rluser.texi revision 165671
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) 1988-2006 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}. If that 340file does not exist or cannot be read, the ultimate default is 341@file{/etc/inputrc}. 342 343When a program which uses the Readline library starts up, the 344init file is read, and the key bindings are set. 345 346In addition, the @code{C-x C-r} command re-reads this init file, thus 347incorporating any changes that you might have made to it. 348 349@menu 350* Readline Init File Syntax:: Syntax for the commands in the inputrc file. 351 352* Conditional Init Constructs:: Conditional key bindings in the inputrc file. 353 354* Sample Init File:: An example inputrc file. 355@end menu 356 357@node Readline Init File Syntax 358@subsection Readline Init File Syntax 359 360There are only a few basic constructs allowed in the 361Readline init file. Blank lines are ignored. 362Lines beginning with a @samp{#} are comments. 363Lines beginning with a @samp{$} indicate conditional 364constructs (@pxref{Conditional Init Constructs}). Other lines 365denote variable settings and key bindings. 366 367@table @asis 368@item Variable Settings 369You can modify the run-time behavior of Readline by 370altering the values of variables in Readline 371using the @code{set} command within the init file. 372The syntax is simple: 373 374@example 375set @var{variable} @var{value} 376@end example 377 378@noindent 379Here, for example, is how to 380change from the default Emacs-like key binding to use 381@code{vi} line editing commands: 382 383@example 384set editing-mode vi 385@end example 386 387Variable names and values, where appropriate, are recognized without regard 388to case. Unrecognized variable names are ignored. 389 390Boolean variables (those that can be set to on or off) are set to on if 391the value is null or empty, @var{on} (case-insensitive), or 1. Any other 392value results in the variable being set to off. 393 394@ifset BashFeatures 395The @w{@code{bind -V}} command lists the current Readline variable names 396and values. @xref{Bash Builtins}. 397@end ifset 398 399A great deal of run-time behavior is changeable with the following 400variables. 401 402@cindex variables, readline 403@table @code 404 405@item bell-style 406@vindex bell-style 407Controls what happens when Readline wants to ring the terminal bell. 408If set to @samp{none}, Readline never rings the bell. If set to 409@samp{visible}, Readline uses a visible bell if one is available. 410If set to @samp{audible} (the default), Readline attempts to ring 411the terminal's bell. 412 413@item bind-tty-special-chars 414@vindex bind-tty-special-chars 415If set to @samp{on}, Readline attempts to bind the control characters 416treated specially by the kernel's terminal driver to their Readline 417equivalents. 418 419@item comment-begin 420@vindex comment-begin 421The string to insert at the beginning of the line when the 422@code{insert-comment} command is executed. The default value 423is @code{"#"}. 424 425@item completion-ignore-case 426If set to @samp{on}, Readline performs filename matching and completion 427in a case-insensitive fashion. 428The default value is @samp{off}. 429 430@item completion-query-items 431@vindex completion-query-items 432The number of possible completions that determines when the user is 433asked whether the list of possibilities should be displayed. 434If the number of possible completions is greater than this value, 435Readline will ask the user whether or not he wishes to view 436them; otherwise, they are simply listed. 437This variable must be set to an integer value greater than or equal to 0. 438A negative value means Readline should never ask. 439The default limit is @code{100}. 440 441@item convert-meta 442@vindex convert-meta 443If set to @samp{on}, Readline will convert characters with the 444eighth bit set to an @sc{ascii} key sequence by stripping the eighth 445bit and prefixing an @key{ESC} character, converting them to a 446meta-prefixed key sequence. The default value is @samp{on}. 447 448@item disable-completion 449@vindex disable-completion 450If set to @samp{On}, Readline will inhibit word completion. 451Completion characters will be inserted into the line as if they had 452been mapped to @code{self-insert}. The default is @samp{off}. 453 454@item editing-mode 455@vindex editing-mode 456The @code{editing-mode} variable controls which default set of 457key bindings is used. By default, Readline starts up in Emacs editing 458mode, where the keystrokes are most similar to Emacs. This variable can be 459set to either @samp{emacs} or @samp{vi}. 460 461@item enable-keypad 462@vindex enable-keypad 463When set to @samp{on}, Readline will try to enable the application 464keypad when it is called. Some systems need this to enable the 465arrow keys. The default is @samp{off}. 466 467@item expand-tilde 468@vindex expand-tilde 469If set to @samp{on}, tilde expansion is performed when Readline 470attempts word completion. The default is @samp{off}. 471 472@item history-preserve-point 473@vindex history-preserve-point 474If set to @samp{on}, the history code attempts to place point at the 475same location on each history line retrieved with @code{previous-history} 476or @code{next-history}. The default is @samp{off}. 477 478@item horizontal-scroll-mode 479@vindex horizontal-scroll-mode 480This variable can be set to either @samp{on} or @samp{off}. Setting it 481to @samp{on} means that the text of the lines being edited will scroll 482horizontally on a single screen line when they are longer than the width 483of the screen, instead of wrapping onto a new screen line. By default, 484this variable is set to @samp{off}. 485 486@item input-meta 487@vindex input-meta 488@vindex meta-flag 489If set to @samp{on}, Readline will enable eight-bit input (it 490will not clear the eighth bit in the characters it reads), 491regardless of what the terminal claims it can support. The 492default value is @samp{off}. The name @code{meta-flag} is a 493synonym for this variable. 494 495@item isearch-terminators 496@vindex isearch-terminators 497The string of characters that should terminate an incremental search without 498subsequently executing the character as a command (@pxref{Searching}). 499If this variable has not been given a value, the characters @key{ESC} and 500@kbd{C-J} will terminate an incremental search. 501 502@item keymap 503@vindex keymap 504Sets Readline's idea of the current keymap for key binding commands. 505Acceptable @code{keymap} names are 506@code{emacs}, 507@code{emacs-standard}, 508@code{emacs-meta}, 509@code{emacs-ctlx}, 510@code{vi}, 511@code{vi-move}, 512@code{vi-command}, and 513@code{vi-insert}. 514@code{vi} is equivalent to @code{vi-command}; @code{emacs} is 515equivalent to @code{emacs-standard}. The default value is @code{emacs}. 516The value of the @code{editing-mode} variable also affects the 517default keymap. 518 519@item mark-directories 520If set to @samp{on}, completed directory names have a slash 521appended. The default is @samp{on}. 522 523@item mark-modified-lines 524@vindex mark-modified-lines 525This variable, when set to @samp{on}, causes Readline to display an 526asterisk (@samp{*}) at the start of history lines which have been modified. 527This variable is @samp{off} by default. 528 529@item mark-symlinked-directories 530@vindex mark-symlinked-directories 531If set to @samp{on}, completed names which are symbolic links 532to directories have a slash appended (subject to the value of 533@code{mark-directories}). 534The default is @samp{off}. 535 536@item match-hidden-files 537@vindex match-hidden-files 538This variable, when set to @samp{on}, causes Readline to match files whose 539names begin with a @samp{.} (hidden files) when performing filename 540completion, unless the leading @samp{.} is 541supplied by the user in the filename to be completed. 542This variable is @samp{on} by default. 543 544@item output-meta 545@vindex output-meta 546If set to @samp{on}, Readline will display characters with the 547eighth bit set directly rather than as a meta-prefixed escape 548sequence. The default is @samp{off}. 549 550@item page-completions 551@vindex page-completions 552If set to @samp{on}, Readline uses an internal @code{more}-like pager 553to display a screenful of possible completions at a time. 554This variable is @samp{on} by default. 555 556@item print-completions-horizontally 557If set to @samp{on}, Readline will display completions with matches 558sorted horizontally in alphabetical order, rather than down the screen. 559The default is @samp{off}. 560 561@item show-all-if-ambiguous 562@vindex show-all-if-ambiguous 563This alters the default behavior of the completion functions. If 564set to @samp{on}, 565words which have more than one possible completion cause the 566matches to be listed immediately instead of ringing the bell. 567The default value is @samp{off}. 568 569@item show-all-if-unmodified 570@vindex show-all-if-unmodified 571This alters the default behavior of the completion functions in 572a fashion similar to @var{show-all-if-ambiguous}. 573If set to @samp{on}, 574words which have more than one possible completion without any 575possible partial completion (the possible completions don't share 576a common prefix) cause the matches to be listed immediately instead 577of ringing the bell. 578The default value is @samp{off}. 579 580@item visible-stats 581@vindex visible-stats 582If set to @samp{on}, a character denoting a file's type 583is appended to the filename when listing possible 584completions. The default is @samp{off}. 585 586@end table 587 588@item Key Bindings 589The syntax for controlling key bindings in the init file is 590simple. First you need to find the name of the command that you 591want to change. The following sections contain tables of the command 592name, the default keybinding, if any, and a short description of what 593the command does. 594 595Once you know the name of the command, simply place on a line 596in the init file the name of the key 597you wish to bind the command to, a colon, and then the name of the 598command. 599There can be no space between the key name and the colon -- that will be 600interpreted as part of the key name. 601The name of the key can be expressed in different ways, depending on 602what you find most comfortable. 603 604In addition to command names, readline allows keys to be bound 605to a string that is inserted when the key is pressed (a @var{macro}). 606 607@ifset BashFeatures 608The @w{@code{bind -p}} command displays Readline function names and 609bindings in a format that can put directly into an initialization file. 610@xref{Bash Builtins}. 611@end ifset 612 613@table @asis 614@item @w{@var{keyname}: @var{function-name} or @var{macro}} 615@var{keyname} is the name of a key spelled out in English. For example: 616@example 617Control-u: universal-argument 618Meta-Rubout: backward-kill-word 619Control-o: "> output" 620@end example 621 622In the above example, @kbd{C-u} is bound to the function 623@code{universal-argument}, 624@kbd{M-DEL} is bound to the function @code{backward-kill-word}, and 625@kbd{C-o} is bound to run the macro 626expressed on the right hand side (that is, to insert the text 627@samp{> output} into the line). 628 629A number of symbolic character names are recognized while 630processing this key binding syntax: 631@var{DEL}, 632@var{ESC}, 633@var{ESCAPE}, 634@var{LFD}, 635@var{NEWLINE}, 636@var{RET}, 637@var{RETURN}, 638@var{RUBOUT}, 639@var{SPACE}, 640@var{SPC}, 641and 642@var{TAB}. 643 644@item @w{"@var{keyseq}": @var{function-name} or @var{macro}} 645@var{keyseq} differs from @var{keyname} above in that strings 646denoting an entire key sequence can be specified, by placing 647the key sequence in double quotes. Some @sc{gnu} Emacs style key 648escapes can be used, as in the following example, but the 649special character names are not recognized. 650 651@example 652"\C-u": universal-argument 653"\C-x\C-r": re-read-init-file 654"\e[11~": "Function Key 1" 655@end example 656 657In the above example, @kbd{C-u} is again bound to the function 658@code{universal-argument} (just as it was in the first example), 659@samp{@kbd{C-x} @kbd{C-r}} is bound to the function @code{re-read-init-file}, 660and @samp{@key{ESC} @key{[} @key{1} @key{1} @key{~}} is bound to insert 661the text @samp{Function Key 1}. 662 663@end table 664 665The following @sc{gnu} Emacs style escape sequences are available when 666specifying key sequences: 667 668@table @code 669@item @kbd{\C-} 670control prefix 671@item @kbd{\M-} 672meta prefix 673@item @kbd{\e} 674an escape character 675@item @kbd{\\} 676backslash 677@item @kbd{\"} 678@key{"}, a double quotation mark 679@item @kbd{\'} 680@key{'}, a single quote or apostrophe 681@end table 682 683In addition to the @sc{gnu} Emacs style escape sequences, a second 684set of backslash escapes is available: 685 686@table @code 687@item \a 688alert (bell) 689@item \b 690backspace 691@item \d 692delete 693@item \f 694form feed 695@item \n 696newline 697@item \r 698carriage return 699@item \t 700horizontal tab 701@item \v 702vertical tab 703@item \@var{nnn} 704the eight-bit character whose value is the octal value @var{nnn} 705(one to three digits) 706@item \x@var{HH} 707the eight-bit character whose value is the hexadecimal value @var{HH} 708(one or two hex digits) 709@end table 710 711When entering the text of a macro, single or double quotes must 712be used to indicate a macro definition. 713Unquoted text is assumed to be a function name. 714In the macro body, the backslash escapes described above are expanded. 715Backslash will quote any other character in the macro text, 716including @samp{"} and @samp{'}. 717For example, the following binding will make @samp{@kbd{C-x} \} 718insert a single @samp{\} into the line: 719@example 720"\C-x\\": "\\" 721@end example 722 723@end table 724 725@node Conditional Init Constructs 726@subsection Conditional Init Constructs 727 728Readline implements a facility similar in spirit to the conditional 729compilation features of the C preprocessor which allows key 730bindings and variable settings to be performed as the result 731of tests. There are four parser directives used. 732 733@table @code 734@item $if 735The @code{$if} construct allows bindings to be made based on the 736editing mode, the terminal being used, or the application using 737Readline. The text of the test extends to the end of the line; 738no characters are required to isolate it. 739 740@table @code 741@item mode 742The @code{mode=} form of the @code{$if} directive is used to test 743whether Readline is in @code{emacs} or @code{vi} mode. 744This may be used in conjunction 745with the @samp{set keymap} command, for instance, to set bindings in 746the @code{emacs-standard} and @code{emacs-ctlx} keymaps only if 747Readline is starting out in @code{emacs} mode. 748 749@item term 750The @code{term=} form may be used to include terminal-specific 751key bindings, perhaps to bind the key sequences output by the 752terminal's function keys. The word on the right side of the 753@samp{=} is tested against both the full name of the terminal and 754the portion of the terminal name before the first @samp{-}. This 755allows @code{sun} to match both @code{sun} and @code{sun-cmd}, 756for instance. 757 758@item application 759The @var{application} construct is used to include 760application-specific settings. Each program using the Readline 761library sets the @var{application name}, and you can test for 762a particular value. 763This could be used to bind key sequences to functions useful for 764a specific program. For instance, the following command adds a 765key sequence that quotes the current or previous word in Bash: 766@example 767$if Bash 768# Quote the current or previous word 769"\C-xq": "\eb\"\ef\"" 770$endif 771@end example 772@end table 773 774@item $endif 775This command, as seen in the previous example, terminates an 776@code{$if} command. 777 778@item $else 779Commands in this branch of the @code{$if} directive are executed if 780the test fails. 781 782@item $include 783This directive takes a single filename as an argument and reads commands 784and bindings from that file. 785For example, the following directive reads from @file{/etc/inputrc}: 786@example 787$include /etc/inputrc 788@end example 789@end table 790 791@node Sample Init File 792@subsection Sample Init File 793 794Here is an example of an @var{inputrc} file. This illustrates key 795binding, variable assignment, and conditional syntax. 796 797@example 798@page 799# This file controls the behaviour of line input editing for 800# programs that use the GNU Readline library. Existing 801# programs include FTP, Bash, and GDB. 802# 803# You can re-read the inputrc file with C-x C-r. 804# Lines beginning with '#' are comments. 805# 806# First, include any systemwide bindings and variable 807# assignments from /etc/Inputrc 808$include /etc/Inputrc 809 810# 811# Set various bindings for emacs mode. 812 813set editing-mode emacs 814 815$if mode=emacs 816 817Meta-Control-h: backward-kill-word Text after the function name is ignored 818 819# 820# Arrow keys in keypad mode 821# 822#"\M-OD": backward-char 823#"\M-OC": forward-char 824#"\M-OA": previous-history 825#"\M-OB": next-history 826# 827# Arrow keys in ANSI mode 828# 829"\M-[D": backward-char 830"\M-[C": forward-char 831"\M-[A": previous-history 832"\M-[B": next-history 833# 834# Arrow keys in 8 bit keypad mode 835# 836#"\M-\C-OD": backward-char 837#"\M-\C-OC": forward-char 838#"\M-\C-OA": previous-history 839#"\M-\C-OB": next-history 840# 841# Arrow keys in 8 bit ANSI mode 842# 843#"\M-\C-[D": backward-char 844#"\M-\C-[C": forward-char 845#"\M-\C-[A": previous-history 846#"\M-\C-[B": next-history 847 848C-q: quoted-insert 849 850$endif 851 852# An old-style binding. This happens to be the default. 853TAB: complete 854 855# Macros that are convenient for shell interaction 856$if Bash 857# edit the path 858"\C-xp": "PATH=$@{PATH@}\e\C-e\C-a\ef\C-f" 859# prepare to type a quoted word -- 860# insert open and close double quotes 861# and move to just after the open quote 862"\C-x\"": "\"\"\C-b" 863# insert a backslash (testing backslash escapes 864# in sequences and macros) 865"\C-x\\": "\\" 866# Quote the current or previous word 867"\C-xq": "\eb\"\ef\"" 868# Add a binding to refresh the line, which is unbound 869"\C-xr": redraw-current-line 870# Edit variable on current line. 871"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y=" 872$endif 873 874# use a visible bell if one is available 875set bell-style visible 876 877# don't strip characters to 7 bits when reading 878set input-meta on 879 880# allow iso-latin1 characters to be inserted rather 881# than converted to prefix-meta sequences 882set convert-meta off 883 884# display characters with the eighth bit set directly 885# rather than as meta-prefixed characters 886set output-meta on 887 888# if there are more than 150 possible completions for 889# a word, ask the user if he wants to see all of them 890set completion-query-items 150 891 892# For FTP 893$if Ftp 894"\C-xg": "get \M-?" 895"\C-xt": "put \M-?" 896"\M-.": yank-last-arg 897$endif 898@end example 899 900@node Bindable Readline Commands 901@section Bindable Readline Commands 902 903@menu 904* Commands For Moving:: Moving about the line. 905* Commands For History:: Getting at previous lines. 906* Commands For Text:: Commands for changing text. 907* Commands For Killing:: Commands for killing and yanking. 908* Numeric Arguments:: Specifying numeric arguments, repeat counts. 909* Commands For Completion:: Getting Readline to do the typing for you. 910* Keyboard Macros:: Saving and re-executing typed characters 911* Miscellaneous Commands:: Other miscellaneous commands. 912@end menu 913 914This section describes Readline commands that may be bound to key 915sequences. 916@ifset BashFeatures 917You can list your key bindings by executing 918@w{@code{bind -P}} or, for a more terse format, suitable for an 919@var{inputrc} file, @w{@code{bind -p}}. (@xref{Bash Builtins}.) 920@end ifset 921Command names without an accompanying key sequence are unbound by default. 922 923In the following descriptions, @dfn{point} refers to the current cursor 924position, and @dfn{mark} refers to a cursor position saved by the 925@code{set-mark} command. 926The text between the point and mark is referred to as the @dfn{region}. 927 928@node Commands For Moving 929@subsection Commands For Moving 930@ftable @code 931@item beginning-of-line (C-a) 932Move to the start of the current line. 933 934@item end-of-line (C-e) 935Move to the end of the line. 936 937@item forward-char (C-f) 938Move forward a character. 939 940@item backward-char (C-b) 941Move back a character. 942 943@item forward-word (M-f) 944Move forward to the end of the next word. Words are composed of 945letters and digits. 946 947@item backward-word (M-b) 948Move back to the start of the current or previous word. Words are 949composed of letters and digits. 950 951@item clear-screen (C-l) 952Clear the screen and redraw the current line, 953leaving the current line at the top of the screen. 954 955@item redraw-current-line () 956Refresh the current line. By default, this is unbound. 957 958@end ftable 959 960@node Commands For History 961@subsection Commands For Manipulating The History 962 963@ftable @code 964@item accept-line (Newline or Return) 965@ifset BashFeatures 966Accept the line regardless of where the cursor is. 967If this line is 968non-empty, add it to the history list according to the setting of 969the @env{HISTCONTROL} and @env{HISTIGNORE} variables. 970If this line is a modified history line, then restore the history line 971to its original state. 972@end ifset 973@ifclear BashFeatures 974Accept the line regardless of where the cursor is. 975If this line is 976non-empty, it may be added to the history list for future recall with 977@code{add_history()}. 978If this line is a modified history line, the history line is restored 979to its original state. 980@end ifclear 981 982@item previous-history (C-p) 983Move `back' through the history list, fetching the previous command. 984 985@item next-history (C-n) 986Move `forward' through the history list, fetching the next command. 987 988@item beginning-of-history (M-<) 989Move to the first line in the history. 990 991@item end-of-history (M->) 992Move to the end of the input history, i.e., the line currently 993being entered. 994 995@item reverse-search-history (C-r) 996Search backward starting at the current line and moving `up' through 997the history as necessary. This is an incremental search. 998 999@item forward-search-history (C-s) 1000Search forward starting at the current line and moving `down' through 1001the the history as necessary. This is an incremental search. 1002 1003@item non-incremental-reverse-search-history (M-p) 1004Search backward starting at the current line and moving `up' 1005through the history as necessary using a non-incremental search 1006for a string supplied by the user. 1007 1008@item non-incremental-forward-search-history (M-n) 1009Search forward starting at the current line and moving `down' 1010through the the history as necessary using a non-incremental search 1011for a string supplied by the user. 1012 1013@item history-search-forward () 1014Search forward through the history for the string of characters 1015between the start of the current line and the point. 1016This is a non-incremental search. 1017By default, this command is unbound. 1018 1019@item history-search-backward () 1020Search backward through the history for the string of characters 1021between the start of the current line and the point. This 1022is a non-incremental search. By default, this command is unbound. 1023 1024@item yank-nth-arg (M-C-y) 1025Insert the first argument to the previous command (usually 1026the second word on the previous line) at point. 1027With an argument @var{n}, 1028insert the @var{n}th word from the previous command (the words 1029in the previous command begin with word 0). A negative argument 1030inserts the @var{n}th word from the end of the previous command. 1031Once the argument @var{n} is computed, the argument is extracted 1032as if the @samp{!@var{n}} history expansion had been specified. 1033 1034@item yank-last-arg (M-. or M-_) 1035Insert last argument to the previous command (the last word of the 1036previous history entry). With an 1037argument, behave exactly like @code{yank-nth-arg}. 1038Successive calls to @code{yank-last-arg} move back through the history 1039list, inserting the last argument of each line in turn. 1040The history expansion facilities are used to extract the last argument, 1041as if the @samp{!$} history expansion had been specified. 1042 1043@end ftable 1044 1045@node Commands For Text 1046@subsection Commands For Changing Text 1047 1048@ftable @code 1049@item delete-char (C-d) 1050Delete the character at point. If point is at the 1051beginning of the line, there are no characters in the line, and 1052the last character typed was not bound to @code{delete-char}, then 1053return @sc{eof}. 1054 1055@item backward-delete-char (Rubout) 1056Delete the character behind the cursor. A numeric argument means 1057to kill the characters instead of deleting them. 1058 1059@item forward-backward-delete-char () 1060Delete the character under the cursor, unless the cursor is at the 1061end of the line, in which case the character behind the cursor is 1062deleted. By default, this is not bound to a key. 1063 1064@item quoted-insert (C-q or C-v) 1065Add the next character typed to the line verbatim. This is 1066how to insert key sequences like @kbd{C-q}, for example. 1067 1068@ifclear BashFeatures 1069@item tab-insert (M-@key{TAB}) 1070Insert a tab character. 1071@end ifclear 1072 1073@item self-insert (a, b, A, 1, !, @dots{}) 1074Insert yourself. 1075 1076@item transpose-chars (C-t) 1077Drag the character before the cursor forward over 1078the character at the cursor, moving the 1079cursor forward as well. If the insertion point 1080is at the end of the line, then this 1081transposes the last two characters of the line. 1082Negative arguments have no effect. 1083 1084@item transpose-words (M-t) 1085Drag the word before point past the word after point, 1086moving point past that word as well. 1087If the insertion point is at the end of the line, this transposes 1088the last two words on the line. 1089 1090@item upcase-word (M-u) 1091Uppercase the current (or following) word. With a negative argument, 1092uppercase the previous word, but do not move the cursor. 1093 1094@item downcase-word (M-l) 1095Lowercase the current (or following) word. With a negative argument, 1096lowercase the previous word, but do not move the cursor. 1097 1098@item capitalize-word (M-c) 1099Capitalize the current (or following) word. With a negative argument, 1100capitalize the previous word, but do not move the cursor. 1101 1102@item overwrite-mode () 1103Toggle overwrite mode. With an explicit positive numeric argument, 1104switches to overwrite mode. With an explicit non-positive numeric 1105argument, switches to insert mode. This command affects only 1106@code{emacs} mode; @code{vi} mode does overwrite differently. 1107Each call to @code{readline()} starts in insert mode. 1108 1109In overwrite mode, characters bound to @code{self-insert} replace 1110the text at point rather than pushing the text to the right. 1111Characters bound to @code{backward-delete-char} replace the character 1112before point with a space. 1113 1114By default, this command is unbound. 1115 1116@end ftable 1117 1118@node Commands For Killing 1119@subsection Killing And Yanking 1120 1121@ftable @code 1122 1123@item kill-line (C-k) 1124Kill the text from point to the end of the line. 1125 1126@item backward-kill-line (C-x Rubout) 1127Kill backward to the beginning of the line. 1128 1129@item unix-line-discard (C-u) 1130Kill backward from the cursor to the beginning of the current line. 1131 1132@item kill-whole-line () 1133Kill all characters on the current line, no matter where point is. 1134By default, this is unbound. 1135 1136@item kill-word (M-d) 1137Kill from point to the end of the current word, or if between 1138words, to the end of the next word. 1139Word boundaries are the same as @code{forward-word}. 1140 1141@item backward-kill-word (M-@key{DEL}) 1142Kill the word behind point. 1143Word boundaries are the same as @code{backward-word}. 1144 1145@item unix-word-rubout (C-w) 1146Kill the word behind point, using white space as a word boundary. 1147The killed text is saved on the kill-ring. 1148 1149@item unix-filename-rubout () 1150Kill the word behind point, using white space and the slash character 1151as the word boundaries. 1152The killed text is saved on the kill-ring. 1153 1154@item delete-horizontal-space () 1155Delete all spaces and tabs around point. By default, this is unbound. 1156 1157@item kill-region () 1158Kill the text in the current region. 1159By default, this command is unbound. 1160 1161@item copy-region-as-kill () 1162Copy the text in the region to the kill buffer, so it can be yanked 1163right away. By default, this command is unbound. 1164 1165@item copy-backward-word () 1166Copy the word before point to the kill buffer. 1167The word boundaries are the same as @code{backward-word}. 1168By default, this command is unbound. 1169 1170@item copy-forward-word () 1171Copy the word following point to the kill buffer. 1172The word boundaries are the same as @code{forward-word}. 1173By default, this command is unbound. 1174 1175@item yank (C-y) 1176Yank the top of the kill ring into the buffer at point. 1177 1178@item yank-pop (M-y) 1179Rotate the kill-ring, and yank the new top. You can only do this if 1180the prior command is @code{yank} or @code{yank-pop}. 1181@end ftable 1182 1183@node Numeric Arguments 1184@subsection Specifying Numeric Arguments 1185@ftable @code 1186 1187@item digit-argument (@kbd{M-0}, @kbd{M-1}, @dots{} @kbd{M--}) 1188Add this digit to the argument already accumulating, or start a new 1189argument. @kbd{M--} starts a negative argument. 1190 1191@item universal-argument () 1192This is another way to specify an argument. 1193If this command is followed by one or more digits, optionally with a 1194leading minus sign, those digits define the argument. 1195If the command is followed by digits, executing @code{universal-argument} 1196again ends the numeric argument, but is otherwise ignored. 1197As a special case, if this command is immediately followed by a 1198character that is neither a digit or minus sign, the argument count 1199for the next command is multiplied by four. 1200The argument count is initially one, so executing this function the 1201first time makes the argument count four, a second time makes the 1202argument count sixteen, and so on. 1203By default, this is not bound to a key. 1204@end ftable 1205 1206@node Commands For Completion 1207@subsection Letting Readline Type For You 1208 1209@ftable @code 1210@item complete (@key{TAB}) 1211Attempt to perform completion on the text before point. 1212The actual completion performed is application-specific. 1213@ifset BashFeatures 1214Bash attempts completion treating the text as a variable (if the 1215text begins with @samp{$}), username (if the text begins with 1216@samp{~}), hostname (if the text begins with @samp{@@}), or 1217command (including aliases and functions) in turn. If none 1218of these produces a match, filename completion is attempted. 1219@end ifset 1220@ifclear BashFeatures 1221The default is filename completion. 1222@end ifclear 1223 1224@item possible-completions (M-?) 1225List the possible completions of the text before point. 1226 1227@item insert-completions (M-*) 1228Insert all completions of the text before point that would have 1229been generated by @code{possible-completions}. 1230 1231@item menu-complete () 1232Similar to @code{complete}, but replaces the word to be completed 1233with a single match from the list of possible completions. 1234Repeated execution of @code{menu-complete} steps through the list 1235of possible completions, inserting each match in turn. 1236At the end of the list of completions, the bell is rung 1237(subject to the setting of @code{bell-style}) 1238and the original text is restored. 1239An argument of @var{n} moves @var{n} positions forward in the list 1240of matches; a negative argument may be used to move backward 1241through the list. 1242This command is intended to be bound to @key{TAB}, but is unbound 1243by default. 1244 1245@item delete-char-or-list () 1246Deletes the character under the cursor if not at the beginning or 1247end of the line (like @code{delete-char}). 1248If at the end of the line, behaves identically to 1249@code{possible-completions}. 1250This command is unbound by default. 1251 1252@ifset BashFeatures 1253@item complete-filename (M-/) 1254Attempt filename completion on the text before point. 1255 1256@item possible-filename-completions (C-x /) 1257List the possible completions of the text before point, 1258treating it as a filename. 1259 1260@item complete-username (M-~) 1261Attempt completion on the text before point, treating 1262it as a username. 1263 1264@item possible-username-completions (C-x ~) 1265List the possible completions of the text before point, 1266treating it as a username. 1267 1268@item complete-variable (M-$) 1269Attempt completion on the text before point, treating 1270it as a shell variable. 1271 1272@item possible-variable-completions (C-x $) 1273List the possible completions of the text before point, 1274treating it as a shell variable. 1275 1276@item complete-hostname (M-@@) 1277Attempt completion on the text before point, treating 1278it as a hostname. 1279 1280@item possible-hostname-completions (C-x @@) 1281List the possible completions of the text before point, 1282treating it as a hostname. 1283 1284@item complete-command (M-!) 1285Attempt completion on the text before point, treating 1286it as a command name. Command completion attempts to 1287match the text against aliases, reserved words, shell 1288functions, shell builtins, and finally executable filenames, 1289in that order. 1290 1291@item possible-command-completions (C-x !) 1292List the possible completions of the text before point, 1293treating it as a command name. 1294 1295@item dynamic-complete-history (M-@key{TAB}) 1296Attempt completion on the text before point, comparing 1297the text against lines from the history list for possible 1298completion matches. 1299 1300@item complete-into-braces (M-@{) 1301Perform filename completion and insert the list of possible completions 1302enclosed within braces so the list is available to the shell 1303(@pxref{Brace Expansion}). 1304 1305@end ifset 1306@end ftable 1307 1308@node Keyboard Macros 1309@subsection Keyboard Macros 1310@ftable @code 1311 1312@item start-kbd-macro (C-x () 1313Begin saving the characters typed into the current keyboard macro. 1314 1315@item end-kbd-macro (C-x )) 1316Stop saving the characters typed into the current keyboard macro 1317and save the definition. 1318 1319@item call-last-kbd-macro (C-x e) 1320Re-execute the last keyboard macro defined, by making the characters 1321in the macro appear as if typed at the keyboard. 1322 1323@end ftable 1324 1325@node Miscellaneous Commands 1326@subsection Some Miscellaneous Commands 1327@ftable @code 1328 1329@item re-read-init-file (C-x C-r) 1330Read in the contents of the @var{inputrc} file, and incorporate 1331any bindings or variable assignments found there. 1332 1333@item abort (C-g) 1334Abort the current editing command and 1335ring the terminal's bell (subject to the setting of 1336@code{bell-style}). 1337 1338@item do-uppercase-version (M-a, M-b, M-@var{x}, @dots{}) 1339If the metafied character @var{x} is lowercase, run the command 1340that is bound to the corresponding uppercase character. 1341 1342@item prefix-meta (@key{ESC}) 1343Metafy the next character typed. This is for keyboards 1344without a meta key. Typing @samp{@key{ESC} f} is equivalent to typing 1345@kbd{M-f}. 1346 1347@item undo (C-_ or C-x C-u) 1348Incremental undo, separately remembered for each line. 1349 1350@item revert-line (M-r) 1351Undo all changes made to this line. This is like executing the @code{undo} 1352command enough times to get back to the beginning. 1353 1354@ifset BashFeatures 1355@item tilde-expand (M-&) 1356@end ifset 1357@ifclear BashFeatures 1358@item tilde-expand (M-~) 1359@end ifclear 1360Perform tilde expansion on the current word. 1361 1362@item set-mark (C-@@) 1363Set the mark to the point. If a 1364numeric argument is supplied, the mark is set to that position. 1365 1366@item exchange-point-and-mark (C-x C-x) 1367Swap the point with the mark. The current cursor position is set to 1368the saved position, and the old cursor position is saved as the mark. 1369 1370@item character-search (C-]) 1371A character is read and point is moved to the next occurrence of that 1372character. A negative count searches for previous occurrences. 1373 1374@item character-search-backward (M-C-]) 1375A character is read and point is moved to the previous occurrence 1376of that character. A negative count searches for subsequent 1377occurrences. 1378 1379@item insert-comment (M-#) 1380Without a numeric argument, the value of the @code{comment-begin} 1381variable is inserted at the beginning of the current line. 1382If a numeric argument is supplied, this command acts as a toggle: if 1383the characters at the beginning of the line do not match the value 1384of @code{comment-begin}, the value is inserted, otherwise 1385the characters in @code{comment-begin} are deleted from the beginning of 1386the line. 1387In either case, the line is accepted as if a newline had been typed. 1388@ifset BashFeatures 1389The default value of @code{comment-begin} causes this command 1390to make the current line a shell comment. 1391If a numeric argument causes the comment character to be removed, the line 1392will be executed by the shell. 1393@end ifset 1394 1395@item dump-functions () 1396Print all of the functions and their key bindings to the 1397Readline output stream. If a numeric argument is supplied, 1398the output is formatted in such a way that it can be made part 1399of an @var{inputrc} file. This command is unbound by default. 1400 1401@item dump-variables () 1402Print all of the settable variables and their values to the 1403Readline output stream. If a numeric argument is supplied, 1404the output is formatted in such a way that it can be made part 1405of an @var{inputrc} file. This command is unbound by default. 1406 1407@item dump-macros () 1408Print all of the Readline key sequences bound to macros and the 1409strings they output. If a numeric argument is supplied, 1410the output is formatted in such a way that it can be made part 1411of an @var{inputrc} file. This command is unbound by default. 1412 1413@ifset BashFeatures 1414@item glob-complete-word (M-g) 1415The word before point is treated as a pattern for pathname expansion, 1416with an asterisk implicitly appended. This pattern is used to 1417generate a list of matching file names for possible completions. 1418 1419@item glob-expand-word (C-x *) 1420The word before point is treated as a pattern for pathname expansion, 1421and the list of matching file names is inserted, replacing the word. 1422If a numeric argument is supplied, a @samp{*} is appended before 1423pathname expansion. 1424 1425@item glob-list-expansions (C-x g) 1426The list of expansions that would have been generated by 1427@code{glob-expand-word} is displayed, and the line is redrawn. 1428If a numeric argument is supplied, a @samp{*} is appended before 1429pathname expansion. 1430 1431@item display-shell-version (C-x C-v) 1432Display version information about the current instance of Bash. 1433 1434@item shell-expand-line (M-C-e) 1435Expand the line as the shell does. 1436This performs alias and history expansion as well as all of the shell 1437word expansions (@pxref{Shell Expansions}). 1438 1439@item history-expand-line (M-^) 1440Perform history expansion on the current line. 1441 1442@item magic-space () 1443Perform history expansion on the current line and insert a space 1444(@pxref{History Interaction}). 1445 1446@item alias-expand-line () 1447Perform alias expansion on the current line (@pxref{Aliases}). 1448 1449@item history-and-alias-expand-line () 1450Perform history and alias expansion on the current line. 1451 1452@item insert-last-argument (M-. or M-_) 1453A synonym for @code{yank-last-arg}. 1454 1455@item operate-and-get-next (C-o) 1456Accept the current line for execution and fetch the next line 1457relative to the current line from the history for editing. Any 1458argument is ignored. 1459 1460@item edit-and-execute-command (C-xC-e) 1461Invoke an editor on the current command line, and execute the result as shell 1462commands. 1463Bash attempts to invoke 1464@code{$VISUAL}, @code{$EDITOR}, and @code{emacs} 1465as the editor, in that order. 1466 1467@end ifset 1468 1469@ifclear BashFeatures 1470@item emacs-editing-mode (C-e) 1471When in @code{vi} command mode, this causes a switch to @code{emacs} 1472editing mode. 1473 1474@item vi-editing-mode (M-C-j) 1475When in @code{emacs} editing mode, this causes a switch to @code{vi} 1476editing mode. 1477 1478@end ifclear 1479 1480@end ftable 1481 1482@node Readline vi Mode 1483@section Readline vi Mode 1484 1485While the Readline library does not have a full set of @code{vi} 1486editing functions, it does contain enough to allow simple editing 1487of the line. The Readline @code{vi} mode behaves as specified in 1488the @sc{posix} 1003.2 standard. 1489 1490@ifset BashFeatures 1491In order to switch interactively between @code{emacs} and @code{vi} 1492editing modes, use the @samp{set -o emacs} and @samp{set -o vi} 1493commands (@pxref{The Set Builtin}). 1494@end ifset 1495@ifclear BashFeatures 1496In order to switch interactively between @code{emacs} and @code{vi} 1497editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode 1498when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode). 1499@end ifclear 1500The Readline default is @code{emacs} mode. 1501 1502When you enter a line in @code{vi} mode, you are already placed in 1503`insertion' mode, as if you had typed an @samp{i}. Pressing @key{ESC} 1504switches you into `command' mode, where you can edit the text of the 1505line with the standard @code{vi} movement keys, move to previous 1506history lines with @samp{k} and subsequent lines with @samp{j}, and 1507so forth. 1508 1509@ifset BashFeatures 1510@node Programmable Completion 1511@section Programmable Completion 1512@cindex programmable completion 1513 1514When word completion is attempted for an argument to a command for 1515which a completion specification (a @var{compspec}) has been defined 1516using the @code{complete} builtin (@pxref{Programmable Completion Builtins}), 1517the programmable completion facilities are invoked. 1518 1519First, the command name is identified. 1520If a compspec has been defined for that command, the 1521compspec is used to generate the list of possible completions for the word. 1522If the command word is a full pathname, a compspec for the full 1523pathname is searched for first. 1524If no compspec is found for the full pathname, an attempt is made to 1525find a compspec for the portion following the final slash. 1526 1527Once a compspec has been found, it is used to generate the list of 1528matching words. 1529If a compspec is not found, the default Bash completion 1530described above (@pxref{Commands For Completion}) is performed. 1531 1532First, the actions specified by the compspec are used. 1533Only matches which are prefixed by the word being completed are 1534returned. 1535When the @option{-f} or @option{-d} option is used for filename or 1536directory name completion, the shell variable @env{FIGNORE} is 1537used to filter the matches. 1538@xref{Bash Variables}, for a description of @env{FIGNORE}. 1539 1540Any completions specified by a filename expansion pattern to the 1541@option{-G} option are generated next. 1542The words generated by the pattern need not match the word being completed. 1543The @env{GLOBIGNORE} shell variable is not used to filter the matches, 1544but the @env{FIGNORE} shell variable is used. 1545 1546Next, the string specified as the argument to the @option{-W} option 1547is considered. 1548The string is first split using the characters in the @env{IFS} 1549special variable as delimiters. 1550Shell quoting is honored. 1551Each word is then expanded using 1552brace expansion, tilde expansion, parameter and variable expansion, 1553command substitution, and arithmetic expansion, 1554as described above (@pxref{Shell Expansions}). 1555The results are split using the rules described above 1556(@pxref{Word Splitting}). 1557The results of the expansion are prefix-matched against the word being 1558completed, and the matching words become the possible completions. 1559 1560After these matches have been generated, any shell function or command 1561specified with the @option{-F} and @option{-C} options is invoked. 1562When the command or function is invoked, the @env{COMP_LINE} and 1563@env{COMP_POINT} variables are assigned values as described above 1564(@pxref{Bash Variables}). 1565If a shell function is being invoked, the @env{COMP_WORDS} and 1566@env{COMP_CWORD} variables are also set. 1567When the function or command is invoked, the first argument is the 1568name of the command whose arguments are being completed, the 1569second argument is the word being completed, and the third argument 1570is the word preceding the word being completed on the current command line. 1571No filtering of the generated completions against the word being completed 1572is performed; the function or command has complete freedom in generating 1573the matches. 1574 1575Any function specified with @option{-F} is invoked first. 1576The function may use any of the shell facilities, including the 1577@code{compgen} builtin described below 1578(@pxref{Programmable Completion Builtins}), to generate the matches. 1579It must put the possible completions in the @env{COMPREPLY} array 1580variable. 1581 1582Next, any command specified with the @option{-C} option is invoked 1583in an environment equivalent to command substitution. 1584It should print a list of completions, one per line, to 1585the standard output. 1586Backslash may be used to escape a newline, if necessary. 1587 1588After all of the possible completions are generated, any filter 1589specified with the @option{-X} option is applied to the list. 1590The filter is a pattern as used for pathname expansion; a @samp{&} 1591in the pattern is replaced with the text of the word being completed. 1592A literal @samp{&} may be escaped with a backslash; the backslash 1593is removed before attempting a match. 1594Any completion that matches the pattern will be removed from the list. 1595A leading @samp{!} negates the pattern; in this case any completion 1596not matching the pattern will be removed. 1597 1598Finally, any prefix and suffix specified with the @option{-P} and @option{-S} 1599options are added to each member of the completion list, and the result is 1600returned to the Readline completion code as the list of possible 1601completions. 1602 1603If the previously-applied actions do not generate any matches, and the 1604@option{-o dirnames} option was supplied to @code{complete} when the 1605compspec was defined, directory name completion is attempted. 1606 1607If the @option{-o plusdirs} option was supplied to @code{complete} when 1608the compspec was defined, directory name completion is attempted and any 1609matches are added to the results of the other actions. 1610 1611By default, if a compspec is found, whatever it generates is returned to 1612the completion code as the full set of possible completions. 1613The default Bash completions are not attempted, and the Readline default 1614of filename completion is disabled. 1615If the @option{-o bashdefault} option was supplied to @code{complete} when 1616the compspec was defined, the default Bash completions are attempted 1617if the compspec generates no matches. 1618If the @option{-o default} option was supplied to @code{complete} when the 1619compspec was defined, Readline's default completion will be performed 1620if the compspec (and, if attempted, the default Bash completions) 1621generate no matches. 1622 1623When a compspec indicates that directory name completion is desired, 1624the programmable completion functions force Readline to append a slash 1625to completed names which are symbolic links to directories, subject to 1626the value of the @var{mark-directories} Readline variable, regardless 1627of the setting of the @var{mark-symlinked-directories} Readline variable. 1628 1629@node Programmable Completion Builtins 1630@section Programmable Completion Builtins 1631@cindex completion builtins 1632 1633Two builtin commands are available to manipulate the programmable completion 1634facilities. 1635 1636@table @code 1637@item compgen 1638@btindex compgen 1639@example 1640@code{compgen [@var{option}] [@var{word}]} 1641@end example 1642 1643Generate possible completion matches for @var{word} according to 1644the @var{option}s, which may be any option accepted by the 1645@code{complete} 1646builtin with the exception of @option{-p} and @option{-r}, and write 1647the matches to the standard output. 1648When using the @option{-F} or @option{-C} options, the various shell variables 1649set by the programmable completion facilities, while available, will not 1650have useful values. 1651 1652The matches will be generated in the same way as if the programmable 1653completion code had generated them directly from a completion specification 1654with the same flags. 1655If @var{word} is specified, only those completions matching @var{word} 1656will be displayed. 1657 1658The return value is true unless an invalid option is supplied, or no 1659matches were generated. 1660 1661@item complete 1662@btindex complete 1663@example 1664@code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-A @var{action}] [-G @var{globpat}] [-W @var{wordlist}] 1665[-P @var{prefix}] [-S @var{suffix}] [-X @var{filterpat}] [-F @var{function}] 1666[-C @var{command}] @var{name} [@var{name} @dots{}]} 1667@code{complete -pr [@var{name} @dots{}]} 1668@end example 1669 1670Specify how arguments to each @var{name} should be completed. 1671If the @option{-p} option is supplied, or if no options are supplied, existing 1672completion specifications are printed in a way that allows them to be 1673reused as input. 1674The @option{-r} option removes a completion specification for 1675each @var{name}, or, if no @var{name}s are supplied, all 1676completion specifications. 1677 1678The process of applying these completion specifications when word completion 1679is attempted is described above (@pxref{Programmable Completion}). 1680 1681Other options, if specified, have the following meanings. 1682The arguments to the @option{-G}, @option{-W}, and @option{-X} options 1683(and, if necessary, the @option{-P} and @option{-S} options) 1684should be quoted to protect them from expansion before the 1685@code{complete} builtin is invoked. 1686 1687 1688@table @code 1689@item -o @var{comp-option} 1690The @var{comp-option} controls several aspects of the compspec's behavior 1691beyond the simple generation of completions. 1692@var{comp-option} may be one of: 1693 1694@table @code 1695 1696@item bashdefault 1697Perform the rest of the default Bash completions if the compspec 1698generates no matches. 1699 1700@item default 1701Use Readline's default filename completion if the compspec generates 1702no matches. 1703 1704@item dirnames 1705Perform directory name completion if the compspec generates no matches. 1706 1707@item filenames 1708Tell Readline that the compspec generates filenames, so it can perform any 1709filename-specific processing (like adding a slash to directory names or 1710suppressing trailing spaces). This option is intended to be used with 1711shell functions specified with @option{-F}. 1712 1713@item nospace 1714Tell Readline not to append a space (the default) to words completed at 1715the end of the line. 1716 1717@item plusdirs 1718After any matches defined by the compspec are generated, 1719directory name completion is attempted and any 1720matches are added to the results of the other actions. 1721 1722@end table 1723 1724@item -A @var{action} 1725The @var{action} may be one of the following to generate a list of possible 1726completions: 1727 1728@table @code 1729@item alias 1730Alias names. May also be specified as @option{-a}. 1731 1732@item arrayvar 1733Array variable names. 1734 1735@item binding 1736Readline key binding names (@pxref{Bindable Readline Commands}). 1737 1738@item builtin 1739Names of shell builtin commands. May also be specified as @option{-b}. 1740 1741@item command 1742Command names. May also be specified as @option{-c}. 1743 1744@item directory 1745Directory names. May also be specified as @option{-d}. 1746 1747@item disabled 1748Names of disabled shell builtins. 1749 1750@item enabled 1751Names of enabled shell builtins. 1752 1753@item export 1754Names of exported shell variables. May also be specified as @option{-e}. 1755 1756@item file 1757File names. May also be specified as @option{-f}. 1758 1759@item function 1760Names of shell functions. 1761 1762@item group 1763Group names. May also be specified as @option{-g}. 1764 1765@item helptopic 1766Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}). 1767 1768@item hostname 1769Hostnames, as taken from the file specified by the 1770@env{HOSTFILE} shell variable (@pxref{Bash Variables}). 1771 1772@item job 1773Job names, if job control is active. May also be specified as @option{-j}. 1774 1775@item keyword 1776Shell reserved words. May also be specified as @option{-k}. 1777 1778@item running 1779Names of running jobs, if job control is active. 1780 1781@item service 1782Service names. May also be specified as @option{-s}. 1783 1784@item setopt 1785Valid arguments for the @option{-o} option to the @code{set} builtin 1786(@pxref{The Set Builtin}). 1787 1788@item shopt 1789Shell option names as accepted by the @code{shopt} builtin 1790(@pxref{Bash Builtins}). 1791 1792@item signal 1793Signal names. 1794 1795@item stopped 1796Names of stopped jobs, if job control is active. 1797 1798@item user 1799User names. May also be specified as @option{-u}. 1800 1801@item variable 1802Names of all shell variables. May also be specified as @option{-v}. 1803@end table 1804 1805@item -G @var{globpat} 1806The filename expansion pattern @var{globpat} is expanded to generate 1807the possible completions. 1808 1809@item -W @var{wordlist} 1810The @var{wordlist} is split using the characters in the 1811@env{IFS} special variable as delimiters, and each resultant word 1812is expanded. 1813The possible completions are the members of the resultant list which 1814match the word being completed. 1815 1816@item -C @var{command} 1817@var{command} is executed in a subshell environment, and its output is 1818used as the possible completions. 1819 1820@item -F @var{function} 1821The shell function @var{function} is executed in the current shell 1822environment. 1823When it finishes, the possible completions are retrieved from the value 1824of the @env{COMPREPLY} array variable. 1825 1826@item -X @var{filterpat} 1827@var{filterpat} is a pattern as used for filename expansion. 1828It is applied to the list of possible completions generated by the 1829preceding options and arguments, and each completion matching 1830@var{filterpat} is removed from the list. 1831A leading @samp{!} in @var{filterpat} negates the pattern; in this 1832case, any completion not matching @var{filterpat} is removed. 1833 1834@item -P @var{prefix} 1835@var{prefix} is added at the beginning of each possible completion 1836after all other options have been applied. 1837 1838@item -S @var{suffix} 1839@var{suffix} is appended to each possible completion 1840after all other options have been applied. 1841@end table 1842 1843The return value is true unless an invalid option is supplied, an option 1844other than @option{-p} or @option{-r} is supplied without a @var{name} 1845argument, an attempt is made to remove a completion specification for 1846a @var{name} for which no specification exists, or 1847an error occurs adding a completion specification. 1848 1849@end table 1850@end ifset 1851