File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / readline / doc / rluser.texi
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Wed Mar 17 01:01:01 2021 UTC (3 years, 3 months ago) by misho
Branches: readline, MAIN
CVS tags: v8_2p0, v8_1p0, HEAD
readline 8.1

    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: 
    5: @ignore
    6: This file documents the end user interface to the GNU command line
    7: editing features.  It is to be an appendix to manuals for programs which
    8: use these features.  There is a document entitled "readline.texinfo"
    9: which contains both end-user and programmer documentation for the
   10: GNU Readline Library.
   11: 
   12: Copyright (C) 1988--2020 Free Software Foundation, Inc.
   13: 
   14: Authored by Brian Fox and Chet Ramey.
   15: 
   16: Permission is granted to process this file through Tex and print the
   17: results, provided the printed document carries copying permission notice
   18: identical to this one except for the removal of this paragraph (this
   19: paragraph not being relevant to the printed manual).
   20: 
   21: Permission is granted to make and distribute verbatim copies of this manual
   22: provided the copyright notice and this permission notice are preserved on
   23: all copies.
   24: 
   25: Permission is granted to copy and distribute modified versions of this
   26: manual under the conditions for verbatim copying, provided also that the
   27: GNU Copyright statement is available to the distributee, and provided that
   28: the entire resulting derived work is distributed under the terms of a
   29: permission notice identical to this one.
   30: 
   31: Permission is granted to copy and distribute translations of this manual
   32: into another language, under the above conditions for modified versions.
   33: @end ignore
   34: 
   35: @comment If you are including this manual as an appendix, then set the
   36: @comment variable readline-appendix.
   37: 
   38: @ifclear BashFeatures
   39: @defcodeindex bt
   40: @end ifclear
   41: 
   42: @node Command Line Editing
   43: @chapter Command Line Editing
   44: 
   45: This chapter describes the basic features of the @sc{gnu}
   46: command line editing interface.
   47: @ifset BashFeatures
   48: Command line editing is provided by the Readline library, which is
   49: used by several different programs, including Bash.
   50: Command line editing is enabled by default when using an interactive shell,
   51: unless the @option{--noediting} option is supplied at shell invocation.
   52: Line editing is also used when using the @option{-e} option to the
   53: @code{read} builtin command (@pxref{Bash Builtins}).
   54: By default, the line editing commands are similar to those of Emacs.
   55: A vi-style line editing interface is also available.
   56: Line editing can be enabled at any time using the @option{-o emacs} or
   57: @option{-o vi} options to the @code{set} builtin command
   58: (@pxref{The Set Builtin}), or disabled using the @option{+o emacs} or 
   59: @option{+o vi} options to @code{set}.
   60: @end ifset
   61: 
   62: @menu
   63: * Introduction and Notation::	Notation used in this text.
   64: * Readline Interaction::	The minimum set of commands for editing a line.
   65: * Readline Init File::		Customizing Readline from a user's view.
   66: * Bindable Readline Commands::	A description of most of the Readline commands
   67: 				available for binding
   68: * Readline vi Mode::		A short description of how to make Readline
   69: 				behave like the vi editor.
   70: @ifset BashFeatures
   71: * Programmable Completion::	How to specify the possible completions for
   72: 				a specific command.
   73: * Programmable Completion Builtins::	Builtin commands to specify how to
   74: 				complete arguments for a particular command.
   75: * A Programmable Completion Example::	An example shell function for
   76: 				generating possible completions.
   77: @end ifset
   78: @end menu
   79: 
   80: @node Introduction and Notation
   81: @section Introduction to Line Editing
   82: 
   83: The following paragraphs describe the notation used to represent
   84: keystrokes.
   85: 
   86: The text @kbd{C-k} is read as `Control-K' and describes the character
   87: produced when the @key{k} key is pressed while the Control key
   88: is depressed.
   89: 
   90: The text @kbd{M-k} is read as `Meta-K' and describes the character
   91: produced when the Meta key (if you have one) is depressed, and the @key{k}
   92: key is pressed.
   93: The Meta key is labeled @key{ALT} on many keyboards.
   94: On keyboards with two keys labeled @key{ALT} (usually to either side of
   95: the space bar), the @key{ALT} on the left side is generally set to
   96: work as a Meta key.
   97: The @key{ALT} key on the right may also be configured to work as a
   98: Meta key or may be configured as some other modifier, such as a
   99: Compose key for typing accented characters.
  100: 
  101: If you do not have a Meta or @key{ALT} key, or another key working as
  102: a Meta key, the identical keystroke can be generated by typing @key{ESC}
  103: @emph{first}, and then typing @key{k}.
  104: Either process is known as @dfn{metafying} the @key{k} key.
  105: 
  106: The text @kbd{M-C-k} is read as `Meta-Control-k' and describes the
  107: character produced by @dfn{metafying} @kbd{C-k}.
  108: 
  109: In addition, several keys have their own names.  Specifically,
  110: @key{DEL}, @key{ESC}, @key{LFD}, @key{SPC}, @key{RET}, and @key{TAB} all
  111: stand for themselves when seen in this text, or in an init file
  112: (@pxref{Readline Init File}).
  113: If your keyboard lacks a @key{LFD} key, typing @key{C-j} will
  114: produce the desired character.
  115: The @key{RET} key may be labeled @key{Return} or @key{Enter} on
  116: some keyboards.
  117: 
  118: @node Readline Interaction
  119: @section Readline Interaction
  120: @cindex interaction, readline
  121: 
  122: Often during an interactive session you type in a long line of text,
  123: only to notice that the first word on the line is misspelled.  The
  124: Readline library gives you a set of commands for manipulating the text
  125: as you type it in, allowing you to just fix your typo, and not forcing
  126: you to retype the majority of the line.  Using these editing commands,
  127: you move the cursor to the place that needs correction, and delete or
  128: insert the text of the corrections.  Then, when you are satisfied with
  129: the line, you simply press @key{RET}.  You do not have to be at the
  130: end of the line to press @key{RET}; the entire line is accepted
  131: regardless of the location of the cursor within the line.
  132: 
  133: @menu
  134: * Readline Bare Essentials::	The least you need to know about Readline.
  135: * Readline Movement Commands::	Moving about the input line.
  136: * Readline Killing Commands::	How to delete text, and how to get it back!
  137: * Readline Arguments::		Giving numeric arguments to commands.
  138: * Searching::			Searching through previous lines.
  139: @end menu
  140: 
  141: @node Readline Bare Essentials
  142: @subsection Readline Bare Essentials
  143: @cindex notation, readline
  144: @cindex command editing
  145: @cindex editing command lines
  146: 
  147: In order to enter characters into the line, simply type them.  The typed
  148: character appears where the cursor was, and then the cursor moves one
  149: space to the right.  If you mistype a character, you can use your
  150: erase character to back up and delete the mistyped character.
  151: 
  152: Sometimes you may mistype a character, and
  153: not notice the error until you have typed several other characters.  In
  154: that case, you can type @kbd{C-b} to move the cursor to the left, and then
  155: correct your mistake.  Afterwards, you can move the cursor to the right
  156: with @kbd{C-f}.
  157: 
  158: When you add text in the middle of a line, you will notice that characters
  159: to the right of the cursor are `pushed over' to make room for the text
  160: that you have inserted.  Likewise, when you delete text behind the cursor,
  161: characters to the right of the cursor are `pulled back' to fill in the
  162: blank space created by the removal of the text.  A list of the bare
  163: essentials for editing the text of an input line follows.
  164: 
  165: @table @asis
  166: @item @kbd{C-b}
  167: Move back one character.
  168: @item @kbd{C-f}
  169: Move forward one character.
  170: @item @key{DEL} or @key{Backspace}
  171: Delete the character to the left of the cursor.
  172: @item @kbd{C-d}
  173: Delete the character underneath the cursor.
  174: @item @w{Printing characters}
  175: Insert the character into the line at the cursor.
  176: @item @kbd{C-_} or @kbd{C-x C-u}
  177: Undo the last editing command.  You can undo all the way back to an
  178: empty line.
  179: @end table
  180: 
  181: @noindent
  182: (Depending on your configuration, the @key{Backspace} key be set to
  183: delete the character to the left of the cursor and the @key{DEL} key set
  184: to delete the character underneath the cursor, like @kbd{C-d}, rather
  185: than the character to the left of the cursor.)
  186: 
  187: @node Readline Movement Commands
  188: @subsection Readline Movement Commands
  189: 
  190: 
  191: The above table describes the most basic keystrokes that you need
  192: in order to do editing of the input line.  For your convenience, many
  193: other commands have been added in addition to @kbd{C-b}, @kbd{C-f},
  194: @kbd{C-d}, and @key{DEL}.  Here are some commands for moving more rapidly
  195: about the line.
  196: 
  197: @table @kbd
  198: @item C-a
  199: Move to the start of the line.
  200: @item C-e
  201: Move to the end of the line.
  202: @item M-f
  203: Move forward a word, where a word is composed of letters and digits.
  204: @item M-b
  205: Move backward a word.
  206: @item C-l
  207: Clear the screen, reprinting the current line at the top.
  208: @end table
  209: 
  210: Notice how @kbd{C-f} moves forward a character, while @kbd{M-f} moves
  211: forward a word.  It is a loose convention that control keystrokes
  212: operate on characters while meta keystrokes operate on words.
  213: 
  214: @node Readline Killing Commands
  215: @subsection Readline Killing Commands
  216: 
  217: @cindex killing text
  218: @cindex yanking text
  219: 
  220: @dfn{Killing} text means to delete the text from the line, but to save
  221: it away for later use, usually by @dfn{yanking} (re-inserting)
  222: it back into the line.
  223: (`Cut' and `paste' are more recent jargon for `kill' and `yank'.)
  224: 
  225: If the description for a command says that it `kills' text, then you can
  226: be sure that you can get the text back in a different (or the same)
  227: place later.
  228: 
  229: When you use a kill command, the text is saved in a @dfn{kill-ring}.
  230: Any number of consecutive kills save all of the killed text together, so
  231: that when you yank it back, you get it all.  The kill
  232: ring is not line specific; the text that you killed on a previously
  233: typed line is available to be yanked back later, when you are typing
  234: another line.
  235: @cindex kill ring
  236: 
  237: Here is the list of commands for killing text.
  238: 
  239: @table @kbd
  240: @item C-k
  241: Kill the text from the current cursor position to the end of the line.
  242: 
  243: @item M-d
  244: Kill from the cursor to the end of the current word, or, if between
  245: words, to the end of the next word.
  246: Word boundaries are the same as those used by @kbd{M-f}.
  247: 
  248: @item M-@key{DEL}
  249: Kill from the cursor the start of the current word, or, if between
  250: words, to the start of the previous word.
  251: Word boundaries are the same as those used by @kbd{M-b}.
  252: 
  253: @item C-w
  254: Kill from the cursor to the previous whitespace.  This is different than
  255: @kbd{M-@key{DEL}} because the word boundaries differ.
  256: 
  257: @end table
  258: 
  259: Here is how to @dfn{yank} the text back into the line.  Yanking
  260: means to copy the most-recently-killed text from the kill buffer.
  261: 
  262: @table @kbd
  263: @item C-y
  264: Yank the most recently killed text back into the buffer at the cursor.
  265: 
  266: @item M-y
  267: Rotate the kill-ring, and yank the new top.  You can only do this if
  268: the prior command is @kbd{C-y} or @kbd{M-y}.
  269: @end table
  270: 
  271: @node Readline Arguments
  272: @subsection Readline Arguments
  273: 
  274: You can pass numeric arguments to Readline commands.  Sometimes the
  275: argument acts as a repeat count, other times it is the @i{sign} of the
  276: argument that is significant.  If you pass a negative argument to a
  277: command which normally acts in a forward direction, that command will
  278: act in a backward direction.  For example, to kill text back to the
  279: start of the line, you might type @samp{M-- C-k}.
  280: 
  281: The general way to pass numeric arguments to a command is to type meta
  282: digits before the command.  If the first `digit' typed is a minus
  283: sign (@samp{-}), then the sign of the argument will be negative.  Once
  284: you have typed one meta digit to get the argument started, you can type
  285: the remainder of the digits, and then the command.  For example, to give
  286: the @kbd{C-d} command an argument of 10, you could type @samp{M-1 0 C-d},
  287: which will delete the next ten characters on the input line.
  288: 
  289: @node Searching
  290: @subsection Searching for Commands in the History
  291: 
  292: Readline provides commands for searching through the command history
  293: @ifset BashFeatures
  294: (@pxref{Bash History Facilities})
  295: @end ifset
  296: for lines containing a specified string.
  297: There are two search modes:  @dfn{incremental} and @dfn{non-incremental}.
  298: 
  299: Incremental searches begin before the user has finished typing the
  300: search string.
  301: As each character of the search string is typed, Readline displays
  302: the next entry from the history matching the string typed so far.
  303: An incremental search requires only as many characters as needed to
  304: find the desired history entry.
  305: To search backward in the history for a particular string, type
  306: @kbd{C-r}.  Typing @kbd{C-s} searches forward through the history.
  307: The characters present in the value of the @code{isearch-terminators} variable
  308: are used to terminate an incremental search.
  309: If that variable has not been assigned a value, the @key{ESC} and
  310: @kbd{C-J} characters will terminate an incremental search.
  311: @kbd{C-g} will abort an incremental search and restore the original line.
  312: When the search is terminated, the history entry containing the
  313: search string becomes the current line.
  314: 
  315: To find other matching entries in the history list, type @kbd{C-r} or
  316: @kbd{C-s} as appropriate.
  317: This will search backward or forward in the history for the next
  318: entry matching the search string typed so far.
  319: Any other key sequence bound to a Readline command will terminate
  320: the search and execute that command.
  321: For instance, a @key{RET} will terminate the search and accept
  322: the line, thereby executing the command from the history list.
  323: A movement command will terminate the search, make the last line found
  324: the current line, and begin editing.
  325: 
  326: Readline remembers the last incremental search string.  If two
  327: @kbd{C-r}s are typed without any intervening characters defining a new
  328: search string, any remembered search string is used.
  329: 
  330: Non-incremental searches read the entire search string before starting
  331: to search for matching history lines.  The search string may be
  332: typed by the user or be part of the contents of the current line.
  333: 
  334: @node Readline Init File
  335: @section Readline Init File
  336: @cindex initialization file, readline
  337: 
  338: Although the Readline library comes with a set of Emacs-like
  339: keybindings installed by default, it is possible to use a different set
  340: of keybindings.
  341: Any user can customize programs that use Readline by putting
  342: commands in an @dfn{inputrc} file, conventionally in his home directory.
  343: The name of this
  344: @ifset BashFeatures
  345: file is taken from the value of the shell variable @env{INPUTRC}.  If
  346: @end ifset
  347: @ifclear BashFeatures
  348: file is taken from the value of the environment variable @env{INPUTRC}.  If
  349: @end ifclear
  350: that variable is unset, the default is @file{~/.inputrc}.  If that
  351: file does not exist or cannot be read, the ultimate default is
  352: @file{/etc/inputrc}.
  353: @ifset BashFeatures
  354: The @w{@code{bind}} builtin command can also be used to set Readline
  355: keybindings and variables.
  356: @xref{Bash Builtins}.
  357: @end ifset
  358: 
  359: When a program which uses the Readline library starts up, the
  360: init file is read, and the key bindings are set.
  361: 
  362: In addition, the @code{C-x C-r} command re-reads this init file, thus
  363: incorporating any changes that you might have made to it.
  364: 
  365: @menu
  366: * Readline Init File Syntax::	Syntax for the commands in the inputrc file.
  367: 
  368: * Conditional Init Constructs::	Conditional key bindings in the inputrc file.
  369: 
  370: * Sample Init File::		An example inputrc file.
  371: @end menu
  372: 
  373: @node Readline Init File Syntax
  374: @subsection Readline Init File Syntax
  375: 
  376: There are only a few basic constructs allowed in the
  377: Readline init file.  Blank lines are ignored.
  378: Lines beginning with a @samp{#} are comments.
  379: Lines beginning with a @samp{$} indicate conditional
  380: constructs (@pxref{Conditional Init Constructs}).  Other lines
  381: denote variable settings and key bindings.
  382: 
  383: @table @asis
  384: @item Variable Settings
  385: You can modify the run-time behavior of Readline by
  386: altering the values of variables in Readline
  387: using the @code{set} command within the init file.
  388: The syntax is simple:
  389: 
  390: @example
  391: set @var{variable} @var{value}
  392: @end example
  393: 
  394: @noindent
  395: Here, for example, is how to
  396: change from the default Emacs-like key binding to use
  397: @code{vi} line editing commands:
  398: 
  399: @example
  400: set editing-mode vi
  401: @end example
  402: 
  403: Variable names and values, where appropriate, are recognized without regard
  404: to case.  Unrecognized variable names are ignored.
  405: 
  406: Boolean variables (those that can be set to on or off) are set to on if
  407: the value is null or empty, @var{on} (case-insensitive), or 1.  Any other
  408: value results in the variable being set to off.
  409: 
  410: @ifset BashFeatures
  411: The @w{@code{bind -V}} command lists the current Readline variable names
  412: and values.  @xref{Bash Builtins}.
  413: @end ifset
  414: 
  415: A great deal of run-time behavior is changeable with the following
  416: variables.
  417: 
  418: @cindex variables, readline
  419: @table @code
  420: 
  421: @item bell-style
  422: @vindex bell-style
  423: Controls what happens when Readline wants to ring the terminal bell.
  424: If set to @samp{none}, Readline never rings the bell.  If set to
  425: @samp{visible}, Readline uses a visible bell if one is available.
  426: If set to @samp{audible} (the default), Readline attempts to ring
  427: the terminal's bell.
  428: 
  429: @item bind-tty-special-chars
  430: @vindex bind-tty-special-chars
  431: If set to @samp{on} (the default), Readline attempts to bind the control
  432: characters   treated specially by the kernel's terminal driver to their
  433: Readline equivalents.
  434: 
  435: @item blink-matching-paren
  436: @vindex blink-matching-paren
  437: If set to @samp{on}, Readline attempts to briefly move the cursor to an
  438: opening parenthesis when a closing parenthesis is inserted.  The default
  439: is @samp{off}.
  440: 
  441: @item colored-completion-prefix
  442: @vindex colored-completion-prefix
  443: If set to @samp{on}, when listing completions, Readline displays the
  444: common prefix of the set of possible completions using a different color.
  445: The color definitions are taken from the value of the @env{LS_COLORS}
  446: environment variable.
  447: The default is @samp{off}.
  448: 
  449: @item colored-stats
  450: @vindex colored-stats
  451: If set to @samp{on}, Readline displays possible completions using different
  452: colors to indicate their file type.
  453: The color definitions are taken from the value of the @env{LS_COLORS}
  454: environment variable.
  455: The default is @samp{off}.
  456: 
  457: @item comment-begin
  458: @vindex comment-begin
  459: The string to insert at the beginning of the line when the
  460: @code{insert-comment} command is executed.  The default value
  461: is @code{"#"}.
  462: 
  463: @item completion-display-width
  464: @vindex completion-display-width
  465: The number of screen columns used to display possible matches
  466: when performing completion.
  467: The value is ignored if it is less than 0 or greater than the terminal
  468: screen width.
  469: A value of 0 will cause matches to be displayed one per line.
  470: The default value is -1.
  471: 
  472: @item completion-ignore-case
  473: @vindex completion-ignore-case
  474: If set to @samp{on}, Readline performs filename matching and completion
  475: in a case-insensitive fashion.
  476: The default value is @samp{off}.
  477: 
  478: @item completion-map-case
  479: @vindex completion-map-case
  480: If set to @samp{on}, and @var{completion-ignore-case} is enabled, Readline
  481: treats hyphens (@samp{-}) and underscores (@samp{_}) as equivalent when
  482: performing case-insensitive filename matching and completion.
  483: The default value is @samp{off}.
  484: 
  485: @item completion-prefix-display-length
  486: @vindex completion-prefix-display-length
  487: The length in characters of the common prefix of a list of possible
  488: completions that is displayed without modification.  When set to a
  489: value greater than zero, common prefixes longer than this value are
  490: replaced with an ellipsis when displaying possible completions.
  491: 
  492: @item completion-query-items
  493: @vindex completion-query-items
  494: The number of possible completions that determines when the user is
  495: asked whether the list of possibilities should be displayed.
  496: If the number of possible completions is greater than or equal to this value,
  497: Readline will ask whether or not the user wishes to view them;
  498: otherwise, they are simply listed.
  499: This variable must be set to an integer value greater than or equal to 0.
  500: A negative value means Readline should never ask.
  501: The default limit is @code{100}.
  502: 
  503: @item convert-meta
  504: @vindex convert-meta
  505: If set to @samp{on}, Readline will convert characters with the
  506: eighth bit set to an @sc{ascii} key sequence by stripping the eighth
  507: bit and prefixing an @key{ESC} character, converting them to a
  508: meta-prefixed key sequence.  The default value is @samp{on}, but
  509: will be set to @samp{off} if the locale is one that contains
  510: eight-bit characters.
  511: 
  512: @item disable-completion
  513: @vindex disable-completion
  514: If set to @samp{On}, Readline will inhibit word completion.
  515: Completion  characters will be inserted into the line as if they had
  516: been mapped to @code{self-insert}.  The default is @samp{off}.
  517: 
  518: @item echo-control-characters
  519: @vindex echo-control-characters
  520: When set to @samp{on}, on operating systems that indicate they support it,
  521: readline echoes a character corresponding to a signal generated from the
  522: keyboard.  The default is @samp{on}.
  523: 
  524: @item editing-mode
  525: @vindex editing-mode
  526: The @code{editing-mode} variable controls which default set of
  527: key bindings is used.  By default, Readline starts up in Emacs editing
  528: mode, where the keystrokes are most similar to Emacs.  This variable can be
  529: set to either @samp{emacs} or @samp{vi}.
  530: 
  531: @item emacs-mode-string
  532: @vindex emacs-mode-string
  533: If the @var{show-mode-in-prompt} variable is enabled,
  534: this string is displayed immediately before the last line of the primary
  535: prompt when emacs editing mode is active.  The value is expanded like a
  536: key binding, so the standard set of meta- and control prefixes and
  537: backslash escape sequences is available.
  538: Use the @samp{\1} and @samp{\2} escapes to begin and end sequences of
  539: non-printing characters, which can be used to embed a terminal control
  540: sequence into the mode string.
  541: The default is @samp{@@}.
  542: 
  543: @item enable-bracketed-paste
  544: @vindex enable-bracketed-paste
  545: When set to @samp{On}, Readline will configure the terminal in a way
  546: that will enable it to insert each paste into the editing buffer as a
  547: single string of characters, instead of treating each character as if
  548: it had been read from the keyboard.  This can prevent pasted characters
  549: from being interpreted as editing commands.  The default is @samp{On}.
  550: 
  551: @item enable-keypad
  552: @vindex enable-keypad
  553: When set to @samp{on}, Readline will try to enable the application
  554: keypad when it is called.  Some systems need this to enable the
  555: arrow keys.  The default is @samp{off}.
  556: 
  557: @item enable-meta-key
  558: When set to @samp{on}, Readline will try to enable any meta modifier
  559: key the terminal claims to support when it is called.  On many terminals,
  560: the meta key is used to send eight-bit characters.
  561: The default is @samp{on}.
  562: 
  563: @item expand-tilde
  564: @vindex expand-tilde
  565: If set to @samp{on}, tilde expansion is performed when Readline
  566: attempts word completion.  The default is @samp{off}.
  567: 
  568: @item history-preserve-point
  569: @vindex history-preserve-point
  570: If set to @samp{on}, the history code attempts to place the point (the
  571: current cursor position) at the
  572: same location on each history line retrieved with @code{previous-history}
  573: or @code{next-history}.  The default is @samp{off}.
  574: 
  575: @item history-size
  576: @vindex history-size
  577: Set the maximum number of history entries saved in the history list.
  578: If set to zero, any existing history entries are deleted and no new entries
  579: are saved.
  580: If set to a value less than zero, the number of history entries is not
  581: limited.
  582: By default, the number of history entries is not limited.
  583: If an attempt is made to set @var{history-size} to a non-numeric value,
  584: the maximum number of history entries will be set to 500.
  585: 
  586: @item horizontal-scroll-mode
  587: @vindex horizontal-scroll-mode
  588: This variable can be set to either @samp{on} or @samp{off}.  Setting it
  589: to @samp{on} means that the text of the lines being edited will scroll
  590: horizontally on a single screen line when they are longer than the width
  591: of the screen, instead of wrapping onto a new screen line.
  592: This variable is automatically set to @samp{on} for terminals of height 1.
  593: By default, this variable is set to @samp{off}.
  594: 
  595: @item input-meta
  596: @vindex input-meta
  597: @vindex meta-flag
  598: If set to @samp{on}, Readline will enable eight-bit input (it
  599: will not clear the eighth bit in the characters it reads),
  600: regardless of what the terminal claims it can support.  The
  601: default value is @samp{off}, but Readline will set it to @samp{on} if the 
  602: locale contains eight-bit characters.
  603: The name @code{meta-flag} is a synonym for this variable.
  604: 
  605: @item isearch-terminators
  606: @vindex isearch-terminators
  607: The string of characters that should terminate an incremental search without
  608: subsequently executing the character as a command (@pxref{Searching}).
  609: If this variable has not been given a value, the characters @key{ESC} and
  610: @kbd{C-J} will terminate an incremental search.
  611: 
  612: @item keymap
  613: @vindex keymap
  614: Sets Readline's idea of the current keymap for key binding commands.
  615: Built-in @code{keymap} names are
  616: @code{emacs},
  617: @code{emacs-standard},
  618: @code{emacs-meta},
  619: @code{emacs-ctlx},
  620: @code{vi},
  621: @code{vi-move},
  622: @code{vi-command}, and
  623: @code{vi-insert}.
  624: @code{vi} is equivalent to @code{vi-command} (@code{vi-move} is also a
  625: synonym); @code{emacs} is equivalent to @code{emacs-standard}.
  626: Applications may add additional names.
  627: The default value is @code{emacs}.
  628: The value of the @code{editing-mode} variable also affects the
  629: default keymap.
  630: 
  631: @item keyseq-timeout
  632: Specifies the duration Readline will wait for a character when reading an
  633: ambiguous key sequence (one that can form a complete key sequence using
  634: the input read so far, or can take additional input to complete a longer
  635: key sequence).
  636: If no input is received within the timeout, Readline will use the shorter
  637: but complete key sequence.
  638: Readline uses this value to determine whether or not input is
  639: available on the current input source (@code{rl_instream} by default).
  640: The value is specified in milliseconds, so a value of 1000 means that
  641: Readline will wait one second for additional input.
  642: If this variable is set to a value less than or equal to zero, or to a
  643: non-numeric value, Readline will wait until another key is pressed to
  644: decide which key sequence to complete.
  645: The default value is @code{500}.
  646: 
  647: @item mark-directories
  648: If set to @samp{on}, completed directory names have a slash
  649: appended.  The default is @samp{on}.
  650: 
  651: @item mark-modified-lines
  652: @vindex mark-modified-lines
  653: This variable, when set to @samp{on}, causes Readline to display an
  654: asterisk (@samp{*}) at the start of history lines which have been modified.
  655: This variable is @samp{off} by default.
  656: 
  657: @item mark-symlinked-directories
  658: @vindex mark-symlinked-directories
  659: If set to @samp{on}, completed names which are symbolic links
  660: to directories have a slash appended (subject to the value of
  661: @code{mark-directories}).
  662: The default is @samp{off}.
  663: 
  664: @item match-hidden-files
  665: @vindex match-hidden-files
  666: This variable, when set to @samp{on}, causes Readline to match files whose
  667: names begin with a @samp{.} (hidden files) when performing filename
  668: completion.
  669: If set to @samp{off}, the leading @samp{.} must be
  670: supplied by the user in the filename to be completed.
  671: This variable is @samp{on} by default.
  672: 
  673: @item menu-complete-display-prefix
  674: @vindex menu-complete-display-prefix
  675: If set to @samp{on}, menu completion displays the common prefix of the
  676: list of possible completions (which may be empty) before cycling through
  677: the list.  The default is @samp{off}.
  678: 
  679: @item output-meta
  680: @vindex output-meta
  681: If set to @samp{on}, Readline will display characters with the
  682: eighth bit set directly rather than as a meta-prefixed escape
  683: sequence.
  684: The default is @samp{off}, but Readline will set it to @samp{on} if the
  685: locale contains eight-bit characters.
  686: 
  687: @item page-completions
  688: @vindex page-completions
  689: If set to @samp{on}, Readline uses an internal @code{more}-like pager
  690: to display a screenful of possible completions at a time.
  691: This variable is @samp{on} by default.
  692: 
  693: @item print-completions-horizontally
  694: If set to @samp{on}, Readline will display completions with matches
  695: sorted horizontally in alphabetical order, rather than down the screen.
  696: The default is @samp{off}.
  697: 
  698: @item revert-all-at-newline
  699: @vindex revert-all-at-newline
  700: If set to @samp{on}, Readline will undo all changes to history lines
  701: before returning when @code{accept-line} is executed.  By default,
  702: history lines may be modified and retain individual undo lists across
  703: calls to @code{readline}.  The default is @samp{off}.
  704: 
  705: @item show-all-if-ambiguous
  706: @vindex show-all-if-ambiguous
  707: This alters the default behavior of the completion functions.  If
  708: set to @samp{on}, 
  709: words which have more than one possible completion cause the
  710: matches to be listed immediately instead of ringing the bell.
  711: The default value is @samp{off}.
  712: 
  713: @item show-all-if-unmodified
  714: @vindex show-all-if-unmodified
  715: This alters the default behavior of the completion functions in
  716: a fashion similar to @var{show-all-if-ambiguous}.
  717: If set to @samp{on}, 
  718: words which have more than one possible completion without any
  719: possible partial completion (the possible completions don't share
  720: a common prefix) cause the matches to be listed immediately instead
  721: of ringing the bell.
  722: The default value is @samp{off}.
  723: 
  724: @item show-mode-in-prompt
  725: @vindex show-mode-in-prompt
  726: If set to @samp{on}, add a string to the beginning of the prompt
  727: indicating the editing mode: emacs, vi command, or vi insertion.
  728: The mode strings are user-settable (e.g., @var{emacs-mode-string}).
  729: The default value is @samp{off}.
  730: 
  731: @item skip-completed-text
  732: @vindex skip-completed-text
  733: If set to @samp{on}, this alters the default completion behavior when
  734: inserting a single match into the line.  It's only active when
  735: performing completion in the middle of a word.  If enabled, readline
  736: does not insert characters from the completion that match characters
  737: after point in the word being completed, so portions of the word
  738: following the cursor are not duplicated.
  739: For instance, if this is enabled, attempting completion when the cursor
  740: is after the @samp{e} in @samp{Makefile} will result in @samp{Makefile}
  741: rather than @samp{Makefilefile}, assuming there is a single possible
  742: completion.
  743: The default value is @samp{off}.
  744: 
  745: @item vi-cmd-mode-string
  746: @vindex vi-cmd-mode-string
  747: If the @var{show-mode-in-prompt} variable is enabled,
  748: this string is displayed immediately before the last line of the primary
  749: prompt when vi editing mode is active and in command mode.
  750: The value is expanded like a
  751: key binding, so the standard set of meta- and control prefixes and
  752: backslash escape sequences is available.
  753: Use the @samp{\1} and @samp{\2} escapes to begin and end sequences of
  754: non-printing characters, which can be used to embed a terminal control
  755: sequence into the mode string.
  756: The default is @samp{(cmd)}.
  757: 
  758: @item vi-ins-mode-string
  759: @vindex vi-ins-mode-string
  760: If the @var{show-mode-in-prompt} variable is enabled,
  761: this string is displayed immediately before the last line of the primary
  762: prompt when vi editing mode is active and in insertion mode.
  763: The value is expanded like a
  764: key binding, so the standard set of meta- and control prefixes and
  765: backslash escape sequences is available.
  766: Use the @samp{\1} and @samp{\2} escapes to begin and end sequences of
  767: non-printing characters, which can be used to embed a terminal control
  768: sequence into the mode string.
  769: The default is @samp{(ins)}.
  770: 
  771: @item visible-stats
  772: @vindex visible-stats
  773: If set to @samp{on}, a character denoting a file's type
  774: is appended to the filename when listing possible
  775: completions.  The default is @samp{off}.
  776: 
  777: @end table
  778: 
  779: @item Key Bindings
  780: The syntax for controlling key bindings in the init file is
  781: simple.  First you need to find the name of the command that you
  782: want to change.  The following sections contain tables of the command
  783: name, the default keybinding, if any, and a short description of what
  784: the command does.
  785: 
  786: Once you know the name of the command, simply place on a line
  787: in the init file the name of the key
  788: you wish to bind the command to, a colon, and then the name of the
  789: command.
  790: There can be no space between the key name and the colon -- that will be
  791: interpreted as part of the key name.
  792: The name of the key can be expressed in different ways, depending on
  793: what you find most comfortable.
  794: 
  795: In addition to command names, readline allows keys to be bound
  796: to a string that is inserted when the key is pressed (a @var{macro}).
  797: 
  798: @ifset BashFeatures
  799: The @w{@code{bind -p}} command displays Readline function names and
  800: bindings in a format that can put directly into an initialization file.
  801: @xref{Bash Builtins}.
  802: @end ifset
  803: 
  804: @table @asis
  805: @item @w{@var{keyname}: @var{function-name} or @var{macro}}
  806: @var{keyname} is the name of a key spelled out in English.  For example:
  807: @example
  808: Control-u: universal-argument
  809: Meta-Rubout: backward-kill-word
  810: Control-o: "> output"
  811: @end example
  812: 
  813: In the example above, @kbd{C-u} is bound to the function
  814: @code{universal-argument},
  815: @kbd{M-DEL} is bound to the function @code{backward-kill-word}, and
  816: @kbd{C-o} is bound to run the macro
  817: expressed on the right hand side (that is, to insert the text
  818: @samp{> output} into the line).
  819: 
  820: A number of symbolic character names are recognized while
  821: processing this key binding syntax:
  822: @var{DEL},
  823: @var{ESC},
  824: @var{ESCAPE},
  825: @var{LFD},
  826: @var{NEWLINE},
  827: @var{RET},
  828: @var{RETURN},
  829: @var{RUBOUT},
  830: @var{SPACE},
  831: @var{SPC},
  832: and
  833: @var{TAB}.
  834: 
  835: @item @w{"@var{keyseq}": @var{function-name} or @var{macro}}
  836: @var{keyseq} differs from @var{keyname} above in that strings
  837: denoting an entire key sequence can be specified, by placing
  838: the key sequence in double quotes.  Some @sc{gnu} Emacs style key
  839: escapes can be used, as in the following example, but the
  840: special character names are not recognized.
  841: 
  842: @example
  843: "\C-u": universal-argument
  844: "\C-x\C-r": re-read-init-file
  845: "\e[11~": "Function Key 1"
  846: @end example
  847: 
  848: In the above example, @kbd{C-u} is again bound to the function
  849: @code{universal-argument} (just as it was in the first example),
  850: @samp{@kbd{C-x} @kbd{C-r}} is bound to the function @code{re-read-init-file},
  851: and @samp{@key{ESC} @key{[} @key{1} @key{1} @key{~}} is bound to insert
  852: the text @samp{Function Key 1}.
  853: 
  854: @end table
  855: 
  856: The following @sc{gnu} Emacs style escape sequences are available when
  857: specifying key sequences:
  858: 
  859: @table @code
  860: @item @kbd{\C-}
  861: control prefix
  862: @item @kbd{\M-}
  863: meta prefix
  864: @item @kbd{\e}
  865: an escape character
  866: @item @kbd{\\}
  867: backslash
  868: @item @kbd{\"}
  869: @key{"}, a double quotation mark
  870: @item @kbd{\'}
  871: @key{'}, a single quote or apostrophe
  872: @end table
  873: 
  874: In addition to the @sc{gnu} Emacs style escape sequences, a second
  875: set of backslash escapes is available:
  876: 
  877: @table @code
  878: @item \a
  879: alert (bell)
  880: @item \b
  881: backspace
  882: @item \d
  883: delete
  884: @item \f
  885: form feed
  886: @item \n
  887: newline
  888: @item \r
  889: carriage return
  890: @item \t
  891: horizontal tab
  892: @item \v
  893: vertical tab
  894: @item \@var{nnn}
  895: the eight-bit character whose value is the octal value @var{nnn}
  896: (one to three digits)
  897: @item \x@var{HH}
  898: the eight-bit character whose value is the hexadecimal value @var{HH}
  899: (one or two hex digits)
  900: @end table
  901: 
  902: When entering the text of a macro, single or double quotes must
  903: be used to indicate a macro definition.
  904: Unquoted text is assumed to be a function name.
  905: In the macro body, the backslash escapes described above are expanded.
  906: Backslash will quote any other character in the macro text,
  907: including @samp{"} and @samp{'}.
  908: For example, the following binding will make @samp{@kbd{C-x} \}
  909: insert a single @samp{\} into the line:
  910: @example
  911: "\C-x\\": "\\"
  912: @end example
  913: 
  914: @end table
  915: 
  916: @node Conditional Init Constructs
  917: @subsection Conditional Init Constructs
  918: 
  919: Readline implements a facility similar in spirit to the conditional
  920: compilation features of the C preprocessor which allows key
  921: bindings and variable settings to be performed as the result
  922: of tests.  There are four parser directives used.
  923: 
  924: @table @code
  925: @item $if
  926: The @code{$if} construct allows bindings to be made based on the
  927: editing mode, the terminal being used, or the application using
  928: Readline.  The text of the test, after any comparison operator,
  929: extends to the end of the line;
  930: unless otherwise noted, no characters are required to isolate it.
  931: 
  932: @table @code
  933: @item mode
  934: The @code{mode=} form of the @code{$if} directive is used to test
  935: whether Readline is in @code{emacs} or @code{vi} mode.
  936: This may be used in conjunction
  937: with the @samp{set keymap} command, for instance, to set bindings in
  938: the @code{emacs-standard} and @code{emacs-ctlx} keymaps only if
  939: Readline is starting out in @code{emacs} mode.
  940: 
  941: @item term
  942: The @code{term=} form may be used to include terminal-specific
  943: key bindings, perhaps to bind the key sequences output by the
  944: terminal's function keys.  The word on the right side of the
  945: @samp{=} is tested against both the full name of the terminal and
  946: the portion of the terminal name before the first @samp{-}.  This
  947: allows @code{sun} to match both @code{sun} and @code{sun-cmd},
  948: for instance.
  949: 
  950: @item version
  951: The @code{version} test may be used to perform comparisons against
  952: specific Readline versions.
  953: The @code{version} expands to the current Readline version.
  954: The set of comparison operators includes
  955: @samp{=} (and @samp{==}), @samp{!=}, @samp{<=}, @samp{>=}, @samp{<},
  956: and @samp{>}.
  957: The version number supplied on the right side of the operator consists
  958: of a major version number, an optional decimal point, and an optional
  959: minor version (e.g., @samp{7.1}). If the minor version is omitted, it
  960: is assumed to be @samp{0}.
  961: The operator may be separated from the string @code{version} and
  962: from the version number argument by whitespace.
  963: The following example sets a variable if the Readline version being used
  964: is 7.0 or newer:
  965: @example
  966: $if version >= 7.0
  967: set show-mode-in-prompt on
  968: $endif
  969: @end example
  970: 
  971: @item application
  972: The @var{application} construct is used to include
  973: application-specific settings.  Each program using the Readline
  974: library sets the @var{application name}, and you can test for
  975: a particular value. 
  976: This could be used to bind key sequences to functions useful for
  977: a specific program.  For instance, the following command adds a
  978: key sequence that quotes the current or previous word in Bash:
  979: @example
  980: $if Bash
  981: # Quote the current or previous word
  982: "\C-xq": "\eb\"\ef\""
  983: $endif
  984: @end example
  985: 
  986: @item variable
  987: The @var{variable} construct provides simple equality tests for Readline
  988: variables and values.
  989: The permitted comparison operators are @samp{=}, @samp{==}, and @samp{!=}.
  990: The variable name must be separated from the comparison operator by
  991: whitespace; the operator may be separated from the value on the right hand
  992: side by whitespace.
  993: Both string and boolean variables may be tested. Boolean variables must be
  994: tested against the values @var{on} and @var{off}.
  995: The following example is equivalent to the @code{mode=emacs} test described
  996: above:
  997: @example
  998: $if editing-mode == emacs
  999: set show-mode-in-prompt on
 1000: $endif
 1001: @end example
 1002: @end table
 1003: 
 1004: @item $endif
 1005: This command, as seen in the previous example, terminates an
 1006: @code{$if} command.
 1007: 
 1008: @item $else
 1009: Commands in this branch of the @code{$if} directive are executed if
 1010: the test fails.
 1011: 
 1012: @item $include
 1013: This directive takes a single filename as an argument and reads commands
 1014: and bindings from that file.
 1015: For example, the following directive reads from @file{/etc/inputrc}:
 1016: @example
 1017: $include /etc/inputrc
 1018: @end example
 1019: @end table
 1020: 
 1021: @node Sample Init File
 1022: @subsection Sample Init File
 1023: 
 1024: Here is an example of an @var{inputrc} file.  This illustrates key
 1025: binding, variable assignment, and conditional syntax.
 1026: 
 1027: @example
 1028: @page
 1029: # This file controls the behaviour of line input editing for
 1030: # programs that use the GNU Readline library.  Existing
 1031: # programs include FTP, Bash, and GDB.
 1032: #
 1033: # You can re-read the inputrc file with C-x C-r.
 1034: # Lines beginning with '#' are comments.
 1035: #
 1036: # First, include any system-wide bindings and variable
 1037: # assignments from /etc/Inputrc
 1038: $include /etc/Inputrc
 1039: 
 1040: #
 1041: # Set various bindings for emacs mode.
 1042: 
 1043: set editing-mode emacs 
 1044: 
 1045: $if mode=emacs
 1046: 
 1047: Meta-Control-h:	backward-kill-word	Text after the function name is ignored
 1048: 
 1049: #
 1050: # Arrow keys in keypad mode
 1051: #
 1052: #"\M-OD":        backward-char
 1053: #"\M-OC":        forward-char
 1054: #"\M-OA":        previous-history
 1055: #"\M-OB":        next-history
 1056: #
 1057: # Arrow keys in ANSI mode
 1058: #
 1059: "\M-[D":        backward-char
 1060: "\M-[C":        forward-char
 1061: "\M-[A":        previous-history
 1062: "\M-[B":        next-history
 1063: #
 1064: # Arrow keys in 8 bit keypad mode
 1065: #
 1066: #"\M-\C-OD":       backward-char
 1067: #"\M-\C-OC":       forward-char
 1068: #"\M-\C-OA":       previous-history
 1069: #"\M-\C-OB":       next-history
 1070: #
 1071: # Arrow keys in 8 bit ANSI mode
 1072: #
 1073: #"\M-\C-[D":       backward-char
 1074: #"\M-\C-[C":       forward-char
 1075: #"\M-\C-[A":       previous-history
 1076: #"\M-\C-[B":       next-history
 1077: 
 1078: C-q: quoted-insert
 1079: 
 1080: $endif
 1081: 
 1082: # An old-style binding.  This happens to be the default.
 1083: TAB: complete
 1084: 
 1085: # Macros that are convenient for shell interaction
 1086: $if Bash
 1087: # edit the path
 1088: "\C-xp": "PATH=$@{PATH@}\e\C-e\C-a\ef\C-f"
 1089: # prepare to type a quoted word --
 1090: # insert open and close double quotes
 1091: # and move to just after the open quote
 1092: "\C-x\"": "\"\"\C-b"
 1093: # insert a backslash (testing backslash escapes
 1094: # in sequences and macros)
 1095: "\C-x\\": "\\"
 1096: # Quote the current or previous word
 1097: "\C-xq": "\eb\"\ef\""
 1098: # Add a binding to refresh the line, which is unbound
 1099: "\C-xr": redraw-current-line
 1100: # Edit variable on current line.
 1101: "\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="
 1102: $endif
 1103: 
 1104: # use a visible bell if one is available
 1105: set bell-style visible
 1106: 
 1107: # don't strip characters to 7 bits when reading
 1108: set input-meta on
 1109: 
 1110: # allow iso-latin1 characters to be inserted rather
 1111: # than converted to prefix-meta sequences
 1112: set convert-meta off
 1113: 
 1114: # display characters with the eighth bit set directly
 1115: # rather than as meta-prefixed characters
 1116: set output-meta on
 1117: 
 1118: # if there are 150 or more possible completions for a word,
 1119: # ask whether or not the user wants to see all of them
 1120: set completion-query-items 150
 1121: 
 1122: # For FTP
 1123: $if Ftp
 1124: "\C-xg": "get \M-?"
 1125: "\C-xt": "put \M-?"
 1126: "\M-.": yank-last-arg
 1127: $endif
 1128: @end example
 1129: 
 1130: @node Bindable Readline Commands
 1131: @section Bindable Readline Commands
 1132: 
 1133: @menu
 1134: * Commands For Moving::		Moving about the line.
 1135: * Commands For History::	Getting at previous lines.
 1136: * Commands For Text::		Commands for changing text.
 1137: * Commands For Killing::	Commands for killing and yanking.
 1138: * Numeric Arguments::		Specifying numeric arguments, repeat counts.
 1139: * Commands For Completion::	Getting Readline to do the typing for you.
 1140: * Keyboard Macros::		Saving and re-executing typed characters
 1141: * Miscellaneous Commands::	Other miscellaneous commands.
 1142: @end menu
 1143: 
 1144: This section describes Readline commands that may be bound to key
 1145: sequences.
 1146: @ifset BashFeatures
 1147: You can list your key bindings by executing
 1148: @w{@code{bind -P}} or, for a more terse format, suitable for an
 1149: @var{inputrc} file, @w{@code{bind -p}}.  (@xref{Bash Builtins}.)
 1150: @end ifset
 1151: Command names without an accompanying key sequence are unbound by default.
 1152: 
 1153: In the following descriptions, @dfn{point} refers to the current cursor
 1154: position, and @dfn{mark} refers to a cursor position saved by the
 1155: @code{set-mark} command.
 1156: The text between the point and mark is referred to as the @dfn{region}.
 1157: 
 1158: @node Commands For Moving
 1159: @subsection Commands For Moving
 1160: @ftable @code
 1161: @item beginning-of-line (C-a)
 1162: Move to the start of the current line.
 1163: 
 1164: @item end-of-line (C-e)
 1165: Move to the end of the line.
 1166: 
 1167: @item forward-char (C-f)
 1168: Move forward a character.
 1169: 
 1170: @item backward-char (C-b)
 1171: Move back a character.
 1172: 
 1173: @item forward-word (M-f)
 1174: Move forward to the end of the next word.
 1175: Words are composed of letters and digits.
 1176: 
 1177: @item backward-word (M-b)
 1178: Move back to the start of the current or previous word.
 1179: Words are composed of letters and digits.
 1180: 
 1181: @ifset BashFeatures
 1182: @item shell-forward-word (M-C-f)
 1183: Move forward to the end of the next word.
 1184: Words are delimited by non-quoted shell metacharacters.
 1185: 
 1186: @item shell-backward-word (M-C-b)
 1187: Move back to the start of the current or previous word.
 1188: Words are delimited by non-quoted shell metacharacters.
 1189: @end ifset
 1190: 
 1191: @item previous-screen-line ()
 1192: Attempt to move point to the same physical screen column on the previous
 1193: physical screen line. This will not have the desired effect if the current
 1194: Readline line does not take up more than one physical line or if point is not
 1195: greater than the length of the prompt plus the screen width.
 1196: 
 1197: @item next-screen-line ()
 1198: Attempt to move point to the same physical screen column on the next
 1199: physical screen line. This will not have the desired effect if the current
 1200: Readline line does not take up more than one physical line or if the length
 1201: of the current Readline line is not greater than the length of the prompt
 1202: plus the screen width.
 1203: 
 1204: @item clear-display (M-C-l)
 1205: Clear the screen and, if possible, the terminal's scrollback buffer,
 1206: then redraw the current line,
 1207: leaving the current line at the top of the screen.
 1208: 
 1209: @item clear-screen (C-l)
 1210: Clear the screen,
 1211: then redraw the current line,
 1212: leaving the current line at the top of the screen.
 1213: 
 1214: @item redraw-current-line ()
 1215: Refresh the current line.  By default, this is unbound.
 1216: 
 1217: @end ftable
 1218: 
 1219: @node Commands For History
 1220: @subsection Commands For Manipulating The History
 1221: 
 1222: @ftable @code
 1223: @item accept-line (Newline or Return)
 1224: @ifset BashFeatures
 1225: Accept the line regardless of where the cursor is.
 1226: If this line is
 1227: non-empty, add it to the history list according to the setting of
 1228: the @env{HISTCONTROL} and @env{HISTIGNORE} variables.
 1229: If this line is a modified history line, then restore the history line
 1230: to its original state.
 1231: @end ifset
 1232: @ifclear BashFeatures
 1233: Accept the line regardless of where the cursor is.
 1234: If this line is
 1235: non-empty, it may be added to the history list for future recall with
 1236: @code{add_history()}.
 1237: If this line is a modified history line, the history line is restored
 1238: to its original state.
 1239: @end ifclear
 1240: 
 1241: @item previous-history (C-p)
 1242: Move `back' through the history list, fetching the previous command.
 1243: 
 1244: @item next-history (C-n)
 1245: Move `forward' through the history list, fetching the next command.
 1246: 
 1247: @item beginning-of-history (M-<)
 1248: Move to the first line in the history.
 1249: 
 1250: @item end-of-history (M->)
 1251: Move to the end of the input history, i.e., the line currently
 1252: being entered.
 1253: 
 1254: @item reverse-search-history (C-r)
 1255: Search backward starting at the current line and moving `up' through
 1256: the history as necessary.  This is an incremental search.
 1257: This command sets the region to the matched text and activates the mark.
 1258: 
 1259: @item forward-search-history (C-s)
 1260: Search forward starting at the current line and moving `down' through
 1261: the history as necessary.  This is an incremental search.
 1262: This command sets the region to the matched text and activates the mark.
 1263: 
 1264: @item non-incremental-reverse-search-history (M-p)
 1265: Search backward starting at the current line and moving `up'
 1266: through the history as necessary using a non-incremental search
 1267: for a string supplied by the user.
 1268: The search string may match anywhere in a history line.
 1269: 
 1270: @item non-incremental-forward-search-history (M-n)
 1271: Search forward starting at the current line and moving `down'
 1272: through the history as necessary using a non-incremental search
 1273: for a string supplied by the user.
 1274: The search string may match anywhere in a history line.
 1275: 
 1276: @item history-search-forward ()
 1277: Search forward through the history for the string of characters
 1278: between the start of the current line and the point.
 1279: The search string must match at the beginning of a history line.
 1280: This is a non-incremental search.
 1281: By default, this command is unbound.
 1282: 
 1283: @item history-search-backward ()
 1284: Search backward through the history for the string of characters
 1285: between the start of the current line and the point.
 1286: The search string must match at the beginning of a history line.
 1287: This is a non-incremental search.
 1288: By default, this command is unbound.
 1289: 
 1290: @item history-substring-search-forward ()
 1291: Search forward through the history for the string of characters
 1292: between the start of the current line and the point.
 1293: The search string may match anywhere in a history line.
 1294: This is a non-incremental search.
 1295: By default, this command is unbound.
 1296: 
 1297: @item history-substring-search-backward ()
 1298: Search backward through the history for the string of characters
 1299: between the start of the current line and the point.
 1300: The search string may match anywhere in a history line.
 1301: This is a non-incremental search.
 1302: By default, this command is unbound.
 1303: 
 1304: @item yank-nth-arg (M-C-y)
 1305: Insert the first argument to the previous command (usually
 1306: the second word on the previous line) at point.
 1307: With an argument @var{n},
 1308: insert the @var{n}th word from the previous command (the words
 1309: in the previous command begin with word 0).  A negative argument
 1310: inserts the @var{n}th word from the end of the previous command.
 1311: Once the argument @var{n} is computed, the argument is extracted
 1312: as if the @samp{!@var{n}} history expansion had been specified.
 1313: 
 1314: @item yank-last-arg (M-. or M-_)
 1315: Insert last argument to the previous command (the last word of the
 1316: previous history entry).
 1317: With a numeric argument, behave exactly like @code{yank-nth-arg}.
 1318: Successive calls to @code{yank-last-arg} move back through the history
 1319: list, inserting the last word (or the word specified by the argument to
 1320: the first call) of each line in turn.
 1321: Any numeric argument supplied to these successive calls determines
 1322: the direction to move through the history.  A negative argument switches
 1323: the direction through the history (back or forward).
 1324: The history expansion facilities are used to extract the last argument,
 1325: as if the @samp{!$} history expansion had been specified.
 1326: 
 1327: @item operate-and-get-next (C-o)
 1328: Accept the current line for return to the calling application as if a
 1329: newline had been entered,
 1330: and fetch the next line relative to the current line from the history
 1331: for editing.
 1332: A numeric argument, if supplied, specifies the history entry to use instead
 1333: of the current line.
 1334: 
 1335: @end ftable
 1336: 
 1337: @node Commands For Text
 1338: @subsection Commands For Changing Text
 1339: 
 1340: @ftable @code
 1341: 
 1342: @item @i{end-of-file} (usually C-d)
 1343: The character indicating end-of-file as set, for example, by
 1344: @code{stty}.  If this character is read when there are no characters
 1345: on the line, and point is at the beginning of the line, Readline
 1346: interprets it as the end of input and returns @sc{eof}.
 1347: 
 1348: @item delete-char (C-d)
 1349: Delete the character at point.  If this function is bound to the
 1350: same character as the tty @sc{eof} character, as @kbd{C-d}
 1351: commonly is, see above for the effects.
 1352: 
 1353: @item backward-delete-char (Rubout)
 1354: Delete the character behind the cursor.  A numeric argument means
 1355: to kill the characters instead of deleting them.
 1356: 
 1357: @item forward-backward-delete-char ()
 1358: Delete the character under the cursor, unless the cursor is at the
 1359: end of the line, in which case the character behind the cursor is
 1360: deleted.  By default, this is not bound to a key.
 1361: 
 1362: @item quoted-insert (C-q or C-v)
 1363: Add the next character typed to the line verbatim.  This is
 1364: how to insert key sequences like @kbd{C-q}, for example.
 1365: 
 1366: @ifclear BashFeatures
 1367: @item tab-insert (M-@key{TAB})
 1368: Insert a tab character.
 1369: @end ifclear
 1370: 
 1371: @item self-insert (a, b, A, 1, !, @dots{})
 1372: Insert yourself.
 1373: 
 1374: @item bracketed-paste-begin ()
 1375: This function is intended to be bound to the "bracketed paste" escape
 1376: sequence sent by some terminals, and such a binding is assigned by default.
 1377: It allows Readline to insert the pasted text as a single unit without treating
 1378: each character as if it had been read from the keyboard.  The characters
 1379: are inserted as if each one was bound to @code{self-insert} instead of
 1380: executing any editing commands.
 1381: 
 1382: Bracketed paste sets the region (the characters between point and the mark)
 1383: to the inserted text. It uses the concept of an @emph{active mark}: when the
 1384: mark is active, Readline redisplay uses the terminal's standout mode to
 1385: denote the region.
 1386: 
 1387: @item transpose-chars (C-t)
 1388: Drag the character before the cursor forward over
 1389: the character at the cursor, moving the
 1390: cursor forward as well.  If the insertion point
 1391: is at the end of the line, then this
 1392: transposes the last two characters of the line.
 1393: Negative arguments have no effect.
 1394: 
 1395: @item transpose-words (M-t)
 1396: Drag the word before point past the word after point,
 1397: moving point past that word as well.
 1398: If the insertion point is at the end of the line, this transposes
 1399: the last two words on the line.
 1400: 
 1401: @item upcase-word (M-u)
 1402: Uppercase the current (or following) word.  With a negative argument,
 1403: uppercase the previous word, but do not move the cursor.
 1404: 
 1405: @item downcase-word (M-l)
 1406: Lowercase the current (or following) word.  With a negative argument,
 1407: lowercase the previous word, but do not move the cursor.
 1408: 
 1409: @item capitalize-word (M-c)
 1410: Capitalize the current (or following) word.  With a negative argument,
 1411: capitalize the previous word, but do not move the cursor.
 1412: 
 1413: @item overwrite-mode ()
 1414: Toggle overwrite mode.  With an explicit positive numeric argument,
 1415: switches to overwrite mode.  With an explicit non-positive numeric
 1416: argument, switches to insert mode.  This command affects only
 1417: @code{emacs} mode; @code{vi} mode does overwrite differently.
 1418: Each call to @code{readline()} starts in insert mode.
 1419: 
 1420: In overwrite mode, characters bound to @code{self-insert} replace
 1421: the text at point rather than pushing the text to the right.
 1422: Characters bound to @code{backward-delete-char} replace the character
 1423: before point with a space.
 1424: 
 1425: By default, this command is unbound.
 1426: 
 1427: @end ftable
 1428: 
 1429: @node Commands For Killing
 1430: @subsection Killing And Yanking
 1431: 
 1432: @ftable @code
 1433: 
 1434: @item kill-line (C-k)
 1435: Kill the text from point to the end of the line.
 1436: With a negative numeric argument, kill backward from the cursor to the
 1437: beginning of the current line.
 1438: 
 1439: @item backward-kill-line (C-x Rubout)
 1440: Kill backward from the cursor to the beginning of the current line.
 1441: With a negative numeric argument, kill forward from the cursor to the
 1442: end of the current line.
 1443: 
 1444: @item unix-line-discard (C-u)
 1445: Kill backward from the cursor to the beginning of the current line.
 1446: 
 1447: @item kill-whole-line ()
 1448: Kill all characters on the current line, no matter where point is.
 1449: By default, this is unbound.
 1450: 
 1451: @item kill-word (M-d)
 1452: Kill from point to the end of the current word, or if between
 1453: words, to the end of the next word.
 1454: Word boundaries are the same as @code{forward-word}.
 1455: 
 1456: @item backward-kill-word (M-@key{DEL})
 1457: Kill the word behind point.
 1458: Word boundaries are the same as @code{backward-word}.
 1459: 
 1460: @ifset BashFeatures
 1461: @item shell-kill-word (M-C-d)
 1462: Kill from point to the end of the current word, or if between
 1463: words, to the end of the next word.
 1464: Word boundaries are the same as @code{shell-forward-word}.
 1465: 
 1466: @item shell-backward-kill-word ()
 1467: Kill the word behind point.
 1468: Word boundaries are the same as @code{shell-backward-word}.
 1469: @end ifset
 1470: 
 1471: @item shell-transpose-words (M-C-t)
 1472: Drag the word before point past the word after point,
 1473: moving point past that word as well.
 1474: If the insertion point is at the end of the line, this transposes
 1475: the last two words on the line.
 1476: Word boundaries are the same as @code{shell-forward-word} and
 1477: @code{shell-backward-word}.
 1478: 
 1479: @item unix-word-rubout (C-w)
 1480: Kill the word behind point, using white space as a word boundary.
 1481: The killed text is saved on the kill-ring.
 1482: 
 1483: @item unix-filename-rubout ()
 1484: Kill the word behind point, using white space and the slash character
 1485: as the word boundaries.
 1486: The killed text is saved on the kill-ring.
 1487: 
 1488: @item delete-horizontal-space ()
 1489: Delete all spaces and tabs around point.  By default, this is unbound.
 1490: 
 1491: @item kill-region ()
 1492: Kill the text in the current region.
 1493: By default, this command is unbound.
 1494: 
 1495: @item copy-region-as-kill ()
 1496: Copy the text in the region to the kill buffer, so it can be yanked
 1497: right away.  By default, this command is unbound.
 1498: 
 1499: @item copy-backward-word ()
 1500: Copy the word before point to the kill buffer.
 1501: The word boundaries are the same as @code{backward-word}.
 1502: By default, this command is unbound.
 1503: 
 1504: @item copy-forward-word ()
 1505: Copy the word following point to the kill buffer.
 1506: The word boundaries are the same as @code{forward-word}.
 1507: By default, this command is unbound.
 1508: 
 1509: @item yank (C-y)
 1510: Yank the top of the kill ring into the buffer at point.
 1511: 
 1512: @item yank-pop (M-y)
 1513: Rotate the kill-ring, and yank the new top.  You can only do this if
 1514: the prior command is @code{yank} or @code{yank-pop}.
 1515: @end ftable
 1516: 
 1517: @node Numeric Arguments
 1518: @subsection Specifying Numeric Arguments
 1519: @ftable @code
 1520: 
 1521: @item digit-argument (@kbd{M-0}, @kbd{M-1}, @dots{} @kbd{M--})
 1522: Add this digit to the argument already accumulating, or start a new
 1523: argument.  @kbd{M--} starts a negative argument.
 1524: 
 1525: @item universal-argument ()
 1526: This is another way to specify an argument.
 1527: If this command is followed by one or more digits, optionally with a
 1528: leading minus sign, those digits define the argument.
 1529: If the command is followed by digits, executing @code{universal-argument}
 1530: again ends the numeric argument, but is otherwise ignored.
 1531: As a special case, if this command is immediately followed by a
 1532: character that is neither a digit nor minus sign, the argument count
 1533: for the next command is multiplied by four.
 1534: The argument count is initially one, so executing this function the
 1535: first time makes the argument count four, a second time makes the
 1536: argument count sixteen, and so on.
 1537: By default, this is not bound to a key.
 1538: @end ftable
 1539: 
 1540: @node Commands For Completion
 1541: @subsection Letting Readline Type For You
 1542: 
 1543: @ftable @code
 1544: @item complete (@key{TAB})
 1545: Attempt to perform completion on the text before point.
 1546: The actual completion performed is application-specific.
 1547: @ifset BashFeatures
 1548: Bash attempts completion treating the text as a variable (if the
 1549: text begins with @samp{$}), username (if the text begins with
 1550: @samp{~}), hostname (if the text begins with @samp{@@}), or
 1551: command (including aliases and functions) in turn.  If none 
 1552: of these produces a match, filename completion is attempted.
 1553: @end ifset
 1554: @ifclear BashFeatures
 1555: The default is filename completion.
 1556: @end ifclear
 1557: 
 1558: @item possible-completions (M-?)
 1559: List the possible completions of the text before point.
 1560: When displaying completions, Readline sets the number of columns used
 1561: for display to the value of @code{completion-display-width}, the value of
 1562: the environment variable @env{COLUMNS}, or the screen width, in that order.
 1563: 
 1564: @item insert-completions (M-*)
 1565: Insert all completions of the text before point that would have
 1566: been generated by @code{possible-completions}.
 1567: 
 1568: @item menu-complete ()
 1569: Similar to @code{complete}, but replaces the word to be completed
 1570: with a single match from the list of possible completions.
 1571: Repeated execution of @code{menu-complete} steps through the list
 1572: of possible completions, inserting each match in turn.
 1573: At the end of the list of completions, the bell is rung
 1574: (subject to the setting of @code{bell-style})
 1575: and the original text is restored.
 1576: An argument of @var{n} moves @var{n} positions forward in the list
 1577: of matches; a negative argument may be used to move backward
 1578: through the list.
 1579: This command is intended to be bound to @key{TAB}, but is unbound
 1580: by default.
 1581: 
 1582: @item menu-complete-backward ()
 1583: Identical to @code{menu-complete}, but moves backward through the list
 1584: of possible completions, as if @code{menu-complete} had been given a
 1585: negative argument.
 1586: 
 1587: @item delete-char-or-list ()
 1588: Deletes the character under the cursor if not at the beginning or
 1589: end of the line (like @code{delete-char}).
 1590: If at the end of the line, behaves identically to
 1591: @code{possible-completions}.
 1592: This command is unbound by default.
 1593: 
 1594: @ifset BashFeatures
 1595: @item complete-filename (M-/)
 1596: Attempt filename completion on the text before point.
 1597: 
 1598: @item possible-filename-completions (C-x /)
 1599: List the possible completions of the text before point,
 1600: treating it as a filename.
 1601: 
 1602: @item complete-username (M-~)
 1603: Attempt completion on the text before point, treating
 1604: it as a username.
 1605: 
 1606: @item possible-username-completions (C-x ~)
 1607: List the possible completions of the text before point,
 1608: treating it as a username.
 1609: 
 1610: @item complete-variable (M-$)
 1611: Attempt completion on the text before point, treating
 1612: it as a shell variable.
 1613: 
 1614: @item possible-variable-completions (C-x $)
 1615: List the possible completions of the text before point,
 1616: treating it as a shell variable.
 1617: 
 1618: @item complete-hostname (M-@@)
 1619: Attempt completion on the text before point, treating
 1620: it as a hostname.
 1621: 
 1622: @item possible-hostname-completions (C-x @@)
 1623: List the possible completions of the text before point,
 1624: treating it as a hostname.
 1625: 
 1626: @item complete-command (M-!)
 1627: Attempt completion on the text before point, treating
 1628: it as a command name.  Command completion attempts to
 1629: match the text against aliases, reserved words, shell
 1630: functions, shell builtins, and finally executable filenames,
 1631: in that order.
 1632: 
 1633: @item possible-command-completions (C-x !)
 1634: List the possible completions of the text before point,
 1635: treating it as a command name.
 1636: 
 1637: @item dynamic-complete-history (M-@key{TAB})
 1638: Attempt completion on the text before point, comparing
 1639: the text against lines from the history list for possible
 1640: completion matches.
 1641: 
 1642: @item dabbrev-expand ()
 1643: Attempt menu completion on the text before point, comparing
 1644: the text against lines from the history list for possible
 1645: completion matches.
 1646: 
 1647: @item complete-into-braces (M-@{)
 1648: Perform filename completion and insert the list of possible completions
 1649: enclosed within braces so the list is available to the shell
 1650: (@pxref{Brace Expansion}).
 1651: 
 1652: @end ifset
 1653: @end ftable
 1654: 
 1655: @node Keyboard Macros
 1656: @subsection Keyboard Macros
 1657: @ftable @code
 1658: 
 1659: @item start-kbd-macro (C-x ()
 1660: Begin saving the characters typed into the current keyboard macro.
 1661: 
 1662: @item end-kbd-macro (C-x ))
 1663: Stop saving the characters typed into the current keyboard macro
 1664: and save the definition.
 1665: 
 1666: @item call-last-kbd-macro (C-x e)
 1667: Re-execute the last keyboard macro defined, by making the characters
 1668: in the macro appear as if typed at the keyboard.
 1669: 
 1670: @item print-last-kbd-macro ()
 1671: Print the last keboard macro defined in a format suitable for the
 1672: @var{inputrc} file.
 1673: 
 1674: @end ftable
 1675: 
 1676: @node Miscellaneous Commands
 1677: @subsection Some Miscellaneous Commands
 1678: @ftable @code
 1679: 
 1680: @item re-read-init-file (C-x C-r)
 1681: Read in the contents of the @var{inputrc} file, and incorporate
 1682: any bindings or variable assignments found there.
 1683: 
 1684: @item abort (C-g)
 1685: Abort the current editing command and
 1686: ring the terminal's bell (subject to the setting of
 1687: @code{bell-style}).
 1688: 
 1689: @item do-lowercase-version (M-A, M-B, M-@var{x}, @dots{})
 1690: If the metafied character @var{x} is upper case, run the command
 1691: that is bound to the corresponding metafied lower case character.
 1692: The behavior is undefined if @var{x} is already lower case.
 1693: 
 1694: @item prefix-meta (@key{ESC})
 1695: Metafy the next character typed.  This is for keyboards
 1696: without a meta key.  Typing @samp{@key{ESC} f} is equivalent to typing
 1697: @kbd{M-f}.
 1698: 
 1699: @item undo (C-_ or C-x C-u)
 1700: Incremental undo, separately remembered for each line.
 1701: 
 1702: @item revert-line (M-r)
 1703: Undo all changes made to this line.  This is like executing the @code{undo}
 1704: command enough times to get back to the beginning.
 1705: 
 1706: @ifset BashFeatures
 1707: @item tilde-expand (M-&)
 1708: @end ifset
 1709: @ifclear BashFeatures
 1710: @item tilde-expand (M-~)
 1711: @end ifclear
 1712: Perform tilde expansion on the current word.
 1713: 
 1714: @item set-mark (C-@@)
 1715: Set the mark to the point.  If a
 1716: numeric argument is supplied, the mark is set to that position.
 1717: 
 1718: @item exchange-point-and-mark (C-x C-x)
 1719: Swap the point with the mark.  The current cursor position is set to
 1720: the saved position, and the old cursor position is saved as the mark.
 1721: 
 1722: @item character-search (C-])
 1723: A character is read and point is moved to the next occurrence of that
 1724: character.  A negative count searches for previous occurrences.
 1725: 
 1726: @item character-search-backward (M-C-])
 1727: A character is read and point is moved to the previous occurrence
 1728: of that character.  A negative count searches for subsequent
 1729: occurrences.
 1730: 
 1731: @item skip-csi-sequence ()
 1732: Read enough characters to consume a multi-key sequence such as those
 1733: defined for keys like Home and End.  Such sequences begin with a
 1734: Control Sequence Indicator (CSI), usually ESC-[.  If this sequence is
 1735: bound to "\e[", keys producing such sequences will have no effect
 1736: unless explicitly bound to a readline command, instead of inserting
 1737: stray characters into the editing buffer.  This is unbound by default,
 1738: but usually bound to ESC-[.
 1739: 
 1740: @item insert-comment (M-#)
 1741: Without a numeric argument, the value of the @code{comment-begin}
 1742: variable is inserted at the beginning of the current line.
 1743: If a numeric argument is supplied, this command acts as a toggle:  if
 1744: the characters at the beginning of the line do not match the value
 1745: of @code{comment-begin}, the value is inserted, otherwise
 1746: the characters in @code{comment-begin} are deleted from the beginning of
 1747: the line.
 1748: In either case, the line is accepted as if a newline had been typed.
 1749: @ifset BashFeatures
 1750: The default value of @code{comment-begin} causes this command
 1751: to make the current line a shell comment.
 1752: If a numeric argument causes the comment character to be removed, the line
 1753: will be executed by the shell.
 1754: @end ifset
 1755: 
 1756: @item dump-functions ()
 1757: Print all of the functions and their key bindings to the
 1758: Readline output stream.  If a numeric argument is supplied,
 1759: the output is formatted in such a way that it can be made part
 1760: of an @var{inputrc} file.  This command is unbound by default.
 1761: 
 1762: @item dump-variables ()
 1763: Print all of the settable variables and their values to the
 1764: Readline output stream.  If a numeric argument is supplied,
 1765: the output is formatted in such a way that it can be made part
 1766: of an @var{inputrc} file.  This command is unbound by default.
 1767: 
 1768: @item dump-macros ()
 1769: Print all of the Readline key sequences bound to macros and the
 1770: strings they output.  If a numeric argument is supplied,
 1771: the output is formatted in such a way that it can be made part
 1772: of an @var{inputrc} file.  This command is unbound by default.
 1773: 
 1774: @ifset BashFeatures
 1775: @item glob-complete-word (M-g)
 1776: The word before point is treated as a pattern for pathname expansion,
 1777: with an asterisk implicitly appended.  This pattern is used to
 1778: generate a list of matching file names for possible completions.
 1779: 
 1780: @item glob-expand-word (C-x *)
 1781: The word before point is treated as a pattern for pathname expansion,
 1782: and the list of matching file names is inserted, replacing the word.
 1783: If a numeric argument is supplied, a @samp{*} is appended before
 1784: pathname expansion.
 1785: 
 1786: @item glob-list-expansions (C-x g)
 1787: The list of expansions that would have been generated by
 1788: @code{glob-expand-word} is displayed, and the line is redrawn.
 1789: If a numeric argument is supplied, a @samp{*} is appended before
 1790: pathname expansion.
 1791: 
 1792: @item display-shell-version (C-x C-v)
 1793: Display version information about the current instance of Bash.
 1794: 
 1795: @item shell-expand-line (M-C-e)
 1796: Expand the line as the shell does.
 1797: This performs alias and history expansion as well as all of the shell
 1798: word expansions (@pxref{Shell Expansions}).
 1799: 
 1800: @item history-expand-line (M-^)
 1801: Perform history expansion on the current line.
 1802: 
 1803: @item magic-space ()
 1804: Perform history expansion on the current line and insert a space
 1805: (@pxref{History Interaction}).
 1806: 
 1807: @item alias-expand-line ()
 1808: Perform alias expansion on the current line (@pxref{Aliases}).
 1809: 
 1810: @item history-and-alias-expand-line ()
 1811: Perform history and alias expansion on the current line.
 1812: 
 1813: @item insert-last-argument (M-. or M-_)
 1814: A synonym for @code{yank-last-arg}.
 1815: 
 1816: @item edit-and-execute-command (C-x C-e)
 1817: Invoke an editor on the current command line, and execute the result as shell
 1818: commands.
 1819: Bash attempts to invoke
 1820: @code{$VISUAL}, @code{$EDITOR}, and @code{emacs}
 1821: as the editor, in that order.
 1822: 
 1823: @end ifset
 1824: 
 1825: @ifclear BashFeatures
 1826: @item emacs-editing-mode (C-e)
 1827: When in @code{vi} command mode, this causes a switch to @code{emacs}
 1828: editing mode.
 1829: 
 1830: @item vi-editing-mode (M-C-j)
 1831: When in @code{emacs} editing mode, this causes a switch to @code{vi}
 1832: editing mode.
 1833: 
 1834: @end ifclear
 1835: 
 1836: @end ftable
 1837: 
 1838: @node Readline vi Mode
 1839: @section Readline vi Mode
 1840: 
 1841: While the Readline library does not have a full set of @code{vi}
 1842: editing functions, it does contain enough to allow simple editing
 1843: of the line.  The Readline @code{vi} mode behaves as specified in
 1844: the @sc{posix} standard.
 1845: 
 1846: @ifset BashFeatures
 1847: In order to switch interactively between @code{emacs} and @code{vi}
 1848: editing modes, use the @samp{set -o emacs} and @samp{set -o vi}
 1849: commands (@pxref{The Set Builtin}).
 1850: @end ifset
 1851: @ifclear BashFeatures
 1852: In order to switch interactively between @code{emacs} and @code{vi}
 1853: editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode
 1854: when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode).
 1855: @end ifclear
 1856: The Readline default is @code{emacs} mode.
 1857: 
 1858: When you enter a line in @code{vi} mode, you are already placed in
 1859: `insertion' mode, as if you had typed an @samp{i}.  Pressing @key{ESC}
 1860: switches you into `command' mode, where you can edit the text of the
 1861: line with the standard @code{vi} movement keys, move to previous
 1862: history lines with @samp{k} and subsequent lines with @samp{j}, and
 1863: so forth.
 1864: 
 1865: @ifset BashFeatures
 1866: @node Programmable Completion
 1867: @section Programmable Completion
 1868: @cindex programmable completion
 1869: 
 1870: When word completion is attempted for an argument to a command for
 1871: which a completion specification (a @var{compspec}) has been defined
 1872: using the @code{complete} builtin (@pxref{Programmable Completion Builtins}),
 1873: the programmable completion facilities are invoked. 
 1874: 
 1875: First, the command name is identified.
 1876: If a compspec has been defined for that command, the
 1877: compspec is used to generate the list of possible completions for the word.
 1878: If the command word is the empty string (completion attempted at the
 1879: beginning of an empty line), any compspec defined with
 1880: the @option{-E} option to @code{complete} is used.
 1881: If the command word is a full pathname, a compspec for the full
 1882: pathname is searched for first.
 1883: If no compspec is found for the full pathname, an attempt is made to
 1884: find a compspec for the portion following the final slash.
 1885: If those searches do not result in a compspec, any compspec defined with
 1886: the @option{-D} option to @code{complete} is used as the default.
 1887: If there is no default compspec, Bash attempts alias expansion
 1888: on the command word as a final resort, and attempts to find a compspec
 1889: for the command word from any successful expansion 
 1890: 
 1891: Once a compspec has been found, it is used to generate the list of
 1892: matching words.
 1893: If a compspec is not found, the default Bash completion
 1894: described above (@pxref{Commands For Completion}) is performed.
 1895: 
 1896: First, the actions specified by the compspec are used.
 1897: Only matches which are prefixed by the word being completed are
 1898: returned.
 1899: When the @option{-f} or @option{-d} option is used for filename or
 1900: directory name completion, the shell variable @env{FIGNORE} is
 1901: used to filter the matches.
 1902: @xref{Bash Variables}, for a description of @env{FIGNORE}.
 1903: 
 1904: Any completions specified by a filename expansion pattern to the
 1905: @option{-G} option are generated next.
 1906: The words generated by the pattern need not match the word being completed.
 1907: The @env{GLOBIGNORE} shell variable is not used to filter the matches,
 1908: but the @env{FIGNORE} shell variable is used.
 1909: 
 1910: Next, the string specified as the argument to the @option{-W} option
 1911: is considered.
 1912: The string is first split using the characters in the @env{IFS}
 1913: special variable as delimiters.
 1914: Shell quoting is honored within the string, in order to provide a
 1915: mechanism for the words to contain shell metacharacters or characters
 1916: in the value of @env{IFS}.
 1917: Each word is then expanded using
 1918: brace expansion, tilde expansion, parameter and variable expansion,
 1919: command substitution, and arithmetic expansion,
 1920: as described above (@pxref{Shell Expansions}).
 1921: The results are split using the rules described above
 1922: (@pxref{Word Splitting}).
 1923: The results of the expansion are prefix-matched against the word being
 1924: completed, and the matching words become the possible completions.
 1925: 
 1926: After these matches have been generated, any shell function or command
 1927: specified with the @option{-F} and @option{-C} options is invoked.
 1928: When the command or function is invoked, the @env{COMP_LINE},
 1929: @env{COMP_POINT}, @env{COMP_KEY}, and @env{COMP_TYPE} variables are
 1930: assigned values as described above (@pxref{Bash Variables}).
 1931: If a shell function is being invoked, the @env{COMP_WORDS} and
 1932: @env{COMP_CWORD} variables are also set.
 1933: When the function or command is invoked, the first argument ($1) is the
 1934: name of the command whose arguments are being completed, the
 1935: second argument ($2) is the word being completed, and the third argument
 1936: ($3) is the word preceding the word being completed on the current command
 1937: line.
 1938: No filtering of the generated completions against the word being completed
 1939: is performed; the function or command has complete freedom in generating
 1940: the matches.
 1941: 
 1942: Any function specified with @option{-F} is invoked first.
 1943: The function may use any of the shell facilities, including the
 1944: @code{compgen} and @code{compopt} builtins described below
 1945: (@pxref{Programmable Completion Builtins}), to generate the matches.
 1946: It must put the possible completions in the @env{COMPREPLY} array
 1947: variable, one per array element.
 1948: 
 1949: Next, any command specified with the @option{-C} option is invoked
 1950: in an environment equivalent to command substitution.
 1951: It should print a list of completions, one per line, to
 1952: the standard output.
 1953: Backslash may be used to escape a newline, if necessary.
 1954: 
 1955: After all of the possible completions are generated, any filter
 1956: specified with the @option{-X} option is applied to the list.
 1957: The filter is a pattern as used for pathname expansion; a @samp{&}
 1958: in the pattern is replaced with the text of the word being completed.
 1959: A literal @samp{&} may be escaped with a backslash; the backslash
 1960: is removed before attempting a match.
 1961: Any completion that matches the pattern will be removed from the list.
 1962: A leading @samp{!} negates the pattern; in this case any completion
 1963: not matching the pattern will be removed.
 1964: If the @code{nocasematch} shell option
 1965: (see the description of @code{shopt} in @ref{The Shopt Builtin})
 1966: is enabled, the match is performed without regard to the case
 1967: of alphabetic characters.
 1968: 
 1969: Finally, any prefix and suffix specified with the @option{-P} and @option{-S}
 1970: options are added to each member of the completion list, and the result is
 1971: returned to the Readline completion code as the list of possible
 1972: completions.
 1973: 
 1974: If the previously-applied actions do not generate any matches, and the
 1975: @option{-o dirnames} option was supplied to @code{complete} when the
 1976: compspec was defined, directory name completion is attempted. 
 1977: 
 1978: If the @option{-o plusdirs} option was supplied to @code{complete} when
 1979: the compspec was defined, directory name completion is attempted and any
 1980: matches are added to the results of the other actions.
 1981: 
 1982: By default, if a compspec is found, whatever it generates is returned to
 1983: the completion code as the full set of possible completions.
 1984: The default Bash completions are not attempted, and the Readline default
 1985: of filename completion is disabled.
 1986: If the @option{-o bashdefault} option was supplied to @code{complete} when
 1987: the compspec was defined, the default Bash completions are attempted
 1988: if the compspec generates no matches.
 1989: If the @option{-o default} option was supplied to @code{complete} when the
 1990: compspec was defined, Readline's default completion will be performed
 1991: if the compspec (and, if attempted, the default Bash completions)
 1992: generate no matches.
 1993: 
 1994: When a compspec indicates that directory name completion is desired,
 1995: the programmable completion functions force Readline to append a slash
 1996: to completed names which are symbolic links to directories, subject to
 1997: the value of the @var{mark-directories} Readline variable, regardless
 1998: of the setting of the @var{mark-symlinked-directories} Readline variable.
 1999: 
 2000: There is some support for dynamically modifying completions.  This is
 2001: most useful when used in combination with a default completion specified
 2002: with @option{-D}.  It's possible for shell functions executed as completion
 2003: handlers to indicate that completion should be retried by returning an
 2004: exit status of 124.  If a shell function returns 124, and changes
 2005: the compspec associated with the command on which completion is being
 2006: attempted (supplied as the first argument when the function is executed),
 2007: programmable completion restarts from the beginning, with an
 2008: attempt to find a new compspec for that command.  This allows a set of
 2009: completions to be built dynamically as completion is attempted, rather than
 2010: being loaded all at once.
 2011: 
 2012: For instance, assuming that there is a library of compspecs, each kept in a
 2013: file corresponding to the name of the command, the following default
 2014: completion function would load completions dynamically:
 2015: 
 2016: @example
 2017: _completion_loader()
 2018: @{
 2019:     . "/etc/bash_completion.d/$1.sh" >/dev/null 2>&1 && return 124
 2020: @}
 2021: complete -D -F _completion_loader -o bashdefault -o default
 2022: @end example
 2023: 
 2024: @node Programmable Completion Builtins
 2025: @section Programmable Completion Builtins
 2026: @cindex completion builtins
 2027: 
 2028: Three builtin commands are available to manipulate the programmable completion
 2029: facilities: one to specify how the arguments to a particular command are to
 2030: be completed, and two to modify the completion as it is happening.
 2031: 
 2032: @table @code
 2033: @item compgen
 2034: @btindex compgen
 2035: @example
 2036: @code{compgen [@var{option}] [@var{word}]}
 2037: @end example
 2038: 
 2039: Generate possible completion matches for @var{word} according to
 2040: the @var{option}s, which may be any option accepted by the
 2041: @code{complete}
 2042: builtin with the exception of @option{-p} and @option{-r}, and write
 2043: the matches to the standard output.
 2044: When using the @option{-F} or @option{-C} options, the various shell variables
 2045: set by the programmable completion facilities, while available, will not
 2046: have useful values.
 2047: 
 2048: The matches will be generated in the same way as if the programmable
 2049: completion code had generated them directly from a completion specification
 2050: with the same flags.
 2051: If @var{word} is specified, only those completions matching @var{word}
 2052: will be displayed.
 2053: 
 2054: The return value is true unless an invalid option is supplied, or no
 2055: matches were generated.
 2056: 
 2057: @item complete
 2058: @btindex complete
 2059: @example
 2060: @code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-DEI] [-A @var{action}] [-G @var{globpat}]
 2061: [-W @var{wordlist}] [-F @var{function}] [-C @var{command}] [-X @var{filterpat}]
 2062: [-P @var{prefix}] [-S @var{suffix}] @var{name} [@var{name} @dots{}]}
 2063: @code{complete -pr [-DEI] [@var{name} @dots{}]}
 2064: @end example
 2065: 
 2066: Specify how arguments to each @var{name} should be completed.
 2067: If the @option{-p} option is supplied, or if no options are supplied, existing
 2068: completion specifications are printed in a way that allows them to be
 2069: reused as input.
 2070: The @option{-r} option removes a completion specification for
 2071: each @var{name}, or, if no @var{name}s are supplied, all
 2072: completion specifications.
 2073: The @option{-D} option indicates that other supplied options and actions should
 2074: apply to the ``default'' command completion; that is, completion attempted
 2075: on a command for which no completion has previously been defined.
 2076: The @option{-E} option indicates that other supplied options and actions should
 2077: apply to ``empty'' command completion; that is, completion attempted on a 
 2078: blank line.
 2079: The @option{-I} option indicates that other supplied options and actions should
 2080: apply to completion on the initial non-assignment word on the line, or after a
 2081: command delimiter such as @samp{;} or @samp{|}, which is usually command
 2082: name completion.
 2083: If multiple options are supplied, the @option{-D} option takes precedence
 2084: over @option{-E}, and both take precedence over @option{-I}.
 2085: If any of @option{-D}, @option{-E}, or @option{-I} are supplied, any other
 2086: @var{name} arguments are ignored; these completions only apply to the case
 2087: specified by the option.
 2088: 
 2089: The process of applying these completion specifications when word completion
 2090: is attempted is described above (@pxref{Programmable Completion}).
 2091: 
 2092: Other options, if specified, have the following meanings.
 2093: The arguments to the @option{-G}, @option{-W}, and @option{-X} options
 2094: (and, if necessary, the @option{-P} and @option{-S} options)
 2095: should be quoted to protect them from expansion before the
 2096: @code{complete} builtin is invoked.
 2097: 
 2098: 
 2099: @table @code
 2100: @item -o @var{comp-option}
 2101: The @var{comp-option} controls several aspects of the compspec's behavior
 2102: beyond the simple generation of completions.
 2103: @var{comp-option} may be one of: 
 2104: 
 2105: @table @code
 2106: 
 2107: @item bashdefault
 2108: Perform the rest of the default Bash completions if the compspec
 2109: generates no matches.
 2110: 
 2111: @item default
 2112: Use Readline's default filename completion if the compspec generates
 2113: no matches.
 2114: 
 2115: @item dirnames
 2116: Perform directory name completion if the compspec generates no matches.
 2117: 
 2118: @item filenames
 2119: Tell Readline that the compspec generates filenames, so it can perform any
 2120: filename-specific processing (like adding a slash to directory names,
 2121: quoting special characters, or suppressing trailing spaces).
 2122: This option is intended to be used with shell functions specified
 2123: with @option{-F}.
 2124: 
 2125: @item noquote
 2126: Tell Readline not to quote the completed words if they are filenames
 2127: (quoting filenames is the default).
 2128: 
 2129: @item nosort
 2130: Tell Readline not to sort the list of possible completions alphabetically.
 2131: 
 2132: @item nospace
 2133: Tell Readline not to append a space (the default) to words completed at
 2134: the end of the line.
 2135: 
 2136: @item plusdirs
 2137: After any matches defined by the compspec are generated, 
 2138: directory name completion is attempted and any
 2139: matches are added to the results of the other actions.
 2140: 
 2141: @end table
 2142: 
 2143: @item -A @var{action}
 2144: The @var{action} may be one of the following to generate a list of possible
 2145: completions:
 2146: 
 2147: @table @code
 2148: @item alias
 2149: Alias names.  May also be specified as @option{-a}.
 2150: 
 2151: @item arrayvar
 2152: Array variable names.
 2153: 
 2154: @item binding
 2155: Readline key binding names (@pxref{Bindable Readline Commands}).
 2156: 
 2157: @item builtin
 2158: Names of shell builtin commands.  May also be specified as @option{-b}.
 2159: 
 2160: @item command
 2161: Command names.  May also be specified as @option{-c}.
 2162: 
 2163: @item directory
 2164: Directory names.  May also be specified as @option{-d}.
 2165: 
 2166: @item disabled
 2167: Names of disabled shell builtins.
 2168: 
 2169: @item enabled
 2170: Names of enabled shell builtins.
 2171: 
 2172: @item export
 2173: Names of exported shell variables.  May also be specified as @option{-e}.
 2174: 
 2175: @item file
 2176: File names.  May also be specified as @option{-f}.
 2177: 
 2178: @item function
 2179: Names of shell functions.
 2180: 
 2181: @item group
 2182: Group names.  May also be specified as @option{-g}.
 2183: 
 2184: @item helptopic
 2185: Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}).
 2186: 
 2187: @item hostname
 2188: Hostnames, as taken from the file specified by the
 2189: @env{HOSTFILE} shell variable (@pxref{Bash Variables}).
 2190: 
 2191: @item job
 2192: Job names, if job control is active.  May also be specified as @option{-j}.
 2193: 
 2194: @item keyword
 2195: Shell reserved words.  May also be specified as @option{-k}.
 2196: 
 2197: @item running
 2198: Names of running jobs, if job control is active.
 2199: 
 2200: @item service
 2201: Service names.  May also be specified as @option{-s}.
 2202: 
 2203: @item setopt
 2204: Valid arguments for the @option{-o} option to the @code{set} builtin
 2205: (@pxref{The Set Builtin}).
 2206: 
 2207: @item shopt
 2208: Shell option names as accepted by the @code{shopt} builtin
 2209: (@pxref{Bash Builtins}).
 2210: 
 2211: @item signal
 2212: Signal names.
 2213: 
 2214: @item stopped
 2215: Names of stopped jobs, if job control is active.
 2216: 
 2217: @item user
 2218: User names.  May also be specified as @option{-u}.
 2219: 
 2220: @item variable
 2221: Names of all shell variables.  May also be specified as @option{-v}.
 2222: @end table
 2223: 
 2224: @item -C @var{command}
 2225: @var{command} is executed in a subshell environment, and its output is
 2226: used as the possible completions.
 2227: 
 2228: @item -F @var{function}
 2229: The shell function @var{function} is executed in the current shell
 2230: environment.
 2231: When it is executed, $1 is the name of the command whose arguments are
 2232: being completed, $2 is the word being completed, and $3 is the word
 2233: preceding the word being completed, as described above
 2234: (@pxref{Programmable Completion}).
 2235: When it finishes, the possible completions are retrieved from the value
 2236: of the @env{COMPREPLY} array variable.
 2237: 
 2238: @item -G @var{globpat}
 2239: The filename expansion pattern @var{globpat} is expanded to generate
 2240: the possible completions.
 2241: 
 2242: @item -P @var{prefix}
 2243: @var{prefix} is added at the beginning of each possible completion
 2244: after all other options have been applied.
 2245: 
 2246: @item -S @var{suffix}
 2247: @var{suffix} is appended to each possible completion
 2248: after all other options have been applied.
 2249: 
 2250: @item -W @var{wordlist}
 2251: The @var{wordlist} is split using the characters in the
 2252: @env{IFS} special variable as delimiters, and each resultant word
 2253: is expanded.
 2254: The possible completions are the members of the resultant list which
 2255: match the word being completed.
 2256: 
 2257: @item -X @var{filterpat}
 2258: @var{filterpat} is a pattern as used for filename expansion.
 2259: It is applied to the list of possible completions generated by the
 2260: preceding options and arguments, and each completion matching
 2261: @var{filterpat} is removed from the list.
 2262: A leading @samp{!} in @var{filterpat} negates the pattern; in this
 2263: case, any completion not matching @var{filterpat} is removed.
 2264: @end table
 2265: 
 2266: The return value is true unless an invalid option is supplied, an option
 2267: other than @option{-p} or @option{-r} is supplied without a @var{name}
 2268: argument, an attempt is made to remove a completion specification for
 2269: a @var{name} for which no specification exists, or
 2270: an error occurs adding a completion specification.
 2271: 
 2272: @item compopt
 2273: @btindex compopt
 2274: @example
 2275: @code{compopt} [-o @var{option}] [-DEI] [+o @var{option}] [@var{name}]
 2276: @end example
 2277: Modify completion options for each @var{name} according to the
 2278: @var{option}s, or for the currently-executing completion if no @var{name}s
 2279: are supplied.
 2280: If no @var{option}s are given, display the completion options for each
 2281: @var{name} or the current completion.
 2282: The possible values of @var{option} are those valid for the @code{complete}
 2283: builtin described above.
 2284: The @option{-D} option indicates that other supplied options should
 2285: apply to the ``default'' command completion; that is, completion attempted
 2286: on a command for which no completion has previously been defined.
 2287: The @option{-E} option indicates that other supplied options should
 2288: apply to ``empty'' command completion; that is, completion attempted on a 
 2289: blank line.
 2290: The @option{-I} option indicates that other supplied options should
 2291: apply to completion on the initial non-assignment word on the line, or after a
 2292: command delimiter such as @samp{;} or @samp{|}, which is usually command
 2293: name completion.
 2294: 
 2295: If multiple options are supplied, the @option{-D} option takes precedence
 2296: over @option{-E}, and both take precedence over @option{-I}
 2297: 
 2298: The return value is true unless an invalid option is supplied, an attempt
 2299: is made to modify the options for a @var{name} for which no completion
 2300: specification exists, or an output error occurs.
 2301: 
 2302: @end table
 2303: 
 2304: @node A Programmable Completion Example
 2305: @section A Programmable Completion Example
 2306: 
 2307: The most common way to obtain additional completion functionality beyond
 2308: the default actions @code{complete} and @code{compgen} provide is to use
 2309: a shell function and bind it to a particular command using @code{complete -F}.
 2310: 
 2311: The following function provides completions for the @code{cd} builtin.
 2312: It is a reasonably good example of what shell functions must do when
 2313: used for completion.  This function uses the word passed as @code{$2}
 2314: to determine the directory name to complete.  You can also use the
 2315: @code{COMP_WORDS} array variable; the current word is indexed by the
 2316: @code{COMP_CWORD} variable.
 2317: 
 2318: The function relies on the @code{complete} and @code{compgen} builtins
 2319: to do much of the work, adding only the things that the Bash @code{cd}
 2320: does beyond accepting basic directory names:
 2321: tilde expansion (@pxref{Tilde Expansion}),
 2322: searching directories in @var{$CDPATH}, which is described above
 2323: (@pxref{Bourne Shell Builtins}),
 2324: and basic support for the @code{cdable_vars} shell option
 2325: (@pxref{The Shopt Builtin}).
 2326: @code{_comp_cd} modifies the value of @var{IFS} so that it contains only
 2327: a newline to accommodate file names containing spaces and tabs --
 2328: @code{compgen} prints the possible completions it generates one per line.
 2329: 
 2330: Possible completions go into the @var{COMPREPLY} array variable, one
 2331: completion per array element.  The programmable completion system retrieves
 2332: the completions from there when the function returns.
 2333: 
 2334: @example
 2335: # A completion function for the cd builtin
 2336: # based on the cd completion function from the bash_completion package
 2337: _comp_cd()
 2338: @{
 2339:     local IFS=$' \t\n'    # normalize IFS
 2340:     local cur _skipdot _cdpath
 2341:     local i j k
 2342: 
 2343:     # Tilde expansion, which also expands tilde to full pathname
 2344:     case "$2" in
 2345:     \~*)    eval cur="$2" ;;
 2346:     *)      cur=$2 ;;
 2347:     esac
 2348: 
 2349:     # no cdpath or absolute pathname -- straight directory completion
 2350:     if [[ -z "$@{CDPATH:-@}" ]] || [[ "$cur" == @@(./*|../*|/*) ]]; then
 2351:         # compgen prints paths one per line; could also use while loop
 2352:         IFS=$'\n'
 2353:         COMPREPLY=( $(compgen -d -- "$cur") )
 2354:         IFS=$' \t\n'
 2355:     # CDPATH+directories in the current directory if not in CDPATH
 2356:     else
 2357:         IFS=$'\n'
 2358:         _skipdot=false
 2359:         # preprocess CDPATH to convert null directory names to .
 2360:         _cdpath=$@{CDPATH/#:/.:@}
 2361:         _cdpath=$@{_cdpath//::/:.:@}
 2362:         _cdpath=$@{_cdpath/%:/:.@}
 2363:         for i in $@{_cdpath//:/$'\n'@}; do
 2364:             if [[ $i -ef . ]]; then _skipdot=true; fi
 2365:             k="$@{#COMPREPLY[@@]@}"
 2366:             for j in $( compgen -d -- "$i/$cur" ); do
 2367:                 COMPREPLY[k++]=$@{j#$i/@}        # cut off directory
 2368:             done
 2369:         done
 2370:         $_skipdot || COMPREPLY+=( $(compgen -d -- "$cur") )
 2371:         IFS=$' \t\n'
 2372:     fi
 2373: 
 2374:     # variable names if appropriate shell option set and no completions
 2375:     if shopt -q cdable_vars && [[ $@{#COMPREPLY[@@]@} -eq 0 ]]; then
 2376:         COMPREPLY=( $(compgen -v -- "$cur") )
 2377:     fi
 2378: 
 2379:     return 0
 2380: @}
 2381: @end example
 2382: 
 2383: We install the completion function using the @option{-F} option to
 2384: @code{complete}:
 2385: 
 2386: @example
 2387: # Tell readline to quote appropriate and append slashes to directories;
 2388: # use the bash default completion for other arguments
 2389: complete -o filenames -o nospace -o bashdefault -F _comp_cd cd
 2390: @end example
 2391: 
 2392: @noindent
 2393: Since we'd like Bash and Readline to take care of some
 2394: of the other details for us, we use several other options to tell Bash
 2395: and Readline what to do.  The @option{-o filenames} option tells Readline
 2396: that the possible completions should be treated as filenames, and quoted
 2397: appropriately.  That option will also cause Readline to append a slash to
 2398: filenames it can determine are directories (which is why we might want to
 2399: extend @code{_comp_cd} to append a slash if we're using directories found
 2400: via @var{CDPATH}: Readline can't tell those completions are directories).
 2401: The @option{-o nospace} option tells Readline to not append a space
 2402: character to the directory name, in case we want to append to it.
 2403: The @option{-o bashdefault} option brings in the rest of the "Bash default"
 2404: completions -- possible completion that Bash adds to the default Readline
 2405: set.  These include things like command name completion, variable completion
 2406: for words beginning with @samp{$} or @samp{$@{}, completions containing pathname
 2407: expansion patterns (@pxref{Filename Expansion}), and so on.
 2408: 
 2409: Once installed using @code{complete}, @code{_comp_cd} will be called every
 2410: time we attempt word completion for a @code{cd} command.
 2411: 
 2412: Many more examples -- an extensive collection of completions for most of
 2413: the common GNU, Unix, and Linux commands -- are available as part of the
 2414: bash_completion project.  This is installed by default on many GNU/Linux
 2415: distributions.  Originally written by Ian Macdonald, the project now lives
 2416: at @url{https://github.com/scop/bash-completion/}.  There are ports for
 2417: other systems such as Solaris and Mac OS X.
 2418: 
 2419: An older version of the bash_completion package is distributed with bash
 2420: in the @file{examples/complete} subdirectory.
 2421: 
 2422: @end ifset

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