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READLINE(3) Library Functions Manual READLINE(3)
readline - get a line from a user with editing
#include <stdio.h>
#include <readline/readline.h>
#include <readline/history.h>
char *
readline (const char *prompt);
Readline is Copyright (C) 1989-2020 Free Software Foundation,
Inc.
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.
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.
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.
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
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.
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.
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
The Gnu Readline Library, Brian Fox and Chet Ramey
The Gnu History Library, Brian Fox and Chet Ramey
bash(1)
~/.inputrc
Individual readline initialization file
Brian Fox, Free Software Foundation
bfox@gnu.org
Chet Ramey, Case Western Reserve University
chet.ramey@case.edu
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.
It's too big and too slow.
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 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-01-14.) 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)
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