man > readline(3readline)

READLINE(3)                           Library Functions Manual                           READLINE(3)

NAME
       readline - get a line from a user with editing

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

       char *
       readline (const char *prompt);

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

DESCRIPTION
       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  informa‐
       tion.

RETURN VALUE
       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
       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 Es‐
       cape 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  com‐
       mand  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
       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 vari‐
       able 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 begin‐
       ning 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  dig‐
                     its)
              \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 back‐
       slash 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 op‐
       tion to the set builtin command.  Other programs using this library  provide  similar  mecha‐
       nisms.   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  dis‐
              playing  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 indi‐
              cate 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 comple‐
              tion.  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 pre‐
              fixes  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  comple‐
              tions  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 ef‐
              fect,  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 pre‐
              fixes 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 termi‐
              nal'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 hor‐
              izontally  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  subse‐
              quently  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-stan‐
              dard,  emacs-meta,  emacs-ctlx, vi, vi-move, vi-command, and vi-insert.  vi is equiva‐
              lent 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 re‐
              ceived 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 as‐
              terisk (*).
       mark-symlinked-directories (Off)
              If set to On, completed names which are symbolic links to directories have a slash ap‐
              pended (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  com‐
              pletions (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 pos‐
              sible 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  indi‐
              vidual 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  immedi‐
              ately 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  comple‐
              tion  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  com‐
              mand 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 es‐
              capes to begin and end sequences of non-printing characters, which can be used to  em‐
              bed 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  in‐
              sertion  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 re‐
       sult 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  com‐
              parison  operator,  extends to the end of the line; unless otherwise noted, no charac‐
              ters 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 ini‐
                     tialization 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  vari‐
                     able name must be separated from the comparison operator by whitespace; the op‐
                     erator  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
       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
       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  charac‐
              ters (letters and digits).
       backward-word (M-b)
              Move  back  to  the  start of the current or previous word.  Words are composed of al‐
              phanumeric 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  cur‐
              rent 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-incremen‐
              tal 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 sup‐
              plied 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 pre‐
              vious line) at point.  With an argument n, insert the nth word from the previous  com‐
              mand  (the  words in the previous command begin with word 0).  A negative argument in‐
              serts the nth word from the end of the previous command.  Once the argument n is  com‐
              puted, 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 his‐
              tory 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 nu‐
              meric 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  ar‐
              gument, 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 char‐
              acter 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 for‐
              ward  as well.  If point is at the end of the line, then this transposes the two char‐
              acters 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 over‐
              write 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-in‐
              sert  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 de‐
              fault, 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  back‐
              ward-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 re‐
              ferred 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  nu‐
              meric argument, but is otherwise ignored.  As a special case, if this command is imme‐
              diately  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 per‐
              formed 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  at‐
              tempts 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-dis‐
              play-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 pos‐
              sible-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 com‐
              mand 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 comple‐
              tions, as if menu-complete had been given a negative argument.  This  command  is  un‐
              bound 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-com‐
              pletions.

   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 defini‐
              tion.
       call-last-kbd-macro (C-x e)
              Re-execute  the last keyboard macro defined, by making the characters in the macro ap‐
              pear 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 as‐
              signments 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  corre‐
              sponding metafied lowercase character.  The behavior is undefined if x is already low‐
              ercase.
       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  posi‐
              tion, 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), usu‐
              ally 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 in‐
              serted 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  com‐
              ment-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
       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  in‐
       sertion 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
       The Gnu Readline Library, Brian Fox and Chet Ramey
       The Gnu History Library, Brian Fox and Chet Ramey
       bash(1)

FILES
       ~/.inputrc
              Individual readline initialization file

AUTHORS
       Brian Fox, Free Software Foundation
       bfox AT gnu.org

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

BUG REPORTS
       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-read‐
       line@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 AT case.edu.

BUGS
       It's too big and too slow.

GNU Readline 8.2                          2022 September 19                              READLINE(3)
readline(3readline) □✕
NAME SYNOPSIS
#include #include #include
COPYRIGHT DESCRIPTION RETURN VALUE NOTATION INITIALIZATION FILE
Key Bindings Variables active-region-start-color active-region-end-color bell-style (audible) bind-tty-special-chars (On) blink-matching-paren (Off) colored-completion-prefix (Off) colored-stats (Off) comment-begin (``#'') completion-display-width (-1) completion-ignore-case (Off) completion-map-case (Off) completion-prefix-display-length (0) completion-query-items (100) convert-meta (On) disable-completion (Off) echo-control-characters (On) editing-mode (emacs) emacs-mode-string (@) enable-active-region (On) enable-bracketed-paste (On) enable-keypad (Off) enable-meta-key (On) expand-tilde (Off) history-preserve-point (Off) history-size (unset) horizontal-scroll-mode (Off) input-meta (Off) isearch-terminators (``C-[ C-J'') keymap (emacs) keyseq-timeout (500) mark-directories (On) mark-modified-lines (Off) mark-symlinked-directories (Off) match-hidden-files (On) menu-complete-display-prefix (Off) output-meta (Off) page-completions (On) print-completions-horizontally (Off) revert-all-at-newline (Off) show-all-if-ambiguous (Off) show-all-if-unmodified (Off) show-mode-in-prompt (Off) skip-completed-text (Off) vi-cmd-mode-string ((cmd)) vi-ins-mode-string ((ins)) visible-stats (Off) Conditional Constructs $include
SEARCHING EDITING COMMANDS
Commands for Moving beginning-of-line (C-a) end-of-line (C-e) forward-char (C-f) backward-char (C-b) forward-word (M-f) backward-word (M-b) previous-screen-line next-screen-line clear-display (M-C-l) clear-screen (C-l) redraw-current-line Commands for Manipulating the History accept-line (Newline, Return) previous-history (C-p) next-history (C-n) beginning-of-history (M- end-of-history (M->) operate-and-get-next (C-o) fetch-history reverse-search-history (C-r) forward-search-history (C-s) non-incremental-reverse-search-history (M-p) non-incremental-forward-search-history (M-n) history-search-backward history-search-forward history-substring-search-backward history-substring-search-forward yank-nth-arg (M-C-y) yank-last-arg (M-., M-_) Commands for Changing Text delete-char (C-d) backward-delete-char (Rubout) forward-backward-delete-char quoted-insert (C-q, C-v) tab-insert (M-TAB) self-insert (a, b, A, 1, !, ...) transpose-chars (C-t) transpose-words (M-t) upcase-word (M-u) downcase-word (M-l) capitalize-word (M-c) overwrite-mode Killing and Yanking kill-line (C-k) backward-kill-line (C-x Rubout) unix-line-discard (C-u) kill-whole-line kill-word (M-d) backward-kill-word (M-Rubout) unix-word-rubout (C-w) unix-filename-rubout delete-horizontal-space (M-\) kill-region copy-region-as-kill copy-backward-word copy-forward-word yank (C-y) yank-pop (M-y) Numeric Arguments digit-argument (M-0, M-1, ..., M--) universal-argument Completing complete (TAB) possible-completions (M-?) menu-complete menu-complete-backward delete-char-or-list Keyboard Macros start-kbd-macro (C-x () end-kbd-macro (C-x )) call-last-kbd-macro (C-x e) print-last-kbd-macro () Miscellaneous re-read-init-file (C-x C-r) abort (C-g) prefix-meta (ESC) undo (C-_, C-x C-u) revert-line (M-r) tilde-expand (M-&) set-mark (C-@, M-) exchange-point-and-mark (C-x C-x) character-search (C-]) character-search-backward (M-C-]) skip-csi-sequence insert-comment (M-#) dump-functions dump-variables dump-macros emacs-editing-mode (C-e) vi-editing-mode (M-C-j)
DEFAULT KEY BINDINGS
Emacs Mode VI Mode bindings
SEE ALSO FILES AUTHORS BUG REPORTS BUGS

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