun} and @code{sun-cmd}, 740for instance. 741 742@item application 743The @var{application} construct is used to include 744application-specific settings. Each program using the Readline 745library sets the @var{application name}, and you can test for 746a particular value. 747This could be used to bind key sequences to functions useful for 748a specific program. For instance, the following command adds a 749key sequence that quotes the current or previous word in Bash: 750@example 751$if Bash 752# Quote the current or previous word 753"\C-xq": "\eb\"\ef\"" 754$endif 755@end example 756@end table 757 758@item $endif 759This command, as seen in the previous example, terminates an 760@code{$if} command. 761 762@item $else 763Commands in this branch of the @code{$if} directive are executed if 764the test fails. 765 766@item $include 767This directive takes a single filename as an argument and reads commands 768and bindings from that file. 769For example, the following directive reads from @file{/etc/inputrc}: 770@example 771$include /etc/inputrc 772@end example 773@end table 774 775@node Sample Init File 776@subsection Sample Init File 777 778Here is an example of an @var{inputrc} file. This illustrates key 779binding, variable assignment, and conditional syntax. 780 781@example 782@page 783# This file controls the behaviour of line input editing for 784# programs that use the GNU Readline library. Existing 785# programs include FTP, Bash, and GDB. 786# 787# You can re-read the inputrc file with C-x C-r. 788# Lines beginning with '#' are comments. 789# 790# First, include any systemwide bindings and variable 791# assignments from /etc/Inputrc 792$include /etc/Inputrc 793 794# 795# Set various bindings for emacs mode. 796 797set editing-mode emacs 798 799$if mode=emacs 800 801Meta-Control-h: backward-kill-word Text after the function name is ignored 802 803# 804# Arrow keys in keypad mode 805# 806#"\M-OD": backward-char 807#"\M-OC": forward-char 808#"\M-OA": previous-history 809#"\M-OB": next-history 810# 811# Arrow keys in ANSI mode 812# 813"\M-[D": backward-char 814"\M-[C": forward-char 815"\M-[A": previous-history 816"\M-[B": next-history 817# 818# Arrow keys in 8 bit keypad mode 819# 820#"\M-\C-OD": backward-char 821#"\M-\C-OC": forward-char 822#"\M-\C-OA": previous-history 823#"\M-\C-OB": next-history 824# 825# Arrow keys in 8 bit ANSI mode 826# 827#"\M-\C-[D": backward-char 828#"\M-\C-[C": forward-char 829#"\M-\C-[A": previous-history 830#"\M-\C-[B": next-history 831 832C-q: quoted-insert 833 834$endif 835 836# An old-style binding. This happens to be the default. 837TAB: complete 838 839# Macros that are convenient for shell interaction 840$if Bash 841# edit the path 842"\C-xp": "PATH=$@{PATH@}\e\C-e\C-a\ef\C-f" 843# prepare to type a quoted word -- 844# insert open and close double quotes 845# and move to just after the open quote 846"\C-x\"": "\"\"\C-b" 847# insert a backslash (testing backslash escapes 848# in sequences and macros) 849"\C-x\\": "\\" 850# Quote the current or previous word 851"\C-xq": "\eb\"\ef\"" 852# Add a binding to refresh the line, which is unbound 853"\C-xr": redraw-current-line 854# Edit variable on current line. 855"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y=" 856$endif 857 858# use a visible bell if one is available 859set bell-style visible 860 861# don't strip characters to 7 bits when reading 862set input-meta on 863 864# allow iso-latin1 characters to be inserted rather 865# than converted to prefix-meta sequences 866set convert-meta off 867 868# display characters with the eighth bit set directly 869# rather than as meta-prefixed characters 870set output-meta on 871 872# if there are more than 150 possible completions for 873# a word, ask the user if he wants to see all of them 874set completion-query-items 150 875 876# For FTP 877$if Ftp 878"\C-xg": "get \M-?" 879"\C-xt": "put \M-?" 880"\M-.": yank-last-arg 881$endif 882@end example 883 884@node Bindable Readline Commands 885@section Bindable Readline Commands 886 887@menu 888* Commands For Moving:: Moving about the line. 889* Commands For History:: Getting at previous lines. 890* Commands For Text:: Commands for changing text. 891* Commands For Killing:: Commands for killing and yanking. 892* Numeric Arguments:: Specifying numeric arguments, repeat counts. 893* Commands For Completion:: Getting Readline to do the typing for you. 894* Keyboard Macros:: Saving and re-executing typed characters 895* Miscellaneous Commands:: Other miscellaneous commands. 896@end menu 897 898This section describes Readline commands that may be bound to key 899sequences. 900@ifset BashFeatures 901You can list your key bindings by executing 902@w{@code{bind -P}} or, for a more terse format, suitable for an 903@var{inputrc} file, @w{@code{bind -p}}. (@xref{Bash Builtins}.) 904@end ifset 905Command names without an accompanying key sequence are unbound by default. 906 907In the following descriptions, @dfn{point} refers to the current cursor 908position, and @dfn{mark} refers to a cursor position saved by the 909@code{set-mark} command. 910The text between the point and mark is referred to as the @dfn{region}. 911 912@node Commands For Moving 913@subsection Commands For Moving 914@ftable @code 915@item beginning-of-line (C-a) 916Move to the start of the current line. 917 918@item end-of-line (C-e) 919Move to the end of the line. 920 921@item forward-char (C-f) 922Move forward a character. 923 924@item backward-char (C-b) 925Move back a character. 926 927@item forward-word (M-f) 928Move forward to the end of the next word. Words are composed of 929letters and digits. 930 931@item backward-word (M-b) 932Move back to the start of the current or previous word. Words are 933composed of letters and digits. 934 935@item clear-screen (C-l) 936Clear the screen and redraw the current line, 937leaving the current line at the top of the screen. 938 939@item redraw-current-line () 940Refresh the current line. By default, this is unbound. 941 942@end ftable 943 944@node Commands For History 945@subsection Commands For Manipulating The History 946 947@ftable @code 948@item accept-line (Newline or Return) 949@ifset BashFeatures 950Accept the line regardless of where the cursor is. 951If this line is 952non-empty, add it to the history list according to the setting of 953the @env{HISTCONTROL} and @env{HISTIGNORE} variables. 954If this line is a modified history line, then restore the history line 955to its original state. 956@end ifset 957@ifclear BashFeatures 958Accept the line regardless of where the cursor is. 959If this line is 960non-empty, it may be added to the history list for future recall with 961@code{add_history()}. 962If this line is a modified history line, the history line is restored 963to its original state. 964@end ifclear 965 966@item previous-history (C-p) 967Move `back' through the history list, fetching the previous command. 968 969@item next-history (C-n) 970Move `forward' through the history list, fetching the next command. 971 972@item beginning-of-history (M-<) 973Move to the first line in the history. 974 975@item end-of-history (M->) 976Move to the end of the input history, i.e., the line currently 977being entered. 978 979@item reverse-search-history (C-r) 980Search backward starting at the current line and moving `up' through 981the history as necessary. This is an incremental search. 982 983@item forward-search-history (C-s) 984Search forward starting at the current line and moving `down' through 985the the history as necessary. This is an incremental search. 986 987@item non-incremental-reverse-search-history (M-p) 988Search backward starting at the current line and moving `up' 989through the history as necessary using a non-incremental search 990for a string supplied by the user. 991 992@item non-incremental-forward-search-history (M-n) 993Search forward starting at the current line and moving `down' 994through the the history as necessary using a non-incremental search 995for a string supplied by the user. 996 997@item history-search-forward () 998Search forward through the history for the string of characters 999between the start of the current line and the point. 1000This is a non-incremental search. 1001By default, this command is unbound. 1002 1003@item history-search-backward () 1004Search backward through the history for the string of characters 1005between the start of the current line and the point. This 1006is a non-incremental search. By default, this command is unbound. 1007 1008@item yank-nth-arg (M-C-y) 1009Insert the first argument to the previous command (usually 1010the second word on the previous line) at point. 1011With an argument @var{n}, 1012insert the @var{n}th word from the previous command (the words 1013in the previous command begin with word 0). A negative argument 1014inserts the @var{n}th word from the end of the previous command. 1015 1016@item yank-last-arg (M-. or M-_) 1017Insert last argument to the previous command (the last word of the 1018previous history entry). With an 1019argument, behave exactly like @code{yank-nth-arg}. 1020Successive calls to @code{yank-last-arg} move back through the history 1021list, inserting the last argument of each line in turn. 1022 1023@end ftable 1024 1025@node Commands For Text 1026@subsection Commands For Changing Text 1027 1028@ftable @code 1029@item delete-char (C-d) 1030Delete the character at point. If point is at the 1031beginning of the line, there are no characters in the line, and 1032the last character typed was not bound to @code{delete-char}, then 1033return @sc{eof}. 1034 1035@item backward-delete-char (Rubout) 1036Delete the character behind the cursor. A numeric argument means 1037to kill the characters instead of deleting them. 1038 1039@item forward-backward-delete-char () 1040Delete the character under the cursor, unless the cursor is at the 1041end of the line, in which case the character behind the cursor is 1042deleted. By default, this is not bound to a key. 1043 1044@item quoted-insert (C-q or C-v) 1045Add the next character typed to the line verbatim. This is 1046how to insert key sequences like @kbd{C-q}, for example. 1047 1048@ifclear BashFeatures 1049@item tab-insert (M-@key{TAB}) 1050Insert a tab character. 1051@end ifclear 1052 1053@item self-insert (a, b, A, 1, !, @dots{}) 1054Insert yourself. 1055 1056@item transpose-chars (C-t) 1057Drag the character before the cursor forward over 1058the character at the cursor, moving the 1059cursor forward as well. If the insertion point 1060is at the end of the line, then this 1061transposes the last two characters of the line. 1062Negative arguments have no effect. 1063 1064@item transpose-words (M-t) 1065Drag the word before point past the word after point, 1066moving point past that word as well. 1067If the insertion point is at the end of the line, this transposes 1068the last two words on the line. 1069 1070@item upcase-word (M-u) 1071Uppercase the current (or following) word. With a negative argument, 1072uppercase the previous word, but do not move the cursor. 1073 1074@item downcase-word (M-l) 1075Lowercase the current (or following) word. With a negative argument, 1076lowercase the previous word, but do not move the cursor. 1077 1078@item capitalize-word (M-c) 1079Capitalize the current (or following) word. With a negative argument, 1080capitalize the previous word, but do not move the cursor. 1081 1082@item overwrite-mode () 1083Toggle overwrite mode. With an explicit positive numeric argument, 1084switches to overwrite mode. With an explicit non-positive numeric 1085argument, switches to insert mode. This command affects only 1086@code{emacs} mode; @code{vi} mode does overwrite differently. 1087Each call to @code{readline()} starts in insert mode. 1088 1089In overwrite mode, characters bound to @code{self-insert} replace 1090the text at point rather than pushing the text to the right. 1091Characters bound to @code{backward-delete-char} replace the character 1092before point with a space. 1093 1094By default, this command is unbound. 1095 1096@end ftable 1097 1098@node Commands For Killing 1099@subsection Killing And Yanking 1100 1101@ftable @code 1102 1103@item kill-line (C-k) 1104Kill the text from point to the end of the line. 1105 1106@item backward-kill-line (C-x Rubout) 1107Kill backward to the beginning of the line. 1108 1109@item unix-line-discard (C-u) 1110Kill backward from the cursor to the beginning of the current line. 1111 1112@item kill-whole-line () 1113Kill all characters on the current line, no matter where point is. 1114By default, this is unbound. 1115 1116@item kill-word (M-d) 1117Kill from point to the end of the current word, or if between 1118words, to the end of the next word. 1119Word boundaries are the same as @code{forward-word}. 1120 1121@item backward-kill-word (M-@key{DEL}) 1122Kill the word behind point. 1123Word boundaries are the same as @code{backward-word}. 1124 1125@item unix-word-rubout (C-w) 1126Kill the word behind point, using white space as a word boundary. 1127The killed text is saved on the kill-ring. 1128 1129@item unix-filename-rubout () 1130Kill the word behind point, using white space and the slash character 1131as the word boundaries. 1132The killed text is saved on the kill-ring. 1133 1134@item delete-horizontal-space () 1135Delete all spaces and tabs around point. By default, this is unbound. 1136 1137@item kill-region () 1138Kill the text in the current region. 1139By default, this command is unbound. 1140 1141@item copy-region-as-kill () 1142Copy the text in the region to the kill buffer, so it can be yanked 1143right away. By default, this command is unbound. 1144 1145@item copy-backward-word () 1146Copy the word before point to the kill buffer. 1147The word boundaries are the same as @code{backward-word}. 1148By default, this command is unbound. 1149 1150@item copy-forward-word () 1151Copy the word following point to the kill buffer. 1152The word boundaries are the same as @code{forward-word}. 1153By default, this command is unbound. 1154 1155@item yank (C-y) 1156Yank the top of the kill ring into the buffer at point. 1157 1158@item yank-pop (M-y) 1159Rotate the kill-ring, and yank the new top. You can only do this if 1160the prior command is @code{yank} or @code{yank-pop}. 1161@end ftable 1162 1163@node Numeric Arguments 1164@subsection Specifying Numeric Arguments 1165@ftable @code 1166 1167@item digit-argument (@kbd{M-0}, @kbd{M-1}, @dots{} @kbd{M--}) 1168Add this digit to the argument already accumulating, or start a new 1169argument. @kbd{M--} starts a negative argument. 1170 1171@item universal-argument () 1172This is another way to specify an argument. 1173If this command is followed by one or more digits, optionally with a 1174leading minus sign, those digits define the argument. 1175If the command is followed by digits, executing @code{universal-argument} 1176again ends the numeric argument, but is otherwise ignored. 1177As a special case, if this command is immediately followed by a 1178character that is neither a digit or minus sign, the argument count 1179for the next command is multiplied by four. 1180The argument count is initially one, so executing this function the 1181first time makes the argument count four, a second time makes the 1182argument count sixteen, and so on. 1183By default, this is not bound to a key. 1184@end ftable 1185 1186@node Commands For Completion 1187@subsection Letting Readline Type For You 1188 1189@ftable @code 1190@item complete (@key{TAB}) 1191Attempt to perform completion on the text before point. 1192The actual completion performed is application-specific. 1193@ifset BashFeatures 1194Bash attempts completion treating the text as a variable (if the 1195text begins with @samp{$}), username (if the text begins with 1196@samp{~}), hostname (if the text begins with @samp{@@}), or 1197command (including aliases and functions) in turn. If none 1198of these produces a match, filename completion is attempted. 1199@end ifset 1200@ifclear BashFeatures 1201The default is filename completion. 1202@end ifclear 1203 1204@item possible-completions (M-?) 1205List the possible completions of the text before point. 1206 1207@item insert-completions (M-*) 1208Insert all completions of the text before point that would have 1209been generated by @code{possible-completions}. 1210 1211@item menu-complete () 1212Similar to @code{complete}, but replaces the word to be completed 1213with a single match from the list of possible completions. 1214Repeated execution of @code{menu-complete} steps through the list 1215of possible completions, inserting each match in turn. 1216At the end of the list of completions, the bell is rung 1217(subject to the setting of @code{bell-style}) 1218and the original text is restored. 1219An argument of @var{n} moves @var{n} positions forward in the list 1220of matches; a negative argument may be used to move backward 1221through the list. 1222This command is intended to be bound to @key{TAB}, but is unbound 1223by default. 1224 1225@item delete-char-or-list () 1226Deletes the character under the cursor if not at the beginning or 1227end of the line (like @code{delete-char}). 1228If at the end of the line, behaves identically to 1229@code{possible-completions}. 1230This command is unbound by default. 1231 1232@ifset BashFeatures 1233@item complete-filename (M-/) 1234Attempt filename completion on the text before point. 1235 1236@item possible-filename-completions (C-x /) 1237List the possible completions of the text before point, 1238treating it as a filename. 1239 1240@item complete-username (M-~) 1241Attempt completion on the text before point, treating 1242it as a username. 1243 1244@item possible-username-completions (C-x ~) 1245List the possible completions of the text before point, 1246treating it as a username. 1247 1248@item complete-variable (M-$) 1249Attempt completion on the text before point, treating 1250it as a shell variable. 1251 1252@item possible-variable-completions (C-x $) 1253List the possible completions of the text before point, 1254treating it as a shell variable. 1255 1256@item complete-hostname (M-@@) 1257Attempt completion on the text before point, treating 1258it as a hostname. 1259 1260@item possible-hostname-completions (C-x @@) 1261List the possible completions of the text before point, 1262treating it as a hostname. 1263 1264@item complete-command (M-!) 1265Attempt completion on the text before point, treating 1266it as a command name. Command completion attempts to 1267match the text against aliases, reserved words, shell 1268functions, shell builtins, and finally executable filenames, 1269in that order. 1270 1271@item possible-command-completions (C-x !) 1272List the possible completions of the text before point, 1273treating it as a command name. 1274 1275@item dynamic-complete-history (M-@key{TAB}) 1276Attempt completion on the text before point, comparing 1277the text against lines from the history list for possible 1278completion matches. 1279 1280@item complete-into-braces (M-@{) 1281Perform filename completion and insert the list of possible completions 1282enclosed within braces so the list is available to the shell 1283(@pxref{Brace Expansion}). 1284 1285@end ifset 1286@end ftable 1287 1288@node Keyboard Macros 1289@subsection Keyboard Macros 1290@ftable @code 1291 1292@item start-kbd-macro (C-x () 1293Begin saving the characters typed into the current keyboard macro. 1294 1295@item end-kbd-macro (C-x )) 1296Stop saving the characters typed into the current keyboard macro 1297and save the definition. 1298 1299@item call-last-kbd-macro (C-x e) 1300Re-execute the last keyboard macro defined, by making the characters 1301in the macro appear as if typed at the keyboard. 1302 1303@end ftable 1304 1305@node Miscellaneous Commands 1306@subsection Some Miscellaneous Commands 1307@ftable @code 1308 1309@item re-read-init-file (C-x C-r) 1310Read in the contents of the @var{inputrc} file, and incorporate 1311any bindings or variable assignments found there. 1312 1313@item abort (C-g) 1314Abort the current editing command and 1315ring the terminal's bell (subject to the setting of 1316@code{bell-style}). 1317 1318@item do-uppercase-version (M-a, M-b, M-@var{x}, @dots{}) 1319If the metafied character @var{x} is lowercase, run the command 1320that is bound to the corresponding uppercase character. 1321 1322@item prefix-meta (@key{ESC}) 1323Metafy the next character typed. This is for keyboards 1324without a meta key. Typing @samp{@key{ESC} f} is equivalent to typing 1325@kbd{M-f}. 1326 1327@item undo (C-_ or C-x C-u) 1328Incremental undo, separately remembered for each line. 1329 1330@item revert-line (M-r) 1331Undo all changes made to this line. This is like executing the @code{undo} 1332command enough times to get back to the beginning. 1333 1334@ifset BashFeatures 1335@item tilde-expand (M-&) 1336@end ifset 1337@ifclear BashFeatures 1338@item tilde-expand (M-~) 1339@end ifclear 1340Perform tilde expansion on the current word. 1341 1342@item set-mark (C-@@) 1343Set the mark to the point. If a 1344numeric argument is supplied, the mark is set to that position. 1345 1346@item exchange-point-and-mark (C-x C-x) 1347Swap the point with the mark. The current cursor position is set to 1348the saved position, and the old cursor position is saved as the mark. 1349 1350@item character-search (C-]) 1351A character is read and point is moved to the next occurrence of that 1352character. A negative count searches for previous occurrences. 1353 1354@item character-search-backward (M-C-]) 1355A character is read and point is moved to the previous occurrence 1356of that character. A negative count searches for subsequent 1357occurrences. 1358 1359@item insert-comment (M-#) 1360Without a numeric argument, the value of the @code{comment-begin} 1361variable is inserted at the beginning of the current line. 1362If a numeric argument is supplied, this command acts as a toggle: if 1363the characters at the beginning of the line do not match the value 1364of @code{comment-begin}, the value is inserted, otherwise 1365the characters in @code{comment-begin} are deleted from the beginning of 1366the line. 1367In either case, the line is accepted as if a newline had been typed. 1368@ifset BashFeatures 1369The default value of @code{comment-begin} causes this command 1370to make the current line a shell comment. 1371If a numeric argument causes the comment character to be removed, the line 1372will be executed by the shell. 1373@end ifset 1374 1375@item dump-functions () 1376Print all of the functions and their key bindings to the 1377Readline output stream. If a numeric argument is supplied, 1378the output is formatted in such a way that it can be made part 1379of an @var{inputrc} file. This command is unbound by default. 1380 1381@item dump-variables () 1382Print all of the settable variables and their values to the 1383Readline output stream. If a numeric argument is supplied, 1384the output is formatted in such a way that it can be made part 1385of an @var{inputrc} file. This command is unbound by default. 1386 1387@item dump-macros () 1388Print all of the Readline key sequences bound to macros and the 1389strings they output. If a numeric argument is supplied, 1390the output is formatted in such a way that it can be made part 1391of an @var{inputrc} file. This command is unbound by default. 1392 1393@ifset BashFeatures 1394@item glob-complete-word (M-g) 1395The word before point is treated as a pattern for pathname expansion, 1396with an asterisk implicitly appended. This pattern is used to 1397generate a list of matching file names for possible completions. 1398 1399@item glob-expand-word (C-x *) 1400The word before point is treated as a pattern for pathname expansion, 1401and the list of matching file names is inserted, replacing the word. 1402If a numeric argument is supplied, a @samp{*} is appended before 1403pathname expansion. 1404 1405@item glob-list-expansions (C-x g) 1406The list of expansions that would have been generated by 1407@code{glob-expand-word} is displayed, and the line is redrawn. 1408If a numeric argument is supplied, a @samp{*} is appended before 1409pathname expansion. 1410 1411@item display-shell-version (C-x C-v) 1412Display version information about the current instance of Bash. 1413 1414@item shell-expand-line (M-C-e) 1415Expand the line as the shell does. 1416This performs alias and history expansion as well as all of the shell 1417word expansions (@pxref{Shell Expansions}). 1418 1419@item history-expand-line (M-^) 1420Perform history expansion on the current line. 1421 1422@item magic-space () 1423Perform history expansion on the current line and insert a space 1424(@pxref{History Interaction}). 1425 1426@item alias-expand-line () 1427Perform alias expansion on the current line (@pxref{Aliases}). 1428 1429@item history-and-alias-expand-line () 1430Perform history and alias expansion on the current line. 1431 1432@item insert-last-argument (M-. or M-_) 1433A synonym for @code{yank-last-arg}. 1434 1435@item operate-and-get-next (C-o) 1436Accept the current line for execution and fetch the next line 1437relative to the current line from the history for editing. Any 1438argument is ignored. 1439 1440@item edit-and-execute-command (C-xC-e) 1441Invoke an editor on the current command line, and execute the result as shell 1442commands. 1443Bash attempts to invoke 1444@code{$VISUAL}, @code{$EDITOR}, and @code{emacs} 1445as the editor, in that order. 1446 1447@end ifset 1448 1449@ifclear BashFeatures 1450@item emacs-editing-mode (C-e) 1451When in @code{vi} command mode, this causes a switch to @code{emacs} 1452editing mode. 1453 1454@item vi-editing-mode (M-C-j) 1455When in @code{emacs} editing mode, this causes a switch to @code{vi} 1456editing mode. 1457 1458@end ifclear 1459 1460@end ftable 1461 1462@node Readline vi Mode 1463@section Readline vi Mode 1464 1465While the Readline library does not have a full set of @code{vi} 1466editing functions, it does contain enough to allow simple editing 1467of the line. The Readline @code{vi} mode behaves as specified in 1468the @sc{posix} 1003.2 standard. 1469 1470@ifset BashFeatures 1471In order to switch interactively between @code{emacs} and @code{vi} 1472editing modes, use the @samp{set -o emacs} and @samp{set -o vi} 1473commands (@pxref{The Set Builtin}). 1474@end ifset 1475@ifclear BashFeatures 1476In order to switch interactively between @code{emacs} and @code{vi} 1477editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode 1478when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode). 1479@end ifclear 1480The Readline default is @code{emacs} mode. 1481 1482When you enter a line in @code{vi} mode, you are already placed in 1483`insertion' mode, as if you had typed an @samp{i}. Pressing @key{ESC} 1484switches you into `command' mode, where you can edit the text of the 1485line with the standard @code{vi} movement keys, move to previous 1486history lines with @samp{k} and subsequent lines with @samp{j}, and 1487so forth. 1488 1489@ifset BashFeatures 1490@node Programmable Completion 1491@section Programmable Completion 1492@cindex programmable completion 1493 1494When word completion is attempted for an argument to a command for 1495which a completion specification (a @var{compspec}) has been defined 1496using the @code{complete} builtin (@pxref{Programmable Completion Builtins}), 1497the programmable completion facilities are invoked. 1498 1499First, the command name is identified. 1500If a compspec has been defined for that command, the 1501compspec is used to generate the list of possible completions for the word. 1502If the command word is a full pathname, a compspec for the full 1503pathname is searched for first. 1504If no compspec is found for the full pathname, an attempt is made to 1505find a compspec for the portion following the final slash. 1506 1507Once a compspec has been found, it is used to generate the list of 1508matching words. 1509If a compspec is not found, the default Bash completion 1510described above (@pxref{Commands For Completion}) is performed. 1511 1512First, the actions specified by the compspec are used. 1513Only matches which are prefixed by the word being completed are 1514returned. 1515When the @option{-f} or @option{-d} option is used for filename or 1516directory name completion, the shell variable @env{FIGNORE} is 1517used to filter the matches. 1518@xref{Bash Variables}, for a description of @env{FIGNORE}. 1519 1520Any completions specified by a filename expansion pattern to the 1521@option{-G} option are generated next. 1522The words generated by the pattern need not match the word being completed. 1523The @env{GLOBIGNORE} shell variable is not used to filter the matches, 1524but the @env{FIGNORE} shell variable is used. 1525 1526Next, the string specified as the argument to the @option{-W} option 1527is considered. 1528The string is first split using the characters in the @env{IFS} 1529special variable as delimiters. 1530Shell quoting is honored. 1531Each word is then expanded using 1532brace expansion, tilde expansion, parameter and variable expansion, 1533command substitution, arithmetic expansion, and pathname expansion, 1534as described above (@pxref{Shell Expansions}). 1535The results are split using the rules described above 1536(@pxref{Word Splitting}). 1537The results of the expansion are prefix-matched against the word being 1538completed, and the matching words become the possible completions. 1539 1540After these matches have been generated, any shell function or command 1541specified with the @option{-F} and @option{-C} options is invoked. 1542When the command or function is invoked, the @env{COMP_LINE} and 1543@env{COMP_POINT} variables are assigned values as described above 1544(@pxref{Bash Variables}). 1545If a shell function is being invoked, the @env{COMP_WORDS} and 1546@env{COMP_CWORD} variables are also set. 1547When the function or command is invoked, the first argument is the 1548name of the command whose arguments are being completed, the 1549second argument is the word being completed, and the third argument 1550is the word preceding the word being completed on the current command line. 1551No filtering of the generated completions against the word being completed 1552is performed; the function or command has complete freedom in generating 1553the matches. 1554 1555Any function specified with @option{-F} is invoked first. 1556The function may use any of the shell facilities, including the 1557@code{compgen} builtin described below 1558(@pxref{Programmable Completion Builtins}), to generate the matches. 1559It must put the possible completions in the @env{COMPREPLY} array 1560variable. 1561 1562Next, any command specified with the @option{-C} option is invoked 1563in an environment equivalent to command substitution. 1564It should print a list of completions, one per line, to 1565the standard output. 1566Backslash may be used to escape a newline, if necessary. 1567 1568After all of the possible completions are generated, any filter 1569specified with the @option{-X} option is applied to the list. 1570The filter is a pattern as used for pathname expansion; a @samp{&} 1571in the pattern is replaced with the text of the word being completed. 1572A literal @samp{&} may be escaped with a backslash; the backslash 1573is removed before attempting a match. 1574Any completion that matches the pattern will be removed from the list. 1575A leading @samp{!} negates the pattern; in this case any completion 1576not matching the pattern will be removed. 1577 1578Finally, any prefix and suffix specified with the @option{-P} and @option{-S} 1579options are added to each member of the completion list, and the result is 1580returned to the Readline completion code as the list of possible 1581completions. 1582 1583If the previously-applied actions do not generate any matches, and the 1584@option{-o dirnames} option was supplied to @code{complete} when the 1585compspec was defined, directory name completion is attempted. 1586 1587If the @option{-o plusdirs} option was supplied to @code{complete} when 1588the compspec was defined, directory name completion is attempted and any 1589matches are added to the results of the other actions. 1590 1591By default, if a compspec is found, whatever it generates is returned to 1592the completion code as the full set of possible completions. 1593The default Bash completions are not attempted, and the Readline default 1594of filename completion is disabled. 1595If the @option{-o bashdefault} option was supplied to @code{complete} when 1596the compspec was defined, the default Bash completions are attempted 1597if the compspec generates no matches. 1598If the @option{-o default} option was supplied to @code{complete} when the 1599compspec was defined, Readline's default completion will be performed 1600if the compspec (and, if attempted, the default Bash completions) 1601generate no matches. 1602 1603When a compspec indicates that directory name completion is desired, 1604the programmable completion functions force Readline to append a slash 1605to completed names which are symbolic links to directories, subject to 1606the value of the @var{mark-directories} Readline variable, regardless 1607of the setting of the @var{mark-symlinked-directories} Readline variable. 1608 1609@node Programmable Completion Builtins 1610@section Programmable Completion Builtins 1611@cindex completion builtins 1612 1613Two builtin commands are available to manipulate the programmable completion 1614facilities. 1615 1616@table @code 1617@item compgen 1618@btindex compgen 1619@example 1620@code{compgen [@var{option}] [@var{word}]} 1621@end example 1622 1623Generate possible completion matches for @var{word} according to 1624the @var{option}s, which may be any option accepted by the 1625@code{complete} 1626builtin with the exception of @option{-p} and @option{-r}, and write 1627the matches to the standard output. 1628When using the @option{-F} or @option{-C} options, the various shell variables 1629set by the programmable completion facilities, while available, will not 1630have useful values. 1631 1632The matches will be generated in the same way as if the programmable 1633completion code had generated them directly from a completion specification 1634with the same flags. 1635If @var{word} is specified, only those completions matching @var{word} 1636will be displayed. 1637 1638The return value is true unless an invalid option is supplied, or no 1639matches were generated. 1640 1641@item complete 1642@btindex complete 1643@example 1644@code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-A @var{action}] [-G @var{globpat}] [-W @var{wordlist}] 1645[-P @var{prefix}] [-S @var{suffix}] [-X @var{filterpat}] [-F @var{function}] 1646[-C @var{command}] @var{name} [@var{name} @dots{}]} 1647@code{complete -pr [@var{name} @dots{}]} 1648@end example 1649 1650Specify how arguments to each @var{name} should be completed. 1651If the @option{-p} option is supplied, or if no options are supplied, existing 1652completion specifications are printed in a way that allows them to be 1653reused as input. 1654The @option{-r} option removes a completion specification for 1655each @var{name}, or, if no @var{name}s are supplied, all 1656completion specifications. 1657 1658The process of applying these completion specifications when word completion 1659is attempted is described above (@pxref{Programmable Completion}). 1660 1661Other options, if specified, have the following meanings. 1662The arguments to the @option{-G}, @option{-W}, and @option{-X} options 1663(and, if necessary, the @option{-P} and @option{-S} options) 1664should be quoted to protect them from expansion before the 1665@code{complete} builtin is invoked. 1666 1667 1668@table @code 1669@item -o @var{comp-option} 1670The @var{comp-option} controls several aspects of the compspec's behavior 1671beyond the simple generation of completions. 1672@var{comp-option} may be one of: 1673 1674@table @code 1675 1676@item bashdefault 1677Perform the rest of the default Bash completions if the compspec 1678generates no matches. 1679 1680@item default 1681Use Readline's default filename completion if the compspec generates 1682no matches. 1683 1684@item dirnames 1685Perform directory name completion if the compspec generates no matches. 1686 1687@item filenames 1688Tell Readline that the compspec generates filenames, so it can perform any 1689filename-specific processing (like adding a slash to directory names or 1690suppressing trailing spaces). This option is intended to be used with 1691shell functions specified with @option{-F}. 1692 1693@item nospace 1694Tell Readline not to append a space (the default) to words completed at 1695the end of the line. 1696@end table 1697 1698@item -A @var{action} 1699The @var{action} may be one of the following to generate a list of possible 1700completions: 1701 1702@table @code 1703@item alias 1704Alias names. May also be specified as @option{-a}. 1705 1706@item arrayvar 1707Array variable names. 1708 1709@item binding 1710Readline key binding names (@pxref{Bindable Readline Commands}). 1711 1712@item builtin 1713Names of shell builtin commands. May also be specified as @option{-b}. 1714 1715@item command 1716Command names. May also be specified as @option{-c}. 1717 1718@item directory 1719Directory names. May also be specified as @option{-d}. 1720 1721@item disabled 1722Names of disabled shell builtins. 1723 1724@item enabled 1725Names of enabled shell builtins. 1726 1727@item export 1728Names of exported shell variables. May also be specified as @option{-e}. 1729 1730@item file 1731File names. May also be specified as @option{-f}. 1732 1733@item function 1734Names of shell functions. 1735 1736@item group 1737Group names. May also be specified as @option{-g}. 1738 1739@item helptopic 1740Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}). 1741 1742@item hostname 1743Hostnames, as taken from the file specified by the 1744@env{HOSTFILE} shell variable (@pxref{Bash Variables}). 1745 1746@item job 1747Job names, if job control is active. May also be specified as @option{-j}. 1748 1749@item keyword 1750Shell reserved words. May also be specified as @option{-k}. 1751 1752@item running 1753Names of running jobs, if job control is active. 1754 1755@item service 1756Service names. May also be specified as @option{-s}. 1757 1758@item setopt 1759Valid arguments for the @option{-o} option to the @code{set} builtin 1760(@pxref{The Set Builtin}). 1761 1762@item shopt 1763Shell option names as accepted by the @code{shopt} builtin 1764(@pxref{Bash Builtins}). 1765 1766@item signal 1767Signal names. 1768 1769@item stopped 1770Names of stopped jobs, if job control is active. 1771 1772@item user 1773User names. May also be specified as @option{-u}. 1774 1775@item variable 1776Names of all shell variables. May also be specified as @option{-v}. 1777@end table 1778 1779@item -G @var{globpat} 1780The filename expansion pattern @var{globpat} is expanded to generate 1781the possible completions. 1782 1783@item -W @var{wordlist} 1784The @var{wordlist} is split using the characters in the 1785@env{IFS} special variable as delimiters, and each resultant word 1786is expanded. 1787The possible completions are the members of the resultant list which 1788match the word being completed. 1789 1790@item -C @var{command} 1791@var{command} is executed in a subshell environment, and its output is 1792used as the possible completions. 1793 1794@item -F @var{function} 1795The shell function @var{function} is executed in the current shell 1796environment. 1797When it finishes, the possible completions are retrieved from the value 1798of the @env{COMPREPLY} array variable. 1799 1800@item -X @var{filterpat} 1801@var{filterpat} is a pattern as used for filename expansion. 1802It is applied to the list of possible completions generated by the 1803preceding options and arguments, and each completion matching 1804@var{filterpat} is removed from the list. 1805A leading @samp{!} in @var{filterpat} negates the pattern; in this 1806case, any completion not matching @var{filterpat} is removed. 1807 1808@item -P @var{prefix} 1809@var{prefix} is added at the beginning of each possible completion 1810after all other options have been applied. 1811 1812@item -S @var{suffix} 1813@var{suffix} is appended to each possible completion 1814after all other options have been applied. 1815@end table 1816 1817The return value is true unless an invalid option is supplied, an option 1818other than @option{-p} or @option{-r} is supplied without a @var{name} 1819argument, an attempt is made to remove a completion specification for 1820a @var{name} for which no specification exists, or 1821an error occurs adding a completion specification. 1822 1823@end table 1824@end ifset 1825