readline(3) — Linux manual page

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READLINE(3)             Library Functions Manual             READLINE(3)

NAME         top

       readline - get a line from a user with editing

SYNOPSIS         top

       #include <stdio.h>
       #include <readline/readline.h>
       #include <readline/history.h>

       char *
       readline (const char *prompt);

COPYRIGHT         top

       Readline is Copyright (C) 1989-2020 Free Software Foundation,
       Inc.

DESCRIPTION         top

       readline will read a line from the terminal and return it, using
       prompt as a prompt.  If prompt is NULL or the empty string, no
       prompt is issued.  The line returned is allocated with malloc(3);
       the caller must free it when finished.  The line returned has the
       final newline removed, so only the text of the line remains.

       readline offers editing capabilities while the user is entering
       the line.  By default, the line editing commands are similar to
       those of emacs.  A vi-style line editing interface is also
       available.

       This manual page describes only the most basic use of readline.
       Much more functionality is available; see The GNU Readline
       Library and The GNU History Library for additional information.

RETURN VALUE         top

       readline returns the text of the line read.  A blank line returns
       the empty string.  If EOF is encountered while reading a line,
       and the line is empty, NULL is returned.  If an EOF is read with
       a non-empty line, it is treated as a newline.

NOTATION         top

       An Emacs-style notation is used to denote keystrokes.  Control
       keys are denoted by C-key, e.g., C-n means Control-N.  Similarly,
       meta keys are denoted by M-key, so M-x means Meta-X.  (On
       keyboards without a meta key, M-x means ESC x, i.e., press the
       Escape key then the x key.  This makes ESC the meta prefix.  The
       combination M-C-x means ESC-Control-x, or press the Escape key
       then hold the Control key while pressing the x key.)

       Readline commands may be given numeric arguments, which normally
       act as a repeat count.  Sometimes, however, it is the sign of the
       argument that is significant.  Passing a negative argument to a
       command that acts in the forward direction (e.g., kill-line)
       causes that command to act in a backward direction.  Commands
       whose behavior with arguments deviates from this are noted below.

       When a command is described as killing text, the text deleted is
       saved for possible future retrieval (yanking).  The killed text
       is saved in a kill ring.  Consecutive kills cause the text to be
       accumulated into one unit, which can be yanked all at once.
       Commands which do not kill text separate the chunks of text on
       the kill ring.

INITIALIZATION FILE         top

       Readline is customized by putting commands in an initialization
       file (the inputrc file).  The name of this file is taken from the
       value of the INPUTRC environment variable.  If that variable is
       unset, the default is ~/.inputrc.  If that file  does not exist
       or cannot be read, the ultimate default is /etc/inputrc.  When a
       program which uses the readline library starts up, the init file
       is read, and the key bindings and variables are set.  There are
       only a few basic constructs allowed in the readline init file.
       Blank lines are ignored.  Lines beginning with a # are comments.
       Lines beginning with a $ indicate conditional constructs.  Other
       lines denote key bindings and variable settings.  Each program
       using this library may add its own commands and bindings.

       For example, placing

              M-Control-u: universal-argument
       or
              C-Meta-u: universal-argument

       into the inputrc would make M-C-u execute the readline command
       universal-argument.

       The following symbolic character names are recognized while
       processing key bindings: DEL, ESC, ESCAPE, LFD, NEWLINE, RET,
       RETURN, RUBOUT, SPACE, SPC, and TAB.

       In addition to command names, readline allows keys to be bound to
       a string that is inserted when the key is pressed (a macro).

   Key Bindings
       The syntax for controlling key bindings in the inputrc file is
       simple.  All that is required is the name of the command or the
       text of a macro and a key sequence to which it should be bound.
       The name may be specified in one of two ways: as a symbolic key
       name, possibly with Meta- or Control- prefixes, or as a key
       sequence.  The name and key sequence are separated by a colon.
       There can be no whitespace between the name and the colon.

       When using the form keyname:function-name or macro, keyname is
       the name of a key spelled out in English.  For example:

              Control-u: universal-argument
              Meta-Rubout: backward-kill-word
              Control-o: "> output"

       In the above example, C-u is bound to the function
       universal-argument, M-DEL is bound to the function
       backward-kill-word, and C-o is bound to run the macro expressed
       on the right hand side (that is, to insert the text ``> output''
       into the line).

       In the second form, "keyseq":function-name or macro, keyseq
       differs from keyname above in that strings denoting an entire key
       sequence may be specified by placing the sequence within double
       quotes.  Some GNU Emacs style key escapes can be used, as in the
       following example, but the symbolic character names are not
       recognized.

              "\C-u": universal-argument
              "\C-x\C-r": re-read-init-file
              "\e[11~": "Function Key 1"

       In this example, C-u is again bound to the function
       universal-argument.  C-x C-r is bound to the function
       re-read-init-file, and ESC [ 1 1 ~ is bound to insert the text
       ``Function Key 1''.

       The full set of GNU Emacs style escape sequences available when
       specifying key sequences is
              \C-    control prefix
              \M-    meta prefix
              \e     an escape character
              \\     backslash
              \"     literal ", a double quote
              \'     literal ', a single quote

       In addition to the GNU Emacs style escape sequences, a second set
       of backslash escapes is available:
              \a     alert (bell)
              \b     backspace
              \d     delete
              \f     form feed
              \n     newline
              \r     carriage return
              \t     horizontal tab
              \v     vertical tab
              \nnn   the eight-bit character whose value is the octal
                     value nnn (one to three digits)
              \xHH   the eight-bit character whose value is the
                     hexadecimal value HH (one or two hex digits)

       When entering the text of a macro, single or double quotes should
       be used to indicate a macro definition.  Unquoted text is assumed
       to be a function name.  In the macro body, the backslash escapes
       described above are expanded.  Backslash will quote any other
       character in the macro text, including " and '.

       Bash allows the current readline key bindings to be displayed or
       modified with the bind builtin command.  The editing mode may be
       switched during interactive use by using the -o option to the set
       builtin command.  Other programs using this library provide
       similar mechanisms.  The inputrc file may be edited and re-read
       if a program does not provide any other means to incorporate new
       bindings.

   Variables
       Readline has variables that can be used to further customize its
       behavior.  A variable may be set in the inputrc file with a
       statement of the form

              set variable-name value

       Except where noted, readline variables can take the values On or
       Off (without regard to case).  Unrecognized variable names are
       ignored.  When a variable value is read, empty or null values,
       "on" (case-insensitive), and "1" are equivalent to On.  All other
       values are equivalent to Off.  The variables and their default
       values are:

       active-region-start-color
              A string variable that controls the text color and
              background when displaying the text in the active region
              (see the description of enable-active-region below).  This
              string must not take up any physical character positions
              on the display, so it should consist only of terminal
              escape sequences.  It is output to the terminal before
              displaying the text in the active region.  This variable
              is reset to the default value whenever the terminal type
              changes.  The default value is the string that puts the
              terminal in standout mode, as obtained from the terminal's
              terminfo description.  A sample value might be
              "\e[01;33m".
       active-region-end-color
              A string variable that "undoes" the effects of
              active-region-start-color and restores "normal" terminal
              display appearance after displaying text in the active
              region.  This string must not take up any physical
              character positions on the display, so it should consist
              only of terminal escape sequences.  It is output to the
              terminal after displaying the text in the active region.
              This variable is reset to the default value whenever the
              terminal type changes.  The default value is the string
              that restores the terminal from standout mode, as obtained
              from the terminal's terminfo description.  A sample value
              might be "\e[0m".
       bell-style (audible)
              Controls what happens when readline wants to ring the
              terminal bell.  If set to none, readline never rings the
              bell.  If set to visible, readline uses a visible bell if
              one is available.  If set to audible, readline attempts to
              ring the terminal's bell.
       bind-tty-special-chars (On)
              If set to On (the default), readline attempts to bind the
              control characters   treated specially by the kernel's
              terminal driver to their readline equivalents.
       blink-matching-paren (Off)
              If set to On, readline attempts to briefly move the cursor
              to an opening parenthesis when a closing parenthesis is
              inserted.
       colored-completion-prefix (Off)
              If set to On, when listing completions, readline displays
              the common prefix of the set of possible completions using
              a different color.  The color definitions are taken from
              the value of the LS_COLORS environment variable.  If there
              is a color definition in $LS_COLORS for the custom suffix
              "readline-colored-completion-prefix", readline uses this
              color for the common prefix instead of its default.
       colored-stats (Off)
              If set to On, readline displays possible completions using
              different colors to indicate their file type.  The color
              definitions are taken from the value of the LS_COLORS
              environment variable.
       comment-begin (``#'')
              The string that is inserted in vi mode when the
              insert-comment command is executed.  This command is bound
              to M-# in emacs mode and to # in vi command mode.
       completion-display-width (-1)
              The number of screen columns used to display possible
              matches when performing completion.  The value is ignored
              if it is less than 0 or greater than the terminal screen
              width.  A value of 0 will cause matches to be displayed
              one per line.  The default value is -1.
       completion-ignore-case (Off)
              If set to On, readline performs filename matching and
              completion in a case-insensitive fashion.
       completion-map-case (Off)
              If set to On, and completion-ignore-case is enabled,
              readline treats hyphens (-) and underscores (_) as
              equivalent when performing case-insensitive filename
              matching and completion.
       completion-prefix-display-length(0)
              The length in characters of the common prefix of a list of
              possible completions that is displayed without
              modification.  When set to a value greater than zero,
              common prefixes longer than this value are replaced with
              an ellipsis when displaying possible completions.
       completion-query-items (100)
              This determines when the user is queried about viewing the
              number of possible completions generated by the
              possible-completions command.  It may be set to any
              integer value greater than or equal to zero.  If the
              number of possible completions is greater than or equal to
              the value of this variable, readline will ask whether or
              not the user wishes to view them; otherwise they are
              simply listed on the terminal.  A negative value causes
              readline to never ask.
       convert-meta (On)
              If set to On, readline will convert characters with the
              eighth bit set to an ASCII key sequence by stripping the
              eighth bit and prefixing it with an escape character (in
              effect, using escape as the meta prefix).  The default is
              On, but readline will set it to Off if the locale contains
              eight-bit characters.  This variable is dependent on the
              LC_CTYPE locale category, and may change if the locale is
              changed.
       disable-completion (Off)
              If set to On, readline will inhibit word completion.
              Completion characters will be inserted into the line as if
              they had been mapped to self-insert.
       echo-control-characters (On)
              When set to On, on operating systems that indicate they
              support it, readline echoes a character corresponding to a
              signal generated from the keyboard.
       editing-mode (emacs)
              Controls whether readline begins with a set of key
              bindings similar to Emacs or vi.  editing-mode can be set
              to either emacs or vi.
       emacs-mode-string (@)
              If the show-mode-in-prompt variable is enabled, this
              string is displayed immediately before the last line of
              the primary prompt when emacs editing mode is active.  The
              value is expanded like a key binding, so the standard set
              of meta- and control prefixes and backslash escape
              sequences is available.  Use the \1 and \2 escapes to
              begin and end sequences of non-printing characters, which
              can be used to embed a terminal control sequence into the
              mode string.
       enable-active-region (On)
              The point is the current cursor position, and mark refers
              to a saved cursor position.  The text between the point
              and mark is referred to as the region.  When this variable
              is set to On, readline allows certain commands to
              designate the region as active.  When the region is
              active, readline highlights the text in the region using
              the value of the active-region-start-color, which defaults
              to the string that enables the terminal's standout mode.
              The active region shows the text inserted by bracketed-
              paste and any matching text found by incremental and non-
              incremental history searches.
       enable-bracketed-paste (On)
              When set to On, readline configures the terminal to insert
              each paste into the editing buffer as a single string of
              characters, instead of treating each character as if it
              had been read from the keyboard.  This prevents readline
              from executing any editing commands bound to key sequences
              appearing in the pasted text.
       enable-keypad (Off)
              When set to On, readline will try to enable the
              application keypad when it is called.  Some systems need
              this to enable the arrow keys.
       enable-meta-key (On)
              When set to On, readline will try to enable any meta
              modifier key the terminal claims to support when it is
              called.  On many terminals, the meta key is used to send
              eight-bit characters.
       expand-tilde (Off)
              If set to On, tilde expansion is performed when readline
              attempts word completion.
       history-preserve-point (Off)
              If set to On, the history code attempts to place point at
              the same location on each history line retrieved with
              previous-history or next-history.
       history-size (unset)
              Set the maximum number of history entries saved in the
              history list.  If set to zero, any existing history
              entries are deleted and no new entries are saved.  If set
              to a value less than zero, the number of history entries
              is not limited.  By default, the number of history entries
              is not limited.  If an attempt is made to set history-size
              to a non-numeric value, the maximum number of history
              entries will be set to 500.
       horizontal-scroll-mode (Off)
              When set to On, makes readline use a single line for
              display, scrolling the input horizontally on a single
              screen line when it becomes longer than the screen width
              rather than wrapping to a new line.  This setting is
              automatically enabled for terminals of height 1.
       input-meta (Off)
              If set to On, readline will enable eight-bit input (that
              is, it will not clear the eighth bit in the characters it
              reads), regardless of what the terminal claims it can
              support.  The name meta-flag is a synonym for this
              variable.  The default is Off, but readline will set it to
              On if the locale contains eight-bit characters.  This
              variable is dependent on the LC_CTYPE locale category, and
              may change if the locale is changed.
       isearch-terminators (``C-[ C-J'')
              The string of characters that should terminate an
              incremental search without subsequently executing the
              character as a command.  If this variable has not been
              given a value, the characters ESC and C-J will terminate
              an incremental search.
       keymap (emacs)
              Set the current readline keymap.  The set of legal keymap
              names is emacs, emacs-standard, emacs-meta, emacs-ctlx,
              vi, vi-move, vi-command, and vi-insert.  vi is equivalent
              to vi-command; emacs is equivalent to emacs-standard.  The
              default value is emacs.  The value of editing-mode also
              affects the default keymap.
       keyseq-timeout (500)
              Specifies the duration readline will wait for a character
              when reading an ambiguous key sequence (one that can form
              a complete key sequence using the input read so far, or
              can take additional input to complete a longer key
              sequence).  If no input is received within the timeout,
              readline will use the shorter but complete key sequence.
              The value is specified in milliseconds, so a value of 1000
              means that readline will wait one second for additional
              input.  If this variable is set to a value less than or
              equal to zero, or to a non-numeric value, readline will
              wait until another key is pressed to decide which key
              sequence to complete.
       mark-directories (On)
              If set to On, completed directory names have a slash
              appended.
       mark-modified-lines (Off)
              If set to On, history lines that have been modified are
              displayed with a preceding asterisk (*).
       mark-symlinked-directories (Off)
              If set to On, completed names which are symbolic links to
              directories have a slash appended (subject to the value of
              mark-directories).
       match-hidden-files (On)
              This variable, when set to On, causes readline to match
              files whose names begin with a `.' (hidden files) when
              performing filename completion.  If set to Off, the
              leading `.' must be supplied by the user in the filename
              to be completed.
       menu-complete-display-prefix (Off)
              If set to On, menu completion displays the common prefix
              of the list of possible completions (which may be empty)
              before cycling through the list.
       output-meta (Off)
              If set to On, readline will display characters with the
              eighth bit set directly rather than as a meta-prefixed
              escape sequence.  The default is Off, but readline will
              set it to On if the locale contains eight-bit characters.
              This variable is dependent on the LC_CTYPE locale
              category, and may change if the locale is changed.
       page-completions (On)
              If set to On, readline uses an internal more-like pager to
              display a screenful of possible completions at a time.
       print-completions-horizontally (Off)
              If set to On, readline will display completions with
              matches sorted horizontally in alphabetical order, rather
              than down the screen.
       revert-all-at-newline (Off)
              If set to On, readline will undo all changes to history
              lines before returning when accept-line is executed.  By
              default, history lines may be modified and retain
              individual undo lists across calls to readline.
       show-all-if-ambiguous (Off)
              This alters the default behavior of the completion
              functions.  If set to On, words which have more than one
              possible completion cause the matches to be listed
              immediately instead of ringing the bell.
       show-all-if-unmodified (Off)
              This alters the default behavior of the completion
              functions in a fashion similar to show-all-if-ambiguous.
              If set to On, words which have more than one possible
              completion without any possible partial completion (the
              possible completions don't share a common prefix) cause
              the matches to be listed immediately instead of ringing
              the bell.
       show-mode-in-prompt (Off)
              If set to On, add a string to the beginning of the prompt
              indicating the editing mode: emacs, vi command, or vi
              insertion.  The mode strings are user-settable (e.g.,
              emacs-mode-string).
       skip-completed-text (Off)
              If set to On, this alters the default completion behavior
              when inserting a single match into the line.  It's only
              active when performing completion in the middle of a word.
              If enabled, readline does not insert characters from the
              completion that match characters after point in the word
              being completed, so portions of the word following the
              cursor are not duplicated.
       vi-cmd-mode-string ((cmd))
              If the show-mode-in-prompt variable is enabled, this
              string is displayed immediately before the last line of
              the primary prompt when vi editing mode is active and in
              command mode.  The value is expanded like a key binding,
              so the standard set of meta- and control prefixes and
              backslash escape sequences is available.  Use the \1 and
              \2 escapes to begin and end sequences of non-printing
              characters, which can be used to embed a terminal control
              sequence into the mode string.
       vi-ins-mode-string ((ins))
              If the show-mode-in-prompt variable is enabled, this
              string is displayed immediately before the last line of
              the primary prompt when vi editing mode is active and in
              insertion mode.  The value is expanded like a key binding,
              so the standard set of meta- and control prefixes and
              backslash escape sequences is available.  Use the \1 and
              \2 escapes to begin and end sequences of non-printing
              characters, which can be used to embed a terminal control
              sequence into the mode string.
       visible-stats (Off)
              If set to On, a character denoting a file's type as
              reported by stat(2) is appended to the filename when
              listing possible completions.

   Conditional Constructs
       Readline implements a facility similar in spirit to the
       conditional compilation features of the C preprocessor which
       allows key bindings and variable settings to be performed as the
       result of tests.  There are four parser directives used.

       $if    The $if construct allows bindings to be made based on the
              editing mode, the terminal being used, or the application
              using readline.  The text of the test, after any
              comparison operator, extends to the end of the line;
              unless otherwise noted, no characters are required to
              isolate it.

              mode   The mode= form of the $if directive is used to test
                     whether readline is in emacs or vi mode.  This may
                     be used in conjunction with the set keymap command,
                     for instance, to set bindings in the emacs-standard
                     and emacs-ctlx keymaps only if readline is starting
                     out in emacs mode.

              term   The term= form may be used to include terminal-
                     specific key bindings, perhaps to bind the key
                     sequences output by the terminal's function keys.
                     The word on the right side of the = is tested
                     against the full name of the terminal and the
                     portion of the terminal name before the first -.
                     This allows sun to match both sun and sun-cmd, for
                     instance.

              version
                     The version test may be used to perform comparisons
                     against specific readline versions.  The version
                     expands to the current readline version.  The set
                     of comparison operators includes =, (and ==), !=,
                     <=, >=, <, and >.  The version number supplied on
                     the right side of the operator consists of a major
                     version number, an optional decimal point, and an
                     optional minor version (e.g., 7.1). If the minor
                     version is omitted, it is assumed to be 0.  The
                     operator may be separated from the string version
                     and from the version number argument by whitespace.

              application
                     The application construct is used to include
                     application-specific settings.  Each program using
                     the readline library sets the application name, and
                     an initialization file can test for a particular
                     value.  This could be used to bind key sequences to
                     functions useful for a specific program.  For
                     instance, the following command adds a key sequence
                     that quotes the current or previous word in bash:

                     $if Bash
                     # Quote the current or previous word
                     "\C-xq": "\eb\"\ef\""
                     $endif

              variable
                     The variable construct provides simple equality
                     tests for readline variables and values.  The
                     permitted comparison operators are =, ==, and !=.
                     The variable name must be separated from the
                     comparison operator by whitespace; the operator may
                     be separated from the value on the right hand side
                     by whitespace.  Both string and boolean variables
                     may be tested. Boolean variables must be tested
                     against the values on and off.

       $endif This command, as seen in the previous example, terminates
              an $if command.

       $else  Commands in this branch of the $if directive are executed
              if the test fails.

       $include
              This directive takes a single filename as an argument and
              reads commands and bindings from that file.  For example,
              the following directive would read /etc/inputrc:

              $include  /etc/inputrc

SEARCHING         top

       Readline provides commands for searching through the command
       history for lines containing a specified string.  There are two
       search modes: incremental and non-incremental.

       Incremental searches begin before the user has finished typing
       the search string.  As each character of the search string is
       typed, readline displays the next entry from the history matching
       the string typed so far.  An incremental search requires only as
       many characters as needed to find the desired history entry.  To
       search backward in the history for a particular string, type C-r.
       Typing C-s searches forward through the history.  The characters
       present in the value of the isearch-terminators variable are used
       to terminate an incremental search.  If that variable has not
       been assigned a value the Escape and C-J characters will
       terminate an incremental search.  C-G will abort an incremental
       search and restore the original line.  When the search is
       terminated, the history entry containing the search string
       becomes the current line.

       To find other matching entries in the history list, type C-s or
       C-r as appropriate.  This will search backward or forward in the
       history for the next line matching the search string typed so
       far.  Any other key sequence bound to a readline command will
       terminate the search and execute that command.  For instance, a
       newline will terminate the search and accept the line, thereby
       executing the command from the history list.  A movement command
       will terminate the search, make the last line found the current
       line, and begin editing.

       Non-incremental searches read the entire search string before
       starting to search for matching history lines.  The search string
       may be typed by the user or be part of the contents of the
       current line.

EDITING COMMANDS         top

       The following is a list of the names of the commands and the
       default key sequences to which they are bound.  Command names
       without an accompanying key sequence are unbound by default.

       In the following descriptions, point refers to the current cursor
       position, and mark refers to a cursor position saved by the
       set-mark command.  The text between the point and mark is
       referred to as the region.

   Commands for Moving
       beginning-of-line (C-a)
              Move to the start of the current line.
       end-of-line (C-e)
              Move to the end of the line.
       forward-char (C-f)
              Move forward a character.
       backward-char (C-b)
              Move back a character.
       forward-word (M-f)
              Move forward to the end of the next word.  Words are
              composed of alphanumeric characters (letters and digits).
       backward-word (M-b)
              Move back to the start of the current or previous word.
              Words are composed of alphanumeric characters (letters and
              digits).
       previous-screen-line
              Attempt to move point to the same physical screen column
              on the previous physical screen line. This will not have
              the desired effect if the current readline line does not
              take up more than one physical line or if point is not
              greater than the length of the prompt plus the screen
              width.
       next-screen-line
              Attempt to move point to the same physical screen column
              on the next physical screen line. This will not have the
              desired effect if the current readline line does not take
              up more than one physical line or if the length of the
              current readline line is not greater than the length of
              the prompt plus the screen width.
       clear-display (M-C-l)
              Clear the screen and, if possible, the terminal's
              scrollback buffer, then redraw the current line, leaving
              the current line at the top of the screen.
       clear-screen (C-l)
              Clear the screen, then redraw the current line, leaving
              the current line at the top of the screen.  With an
              argument, refresh the current line without clearing the
              screen.
       redraw-current-line
              Refresh the current line.

   Commands for Manipulating the History
       accept-line (Newline, Return)
              Accept the line regardless of where the cursor is.  If
              this line is non-empty, it may be added to the history
              list for future recall with add_history().  If the line is
              a modified history line, the history line is restored to
              its original state.
       previous-history (C-p)
              Fetch the previous command from the history list, moving
              back in the list.
       next-history (C-n)
              Fetch the next command from the history list, moving
              forward in the list.
       beginning-of-history (M-<)
              Move to the first line in the history.
       end-of-history (M->)
              Move to the end of the input history, i.e., the line
              currently being entered.
       operate-and-get-next (C-o)
              Accept the current line for return to the calling
              application as if a newline had been entered, and fetch
              the next line relative to the current line from the
              history for editing.  A numeric argument, if supplied,
              specifies the history entry to use instead of the current
              line.
       fetch-history
              With a numeric argument, fetch that entry from the history
              list and make it the current line.  Without an argument,
              move back to the first entry in the history list.
       reverse-search-history (C-r)
              Search backward starting at the current line and moving
              `up' through the history as necessary.  This is an
              incremental search.
       forward-search-history (C-s)
              Search forward starting at the current line and moving
              `down' through the history as necessary.  This is an
              incremental search.
       non-incremental-reverse-search-history (M-p)
              Search backward through the history starting at the
              current line using a non-incremental search for a string
              supplied by the user.
       non-incremental-forward-search-history (M-n)
              Search forward through the history using a non-incremental
              search for a string supplied by the user.
       history-search-backward
              Search backward through the history for the string of
              characters between the start of the current line and the
              current cursor position (the point).  The search string
              must match at the beginning of a history line.  This is a
              non-incremental search.
       history-search-forward
              Search forward through the history for the string of
              characters between the start of the current line and the
              point.  The search string must match at the beginning of a
              history line.  This is a non-incremental search.
       history-substring-search-backward
              Search backward through the history for the string of
              characters between the start of the current line and the
              current cursor position (the point).  The search string
              may match anywhere in a history line.  This is a non-
              incremental search.
       history-substring-search-forward
              Search forward through the history for the string of
              characters between the start of the current line and the
              point.  The search string may match anywhere in a history
              line.  This is a non-incremental search.
       yank-nth-arg (M-C-y)
              Insert the first argument to the previous command (usually
              the second word on the previous line) at point.  With an
              argument n, insert the nth word from the previous command
              (the words in the previous command begin with word 0).  A
              negative argument inserts the nth word from the end of the
              previous command.  Once the argument n is computed, the
              argument is extracted as if the "!n" history expansion had
              been specified.
       yank-last-arg (M-., M-_)
              Insert the last argument to the previous command (the last
              word of the previous history entry).  With a numeric
              argument, behave exactly like yank-nth-arg.  Successive
              calls to yank-last-arg move back through the history list,
              inserting the last word (or the word specified by the
              argument to the first call) of each line in turn.  Any
              numeric argument supplied to these successive calls
              determines the direction to move through the history.  A
              negative argument switches the direction through the
              history (back or forward).  The history expansion
              facilities are used to extract the last argument, as if
              the "!$" history expansion had been specified.

   Commands for Changing Text
       end-of-file (usually C-d)
              The character indicating end-of-file as set, for example,
              by ``stty''.  If this character is read when there are no
              characters on the line, and point is at the beginning of
              the line, readline interprets it as the end of input and
              returns EOF.
       delete-char (C-d)
              Delete the character at point.  If this function is bound
              to the same character as the tty EOF character, as C-d
              commonly is, see above for the effects.
       backward-delete-char (Rubout)
              Delete the character behind the cursor.  When given a
              numeric argument, save the deleted text on the kill ring.
       forward-backward-delete-char
              Delete the character under the cursor, unless the cursor
              is at the end of the line, in which case the character
              behind the cursor is deleted.
       quoted-insert (C-q, C-v)
              Add the next character that you type to the line verbatim.
              This is how to insert characters like C-q, for example.
       tab-insert (M-TAB)
              Insert a tab character.
       self-insert (a, b, A, 1, !, ...)
              Insert the character typed.
       transpose-chars (C-t)
              Drag the character before point forward over the character
              at point, moving point forward as well.  If point is at
              the end of the line, then this transposes the two
              characters before point.  Negative arguments have no
              effect.
       transpose-words (M-t)
              Drag the word before point past the word after point,
              moving point over that word as well.  If point is at the
              end of the line, this transposes the last two words on the
              line.
       upcase-word (M-u)
              Uppercase the current (or following) word.  With a
              negative argument, uppercase the previous word, but do not
              move point.
       downcase-word (M-l)
              Lowercase the current (or following) word.  With a
              negative argument, lowercase the previous word, but do not
              move point.
       capitalize-word (M-c)
              Capitalize the current (or following) word.  With a
              negative argument, capitalize the previous word, but do
              not move point.
       overwrite-mode
              Toggle overwrite mode.  With an explicit positive numeric
              argument, switches to overwrite mode.  With an explicit
              non-positive numeric argument, switches to insert mode.
              This command affects only emacs mode; vi mode does
              overwrite differently.  Each call to readline() starts in
              insert mode.  In overwrite mode, characters bound to
              self-insert replace the text at point rather than pushing
              the text to the right.  Characters bound to
              backward-delete-char replace the character before point
              with a space.  By default, this command is unbound.

   Killing and Yanking
       kill-line (C-k)
              Kill the text from point to the end of the line.
       backward-kill-line (C-x Rubout)
              Kill backward to the beginning of the line.
       unix-line-discard (C-u)
              Kill backward from point to the beginning of the line.
              The killed text is saved on the kill-ring.
       kill-whole-line
              Kill all characters on the current line, no matter where
              point is.
       kill-word (M-d)
              Kill from point the end of the current word, or if between
              words, to the end of the next word.  Word boundaries are
              the same as those used by forward-word.
       backward-kill-word (M-Rubout)
              Kill the word behind point.  Word boundaries are the same
              as those used by backward-word.
       unix-word-rubout (C-w)
              Kill the word behind point, using white space as a word
              boundary.  The killed text is saved on the kill-ring.
       unix-filename-rubout
              Kill the word behind point, using white space and the
              slash character as the word boundaries.  The killed text
              is saved on the kill-ring.
       delete-horizontal-space (M-\)
              Delete all spaces and tabs around point.
       kill-region
              Kill the text between the point and mark (saved cursor
              position).  This text is referred to as the region.
       copy-region-as-kill
              Copy the text in the region to the kill buffer.
       copy-backward-word
              Copy the word before point to the kill buffer.  The word
              boundaries are the same as backward-word.
       copy-forward-word
              Copy the word following point to the kill buffer.  The
              word boundaries are the same as forward-word.
       yank (C-y)
              Yank the top of the kill ring into the buffer at point.
       yank-pop (M-y)
              Rotate the kill ring, and yank the new top.  Only works
              following yank or yank-pop.

   Numeric Arguments
       digit-argument (M-0, M-1, ..., M--)
              Add this digit to the argument already accumulating, or
              start a new argument.  M-- starts a negative argument.
       universal-argument
              This is another way to specify an argument.  If this
              command is followed by one or more digits, optionally with
              a leading minus sign, those digits define the argument.
              If the command is followed by digits, executing
              universal-argument again ends the numeric argument, but is
              otherwise ignored.  As a special case, if this command is
              immediately followed by a character that is neither a
              digit or minus sign, the argument count for the next
              command is multiplied by four.  The argument count is
              initially one, so executing this function the first time
              makes the argument count four, a second time makes the
              argument count sixteen, and so on.

   Completing
       complete (TAB)
              Attempt to perform completion on the text before point.
              The actual completion performed is application-specific.
              Bash, for instance, attempts completion treating the text
              as a variable (if the text begins with $), username (if
              the text begins with ~), hostname (if the text begins with
              @), or command (including aliases and functions) in turn.
              If none of these produces a match, filename completion is
              attempted.  Gdb, on the other hand, allows completion of
              program functions and variables, and only attempts
              filename completion under certain circumstances.
       possible-completions (M-?)
              List the possible completions of the text before point.
              When displaying completions, readline sets the number of
              columns used for display to the value of completion-
              display-width, the value of the environment variable
              COLUMNS, or the screen width, in that order.
       insert-completions (M-*)
              Insert all completions of the text before point that would
              have been generated by possible-completions.
       menu-complete
              Similar to complete, but replaces the word to be completed
              with a single match from the list of possible completions.
              Repeated execution of menu-complete steps through the list
              of possible completions, inserting each match in turn.  At
              the end of the list of completions, the bell is rung
              (subject to the setting of bell-style) and the original
              text is restored.  An argument of n moves n positions
              forward in the list of matches; a negative argument may be
              used to move backward through the list.  This command is
              intended to be bound to TAB, but is unbound by default.
       menu-complete-backward
              Identical to menu-complete, but moves backward through the
              list of possible completions, as if menu-complete had been
              given a negative argument.  This command is unbound by
              default.
       delete-char-or-list
              Deletes the character under the cursor if not at the
              beginning or end of the line (like delete-char).  If at
              the end of the line, behaves identically to possible-
              completions.

   Keyboard Macros
       start-kbd-macro (C-x ()
              Begin saving the characters typed into the current
              keyboard macro.
       end-kbd-macro (C-x ))
              Stop saving the characters typed into the current keyboard
              macro and store the definition.
       call-last-kbd-macro (C-x e)
              Re-execute the last keyboard macro defined, by making the
              characters in the macro appear as if typed at the
              keyboard.
       print-last-kbd-macro ()
              Print the last keyboard macro defined in a format suitable
              for the inputrc file.

   Miscellaneous
       re-read-init-file (C-x C-r)
              Read in the contents of the inputrc file, and incorporate
              any bindings or variable assignments found there.
       abort (C-g)
              Abort the current editing command and ring the terminal's
              bell (subject to the setting of bell-style).
       do-lowercase-version (M-A, M-B, M-x, ...)
              If the metafied character x is uppercase, run the command
              that is bound to the corresponding metafied lowercase
              character.  The behavior is undefined if x is already
              lowercase.
       prefix-meta (ESC)
              Metafy the next character typed.  ESC f is equivalent to
              Meta-f.
       undo (C-_, C-x C-u)
              Incremental undo, separately remembered for each line.
       revert-line (M-r)
              Undo all changes made to this line.  This is like
              executing the undo command enough times to return the line
              to its initial state.
       tilde-expand (M-&)
              Perform tilde expansion on the current word.
       set-mark (C-@, M-<space>)
              Set the mark to the point.  If a numeric argument is
              supplied, the mark is set to that position.
       exchange-point-and-mark (C-x C-x)
              Swap the point with the mark.  The current cursor position
              is set to the saved position, and the old cursor position
              is saved as the mark.
       character-search (C-])
              A character is read and point is moved to the next
              occurrence of that character.  A negative argument
              searches for previous occurrences.
       character-search-backward (M-C-])
              A character is read and point is moved to the previous
              occurrence of that character.  A negative argument
              searches for subsequent occurrences.
       skip-csi-sequence
              Read enough characters to consume a multi-key sequence
              such as those defined for keys like Home and End.  Such
              sequences begin with a Control Sequence Indicator (CSI),
              usually ESC-[.  If this sequence is bound to "\[", keys
              producing such sequences will have no effect unless
              explicitly bound to a readline command, instead of
              inserting stray characters into the editing buffer.  This
              is unbound by default, but usually bound to ESC-[.
       insert-comment (M-#)
              Without a numeric argument, the value of the readline
              comment-begin variable is inserted at the beginning of the
              current line.  If a numeric argument is supplied, this
              command acts as a toggle: if the characters at the
              beginning of the line do not match the value of
              comment-begin, the value is inserted, otherwise the
              characters in comment-begin are deleted from the beginning
              of the line.  In either case, the line is accepted as if a
              newline had been typed.  The default value of
              comment-begin makes the current line a shell comment.  If
              a numeric argument causes the comment character to be
              removed, the line will be executed by the shell.
       dump-functions
              Print all of the functions and their key bindings to the
              readline output stream.  If a numeric argument is
              supplied, the output is formatted in such a way that it
              can be made part of an inputrc file.
       dump-variables
              Print all of the settable variables and their values to
              the readline output stream.  If a numeric argument is
              supplied, the output is formatted in such a way that it
              can be made part of an inputrc file.
       dump-macros
              Print all of the readline key sequences bound to macros
              and the strings they output.  If a numeric argument is
              supplied, the output is formatted in such a way that it
              can be made part of an inputrc file.
       emacs-editing-mode (C-e)
              When in vi command mode, this causes a switch to emacs
              editing mode.
       vi-editing-mode (M-C-j)
              When in emacs editing mode, this causes a switch to vi
              editing mode.

DEFAULT KEY BINDINGS         top

       The following is a list of the default emacs and vi bindings.
       Characters with the eighth bit set are written as M-<character>,
       and are referred to as metafied characters.  The printable ASCII
       characters not mentioned in the list of emacs standard bindings
       are bound to the self-insert function, which just inserts the
       given character into the input line.  In vi insertion mode, all
       characters not specifically mentioned are bound to self-insert.
       Characters assigned to signal generation by stty(1) or the
       terminal driver, such as C-Z or C-C, retain that function.  Upper
       and lower case metafied characters are bound to the same function
       in the emacs mode meta keymap.  The remaining characters are
       unbound, which causes readline to ring the bell (subject to the
       setting of the bell-style variable).

   Emacs Mode
             Emacs Standard bindings

             "C-@"  set-mark
             "C-A"  beginning-of-line
             "C-B"  backward-char
             "C-D"  delete-char
             "C-E"  end-of-line
             "C-F"  forward-char
             "C-G"  abort
             "C-H"  backward-delete-char
             "C-I"  complete
             "C-J"  accept-line
             "C-K"  kill-line
             "C-L"  clear-screen
             "C-M"  accept-line
             "C-N"  next-history
             "C-P"  previous-history
             "C-Q"  quoted-insert
             "C-R"  reverse-search-history
             "C-S"  forward-search-history
             "C-T"  transpose-chars
             "C-U"  unix-line-discard
             "C-V"  quoted-insert
             "C-W"  unix-word-rubout
             "C-Y"  yank
             "C-]"  character-search
             "C-_"  undo
             " " to "/"  self-insert
             "0"  to "9"  self-insert
             ":"  to "~"  self-insert
             "C-?"  backward-delete-char

             Emacs Meta bindings

             "M-C-G"  abort
             "M-C-H"  backward-kill-word
             "M-C-I"  tab-insert
             "M-C-J"  vi-editing-mode
             "M-C-L"  clear-display
             "M-C-M"  vi-editing-mode
             "M-C-R"  revert-line
             "M-C-Y"  yank-nth-arg
             "M-C-["  complete
             "M-C-]"  character-search-backward
             "M-space"  set-mark
             "M-#"  insert-comment
             "M-&"  tilde-expand
             "M-*"  insert-completions
             "M--"  digit-argument
             "M-."  yank-last-arg
             "M-0"  digit-argument
             "M-1"  digit-argument
             "M-2"  digit-argument
             "M-3"  digit-argument
             "M-4"  digit-argument
             "M-5"  digit-argument
             "M-6"  digit-argument
             "M-7"  digit-argument
             "M-8"  digit-argument
             "M-9"  digit-argument
             "M-<"  beginning-of-history
             "M-="  possible-completions
             "M->"  end-of-history
             "M-?"  possible-completions
             "M-B"  backward-word
             "M-C"  capitalize-word
             "M-D"  kill-word
             "M-F"  forward-word
             "M-L"  downcase-word
             "M-N"  non-incremental-forward-search-history
             "M-P"  non-incremental-reverse-search-history
             "M-R"  revert-line
             "M-T"  transpose-words
             "M-U"  upcase-word
             "M-Y"  yank-pop
             "M-\"  delete-horizontal-space
             "M-~"  tilde-expand
             "M-C-?"  backward-kill-word
             "M-_"  yank-last-arg

             Emacs Control-X bindings

             "C-XC-G"  abort
             "C-XC-R"  re-read-init-file
             "C-XC-U"  undo
             "C-XC-X"  exchange-point-and-mark
             "C-X("  start-kbd-macro
             "C-X)"  end-kbd-macro
             "C-XE"  call-last-kbd-macro
             "C-XC-?"  backward-kill-line

   VI Mode bindings
             VI Insert Mode functions

             "C-D"  vi-eof-maybe
             "C-H"  backward-delete-char
             "C-I"  complete
             "C-J"  accept-line
             "C-M"  accept-line
             "C-R"  reverse-search-history
             "C-S"  forward-search-history
             "C-T"  transpose-chars
             "C-U"  unix-line-discard
             "C-V"  quoted-insert
             "C-W"  unix-word-rubout
             "C-Y"  yank
             "C-["  vi-movement-mode
             "C-_"  undo
             " " to "~"  self-insert
             "C-?"  backward-delete-char

             VI Command Mode functions

             "C-D"  vi-eof-maybe
             "C-E"  emacs-editing-mode
             "C-G"  abort
             "C-H"  backward-char
             "C-J"  accept-line
             "C-K"  kill-line
             "C-L"  clear-screen
             "C-M"  accept-line
             "C-N"  next-history
             "C-P"  previous-history
             "C-Q"  quoted-insert
             "C-R"  reverse-search-history
             "C-S"  forward-search-history
             "C-T"  transpose-chars
             "C-U"  unix-line-discard
             "C-V"  quoted-insert
             "C-W"  unix-word-rubout
             "C-Y"  yank
             "C-_"  vi-undo
             " "  forward-char
             "#"  insert-comment
             "$"  end-of-line
             "%"  vi-match
             "&"  vi-tilde-expand
             "*"  vi-complete
             "+"  next-history
             ","  vi-char-search
             "-"  previous-history
             "."  vi-redo
             "/"  vi-search
             "0"  beginning-of-line
             "1" to "9"  vi-arg-digit
             ";"  vi-char-search
             "="  vi-complete
             "?"  vi-search
             "A"  vi-append-eol
             "B"  vi-prev-word
             "C"  vi-change-to
             "D"  vi-delete-to
             "E"  vi-end-word
             "F"  vi-char-search
             "G"  vi-fetch-history
             "I"  vi-insert-beg
             "N"  vi-search-again
             "P"  vi-put
             "R"  vi-replace
             "S"  vi-subst
             "T"  vi-char-search
             "U"  revert-line
             "W"  vi-next-word
             "X"  backward-delete-char
             "Y"  vi-yank-to
             "\"  vi-complete
             "^"  vi-first-print
             "_"  vi-yank-arg
             "`"  vi-goto-mark
             "a"  vi-append-mode
             "b"  vi-prev-word
             "c"  vi-change-to
             "d"  vi-delete-to
             "e"  vi-end-word
             "f"  vi-char-search
             "h"  backward-char
             "i"  vi-insertion-mode
             "j"  next-history
             "k"  prev-history
             "l"  forward-char
             "m"  vi-set-mark
             "n"  vi-search-again
             "p"  vi-put
             "r"  vi-change-char
             "s"  vi-subst
             "t"  vi-char-search
             "u"  vi-undo
             "w"  vi-next-word
             "x"  vi-delete
             "y"  vi-yank-to
             "|"  vi-column
             "~"  vi-change-case

SEE ALSO         top

       The Gnu Readline Library, Brian Fox and Chet Ramey
       The Gnu History Library, Brian Fox and Chet Ramey
       bash(1)

FILES         top

       ~/.inputrc
              Individual readline initialization file

AUTHORS         top

       Brian Fox, Free Software Foundation
       bfox@gnu.org

       Chet Ramey, Case Western Reserve University
       chet.ramey@case.edu

BUG REPORTS         top

       If you find a bug in readline, you should report it.  But first,
       you should make sure that it really is a bug, and that it appears
       in the latest version of the readline library that you have.

       Once you have determined that a bug actually exists, mail a bug
       report to bug-readline@gnu.org.  If you have a fix, you are
       welcome to mail that as well!  Suggestions and `philosophical'
       bug reports may be mailed to bug-readline@gnu.org or posted to
       the Usenet newsgroup gnu.bash.bug.

       Comments and bug reports concerning this manual page should be
       directed to chet.ramey@case.edu.

BUGS         top

       It's too big and too slow.

COLOPHON         top

       This page is part of the readline (GNU Readline library) project.
       Information about the project can be found at 
       ⟨http://www.gnu.org/software/readline/⟩.  If you have a bug report
       for this manual page, see
       ⟨http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html#Bugs⟩.
       This page was obtained from the project's upstream Git repository
       ⟨git://git.savannah.gnu.org/readline.git⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-11-17.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

GNU Readline 8.2            2022 September 19                READLINE(3)

Pages that refer to this page: bash(1)dbpmda(1)curs_termcap(3x)history(3)crash(8)lvm(8)