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) 1988-2002 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 he wants to see the list of possibilities. If the 422number 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 retrived 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 visible-stats 556@vindex visible-stats 557If set to @samp{on}, a character denoting a file's type 558is appended to the filename when listing possible 559completions. The default is @samp{off}. 560 561@end table 562 563@item Key Bindings 564The syntax for controlling key bindings in the init file is 565simple. First you need to find the name of the command that you 566want to change. The following sections contain tables of the command 567name, the default keybinding, if any, and a short description of what 568the command does. 569 570Once you know the name of the command, simply place on a line 571in the init file the name of the key 572you wish to bind the command to, a colon, and then the name of the 573command. The name of the key 574can be expressed in different ways, depending on what you find most 575comfortable. 576 577In addition to command names, readline allows keys to be bound 578to a string that is inserted when the key is pressed (a @var{macro}). 579 580@ifset BashFeatures 581The @w{@code{bind -p}} command displays Readline function names and 582bindings in a format that can put directly into an initialization file. 583@xref{Bash Builtins}. 584@end ifset 585 586@table @asis 587@item @w{@var{keyname}: @var{function-name} or @var{macro}} 588@var{keyname} is the name of a key spelled out in English. For example: 589@example 590Control-u: universal-argument 591Meta-Rubout: backward-kill-word 592Control-o: "> output" 593@end example 594 595In the above example, @kbd{C-u} is bound to the function 596@code{universal-argument}, 597@kbd{M-DEL} is bound to the function @code{backward-kill-word}, and 598@kbd{C-o} is bound to run the macro 599expressed on the right hand side (that is, to insert the text 600@samp{> output} into the line). 601 602A number of symbolic character names are recognized while 603processing this key binding syntax: 604@var{DEL}, 605@var{ESC}, 606@var{ESCAPE}, 607@var{LFD}, 608@var{NEWLINE}, 609@var{RET}, 610@var{RETURN}, 611@var{RUBOUT}, 612@var{SPACE}, 613@var{SPC}, 614and 615@var{TAB}. 616 617@item @w{"@var{keyseq}": @var{function-name} or @var{macro}} 618@var{keyseq} differs from @var{keyname} above in that strings 619denoting an entire key sequence can be specified, by placing 620the key sequence in double quotes. Some @sc{gnu} Emacs style key 621escapes can be used, as in the following example, but the 622special character names are not recognized. 623 624@example 625"\C-u": universal-argument 626"\C-x\C-r": re-read-init-file 627"\e[11~": "Function Key 1" 628@end example 629 630In the above example, @kbd{C-u} is again bound to the function 631@code{universal-argument} (just as it was in the first example), 632@samp{@kbd{C-x} @kbd{C-r}} is bound to the function @code{re-read-init-file}, 633and @samp{@key{ESC} @key{[} @key{1} @key{1} @key{~}} is bound to insert 634the text @samp{Function Key 1}. 635 636@end table 637 638The following @sc{gnu} Emacs style escape sequences are available when 639specifying key sequences: 640 641@table @code 642@item @kbd{\C-} 643control prefix 644@item @kbd{\M-} 645meta prefix 646@item @kbd{\e} 647an escape character 648@item @kbd{\\} 649backslash 650@item @kbd{\"} 651@key{"}, a double quotation mark 652@item @kbd{\'} 653@key{'}, a single quote or apostrophe 654@end table 655 656In addition to the @sc{gnu} Emacs style escape sequences, a second 657set of backslash escapes is available: 658 659@table @code 660@item \a 661alert (bell) 662@item \b 663backspace 664@item \d 665delete 666@item \f 667form feed 668@item \n 669newline 670@item \r 671carriage return 672@item \t 673horizontal tab 674@item \v 675vertical tab 676@item \@var{nnn} 677the eight-bit character whose value is the octal value @var{nnn} 678(one to three digits) 679@item \x@var{HH} 680the eight-bit character whose value is the hexadecimal value @var{HH} 681(one or two hex digits) 682@end table 683 684When entering the text of a macro, single or double quotes must 685be used to indicate a macro definition. 686Unquoted text is assumed to be a function name. 687In the macro body, the backslash escapes described above are expanded. 688Backslash will quote any other character in the macro text, 689including @samp{"} and @samp{'}. 690For example, the following binding will make @samp{@kbd{C-x} \} 691insert a single @samp{\} into the line: 692@example 693"\C-x\\": "\\" 694@end example 695 696@end table 697 698@node Conditional Init Constructs 699@subsection Conditional Init Constructs 700 701Readline implements a facility similar in spirit to the conditional 702compilation features of the C preprocessor which allows key 703bindings and variable settings to be performed as the result 704of tests. There are four parser directives used. 705 706@table @code 707@item $if 708The @code{$if} construct allows bindings to be made based on the 709editing mode, the terminal being used, or the application using 710Readline. The text of the test extends to the end of the line; 711no characters are required to isolate it. 712 713@table @code 714@item mode 715The @code{mode=} form of the @code{$if} directive is used to test 716whether Readline is in @code{emacs} or @code{vi} mode. 717This may be used in conjunction 718with the @samp{set keymap} command, for instance, to set bindings in 719the @code{emacs-standard} and @code{emacs-ctlx} keymaps only if 720Readline is starting out in @code{emacs} mode. 721 722@item term 723The @code{term=} form may be used to include terminal-specific 724key bindings, perhaps to bind the key sequences output by the 725terminal's function keys. The word on the right side of the 726@samp{=} is tested against both the full name of the terminal and 727the portion of the terminal name before the first @samp{-}. This 728allows @code{sun} to match both @code{sun} and @code{sun-cmd}, 729for instance. 730 731@item application 732The @var{application} construct is used to include 733application-specific settings. Each program using the Readline 734library sets the @var{application name}, and you can test for 735a particular value. 736This could be used to bind key sequences to functions useful for 737a specific program. For instance, the following command adds a 738key sequence that quotes the current or previous word in Bash: 739@example 740$if Bash 741# Quote the current or previous word 742"\C-xq": "\eb\"\ef\"" 743$endif 744@end example 745@end table 746 747@item $endif 748This command, as seen in the previous example, terminates an 749@code{$if} command. 750 751@item $else 752Commands in this branch of the @code{$if} directive are executed if 753the test fails. 754 755@item $include 756This directive takes a single filename as an argument and reads commands 757and bindings from that file. 758For example, the following directive reads from @file{/etc/inputrc}: 759@example 760$include /etc/inputrc 761@end example 762@end table 763 764@node Sample Init File 765@subsection Sample Init File 766 767Here is an example of an @var{inputrc} file. This illustrates key 768binding, variable assignment, and conditional syntax. 769 770@example 771@page 772# This file controls the behaviour of line input editing for 773# programs that use the GNU Readline library. Existing 774# programs include FTP, Bash, and GDB. 775# 776# You can re-read the inputrc file with C-x C-r. 777# Lines beginning with '#' are comments. 778# 779# First, include any systemwide bindings and variable 780# assignments from /etc/Inputrc 781$include /etc/Inputrc 782 783# 784# Set various bindings for emacs mode. 785 786set editing-mode emacs 787 788$if mode=emacs 789 790Meta-Control-h: backward-kill-word Text after the function name is ignored 791 792# 793# Arrow keys in keypad mode 794# 795#"\M-OD": backward-char 796#"\M-OC": forward-char 797#"\M-OA": previous-history 798#"\M-OB": next-history 799# 800# Arrow keys in ANSI mode 801# 802"\M-[D": backward-char 803"\M-[C": forward-char 804"\M-[A": previous-history 805"\M-[B": next-history 806# 807# Arrow keys in 8 bit keypad mode 808# 809#"\M-\C-OD": backward-char 810#"\M-\C-OC": forward-char 811#"\M-\C-OA": previous-history 812#"\M-\C-OB": next-history 813# 814# Arrow keys in 8 bit ANSI mode 815# 816#"\M-\C-[D": backward-char 817#"\M-\C-[C": forward-char 818#"\M-\C-[A": previous-history 819#"\M-\C-[B": next-history 820 821C-q: quoted-insert 822 823$endif 824 825# An old-style binding. This happens to be the default. 826TAB: complete 827 828# Macros that are convenient for shell interaction 829$if Bash 830# edit the path 831"\C-xp": "PATH=$@{PATH@}\e\C-e\C-a\ef\C-f" 832# prepare to type a quoted word -- 833# insert open and close double quotes 834# and move to just after the open quote 835"\C-x\"": "\"\"\C-b" 836# insert a backslash (testing backslash escapes 837# in sequences and macros) 838"\C-x\\": "\\" 839# Quote the current or previous word 840"\C-xq": "\eb\"\ef\"" 841# Add a binding to refresh the line, which is unbound 842"\C-xr": redraw-current-line 843# Edit variable on current line. 844"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y=" 845$endif 846 847# use a visible bell if one is available 848set bell-style visible 849 850# don't strip characters to 7 bits when reading 851set input-meta on 852 853# allow iso-latin1 characters to be inserted rather 854# than converted to prefix-meta sequences 855set convert-meta off 856 857# display characters with the eighth bit set directly 858# rather than as meta-prefixed characters 859set output-meta on 860 861# if there are more than 150 possible completions for 862# a word, ask the user if he wants to see all of them 863set completion-query-items 150 864 865# For FTP 866$if Ftp 867"\C-xg": "get \M-?" 868"\C-xt": "put \M-?" 869"\M-.": yank-last-arg 870$endif 871@end example 872 873@node Bindable Readline Commands 874@section Bindable Readline Commands 875 876@menu 877* Commands For Moving:: Moving about the line. 878* Commands For History:: Getting at previous lines. 879* Commands For Text:: Commands for changing text. 880* Commands For Killing:: Commands for killing and yanking. 881* Numeric Arguments:: Specifying numeric arguments, repeat counts. 882* Commands For Completion:: Getting Readline to do the typing for you. 883* Keyboard Macros:: Saving and re-executing typed characters 884* Miscellaneous Commands:: Other miscellaneous commands. 885@end menu 886 887This section describes Readline commands that may be bound to key 888sequences. 889@ifset BashFeatures 890You can list your key bindings by executing 891@w{@code{bind -P}} or, for a more terse format, suitable for an 892@var{inputrc} file, @w{@code{bind -p}}. (@xref{Bash Builtins}.) 893@end ifset 894Command names without an accompanying key sequence are unbound by default. 895 896In the following descriptions, @dfn{point} refers to the current cursor 897position, and @dfn{mark} refers to a cursor position saved by the 898@code{set-mark} command. 899The text between the point and mark is referred to as the @dfn{region}. 900 901@node Commands For Moving 902@subsection Commands For Moving 903@ftable @code 904@item beginning-of-line (C-a) 905Move to the start of the current line. 906 907@item end-of-line (C-e) 908Move to the end of the line. 909 910@item forward-char (C-f) 911Move forward a character. 912 913@item backward-char (C-b) 914Move back a character. 915 916@item forward-word (M-f) 917Move forward to the end of the next word. Words are composed of 918letters and digits. 919 920@item backward-word (M-b) 921Move back to the start of the current or previous word. Words are 922composed of letters and digits. 923 924@item clear-screen (C-l) 925Clear the screen and redraw the current line, 926leaving the current line at the top of the screen. 927 928@item redraw-current-line () 929Refresh the current line. By default, this is unbound. 930 931@end ftable 932 933@node Commands For History 934@subsection Commands For Manipulating The History 935 936@ftable @code 937@item accept-line (Newline or Return) 938@ifset BashFeatures 939Accept the line regardless of where the cursor is. 940If this line is 941non-empty, add it to the history list according to the setting of 942the @env{HISTCONTROL} and @env{HISTIGNORE} variables. 943If this line is a modified history line, then restore the history line 944to its original state. 945@end ifset 946@ifclear BashFeatures 947Accept the line regardless of where the cursor is. 948If this line is 949non-empty, it may be added to the history list for future recall with 950@code{add_history()}. 951If this line is a modified history line, the history line is restored 952to its original state. 953@end ifclear 954 955@item previous-history (C-p) 956Move `back' through the history list, fetching the previous command. 957 958@item next-history (C-n) 959Move `forward' through the history list, fetching the next command. 960 961@item beginning-of-history (M-<) 962Move to the first line in the history. 963 964@item end-of-history (M->) 965Move to the end of the input history, i.e., the line currently 966being entered. 967 968@item reverse-search-history (C-r) 969Search backward starting at the current line and moving `up' through 970the history as necessary. This is an incremental search. 971 972@item forward-search-history (C-s) 973Search forward starting at the current line and moving `down' through 974the the history as necessary. This is an incremental search. 975 976@item non-incremental-reverse-search-history (M-p) 977Search backward starting at the current line and moving `up' 978through the history as necessary using a non-incremental search 979for a string supplied by the user. 980 981@item non-incremental-forward-search-history (M-n) 982Search forward starting at the current line and moving `down' 983through the the history as necessary using a non-incremental search 984for a string supplied by the user. 985 986@item history-search-forward () 987Search forward through the history for the string of characters 988between the start of the current line and the point. 989This is a non-incremental search. 990By default, this command is unbound. 991 992@item history-search-backward () 993Search backward through the history for the string of characters 994between the start of the current line and the point. This 995is a non-incremental search. By default, this command is unbound. 996 997@item yank-nth-arg (M-C-y) 998Insert the first argument to the previous command (usually 999the second word on the previous line) at point. 1000With an argument @var{n}, 1001insert the @var{n}th word from the previous command (the words 1002in the previous command begin with word 0). A negative argument 1003inserts the @var{n}th word from the end of the previous command. 1004 1005@item yank-last-arg (M-. or M-_) 1006Insert last argument to the previous command (the last word of the 1007previous history entry). With an 1008argument, behave exactly like @code{yank-nth-arg}. 1009Successive calls to @code{yank-last-arg} move back through the history 1010list, inserting the last argument of each line in turn. 1011 1012@end ftable 1013 1014@node Commands For Text 1015@subsection Commands For Changing Text 1016 1017@ftable @code 1018@item delete-char (C-d) 1019Delete the character at point. If point is at the 1020beginning of the line, there are no characters in the line, and 1021the last character typed was not bound to @code{delete-char}, then 1022return @sc{eof}. 1023 1024@item backward-delete-char (Rubout) 1025Delete the character behind the cursor. A numeric argument means 1026to kill the characters instead of deleting them. 1027 1028@item forward-backward-delete-char () 1029Delete the character under the cursor, unless the cursor is at the 1030end of the line, in which case the character behind the cursor is 1031deleted. By default, this is not bound to a key. 1032 1033@item quoted-insert (C-q or C-v) 1034Add the next character typed to the line verbatim. This is 1035how to insert key sequences like @kbd{C-q}, for example. 1036 1037@ifclear BashFeatures 1038@item tab-insert (M-@key{TAB}) 1039Insert a tab character. 1040@end ifclear 1041 1042@item self-insert (a, b, A, 1, !, @dots{}) 1043Insert yourself. 1044 1045@item transpose-chars (C-t) 1046Drag the character before the cursor forward over 1047the character at the cursor, moving the 1048cursor forward as well. If the insertion point 1049is at the end of the line, then this 1050transposes the last two characters of the line. 1051Negative arguments have no effect. 1052 1053@item transpose-words (M-t) 1054Drag the word before point past the word after point, 1055moving point past that word as well. 1056If the insertion point is at the end of the line, this transposes 1057the last two words on the line. 1058 1059@item upcase-word (M-u) 1060Uppercase the current (or following) word. With a negative argument, 1061uppercase the previous word, but do not move the cursor. 1062 1063@item downcase-word (M-l) 1064Lowercase the current (or following) word. With a negative argument, 1065lowercase the previous word, but do not move the cursor. 1066 1067@item capitalize-word (M-c) 1068Capitalize the current (or following) word. With a negative argument, 1069capitalize the previous word, but do not move the cursor. 1070 1071@item overwrite-mode () 1072Toggle overwrite mode. With an explicit positive numeric argument, 1073switches to overwrite mode. With an explicit non-positive numeric 1074argument, switches to insert mode. This command affects only 1075@code{emacs} mode; @code{vi} mode does overwrite differently. 1076Each call to @code{readline()} starts in insert mode. 1077 1078In overwrite mode, characters bound to @code{self-insert} replace 1079the text at point rather than pushing the text to the right. 1080Characters bound to @code{backward-delete-char} replace the character 1081before point with a space. 1082 1083By default, this command is unbound. 1084 1085@end ftable 1086 1087@node Commands For Killing 1088@subsection Killing And Yanking 1089 1090@ftable @code 1091 1092@item kill-line (C-k) 1093Kill the text from point to the end of the line. 1094 1095@item backward-kill-line (C-x Rubout) 1096Kill backward to the beginning of the line. 1097 1098@item unix-line-discard (C-u) 1099Kill backward from the cursor to the beginning of the current line. 1100 1101@item kill-whole-line () 1102Kill all characters on the current line, no matter where point is. 1103By default, this is unbound. 1104 1105@item kill-word (M-d) 1106Kill from point to the end of the current word, or if between 1107words, to the end of the next word. 1108Word boundaries are the same as @code{forward-word}. 1109 1110@item backward-kill-word (M-@key{DEL}) 1111Kill the word behind point. 1112Word boundaries are the same as @code{backward-word}. 1113 1114@item unix-word-rubout (C-w) 1115Kill the word behind point, using white space as a word boundary. 1116The killed text is saved on the kill-ring. 1117 1118@item delete-horizontal-space () 1119Delete all spaces and tabs around point. By default, this is unbound. 1120 1121@item kill-region () 1122Kill the text in the current region. 1123By default, this command is unbound. 1124 1125@item copy-region-as-kill () 1126Copy the text in the region to the kill buffer, so it can be yanked 1127right away. By default, this command is unbound. 1128 1129@item copy-backward-word () 1130Copy the word before point to the kill buffer. 1131The word boundaries are the same as @code{backward-word}. 1132By default, this command is unbound. 1133 1134@item copy-forward-word () 1135Copy the word following point to the kill buffer. 1136The word boundaries are the same as @code{forward-word}. 1137By default, this command is unbound. 1138 1139@item yank (C-y) 1140Yank the top of the kill ring into the buffer at point. 1141 1142@item yank-pop (M-y) 1143Rotate the kill-ring, and yank the new top. You can only do this if 1144the prior command is @code{yank} or @code{yank-pop}. 1145@end ftable 1146 1147@node Numeric Arguments 1148@subsection Specifying Numeric Arguments 1149@ftable @code 1150 1151@item digit-argument (@kbd{M-0}, @kbd{M-1}, @dots{} @kbd{M--}) 1152Add this digit to the argument already accumulating, or start a new 1153argument. @kbd{M--} starts a negative argument. 1154 1155@item universal-argument () 1156This is another way to specify an argument. 1157If this command is followed by one or more digits, optionally with a 1158leading minus sign, those digits define the argument. 1159If the command is followed by digits, executing @code{universal-argument} 1160again ends the numeric argument, but is otherwise ignored. 1161As a special case, if this command is immediately followed by a 1162character that is neither a digit or minus sign, the argument count 1163for the next command is multiplied by four. 1164The argument count is initially one, so executing this function the 1165first time makes the argument count four, a second time makes the 1166argument count sixteen, and so on. 1167By default, this is not bound to a key. 1168@end ftable 1169 1170@node Commands For Completion 1171@subsection Letting Readline Type For You 1172 1173@ftable @code 1174@item complete (@key{TAB}) 1175Attempt to perform completion on the text before point. 1176The actual completion performed is application-specific. 1177@ifset BashFeatures 1178Bash attempts completion treating the text as a variable (if the 1179text begins with @samp{$}), username (if the text begins with 1180@samp{~}), hostname (if the text begins with @samp{@@}), or 1181command (including aliases and functions) in turn. If none 1182of these produces a match, filename completion is attempted. 1183@end ifset 1184@ifclear BashFeatures 1185The default is filename completion. 1186@end ifclear 1187 1188@item possible-completions (M-?) 1189List the possible completions of the text before point. 1190 1191@item insert-completions (M-*) 1192Insert all completions of the text before point that would have 1193been generated by @code{possible-completions}. 1194 1195@item menu-complete () 1196Similar to @code{complete}, but replaces the word to be completed 1197with a single match from the list of possible completions. 1198Repeated execution of @code{menu-complete} steps through the list 1199of possible completions, inserting each match in turn. 1200At the end of the list of completions, the bell is rung 1201(subject to the setting of @code{bell-style}) 1202and the original text is restored. 1203An argument of @var{n} moves @var{n} positions forward in the list 1204of matches; a negative argument may be used to move backward 1205through the list. 1206This command is intended to be bound to @key{TAB}, but is unbound 1207by default. 1208 1209@item delete-char-or-list () 1210Deletes the character under the cursor if not at the beginning or 1211end of the line (like @code{delete-char}). 1212If at the end of the line, behaves identically to 1213@code{possible-completions}. 1214This command is unbound by default. 1215 1216@ifset BashFeatures 1217@item complete-filename (M-/) 1218Attempt filename completion on the text before point. 1219 1220@item possible-filename-completions (C-x /) 1221List the possible completions of the text before point, 1222treating it as a filename. 1223 1224@item complete-username (M-~) 1225Attempt completion on the text before point, treating 1226it as a username. 1227 1228@item possible-username-completions (C-x ~) 1229List the possible completions of the text before point, 1230treating it as a username. 1231 1232@item complete-variable (M-$) 1233Attempt completion on the text before point, treating 1234it as a shell variable. 1235 1236@item possible-variable-completions (C-x $) 1237List the possible completions of the text before point, 1238treating it as a shell variable. 1239 1240@item complete-hostname (M-@@) 1241Attempt completion on the text before point, treating 1242it as a hostname. 1243 1244@item possible-hostname-completions (C-x @@) 1245List the possible completions of the text before point, 1246treating it as a hostname. 1247 1248@item complete-command (M-!) 1249Attempt completion on the text before point, treating 1250it as a command name. Command completion attempts to 1251match the text against aliases, reserved words, shell 1252functions, shell builtins, and finally executable filenames, 1253in that order. 1254 1255@item possible-command-completions (C-x !) 1256List the possible completions of the text before point, 1257treating it as a command name. 1258 1259@item dynamic-complete-history (M-@key{TAB}) 1260Attempt completion on the text before point, comparing 1261the text against lines from the history list for possible 1262completion matches. 1263 1264@item complete-into-braces (M-@{) 1265Perform filename completion and insert the list of possible completions 1266enclosed within braces so the list is available to the shell 1267(@pxref{Brace Expansion}). 1268 1269@end ifset 1270@end ftable 1271 1272@node Keyboard Macros 1273@subsection Keyboard Macros 1274@ftable @code 1275 1276@item start-kbd-macro (C-x () 1277Begin saving the characters typed into the current keyboard macro. 1278 1279@item end-kbd-macro (C-x )) 1280Stop saving the characters typed into the current keyboard macro 1281and save the definition. 1282 1283@item call-last-kbd-macro (C-x e) 1284Re-execute the last keyboard macro defined, by making the characters 1285in the macro appear as if typed at the keyboard. 1286 1287@end ftable 1288 1289@node Miscellaneous Commands 1290@subsection Some Miscellaneous Commands 1291@ftable @code 1292 1293@item re-read-init-file (C-x C-r) 1294Read in the contents of the @var{inputrc} file, and incorporate 1295any bindings or variable assignments found there. 1296 1297@item abort (C-g) 1298Abort the current editing command and 1299ring the terminal's bell (subject to the setting of 1300@code{bell-style}). 1301 1302@item do-uppercase-version (M-a, M-b, M-@var{x}, @dots{}) 1303If the metafied character @var{x} is lowercase, run the command 1304that is bound to the corresponding uppercase character. 1305 1306@item prefix-meta (@key{ESC}) 1307Metafy the next character typed. This is for keyboards 1308without a meta key. Typing @samp{@key{ESC} f} is equivalent to typing 1309@kbd{M-f}. 1310 1311@item undo (C-_ or C-x C-u) 1312Incremental undo, separately remembered for each line. 1313 1314@item revert-line (M-r) 1315Undo all changes made to this line. This is like executing the @code{undo} 1316command enough times to get back to the beginning. 1317 1318@ifset BashFeatures 1319@item tilde-expand (M-&) 1320@end ifset 1321@ifclear BashFeatures 1322@item tilde-expand (M-~) 1323@end ifclear 1324Perform tilde expansion on the current word. 1325 1326@item set-mark (C-@@) 1327Set the mark to the point. If a 1328numeric argument is supplied, the mark is set to that position. 1329 1330@item exchange-point-and-mark (C-x C-x) 1331Swap the point with the mark. The current cursor position is set to 1332the saved position, and the old cursor position is saved as the mark. 1333 1334@item character-search (C-]) 1335A character is read and point is moved to the next occurrence of that 1336character. A negative count searches for previous occurrences. 1337 1338@item character-search-backward (M-C-]) 1339A character is read and point is moved to the previous occurrence 1340of that character. A negative count searches for subsequent 1341occurrences. 1342 1343@item insert-comment (M-#) 1344Without a numeric argument, the value of the @code{comment-begin} 1345variable is inserted at the beginning of the current line. 1346If a numeric argument is supplied, this command acts as a toggle: if 1347the characters at the beginning of the line do not match the value 1348of @code{comment-begin}, the value is inserted, otherwise 1349the characters in @code{comment-begin} are deleted from the beginning of 1350the line. 1351In either case, the line is accepted as if a newline had been typed. 1352@ifset BashFeatures 1353The default value of @code{comment-begin} causes this command 1354to make the current line a shell comment. 1355If a numeric argument causes the comment character to be removed, the line 1356will be executed by the shell. 1357@end ifset 1358 1359@item dump-functions () 1360Print all of the functions and their key bindings to the 1361Readline output stream. If a numeric argument is supplied, 1362the output is formatted in such a way that it can be made part 1363of an @var{inputrc} file. This command is unbound by default. 1364 1365@item dump-variables () 1366Print all of the settable variables and their values to the 1367Readline output stream. If a numeric argument is supplied, 1368the output is formatted in such a way that it can be made part 1369of an @var{inputrc} file. This command is unbound by default. 1370 1371@item dump-macros () 1372Print all of the Readline key sequences bound to macros and the 1373strings they output. If a numeric argument is supplied, 1374the output is formatted in such a way that it can be made part 1375of an @var{inputrc} file. This command is unbound by default. 1376 1377@ifset BashFeatures 1378@item glob-complete-word (M-g) 1379The word before point is treated as a pattern for pathname expansion, 1380with an asterisk implicitly appended. This pattern is used to 1381generate a list of matching file names for possible completions. 1382 1383@item glob-expand-word (C-x *) 1384The word before point is treated as a pattern for pathname expansion, 1385and the list of matching file names is inserted, replacing the word. 1386If a numeric argument is supplied, a @samp{*} is appended before 1387pathname expansion. 1388 1389@item glob-list-expansions (C-x g) 1390The list of expansions that would have been generated by 1391@code{glob-expand-word} is displayed, and the line is redrawn. 1392If a numeric argument is supplied, a @samp{*} is appended before 1393pathname expansion. 1394 1395@item display-shell-version (C-x C-v) 1396Display version information about the current instance of Bash. 1397 1398@item shell-expand-line (M-C-e) 1399Expand the line as the shell does. 1400This performs alias and history expansion as well as all of the shell 1401word expansions (@pxref{Shell Expansions}). 1402 1403@item history-expand-line (M-^) 1404Perform history expansion on the current line. 1405 1406@item magic-space () 1407Perform history expansion on the current line and insert a space 1408(@pxref{History Interaction}). 1409 1410@item alias-expand-line () 1411Perform alias expansion on the current line (@pxref{Aliases}). 1412 1413@item history-and-alias-expand-line () 1414Perform history and alias expansion on the current line. 1415 1416@item insert-last-argument (M-. or M-_) 1417A synonym for @code{yank-last-arg}. 1418 1419@item operate-and-get-next (C-o) 1420Accept the current line for execution and fetch the next line 1421relative to the current line from the history for editing. Any 1422argument is ignored. 1423 1424@item edit-and-execute-command (C-xC-e) 1425Invoke an editor on the current command line, and execute the result as shell 1426commands. 1427Bash attempts to invoke 1428@code{$FCEDIT}, @code{$EDITOR}, and @code{emacs} 1429as the editor, in that order. 1430 1431@end ifset 1432 1433@ifclear BashFeatures 1434@item emacs-editing-mode (C-e) 1435When in @code{vi} command mode, this causes a switch to @code{emacs} 1436editing mode. 1437 1438@item vi-editing-mode (M-C-j) 1439When in @code{emacs} editing mode, this causes a switch to @code{vi} 1440editing mode. 1441 1442@end ifclear 1443 1444@end ftable 1445 1446@node Readline vi Mode 1447@section Readline vi Mode 1448 1449While the Readline library does not have a full set of @code{vi} 1450editing functions, it does contain enough to allow simple editing 1451of the line. The Readline @code{vi} mode behaves as specified in 1452the @sc{posix} 1003.2 standard. 1453 1454@ifset BashFeatures 1455In order to switch interactively between @code{emacs} and @code{vi} 1456editing modes, use the @samp{set -o emacs} and @samp{set -o vi} 1457commands (@pxref{The Set Builtin}). 1458@end ifset 1459@ifclear BashFeatures 1460In order to switch interactively between @code{emacs} and @code{vi} 1461editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode 1462when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode). 1463@end ifclear 1464The Readline default is @code{emacs} mode. 1465 1466When you enter a line in @code{vi} mode, you are already placed in 1467`insertion' mode, as if you had typed an @samp{i}. Pressing @key{ESC} 1468switches you into `command' mode, where you can edit the text of the 1469line with the standard @code{vi} movement keys, move to previous 1470history lines with @samp{k} and subsequent lines with @samp{j}, and 1471so forth. 1472 1473@ifset BashFeatures 1474@node Programmable Completion 1475@section Programmable Completion 1476@cindex programmable completion 1477 1478When word completion is attempted for an argument to a command for 1479which a completion specification (a @var{compspec}) has been defined 1480using the @code{complete} builtin (@pxref{Programmable Completion Builtins}), 1481the programmable completion facilities are invoked. 1482 1483First, the command name is identified. 1484If a compspec has been defined for that command, the 1485compspec is used to generate the list of possible completions for the word. 1486If the command word is a full pathname, a compspec for the full 1487pathname is searched for first. 1488If no compspec is found for the full pathname, an attempt is made to 1489find a compspec for the portion following the final slash. 1490 1491Once a compspec has been found, it is used to generate the list of 1492matching words. 1493If a compspec is not found, the default Bash completion 1494described above (@pxref{Commands For Completion}) is performed. 1495 1496First, the actions specified by the compspec are used. 1497Only matches which are prefixed by the word being completed are 1498returned. 1499When the @option{-f} or @option{-d} option is used for filename or 1500directory name completion, the shell variable @env{FIGNORE} is 1501used to filter the matches. 1502@xref{Bash Variables}, for a description of @env{FIGNORE}. 1503 1504Any completions specified by a filename expansion pattern to the 1505@option{-G} option are generated next. 1506The words generated by the pattern need not match the word being completed. 1507The @env{GLOBIGNORE} shell variable is not used to filter the matches, 1508but the @env{FIGNORE} shell variable is used. 1509 1510Next, the string specified as the argument to the @option{-W} option 1511is considered. 1512The string is first split using the characters in the @env{IFS} 1513special variable as delimiters. 1514Shell quoting is honored. 1515Each word is then expanded using 1516brace expansion, tilde expansion, parameter and variable expansion, 1517command substitution, arithmetic expansion, and pathname expansion, 1518as described above (@pxref{Shell Expansions}). 1519The results are split using the rules described above 1520(@pxref{Word Splitting}). 1521The results of the expansion are prefix-matched against the word being 1522completed, and the matching words become the possible completions. 1523 1524After these matches have been generated, any shell function or command 1525specified with the @option{-F} and @option{-C} options is invoked. 1526When the command or function is invoked, the @env{COMP_LINE} and 1527@env{COMP_POINT} variables are assigned values as described above 1528(@pxref{Bash Variables}). 1529If a shell function is being invoked, the @env{COMP_WORDS} and 1530@env{COMP_CWORD} variables are also set. 1531When the function or command is invoked, the first argument is the 1532name of the command whose arguments are being completed, the 1533second argument is the word being completed, and the third argument 1534is the word preceding the word being completed on the current command line. 1535No filtering of the generated completions against the word being completed 1536is performed; the function or command has complete freedom in generating 1537the matches. 1538 1539Any function specified with @option{-F} is invoked first. 1540The function may use any of the shell facilities, including the 1541@code{compgen} builtin described below 1542(@pxref{Programmable Completion Builtins}), to generate the matches. 1543It must put the possible completions in the @env{COMPREPLY} array 1544variable. 1545 1546Next, any command specified with the @option{-C} option is invoked 1547in an environment equivalent to command substitution. 1548It should print a list of completions, one per line, to 1549the standard output. 1550Backslash may be used to escape a newline, if necessary. 1551 1552After all of the possible completions are generated, any filter 1553specified with the @option{-X} option is applied to the list. 1554The filter is a pattern as used for pathname expansion; a @samp{&} 1555in the pattern is replaced with the text of the word being completed. 1556A literal @samp{&} may be escaped with a backslash; the backslash 1557is removed before attempting a match. 1558Any completion that matches the pattern will be removed from the list. 1559A leading @samp{!} negates the pattern; in this case any completion 1560not matching the pattern will be removed. 1561 1562Finally, any prefix and suffix specified with the @option{-P} and @option{-S} 1563options are added to each member of the completion list, and the result is 1564returned to the Readline completion code as the list of possible 1565completions. 1566 1567If the previously-applied actions do not generate any matches, and the 1568@option{-o dirnames} option was supplied to @code{complete} when the 1569compspec was defined, directory name completion is attempted. 1570 1571By default, if a compspec is found, whatever it generates is returned to 1572the completion code as the full set of possible completions. 1573The default Bash completions are not attempted, and the Readline default 1574of filename completion is disabled. 1575If the @option{-o default} option was supplied to @code{complete} when the 1576compspec was defined, Readline's default completion will be performed 1577if the compspec generates no matches. 1578 1579When a compspec indicates that directory name completion is desired, 1580the programmable completion functions force Readline to append a slash 1581to completed names which are symbolic links to directories, subject to 1582the value of the @var{mark-directories} Readline variable, regardless 1583of the setting of the @var{mark-symlinked-directories} Readline variable. 1584 1585@node Programmable Completion Builtins 1586@section Programmable Completion Builtins 1587@cindex completion builtins 1588 1589Two builtin commands are available to manipulate the programmable completion 1590facilities. 1591 1592@table @code 1593@item compgen 1594@btindex compgen 1595@example 1596@code{compgen [@var{option}] [@var{word}]} 1597@end example 1598 1599Generate possible completion matches for @var{word} according to 1600the @var{option}s, which may be any option accepted by the 1601@code{complete} 1602builtin with the exception of @option{-p} and @option{-r}, and write 1603the matches to the standard output. 1604When using the @option{-F} or @option{-C} options, the various shell variables 1605set by the programmable completion facilities, while available, will not 1606have useful values. 1607 1608The matches will be generated in the same way as if the programmable 1609completion code had generated them directly from a completion specification 1610with the same flags. 1611If @var{word} is specified, only those completions matching @var{word} 1612will be displayed. 1613 1614The return value is true unless an invalid option is supplied, or no 1615matches were generated. 1616 1617@item complete 1618@btindex complete 1619@example 1620@code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-A @var{action}] [-G @var{globpat}] [-W @var{wordlist}] 1621[-P @var{prefix}] [-S @var{suffix}] [-X @var{filterpat}] [-F @var{function}] 1622[-C @var{command}] @var{name} [@var{name} @dots{}]} 1623@code{complete -pr [@var{name} @dots{}]} 1624@end example 1625 1626Specify how arguments to each @var{name} should be completed. 1627If the @option{-p} option is supplied, or if no options are supplied, existing 1628completion specifications are printed in a way that allows them to be 1629reused as input. 1630The @option{-r} option removes a completion specification for 1631each @var{name}, or, if no @var{name}s are supplied, all 1632completion specifications. 1633 1634The process of applying these completion specifications when word completion 1635is attempted is described above (@pxref{Programmable Completion}). 1636 1637Other options, if specified, have the following meanings. 1638The arguments to the @option{-G}, @option{-W}, and @option{-X} options 1639(and, if necessary, the @option{-P} and @option{-S} options) 1640should be quoted to protect them from expansion before the 1641@code{complete} builtin is invoked. 1642 1643 1644@table @code 1645@item -o @var{comp-option} 1646The @var{comp-option} controls several aspects of the compspec's behavior 1647beyond the simple generation of completions. 1648@var{comp-option} may be one of: 1649 1650@table @code 1651 1652@item default 1653Use Readline's default filename completion if the compspec generates 1654no matches. 1655 1656@item dirnames 1657Perform directory name completion if the compspec generates no matches. 1658 1659@item filenames 1660Tell Readline that the compspec generates filenames, so it can perform any 1661filename\-specific processing (like adding a slash to directory names or 1662suppressing trailing spaces). This option is intended to be used with 1663shell functions specified with @option{-F}. 1664 1665@item nospace 1666Tell Readline not to append a space (the default) to words completed at 1667the end of the line. 1668@end table 1669 1670@item -A @var{action} 1671The @var{action} may be one of the following to generate a list of possible 1672completions: 1673 1674@table @code 1675@item alias 1676Alias names. May also be specified as @option{-a}. 1677 1678@item arrayvar 1679Array variable names. 1680 1681@item binding 1682Readline key binding names (@pxref{Bindable Readline Commands}). 1683 1684@item builtin 1685Names of shell builtin commands. May also be specified as @option{-b}. 1686 1687@item command 1688Command names. May also be specified as @option{-c}. 1689 1690@item directory 1691Directory names. May also be specified as @option{-d}. 1692 1693@item disabled 1694Names of disabled shell builtins. 1695 1696@item enabled 1697Names of enabled shell builtins. 1698 1699@item export 1700Names of exported shell variables. May also be specified as @option{-e}. 1701 1702@item file 1703File names. May also be specified as @option{-f}. 1704 1705@item function 1706Names of shell functions. 1707 1708@item group 1709Group names. May also be specified as @option{-g}. 1710 1711@item helptopic 1712Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}). 1713 1714@item hostname 1715Hostnames, as taken from the file specified by the 1716@env{HOSTFILE} shell variable (@pxref{Bash Variables}). 1717 1718@item job 1719Job names, if job control is active. May also be specified as @option{-j}. 1720 1721@item keyword 1722Shell reserved words. May also be specified as @option{-k}. 1723 1724@item running 1725Names of running jobs, if job control is active. 1726 1727@item service 1728Service names. May also be specified as @option{-s}. 1729 1730@item setopt 1731Valid arguments for the @option{-o} option to the @code{set} builtin 1732(@pxref{The Set Builtin}). 1733 1734@item shopt 1735Shell option names as accepted by the @code{shopt} builtin 1736(@pxref{Bash Builtins}). 1737 1738@item signal 1739Signal names. 1740 1741@item stopped 1742Names of stopped jobs, if job control is active. 1743 1744@item user 1745User names. May also be specified as @option{-u}. 1746 1747@item variable 1748Names of all shell variables. May also be specified as @option{-v}. 1749@end table 1750 1751@item -G @var{globpat} 1752The filename expansion pattern @var{globpat} is expanded to generate 1753the possible completions. 1754 1755@item -W @var{wordlist} 1756The @var{wordlist} is split using the characters in the 1757@env{IFS} special variable as delimiters, and each resultant word 1758is expanded. 1759The possible completions are the members of the resultant list which 1760match the word being completed. 1761 1762@item -C @var{command} 1763@var{command} is executed in a subshell environment, and its output is 1764used as the possible completions. 1765 1766@item -F @var{function} 1767The shell function @var{function} is executed in the current shell 1768environment. 1769When it finishes, the possible completions are retrieved from the value 1770of the @env{COMPREPLY} array variable. 1771 1772@item -X @var{filterpat} 1773@var{filterpat} is a pattern as used for filename expansion. 1774It is applied to the list of possible completions generated by the 1775preceding options and arguments, and each completion matching 1776@var{filterpat} is removed from the list. 1777A leading @samp{!} in @var{filterpat} negates the pattern; in this 1778case, any completion not matching @var{filterpat} is removed. 1779 1780@item -P @var{prefix} 1781@var{prefix} is added at the beginning of each possible completion 1782after all other options have been applied. 1783 1784@item -S @var{suffix} 1785@var{suffix} is appended to each possible completion 1786after all other options have been applied. 1787@end table 1788 1789The return value is true unless an invalid option is supplied, an option 1790other than @option{-p} or @option{-r} is supplied without a @var{name} 1791argument, an attempt is made to remove a completion specification for 1792a @var{name} for which no specification exists, or 1793an error occurs adding a completion specification. 1794 1795@end table 1796@end ifset 1797