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This is readline.info, produced by makeinfo version 6.5 from rlman.texi.
This manual describes the GNU Readline Library (version 8.0, 30 November
2018), a library which aids in the consistency of user interface across
discrete programs which provide a command line interface.
Copyright (C) 1988-2016 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software
Foundation; with no Invariant Sections, no Front-Cover Texts, and
no Back-Cover Texts. A copy of the license is included in the
section entitled "GNU Free Documentation License".
INFO-DIR-SECTION Libraries
START-INFO-DIR-ENTRY
* Readline: (readline). The GNU readline library API.
END-INFO-DIR-ENTRY

File: readline.info, Node: Top, Next: Command Line Editing, Up: (dir)
GNU Readline Library
********************
This document describes the GNU Readline Library, a utility which aids
in the consistency of user interface across discrete programs which
provide a command line interface. The Readline home page is
<http://www.gnu.org/software/readline/>.
* Menu:
* Command Line Editing:: GNU Readline User's Manual.
* Programming with GNU Readline:: GNU Readline Programmer's Manual.
* GNU Free Documentation License:: License for copying this manual.
* Concept Index:: Index of concepts described in this manual.
* Function and Variable Index:: Index of externally visible functions
and variables.

File: readline.info, Node: Command Line Editing, Next: Programming with GNU Readline, Prev: Top, Up: Top
1 Command Line Editing
**********************
This chapter describes the basic features of the GNU command line
editing interface.
* Menu:
* Introduction and Notation:: Notation used in this text.
* Readline Interaction:: The minimum set of commands for editing a line.
* Readline Init File:: Customizing Readline from a user's view.
* Bindable Readline Commands:: A description of most of the Readline commands
available for binding
* Readline vi Mode:: A short description of how to make Readline
behave like the vi editor.

File: readline.info, Node: Introduction and Notation, Next: Readline Interaction, Up: Command Line Editing
1.1 Introduction to Line Editing
================================
The following paragraphs describe the notation used to represent
keystrokes.
The text 'C-k' is read as 'Control-K' and describes the character
produced when the <k> key is pressed while the Control key is depressed.
The text 'M-k' is read as 'Meta-K' and describes the character
produced when the Meta key (if you have one) is depressed, and the <k>
key is pressed. The Meta key is labeled <ALT> on many keyboards. On
keyboards with two keys labeled <ALT> (usually to either side of the
space bar), the <ALT> on the left side is generally set to work as a
Meta key. The <ALT> key on the right may also be configured to work as
a Meta key or may be configured as some other modifier, such as a
Compose key for typing accented characters.
If you do not have a Meta or <ALT> key, or another key working as a
Meta key, the identical keystroke can be generated by typing <ESC>
_first_, and then typing <k>. Either process is known as "metafying"
the <k> key.
The text 'M-C-k' is read as 'Meta-Control-k' and describes the
character produced by "metafying" 'C-k'.
In addition, several keys have their own names. Specifically, <DEL>,
<ESC>, <LFD>, <SPC>, <RET>, and <TAB> all stand for themselves when seen
in this text, or in an init file (*note Readline Init File::). If your
keyboard lacks a <LFD> key, typing <C-j> will produce the desired
character. The <RET> key may be labeled <Return> or <Enter> on some
keyboards.

File: readline.info, Node: Readline Interaction, Next: Readline Init File, Prev: Introduction and Notation, Up: Command Line Editing
1.2 Readline Interaction
========================
Often during an interactive session you type in a long line of text,
only to notice that the first word on the line is misspelled. The
Readline library gives you a set of commands for manipulating the text
as you type it in, allowing you to just fix your typo, and not forcing
you to retype the majority of the line. Using these editing commands,
you move the cursor to the place that needs correction, and delete or
insert the text of the corrections. Then, when you are satisfied with
the line, you simply press <RET>. You do not have to be at the end of
the line to press <RET>; the entire line is accepted regardless of the
location of the cursor within the line.
* Menu:
* Readline Bare Essentials:: The least you need to know about Readline.
* Readline Movement Commands:: Moving about the input line.
* Readline Killing Commands:: How to delete text, and how to get it back!
* Readline Arguments:: Giving numeric arguments to commands.
* Searching:: Searching through previous lines.

File: readline.info, Node: Readline Bare Essentials, Next: Readline Movement Commands, Up: Readline Interaction
1.2.1 Readline Bare Essentials
------------------------------
In order to enter characters into the line, simply type them. The typed
character appears where the cursor was, and then the cursor moves one
space to the right. If you mistype a character, you can use your erase
character to back up and delete the mistyped character.
Sometimes you may mistype a character, and not notice the error until
you have typed several other characters. In that case, you can type
'C-b' to move the cursor to the left, and then correct your mistake.
Afterwards, you can move the cursor to the right with 'C-f'.
When you add text in the middle of a line, you will notice that
characters to the right of the cursor are 'pushed over' to make room for
the text that you have inserted. Likewise, when you delete text behind
the cursor, characters to the right of the cursor are 'pulled back' to
fill in the blank space created by the removal of the text. A list of
the bare essentials for editing the text of an input line follows.
'C-b'
Move back one character.
'C-f'
Move forward one character.
<DEL> or <Backspace>
Delete the character to the left of the cursor.
'C-d'
Delete the character underneath the cursor.
Printing characters
Insert the character into the line at the cursor.
'C-_' or 'C-x C-u'
Undo the last editing command. You can undo all the way back to an
empty line.
(Depending on your configuration, the <Backspace> key be set to delete
the character to the left of the cursor and the <DEL> key set to delete
the character underneath the cursor, like 'C-d', rather than the
character to the left of the cursor.)

File: readline.info, Node: Readline Movement Commands, Next: Readline Killing Commands, Prev: Readline Bare Essentials, Up: Readline Interaction
1.2.2 Readline Movement Commands
--------------------------------
The above table describes the most basic keystrokes that you need in
order to do editing of the input line. For your convenience, many other
commands have been added in addition to 'C-b', 'C-f', 'C-d', and <DEL>.
Here are some commands for moving more rapidly about the line.
'C-a'
Move to the start of the line.
'C-e'
Move to the end of the line.
'M-f'
Move forward a word, where a word is composed of letters and
digits.
'M-b'
Move backward a word.
'C-l'
Clear the screen, reprinting the current line at the top.
Notice how 'C-f' moves forward a character, while 'M-f' moves forward
a word. It is a loose convention that control keystrokes operate on
characters while meta keystrokes operate on words.

File: readline.info, Node: Readline Killing Commands, Next: Readline Arguments, Prev: Readline Movement Commands, Up: Readline Interaction
1.2.3 Readline Killing Commands
-------------------------------
"Killing" text means to delete the text from the line, but to save it
away for later use, usually by "yanking" (re-inserting) it back into the
line. ('Cut' and 'paste' are more recent jargon for 'kill' and 'yank'.)
If the description for a command says that it 'kills' text, then you
can be sure that you can get the text back in a different (or the same)
place later.
When you use a kill command, the text is saved in a "kill-ring". Any
number of consecutive kills save all of the killed text together, so
that when you yank it back, you get it all. The kill ring is not line
specific; the text that you killed on a previously typed line is
available to be yanked back later, when you are typing another line.
Here is the list of commands for killing text.
'C-k'
Kill the text from the current cursor position to the end of the
line.
'M-d'
Kill from the cursor to 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 'M-f'.
'M-<DEL>'
Kill from the cursor the start of the current word, or, if between
words, to the start of the previous word. Word boundaries are the
same as those used by 'M-b'.
'C-w'
Kill from the cursor to the previous whitespace. This is different
than 'M-<DEL>' because the word boundaries differ.
Here is how to "yank" the text back into the line. Yanking means to
copy the most-recently-killed text from the kill buffer.
'C-y'
Yank the most recently killed text back into the buffer at the
cursor.
'M-y'
Rotate the kill-ring, and yank the new top. You can only do this
if the prior command is 'C-y' or 'M-y'.

File: readline.info, Node: Readline Arguments, Next: Searching, Prev: Readline Killing Commands, Up: Readline Interaction
1.2.4 Readline Arguments
------------------------
You can pass numeric arguments to Readline commands. Sometimes the
argument acts as a repeat count, other times it is the sign of the
argument that is significant. If you pass a negative argument to a
command which normally acts in a forward direction, that command will
act in a backward direction. For example, to kill text back to the
start of the line, you might type 'M-- C-k'.
The general way to pass numeric arguments to a command is to type
meta digits before the command. If the first 'digit' typed is a minus
sign ('-'), then the sign of the argument will be negative. Once you
have typed one meta digit to get the argument started, you can type the
remainder of the digits, and then the command. For example, to give the
'C-d' command an argument of 10, you could type 'M-1 0 C-d', which will
delete the next ten characters on the input line.

File: readline.info, Node: Searching, Prev: Readline Arguments, Up: Readline Interaction
1.2.5 Searching for Commands in the History
-------------------------------------------
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 <ESC> 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-r' or
'C-s' as appropriate. This will search backward or forward in the
history for the next entry 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 <RET> 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.
Readline remembers the last incremental search string. If two 'C-r's
are typed without any intervening characters defining a new search
string, any remembered search string is used.
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.

File: readline.info, Node: Readline Init File, Next: Bindable Readline Commands, Prev: Readline Interaction, Up: Command Line Editing
1.3 Readline Init File
======================
Although the Readline library comes with a set of Emacs-like keybindings
installed by default, it is possible to use a different set of
keybindings. Any user can customize programs that use Readline by
putting commands in an "inputrc" file, conventionally in his home
directory. The name of this file is taken from the value of the
environment variable 'INPUTRC'. 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 are set.
In addition, the 'C-x C-r' command re-reads this init file, thus
incorporating any changes that you might have made to it.
* Menu:
* Readline Init File Syntax:: Syntax for the commands in the inputrc file.
* Conditional Init Constructs:: Conditional key bindings in the inputrc file.
* Sample Init File:: An example inputrc file.

File: readline.info, Node: Readline Init File Syntax, Next: Conditional Init Constructs, Up: Readline Init File
1.3.1 Readline Init File Syntax
-------------------------------
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 (*note
Conditional Init Constructs::). Other lines denote variable settings
and key bindings.
Variable Settings
You can modify the run-time behavior of Readline by altering the
values of variables in Readline using the 'set' command within the
init file. The syntax is simple:
set VARIABLE VALUE
Here, for example, is how to change from the default Emacs-like key
binding to use 'vi' line editing commands:
set editing-mode vi
Variable names and values, where appropriate, are recognized
without regard to case. Unrecognized variable names are ignored.
Boolean variables (those that can be set to on or off) are set to
on if the value is null or empty, ON (case-insensitive), or 1. Any
other value results in the variable being set to off.
A great deal of run-time behavior is changeable with the following
variables.
'bell-style'
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' (the default), Readline
attempts to ring the terminal's bell.
'bind-tty-special-chars'
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'
If set to 'on', Readline attempts to briefly move the cursor
to an opening parenthesis when a closing parenthesis is
inserted. The default is 'off'.
'colored-completion-prefix'
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. The default is
'off'.
'colored-stats'
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. The default is 'off'.
'comment-begin'
The string to insert at the beginning of the line when the
'insert-comment' command is executed. The default value is
'"#"'.
'completion-display-width'
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'
If set to 'on', Readline performs filename matching and
completion in a case-insensitive fashion. The default value
is 'off'.
'completion-map-case'
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. The default value is 'off'.
'completion-prefix-display-length'
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'
The number of possible completions that determines when the
user is asked whether the list of possibilities should be
displayed. If the number of possible completions is greater
than this value, Readline will ask the user whether or not he
wishes to view them; otherwise, they are simply listed. This
variable must be set to an integer value greater than or equal
to 0. A negative value means Readline should never ask. The
default limit is '100'.
'convert-meta'
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 an <ESC> character, converting them
to a meta-prefixed key sequence. The default value is 'on',
but will be set to 'off' if the locale is one that contains
eight-bit characters.
'disable-completion'
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'. The default is 'off'.
'echo-control-characters'
When set to 'on', on operating systems that indicate they
support it, readline echoes a character corresponding to a
signal generated from the keyboard. The default is 'on'.
'editing-mode'
The 'editing-mode' variable controls which default set of key
bindings is used. By default, Readline starts up in Emacs
editing mode, where the keystrokes are most similar to Emacs.
This variable 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. The default is '@'.
'enable-bracketed-paste'
When set to 'On', Readline will configure the terminal in a
way that will enable it 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
can prevent pasted characters from being interpreted as
editing commands. The default is 'off'.
'enable-keypad'
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. The default is 'off'.
'enable-meta-key'
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. The default is 'on'.
'expand-tilde'
If set to 'on', tilde expansion is performed when Readline
attempts word completion. The default is 'off'.
'history-preserve-point'
If set to 'on', the history code attempts to place the point
(the current cursor position) at the same location on each
history line retrieved with 'previous-history' or
'next-history'. The default is 'off'.
'history-size'
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'
This variable can be set to either 'on' or 'off'. Setting it
to 'on' means that the text of the lines being edited will
scroll horizontally on a single screen line when they are
longer than the width of the screen, instead of wrapping onto
a new screen line. By default, this variable is set to 'off'.
'input-meta'
If set to 'on', Readline will enable eight-bit input (it will
not clear the eighth bit in the characters it reads),
regardless of what the terminal claims it can support. The
default value is 'off', but Readline will set it to 'on' if
the locale contains eight-bit characters. The name
'meta-flag' is a synonym for this variable.
'isearch-terminators'
The string of characters that should terminate an incremental
search without subsequently executing the character as a
command (*note Searching::). If this variable has not been
given a value, the characters <ESC> and 'C-J' will terminate
an incremental search.
'keymap'
Sets Readline's idea of the current keymap for key binding
commands. Built-in 'keymap' names are 'emacs',
'emacs-standard', 'emacs-meta', 'emacs-ctlx', 'vi', 'vi-move',
'vi-command', and 'vi-insert'. 'vi' is equivalent to
'vi-command' ('vi-move' is also a synonym); 'emacs' is
equivalent to 'emacs-standard'. Applications may add
additional names. The default value is 'emacs'. The value of
the 'editing-mode' variable also affects the default keymap.
'keyseq-timeout'
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. Readline uses this value
to determine whether or not input is available on the current
input source ('rl_instream' by default). 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. The default
value is '500'.
'mark-directories'
If set to 'on', completed directory names have a slash
appended. The default is 'on'.
'mark-modified-lines'
This variable, when set to 'on', causes Readline to display an
asterisk ('*') at the start of history lines which have been
modified. This variable is 'off' by default.
'mark-symlinked-directories'
If set to 'on', completed names which are symbolic links to
directories have a slash appended (subject to the value of
'mark-directories'). The default is 'off'.
'match-hidden-files'
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. This variable is 'on' by default.
'menu-complete-display-prefix'
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. The default is 'off'.
'output-meta'
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.
'page-completions'
If set to 'on', Readline uses an internal 'more'-like pager to
display a screenful of possible completions at a time. This
variable is 'on' by default.
'print-completions-horizontally'
If set to 'on', Readline will display completions with matches
sorted horizontally in alphabetical order, rather than down
the screen. The default is 'off'.
'revert-all-at-newline'
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'. The default is 'off'.
'show-all-if-ambiguous'
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. The default value is 'off'.
'show-all-if-unmodified'
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. The
default value is 'off'.
'show-mode-in-prompt'
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). The default value is 'off'.
'skip-completed-text'
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. For instance, if this is enabled, attempting
completion when the cursor is after the 'e' in 'Makefile' will
result in 'Makefile' rather than 'Makefilefile', assuming
there is a single possible completion. The default value is
'off'.
'vi-cmd-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 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. The
default is '(cmd)'.
'vi-ins-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 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. The
default is '(ins)'.
'visible-stats'
If set to 'on', a character denoting a file's type is appended
to the filename when listing possible completions. The
default is 'off'.
Key Bindings
The syntax for controlling key bindings in the init file is simple.
First you need to find the name of the command that you want to
change. The following sections contain tables of the command name,
the default keybinding, if any, and a short description of what the
command does.
Once you know the name of the command, simply place on a line in
the init file the name of the key you wish to bind the command to,
a colon, and then the name of the command. There can be no space
between the key name and the colon - that will be interpreted as
part of the key name. The name of the key can be expressed in
different ways, depending on what you find most comfortable.
In addition to command names, readline allows keys to be bound to a
string that is inserted when the key is pressed (a MACRO).
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 example above, '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).
A number of symbolic character names are recognized while
processing this key binding syntax: DEL, ESC, ESCAPE, LFD,
NEWLINE, RET, RETURN, RUBOUT, SPACE, SPC, and TAB.
"KEYSEQ": FUNCTION-NAME or MACRO
KEYSEQ differs from KEYNAME above in that strings denoting an
entire key sequence can be specified, by placing the key
sequence in double quotes. Some GNU Emacs style key escapes
can be used, as in the following example, but the special
character names are not recognized.
"\C-u": universal-argument
"\C-x\C-r": re-read-init-file
"\e[11~": "Function Key 1"
In the above example, 'C-u' is again bound to the function
'universal-argument' (just as it was in the first example),
''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 following GNU Emacs style escape sequences are available when
specifying key sequences:
'\C-'
control prefix
'\M-'
meta prefix
'\e'
an escape character
'\\'
backslash
'\"'
<">, a double quotation mark
'\''
<'>, a single quote or apostrophe
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 must 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 '''. For example,
the following binding will make ''C-x' \' insert a single '\' into
the line:
"\C-x\\": "\\"

File: readline.info, Node: Conditional Init Constructs, Next: Sample Init File, Prev: Readline Init File Syntax, Up: Readline Init File
1.3.2 Conditional Init 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 both 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. The following example sets a
variable if the Readline version being used is 7.0 or newer:
$if version >= 7.0
set show-mode-in-prompt on
$endif
'application'
The APPLICATION construct is used to include
application-specific settings. Each program using the
Readline library sets the APPLICATION NAME, and you 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. The following example is equivalent to the
'mode=emacs' test described above:
$if editing-mode == emacs
set show-mode-in-prompt on
$endif
'$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 reads from '/etc/inputrc':
$include /etc/inputrc

File: readline.info, Node: Sample Init File, Prev: Conditional Init Constructs, Up: Readline Init File
1.3.3 Sample Init File
----------------------
Here is an example of an INPUTRC file. This illustrates key binding,
variable assignment, and conditional syntax.
# This file controls the behaviour of line input editing for
# programs that use the GNU Readline library. Existing
# programs include FTP, Bash, and GDB.
#
# You can re-read the inputrc file with C-x C-r.
# Lines beginning with '#' are comments.
#
# First, include any system-wide bindings and variable
# assignments from /etc/Inputrc
$include /etc/Inputrc
#
# Set various bindings for emacs mode.
set editing-mode emacs
$if mode=emacs
Meta-Control-h: backward-kill-word Text after the function name is ignored
#
# Arrow keys in keypad mode
#
#"\M-OD": backward-char
#"\M-OC": forward-char
#"\M-OA": previous-history
#"\M-OB": next-history
#
# Arrow keys in ANSI mode
#
"\M-[D": backward-char
"\M-[C": forward-char
"\M-[A": previous-history
"\M-[B": next-history
#
# Arrow keys in 8 bit keypad mode
#
#"\M-\C-OD": backward-char
#"\M-\C-OC": forward-char
#"\M-\C-OA": previous-history
#"\M-\C-OB": next-history
#
# Arrow keys in 8 bit ANSI mode
#
#"\M-\C-[D": backward-char
#"\M-\C-[C": forward-char
#"\M-\C-[A": previous-history
#"\M-\C-[B": next-history
C-q: quoted-insert
$endif
# An old-style binding. This happens to be the default.
TAB: complete
# Macros that are convenient for shell interaction
$if Bash
# edit the path
"\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f"
# prepare to type a quoted word --
# insert open and close double quotes
# and move to just after the open quote
"\C-x\"": "\"\"\C-b"
# insert a backslash (testing backslash escapes
# in sequences and macros)
"\C-x\\": "\\"
# Quote the current or previous word
"\C-xq": "\eb\"\ef\""
# Add a binding to refresh the line, which is unbound
"\C-xr": redraw-current-line
# Edit variable on current line.
"\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="
$endif
# use a visible bell if one is available
set bell-style visible
# don't strip characters to 7 bits when reading
set input-meta on
# allow iso-latin1 characters to be inserted rather
# than converted to prefix-meta sequences
set convert-meta off
# display characters with the eighth bit set directly
# rather than as meta-prefixed characters
set output-meta on
# if there are more than 150 possible completions for
# a word, ask the user if he wants to see all of them
set completion-query-items 150
# For FTP
$if Ftp
"\C-xg": "get \M-?"
"\C-xt": "put \M-?"
"\M-.": yank-last-arg
$endif

File: readline.info, Node: Bindable Readline Commands, Next: Readline vi Mode, Prev: Readline Init File, Up: Command Line Editing
1.4 Bindable Readline Commands
==============================
* Menu:
* Commands For Moving:: Moving about the line.
* Commands For History:: Getting at previous lines.
* Commands For Text:: Commands for changing text.
* Commands For Killing:: Commands for killing and yanking.
* Numeric Arguments:: Specifying numeric arguments, repeat counts.
* Commands For Completion:: Getting Readline to do the typing for you.
* Keyboard Macros:: Saving and re-executing typed characters
* Miscellaneous Commands:: Other miscellaneous commands.
This section describes Readline commands that may be bound to key
sequences. 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".

File: readline.info, Node: Commands For Moving, Next: Commands For History, Up: Bindable Readline Commands
1.4.1 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
letters and digits.
'backward-word (M-b)'
Move back to the start of the current or previous word. Words are
composed of 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-screen (C-l)'
Clear the screen and redraw the current line, leaving the current
line at the top of the screen.
'redraw-current-line ()'
Refresh the current line. By default, this is unbound.

File: readline.info, Node: Commands For History, Next: Commands For Text, Prev: Commands For Moving, Up: Bindable Readline Commands
1.4.2 Commands For Manipulating The History
-------------------------------------------
'accept-line (Newline or 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 this line is a modified history line, the
history line is restored to its original state.
'previous-history (C-p)'
Move 'back' through the history list, fetching the previous
command.
'next-history (C-n)'
Move 'forward' through the history list, fetching the next command.
'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.
'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 starting at the current line and moving 'up'
through the history as necessary using a non-incremental search for
a string supplied by the user. The search string may match
anywhere in a history line.
'non-incremental-forward-search-history (M-n)'
Search forward starting at the current line and moving 'down'
through the history as necessary using a non-incremental search for
a string supplied by the user. The search string may match
anywhere in a history line.
'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. By default, this command is unbound.
'history-search-backward ()'
Search backward 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. By default, this command is unbound.
'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. By default, this command is unbound.
'history-substring-search-backward ()'
Search backward 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. By default, this command is unbound.
'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-. or M-_)'
Insert 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.

File: readline.info, Node: Commands For Text, Next: Commands For Killing, Prev: Commands For History, Up: Bindable Readline Commands
1.4.3 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. A numeric argument means
to kill the characters instead of deleting them.
'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. By default, this is not bound to a key.
'quoted-insert (C-q or C-v)'
Add the next character typed to the line verbatim. This is how to
insert key sequences like 'C-q', for example.
'tab-insert (M-<TAB>)'
Insert a tab character.
'self-insert (a, b, A, 1, !, ...)'
Insert yourself.
'bracketed-paste-begin ()'
This function is intended to be bound to the "bracketed paste"
escape sequence sent by some terminals, and such a binding is
assigned by default. It allows Readline to insert the pasted text
as a single unit without treating each character as if it had been
read from the keyboard. The characters are inserted as if each one
was bound to 'self-insert' instead of executing any editing
commands.
'transpose-chars (C-t)'
Drag the character before the cursor forward over the character at
the cursor, moving the cursor forward as well. If the insertion
point is at the end of the line, then this transposes the last two
characters of the line. Negative arguments have no effect.
'transpose-words (M-t)'
Drag the word before point past the word after point, moving point
past that word as well. If the insertion 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 the cursor.
'downcase-word (M-l)'
Lowercase the current (or following) word. With a negative
argument, lowercase the previous word, but do not move the cursor.
'capitalize-word (M-c)'
Capitalize the current (or following) word. With a negative
argument, capitalize the previous word, but do not move the cursor.
'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.

File: readline.info, Node: Commands For Killing, Next: Numeric Arguments, Prev: Commands For Text, Up: Bindable Readline Commands
1.4.4 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 from the cursor to the beginning of the current line.
'unix-line-discard (C-u)'
Kill backward from the cursor to the beginning of the current line.
'kill-whole-line ()'
Kill all characters on the current line, no matter where point is.
By default, this is unbound.
'kill-word (M-d)'
Kill from point to the end of the current word, or if between
words, to the end of the next word. Word boundaries are the same
as 'forward-word'.
'backward-kill-word (M-<DEL>)'
Kill the word behind point. Word boundaries are the same as
'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 ()'
Delete all spaces and tabs around point. By default, this is
unbound.
'kill-region ()'
Kill the text in the current region. By default, this command is
unbound.
'copy-region-as-kill ()'
Copy the text in the region to the kill buffer, so it can be yanked
right away. By default, this command is unbound.
'copy-backward-word ()'
Copy the word before point to the kill buffer. The word boundaries
are the same as 'backward-word'. By default, this command is
unbound.
'copy-forward-word ()'
Copy the word following point to the kill buffer. The word
boundaries are the same as 'forward-word'. By default, this
command is unbound.
'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. You can only do this
if the prior command is 'yank' or 'yank-pop'.

File: readline.info, Node: Numeric Arguments, Next: Commands For Completion, Prev: Commands For Killing, Up: Bindable Readline Commands
1.4.5 Specifying 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 nor 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.
By default, this is not bound to a key.

File: readline.info, Node: Commands For Completion, Next: Keyboard Macros, Prev: Numeric Arguments, Up: Bindable Readline Commands
1.4.6 Letting Readline Type For You
-----------------------------------
'complete (<TAB>)'
Attempt to perform completion on the text before point. The actual
completion performed is application-specific. The default is
filename completion.
'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.
'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'. This command is
unbound by default.

File: readline.info, Node: Keyboard Macros, Next: Miscellaneous Commands, Prev: Commands For Completion, Up: Bindable Readline Commands
1.4.7 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 save 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 keboard macro defined in a format suitable for the
INPUTRC file.

File: readline.info, Node: Miscellaneous Commands, Prev: Keyboard Macros, Up: Bindable Readline Commands
1.4.8 Some Miscellaneous Commands
---------------------------------
'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 upper case, run the command that is
bound to the corresponding metafied lower case character. The
behavior is undefined if X is already lower case.
'prefix-meta (<ESC>)'
Metafy the next character typed. This is for keyboards without a
meta key. Typing '<ESC> f' is equivalent to typing 'M-f'.
'undo (C-_ or 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 get back to the beginning.
'tilde-expand (M-~)'
Perform tilde expansion on the current word.
'set-mark (C-@)'
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 count 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 count 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 "\e[", 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 '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.
'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. This command is unbound by default.
'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. This command is unbound by default.
'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. This command is unbound by default.
'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.

File: readline.info, Node: Readline vi Mode, Prev: Bindable Readline Commands, Up: Command Line Editing
1.5 Readline vi Mode
====================
While the Readline library does not have a full set of 'vi' editing
functions, it does contain enough to allow simple editing of the line.
The Readline 'vi' mode behaves as specified in the POSIX standard.
In order to switch interactively between 'emacs' and 'vi' editing
modes, use the command 'M-C-j' (bound to emacs-editing-mode when in 'vi'
mode and to vi-editing-mode in 'emacs' mode). The Readline default is
'emacs' mode.
When you enter a line in 'vi' mode, you are already placed in
'insertion' mode, as if you had typed an 'i'. Pressing <ESC> switches
you into 'command' mode, where you can edit the text of the line with
the standard 'vi' movement keys, move to previous history lines with 'k'
and subsequent lines with 'j', and so forth.
This document describes the GNU Readline Library, a utility for
aiding in the consistency of user interface across discrete programs
that need to provide a command line interface.
Copyright (C) 1988-2016 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice pare
preserved on all copies.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Foundation.

File: readline.info, Node: Programming with GNU Readline, Next: GNU Free Documentation License, Prev: Command Line Editing, Up: Top
2 Programming with GNU Readline
*******************************
This chapter describes the interface between the GNU Readline Library
and other programs. If you are a programmer, and you wish to include
the features found in GNU Readline such as completion, line editing, and
interactive history manipulation in your own programs, this section is
for you.
* Menu:
* Basic Behavior:: Using the default behavior of Readline.
* Custom Functions:: Adding your own functions to Readline.
* Readline Variables:: Variables accessible to custom
functions.
* Readline Convenience Functions:: Functions which Readline supplies to
aid in writing your own custom
functions.
* Readline Signal Handling:: How Readline behaves when it receives signals.
* Custom Completers:: Supplanting or supplementing Readline's
completion functions.

File: readline.info, Node: Basic Behavior, Next: Custom Functions, Up: Programming with GNU Readline
2.1 Basic Behavior
==================
Many programs provide a command line interface, such as 'mail', 'ftp',
and 'sh'. For such programs, the default behaviour of Readline is
sufficient. This section describes how to use Readline in the simplest
way possible, perhaps to replace calls in your code to 'gets()' or
'fgets()'.
The function 'readline()' prints a prompt PROMPT and then reads and
returns a single line of text from the user. If PROMPT is 'NULL' or the
empty string, no prompt is displayed. The line 'readline' returns is
allocated with 'malloc()'; the caller should 'free()' the line when it
has finished with it. The declaration for 'readline' in ANSI C is
char *readline (const char *PROMPT);
So, one might say
char *line = readline ("Enter a line: ");
in order to read a line of text from the user. The line returned has
the final newline removed, so only the text remains.
If 'readline' encounters an 'EOF' while reading the line, and the
line is empty at that point, then '(char *)NULL' is returned.
Otherwise, the line is ended just as if a newline had been typed.
Readline performs some expansion on the PROMPT before it is displayed
on the screen. See the description of 'rl_expand_prompt' (*note
Redisplay::) for additional details, especially if PROMPT will contain
characters that do not consume physical screen space when displayed.
If you want the user to be able to get at the line later, (with <C-p>
for example), you must call 'add_history()' to save the line away in a
"history" list of such lines.
add_history (line);
For full details on the GNU History Library, see the associated manual.
It is preferable to avoid saving empty lines on the history list,
since users rarely have a burning need to reuse a blank line. Here is a
function which usefully replaces the standard 'gets()' library function,
and has the advantage of no static buffer to overflow:
/* A static variable for holding the line. */
static char *line_read = (char *)NULL;
/* Read a string, and return a pointer to it.
Returns NULL on EOF. */
char *
rl_gets ()
{
/* If the buffer has already been allocated,
return the memory to the free pool. */
if (line_read)
{
free (line_read);
line_read = (char *)NULL;
}
/* Get a line from the user. */
line_read = readline ("");
/* If the line has any text in it,
save it on the history. */
if (line_read && *line_read)
add_history (line_read);
return (line_read);
}
This function gives the user the default behaviour of <TAB>
completion: completion on file names. If you do not want Readline to
complete on filenames, you can change the binding of the <TAB> key with
'rl_bind_key()'.
int rl_bind_key (int KEY, rl_command_func_t *FUNCTION);
'rl_bind_key()' takes two arguments: KEY is the character that you
want to bind, and FUNCTION is the address of the function to call when
KEY is pressed. Binding <TAB> to 'rl_insert()' makes <TAB> insert
itself. 'rl_bind_key()' returns non-zero if KEY is not a valid ASCII
character code (between 0 and 255).
Thus, to disable the default <TAB> behavior, the following suffices:
rl_bind_key ('\t', rl_insert);
This code should be executed once at the start of your program; you
might write a function called 'initialize_readline()' which performs
this and other desired initializations, such as installing custom
completers (*note Custom Completers::).

File: readline.info, Node: Custom Functions, Next: Readline Variables, Prev: Basic Behavior, Up: Programming with GNU Readline
2.2 Custom Functions
====================
Readline provides many functions for manipulating the text of the line,
but it isn't possible to anticipate the needs of all programs. This
section describes the various functions and variables defined within the
Readline library which allow a user program to add customized
functionality to Readline.
Before declaring any functions that customize Readline's behavior, or
using any functionality Readline provides in other code, an application
writer should include the file '<readline/readline.h>' in any file that
uses Readline's features. Since some of the definitions in 'readline.h'
use the 'stdio' library, the file '<stdio.h>' should be included before
'readline.h'.
'readline.h' defines a C preprocessor variable that should be treated
as an integer, 'RL_READLINE_VERSION', which may be used to conditionally
compile application code depending on the installed Readline version.
The value is a hexadecimal encoding of the major and minor version
numbers of the library, of the form 0xMMMM. MM is the two-digit major
version number; MM is the two-digit minor version number. For Readline
4.2, for example, the value of 'RL_READLINE_VERSION' would be '0x0402'.
* Menu:
* Readline Typedefs:: C declarations to make code readable.
* Function Writing:: Variables and calling conventions.

File: readline.info, Node: Readline Typedefs, Next: Function Writing, Up: Custom Functions
2.2.1 Readline Typedefs
-----------------------
For readability, we declare a number of new object types, all pointers
to functions.
The reason for declaring these new types is to make it easier to
write code describing pointers to C functions with appropriately
prototyped arguments and return values.
For instance, say we want to declare a variable FUNC as a pointer to
a function which takes two 'int' arguments and returns an 'int' (this is
the type of all of the Readline bindable functions). Instead of the
classic C declaration
'int (*func)();'
or the ANSI-C style declaration
'int (*func)(int, int);'
we may write
'rl_command_func_t *func;'
The full list of function pointer types available is
'typedef int rl_command_func_t (int, int);'
'typedef char *rl_compentry_func_t (const char *, int);'
'typedef char **rl_completion_func_t (const char *, int, int);'
'typedef char *rl_quote_func_t (char *, int, char *);'
'typedef char *rl_dequote_func_t (char *, int);'
'typedef int rl_compignore_func_t (char **);'
'typedef void rl_compdisp_func_t (char **, int, int);'
'typedef int rl_hook_func_t (void);'
'typedef int rl_getc_func_t (FILE *);'
'typedef int rl_linebuf_func_t (char *, int);'
'typedef int rl_intfunc_t (int);'
'#define rl_ivoidfunc_t rl_hook_func_t'
'typedef int rl_icpfunc_t (char *);'
'typedef int rl_icppfunc_t (char **);'
'typedef void rl_voidfunc_t (void);'
'typedef void rl_vintfunc_t (int);'
'typedef void rl_vcpfunc_t (char *);'
'typedef void rl_vcppfunc_t (char **);'

File: readline.info, Node: Function Writing, Prev: Readline Typedefs, Up: Custom Functions
2.2.2 Writing a New Function
----------------------------
In order to write new functions for Readline, you need to know the
calling conventions for keyboard-invoked functions, and the names of the
variables that describe the current state of the line read so far.
The calling sequence for a command 'foo' looks like
int foo (int count, int key)
where COUNT is the numeric argument (or 1 if defaulted) and KEY is the
key that invoked this function.
It is completely up to the function as to what should be done with
the numeric argument. Some functions use it as a repeat count, some as
a flag, and others to choose alternate behavior (refreshing the current
line as opposed to refreshing the screen, for example). Some choose to
ignore it. In general, if a function uses the numeric argument as a
repeat count, it should be able to do something useful with both
negative and positive arguments. At the very least, it should be aware
that it can be passed a negative argument.
A command function should return 0 if its action completes
successfully, and a value greater than zero if some error occurs. This
is the convention obeyed by all of the builtin Readline bindable command
functions.

File: readline.info, Node: Readline Variables, Next: Readline Convenience Functions, Prev: Custom Functions, Up: Programming with GNU Readline
2.3 Readline Variables
======================
These variables are available to function writers.
-- Variable: char * rl_line_buffer
This is the line gathered so far. You are welcome to modify the
contents of the line, but see *note Allowing Undoing::. The
function 'rl_extend_line_buffer' is available to increase the
memory allocated to 'rl_line_buffer'.
-- Variable: int rl_point
The offset of the current cursor position in 'rl_line_buffer' (the
_point_).
-- Variable: int rl_end
The number of characters present in 'rl_line_buffer'. When
'rl_point' is at the end of the line, 'rl_point' and 'rl_end' are
equal.
-- Variable: int rl_mark
The MARK (saved position) in the current line. If set, the mark
and point define a _region_.
-- Variable: int rl_done
Setting this to a non-zero value causes Readline to return the
current line immediately.
-- Variable: int rl_num_chars_to_read
Setting this to a positive value before calling 'readline()' causes
Readline to return after accepting that many characters, rather
than reading up to a character bound to 'accept-line'.
-- Variable: int rl_pending_input
Setting this to a value makes it the next keystroke read. This is
a way to stuff a single character into the input stream.
-- Variable: int rl_dispatching
Set to a non-zero value if a function is being called from a key
binding; zero otherwise. Application functions can test this to
discover whether they were called directly or by Readline's
dispatching mechanism.
-- Variable: int rl_erase_empty_line
Setting this to a non-zero value causes Readline to completely
erase the current line, including any prompt, any time a newline is
typed as the only character on an otherwise-empty line. The cursor
is moved to the beginning of the newly-blank line.
-- Variable: char * rl_prompt
The prompt Readline uses. This is set from the argument to
'readline()', and should not be assigned to directly. The
'rl_set_prompt()' function (*note Redisplay::) may be used to
modify the prompt string after calling 'readline()'.
-- Variable: char * rl_display_prompt
The string displayed as the prompt. This is usually identical to
RL_PROMPT, but may be changed temporarily by functions that use the
prompt string as a message area, such as incremental search.
-- Variable: int rl_already_prompted
If an application wishes to display the prompt itself, rather than
have Readline do it the first time 'readline()' is called, it
should set this variable to a non-zero value after displaying the
prompt. The prompt must also be passed as the argument to
'readline()' so the redisplay functions can update the display
properly. The calling application is responsible for managing the
value; Readline never sets it.
-- Variable: const char * rl_library_version
The version number of this revision of the library.
-- Variable: int rl_readline_version
An integer encoding the current version of the library. The
encoding is of the form 0xMMMM, where MM is the two-digit major
version number, and MM is the two-digit minor version number. For
example, for Readline-4.2, 'rl_readline_version' would have the
value 0x0402.
-- Variable: int rl_gnu_readline_p
Always set to 1, denoting that this is GNU readline rather than
some emulation.
-- Variable: const char * rl_terminal_name
The terminal type, used for initialization. If not set by the
application, Readline sets this to the value of the 'TERM'
environment variable the first time it is called.
-- Variable: const char * rl_readline_name
This variable is set to a unique name by each application using
Readline. The value allows conditional parsing of the inputrc file
(*note Conditional Init Constructs::).
-- Variable: FILE * rl_instream
The stdio stream from which Readline reads input. If 'NULL',
Readline defaults to STDIN.
-- Variable: FILE * rl_outstream
The stdio stream to which Readline performs output. If 'NULL',
Readline defaults to STDOUT.
-- Variable: int rl_prefer_env_winsize
If non-zero, Readline gives values found in the 'LINES' and
'COLUMNS' environment variables greater precedence than values
fetched from the kernel when computing the screen dimensions.
-- Variable: rl_command_func_t * rl_last_func
The address of the last command function Readline executed. May be
used to test whether or not a function is being executed twice in
succession, for example.
-- Variable: rl_hook_func_t * rl_startup_hook
If non-zero, this is the address of a function to call just before
'readline' prints the first prompt.
-- Variable: rl_hook_func_t * rl_pre_input_hook
If non-zero, this is the address of a function to call after the
first prompt has been printed and just before 'readline' starts
reading input characters.
-- Variable: rl_hook_func_t * rl_event_hook
If non-zero, this is the address of a function to call periodically
when Readline is waiting for terminal input. By default, this will
be called at most ten times a second if there is no keyboard input.
-- Variable: rl_getc_func_t * rl_getc_function
If non-zero, Readline will call indirectly through this pointer to
get a character from the input stream. By default, it is set to
'rl_getc', the default Readline character input function (*note
Character Input::). In general, an application that sets
RL_GETC_FUNCTION should consider setting RL_INPUT_AVAILABLE_HOOK as
well.
-- Variable: rl_hook_func_t * rl_signal_event_hook
If non-zero, this is the address of a function to call if a read
system call is interrupted when Readline is reading terminal input.
-- Variable: rl_hook_func_t * rl_input_available_hook
If non-zero, Readline will use this function's return value when it
needs to determine whether or not there is available input on the
current input source. The default hook checks 'rl_instream'; if an
application is using a different input source, it should set the
hook appropriately. Readline queries for available input when
implementing intra-key-sequence timeouts during input and
incremental searches. This may use an application-specific timeout
before returning a value; Readline uses the value passed to
'rl_set_keyboard_input_timeout()' or the value of the user-settable
KEYSEQ-TIMEOUT variable. This is designed for use by applications
using Readline's callback interface (*note Alternate Interface::),
which may not use the traditional 'read(2)' and file descriptor
interface, or other applications using a different input mechanism.
If an application uses an input mechanism or hook that can
potentially exceed the value of KEYSEQ-TIMEOUT, it should increase
the timeout or set this hook appropriately even when not using the
callback interface. In general, an application that sets
RL_GETC_FUNCTION should consider setting RL_INPUT_AVAILABLE_HOOK as
well.
-- Variable: rl_voidfunc_t * rl_redisplay_function
If non-zero, Readline will call indirectly through this pointer to
update the display with the current contents of the editing buffer.
By default, it is set to 'rl_redisplay', the default Readline
redisplay function (*note Redisplay::).
-- Variable: rl_vintfunc_t * rl_prep_term_function
If non-zero, Readline will call indirectly through this pointer to
initialize the terminal. The function takes a single argument, an
'int' flag that says whether or not to use eight-bit characters.
By default, this is set to 'rl_prep_terminal' (*note Terminal
Management::).
-- Variable: rl_voidfunc_t * rl_deprep_term_function
If non-zero, Readline will call indirectly through this pointer to
reset the terminal. This function should undo the effects of
'rl_prep_term_function'. By default, this is set to
'rl_deprep_terminal' (*note Terminal Management::).
-- Variable: Keymap rl_executing_keymap
This variable is set to the keymap (*note Keymaps::) in which the
currently executing readline function was found.
-- Variable: Keymap rl_binding_keymap
This variable is set to the keymap (*note Keymaps::) in which the
last key binding occurred.
-- Variable: char * rl_executing_macro
This variable is set to the text of any currently-executing macro.
-- Variable: int rl_executing_key
The key that caused the dispatch to the currently-executing
Readline function.
-- Variable: char * rl_executing_keyseq
The full key sequence that caused the dispatch to the
currently-executing Readline function.
-- Variable: int rl_key_sequence_length
The number of characters in RL_EXECUTING_KEYSEQ.
-- Variable: int rl_readline_state
A variable with bit values that encapsulate the current Readline
state. A bit is set with the 'RL_SETSTATE' macro, and unset with
the 'RL_UNSETSTATE' macro. Use the 'RL_ISSTATE' macro to test
whether a particular state bit is set. Current state bits include:
'RL_STATE_NONE'
Readline has not yet been called, nor has it begun to
initialize.
'RL_STATE_INITIALIZING'
Readline is initializing its internal data structures.
'RL_STATE_INITIALIZED'
Readline has completed its initialization.
'RL_STATE_TERMPREPPED'
Readline has modified the terminal modes to do its own input
and redisplay.
'RL_STATE_READCMD'
Readline is reading a command from the keyboard.
'RL_STATE_METANEXT'
Readline is reading more input after reading the meta-prefix
character.
'RL_STATE_DISPATCHING'
Readline is dispatching to a command.
'RL_STATE_MOREINPUT'
Readline is reading more input while executing an editing
command.
'RL_STATE_ISEARCH'
Readline is performing an incremental history search.
'RL_STATE_NSEARCH'
Readline is performing a non-incremental history search.
'RL_STATE_SEARCH'
Readline is searching backward or forward through the history
for a string.
'RL_STATE_NUMERICARG'
Readline is reading a numeric argument.
'RL_STATE_MACROINPUT'
Readline is currently getting its input from a
previously-defined keyboard macro.
'RL_STATE_MACRODEF'
Readline is currently reading characters defining a keyboard
macro.
'RL_STATE_OVERWRITE'
Readline is in overwrite mode.
'RL_STATE_COMPLETING'
Readline is performing word completion.
'RL_STATE_SIGHANDLER'
Readline is currently executing the readline signal handler.
'RL_STATE_UNDOING'
Readline is performing an undo.
'RL_STATE_INPUTPENDING'
Readline has input pending due to a call to
'rl_execute_next()'.
'RL_STATE_TTYCSAVED'
Readline has saved the values of the terminal's special
characters.
'RL_STATE_CALLBACK'
Readline is currently using the alternate (callback) interface
(*note Alternate Interface::).
'RL_STATE_VIMOTION'
Readline is reading the argument to a vi-mode "motion"
command.
'RL_STATE_MULTIKEY'
Readline is reading a multiple-keystroke command.
'RL_STATE_VICMDONCE'
Readline has entered vi command (movement) mode at least one
time during the current call to 'readline()'.
'RL_STATE_DONE'
Readline has read a key sequence bound to 'accept-line' and is
about to return the line to the caller.
-- Variable: int rl_explicit_arg
Set to a non-zero value if an explicit numeric argument was
specified by the user. Only valid in a bindable command function.
-- Variable: int rl_numeric_arg
Set to the value of any numeric argument explicitly specified by
the user before executing the current Readline function. Only
valid in a bindable command function.
-- Variable: int rl_editing_mode
Set to a value denoting Readline's current editing mode. A value
of 1 means Readline is currently in emacs mode; 0 means that vi
mode is active.

File: readline.info, Node: Readline Convenience Functions, Next: Readline Signal Handling, Prev: Readline Variables, Up: Programming with GNU Readline
2.4 Readline Convenience Functions
==================================
* Menu:
* Function Naming:: How to give a function you write a name.
* Keymaps:: Making keymaps.
* Binding Keys:: Changing Keymaps.
* Associating Function Names and Bindings:: Translate function names to
key sequences.
* Allowing Undoing:: How to make your functions undoable.
* Redisplay:: Functions to control line display.
* Modifying Text:: Functions to modify 'rl_line_buffer'.
* Character Input:: Functions to read keyboard input.
* Terminal Management:: Functions to manage terminal settings.
* Utility Functions:: Generally useful functions and hooks.
* Miscellaneous Functions:: Functions that don't fall into any category.
* Alternate Interface:: Using Readline in a 'callback' fashion.
* A Readline Example:: An example Readline function.
* Alternate Interface Example:: An example program using the alternate interface.

File: readline.info, Node: Function Naming, Next: Keymaps, Up: Readline Convenience Functions
2.4.1 Naming a Function
-----------------------
The user can dynamically change the bindings of keys while using
Readline. This is done by representing the function with a descriptive
name. The user is able to type the descriptive name when referring to
the function. Thus, in an init file, one might find
Meta-Rubout: backward-kill-word
This binds the keystroke <Meta-Rubout> to the function
_descriptively_ named 'backward-kill-word'. You, as the programmer,
should bind the functions you write to descriptive names as well.
Readline provides a function for doing that:
-- Function: int rl_add_defun (const char *name, rl_command_func_t
*function, int key)
Add NAME to the list of named functions. Make FUNCTION be the
function that gets called. If KEY is not -1, then bind it to
FUNCTION using 'rl_bind_key()'.
Using this function alone is sufficient for most applications. It is
the recommended way to add a few functions to the default functions that
Readline has built in. If you need to do something other than adding a
function to Readline, you may need to use the underlying functions
described below.

File: readline.info, Node: Keymaps, Next: Binding Keys, Prev: Function Naming, Up: Readline Convenience Functions
2.4.2 Selecting a Keymap
------------------------
Key bindings take place on a "keymap". The keymap is the association
between the keys that the user types and the functions that get run.
You can make your own keymaps, copy existing keymaps, and tell Readline
which keymap to use.
-- Function: Keymap rl_make_bare_keymap (void)
Returns a new, empty keymap. The space for the keymap is allocated
with 'malloc()'; the caller should free it by calling
'rl_free_keymap()' when done.
-- Function: Keymap rl_copy_keymap (Keymap map)
Return a new keymap which is a copy of MAP.
-- Function: Keymap rl_make_keymap (void)
Return a new keymap with the printing characters bound to
rl_insert, the lowercase Meta characters bound to run their
equivalents, and the Meta digits bound to produce numeric
arguments.
-- Function: void rl_discard_keymap (Keymap keymap)
Free the storage associated with the data in KEYMAP. The caller
should free KEYMAP.
-- Function: void rl_free_keymap (Keymap keymap)
Free all storage associated with KEYMAP. This calls
'rl_discard_keymap' to free subordindate keymaps and macros.
-- Function: int rl_empty_keymap (Keymap keymap)
Return non-zero if there are no keys bound to functions in KEYMAP;
zero if there are any keys bound.
Readline has several internal keymaps. These functions allow you to
change which keymap is active.
-- Function: Keymap rl_get_keymap (void)
Returns the currently active keymap.
-- Function: void rl_set_keymap (Keymap keymap)
Makes KEYMAP the currently active keymap.
-- Function: Keymap rl_get_keymap_by_name (const char *name)
Return the keymap matching NAME. NAME is one which would be
supplied in a 'set keymap' inputrc line (*note Readline Init
File::).
-- Function: char * rl_get_keymap_name (Keymap keymap)
Return the name matching KEYMAP. NAME is one which would be
supplied in a 'set keymap' inputrc line (*note Readline Init
File::).
-- Function: int rl_set_keymap_name (const char *name, Keymap keymap)
Set the name of KEYMAP. This name will then be "registered" and
available for use in a 'set keymap' inputrc directive *note
Readline Init File::). The NAME may not be one of Readline's
builtin keymap names; you may not add a different name for one of
Readline's builtin keymaps. You may replace the name associated
with a given keymap by calling this function more than once with
the same KEYMAP argument. You may associate a registered NAME with
a new keymap by calling this function more than once with the same
NAME argument. There is no way to remove a named keymap once the
name has been registered. Readline will make a copy of NAME. The
return value is greater than zero unless NAME is one of Readline's
builtin keymap names or KEYMAP is one of Readline's builtin
keymaps.

File: readline.info, Node: Binding Keys, Next: Associating Function Names and Bindings, Prev: Keymaps, Up: Readline Convenience Functions
2.4.3 Binding Keys
------------------
Key sequences are associate with functions through the keymap. Readline
has several internal keymaps: 'emacs_standard_keymap',
'emacs_meta_keymap', 'emacs_ctlx_keymap', 'vi_movement_keymap', and
'vi_insertion_keymap'. 'emacs_standard_keymap' is the default, and the
examples in this manual assume that.
Since 'readline()' installs a set of default key bindings the first
time it is called, there is always the danger that a custom binding
installed before the first call to 'readline()' will be overridden. An
alternate mechanism is to install custom key bindings in an
initialization function assigned to the 'rl_startup_hook' variable
(*note Readline Variables::).
These functions manage key bindings.
-- Function: int rl_bind_key (int key, rl_command_func_t *function)
Binds KEY to FUNCTION in the currently active keymap. Returns
non-zero in the case of an invalid KEY.
-- Function: int rl_bind_key_in_map (int key, rl_command_func_t
*function, Keymap map)
Bind KEY to FUNCTION in MAP. Returns non-zero in the case of an
invalid KEY.
-- Function: int rl_bind_key_if_unbound (int key, rl_command_func_t
*function)
Binds KEY to FUNCTION if it is not already bound in the currently
active keymap. Returns non-zero in the case of an invalid KEY or
if KEY is already bound.
-- Function: int rl_bind_key_if_unbound_in_map (int key,
rl_command_func_t *function, Keymap map)
Binds KEY to FUNCTION if it is not already bound in MAP. Returns
non-zero in the case of an invalid KEY or if KEY is already bound.
-- Function: int rl_unbind_key (int key)
Bind KEY to the null function in the currently active keymap.
Returns non-zero in case of error.
-- Function: int rl_unbind_key_in_map (int key, Keymap map)
Bind KEY to the null function in MAP. Returns non-zero in case of
error.
-- Function: int rl_unbind_function_in_map (rl_command_func_t
*function, Keymap map)
Unbind all keys that execute FUNCTION in MAP.
-- Function: int rl_unbind_command_in_map (const char *command, Keymap
map)
Unbind all keys that are bound to COMMAND in MAP.
-- Function: int rl_bind_keyseq (const char *keyseq, rl_command_func_t
*function)
Bind the key sequence represented by the string KEYSEQ to the
function FUNCTION, beginning in the current keymap. This makes new
keymaps as necessary. The return value is non-zero if KEYSEQ is
invalid.
-- Function: int rl_bind_keyseq_in_map (const char *keyseq,
rl_command_func_t *function, Keymap map)
Bind the key sequence represented by the string KEYSEQ to the
function FUNCTION. This makes new keymaps as necessary. Initial
bindings are performed in MAP. The return value is non-zero if
KEYSEQ is invalid.
-- Function: int rl_set_key (const char *keyseq, rl_command_func_t
*function, Keymap map)
Equivalent to 'rl_bind_keyseq_in_map'.
-- Function: int rl_bind_keyseq_if_unbound (const char *keyseq,
rl_command_func_t *function)
Binds KEYSEQ to FUNCTION if it is not already bound in the
currently active keymap. Returns non-zero in the case of an
invalid KEYSEQ or if KEYSEQ is already bound.
-- Function: int rl_bind_keyseq_if_unbound_in_map (const char *keyseq,
rl_command_func_t *function, Keymap map)
Binds KEYSEQ to FUNCTION if it is not already bound in MAP.
Returns non-zero in the case of an invalid KEYSEQ or if KEYSEQ is
already bound.
-- Function: int rl_generic_bind (int type, const char *keyseq, char
*data, Keymap map)
Bind the key sequence represented by the string KEYSEQ to the
arbitrary pointer DATA. TYPE says what kind of data is pointed to
by DATA; this can be a function ('ISFUNC'), a macro ('ISMACR'), or
a keymap ('ISKMAP'). This makes new keymaps as necessary. The
initial keymap in which to do bindings is MAP.
-- Function: int rl_parse_and_bind (char *line)
Parse LINE as if it had been read from the 'inputrc' file and
perform any key bindings and variable assignments found (*note
Readline Init File::).
-- Function: int rl_read_init_file (const char *filename)
Read keybindings and variable assignments from FILENAME (*note
Readline Init File::).

File: readline.info, Node: Associating Function Names and Bindings, Next: Allowing Undoing, Prev: Binding Keys, Up: Readline Convenience Functions
2.4.4 Associating Function Names and Bindings
---------------------------------------------
These functions allow you to find out what keys invoke named functions
and the functions invoked by a particular key sequence. You may also
associate a new function name with an arbitrary function.
-- Function: rl_command_func_t * rl_named_function (const char *name)
Return the function with name NAME.
-- Function: rl_command_func_t * rl_function_of_keyseq (const char
*keyseq, Keymap map, int *type)
Return the function invoked by KEYSEQ in keymap MAP. If MAP is
'NULL', the current keymap is used. If TYPE is not 'NULL', the
type of the object is returned in the 'int' variable it points to
(one of 'ISFUNC', 'ISKMAP', or 'ISMACR'). It takes a "translated"
key sequence and should not be used if the key sequence can include
NUL.
-- Function: rl_command_func_t * rl_function_of_keyseq_len (const char
*keyseq, size_t len, Keymap map, int *type)
Return the function invoked by KEYSEQ of length LEN in keymap MAP.
Equivalent to 'rl_function_of_keyseq' with the addition of the LEN
parameter. It takes a "translated" key sequence and should be used
if the key sequence can include NUL.
-- Function: char ** rl_invoking_keyseqs (rl_command_func_t *function)
Return an array of strings representing the key sequences used to
invoke FUNCTION in the current keymap.
-- Function: char ** rl_invoking_keyseqs_in_map (rl_command_func_t
*function, Keymap map)
Return an array of strings representing the key sequences used to
invoke FUNCTION in the keymap MAP.
-- Function: void rl_function_dumper (int readable)
Print the readline function names and the key sequences currently
bound to them to 'rl_outstream'. If READABLE is non-zero, the list
is formatted in such a way that it can be made part of an 'inputrc'
file and re-read.
-- Function: void rl_list_funmap_names (void)
Print the names of all bindable Readline functions to
'rl_outstream'.
-- Function: const char ** rl_funmap_names (void)
Return a NULL terminated array of known function names. The array
is sorted. The array itself is allocated, but not the strings
inside. You should free the array, but not the pointers, using
'free' or 'rl_free' when you are done.
-- Function: int rl_add_funmap_entry (const char *name,
rl_command_func_t *function)
Add NAME to the list of bindable Readline command names, and make
FUNCTION the function to be called when NAME is invoked.

File: readline.info, Node: Allowing Undoing, Next: Redisplay, Prev: Associating Function Names and Bindings, Up: Readline Convenience Functions
2.4.5 Allowing Undoing
----------------------
Supporting the undo command is a painless thing, and makes your
functions much more useful. It is certainly easy to try something if
you know you can undo it.
If your function simply inserts text once, or deletes text once, and
uses 'rl_insert_text()' or 'rl_delete_text()' to do it, then undoing is
already done for you automatically.
If you do multiple insertions or multiple deletions, or any
combination of these operations, you should group them together into one
operation. This is done with 'rl_begin_undo_group()' and
'rl_end_undo_group()'.
The types of events that can be undone are:
enum undo_code { UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END };
Notice that 'UNDO_DELETE' means to insert some text, and
'UNDO_INSERT' means to delete some text. That is, the undo code tells
what to undo, not how to undo it. 'UNDO_BEGIN' and 'UNDO_END' are tags
added by 'rl_begin_undo_group()' and 'rl_end_undo_group()'.
-- Function: int rl_begin_undo_group (void)
Begins saving undo information in a group construct. The undo
information usually comes from calls to 'rl_insert_text()' and
'rl_delete_text()', but could be the result of calls to
'rl_add_undo()'.
-- Function: int rl_end_undo_group (void)
Closes the current undo group started with 'rl_begin_undo_group
()'. There should be one call to 'rl_end_undo_group()' for each
call to 'rl_begin_undo_group()'.
-- Function: void rl_add_undo (enum undo_code what, int start, int end,
char *text)
Remember how to undo an event (according to WHAT). The affected
text runs from START to END, and encompasses TEXT.
-- Function: void rl_free_undo_list (void)
Free the existing undo list.
-- Function: int rl_do_undo (void)
Undo the first thing on the undo list. Returns '0' if there was
nothing to undo, non-zero if something was undone.
Finally, if you neither insert nor delete text, but directly modify
the existing text (e.g., change its case), call 'rl_modifying()' once,
just before you modify the text. You must supply the indices of the
text range that you are going to modify.
-- Function: int rl_modifying (int start, int end)
Tell Readline to save the text between START and END as a single
undo unit. It is assumed that you will subsequently modify that
text.

File: readline.info, Node: Redisplay, Next: Modifying Text, Prev: Allowing Undoing, Up: Readline Convenience Functions
2.4.6 Redisplay
---------------
-- Function: void rl_redisplay (void)
Change what's displayed on the screen to reflect the current
contents of 'rl_line_buffer'.
-- Function: int rl_forced_update_display (void)
Force the line to be updated and redisplayed, whether or not
Readline thinks the screen display is correct.
-- Function: int rl_on_new_line (void)
Tell the update functions that we have moved onto a new (empty)
line, usually after outputting a newline.
-- Function: int rl_on_new_line_with_prompt (void)
Tell the update functions that we have moved onto a new line, with
RL_PROMPT already displayed. This could be used by applications
that want to output the prompt string themselves, but still need
Readline to know the prompt string length for redisplay. It should
be used after setting RL_ALREADY_PROMPTED.
-- Function: int rl_clear_visible_line (void)
Clear the screen lines corresponding to the current line's
contents.
-- Function: int rl_reset_line_state (void)
Reset the display state to a clean state and redisplay the current
line starting on a new line.
-- Function: int rl_crlf (void)
Move the cursor to the start of the next screen line.
-- Function: int rl_show_char (int c)
Display character C on 'rl_outstream'. If Readline has not been
set to display meta characters directly, this will convert meta
characters to a meta-prefixed key sequence. This is intended for
use by applications which wish to do their own redisplay.
-- Function: int rl_message (const char *, ...)
The arguments are a format string as would be supplied to 'printf',
possibly containing conversion specifications such as '%d', and any
additional arguments necessary to satisfy the conversion
specifications. The resulting string is displayed in the "echo
area". The echo area is also used to display numeric arguments and
search strings. You should call 'rl_save_prompt' to save the
prompt information before calling this function.
-- Function: int rl_clear_message (void)
Clear the message in the echo area. If the prompt was saved with a
call to 'rl_save_prompt' before the last call to 'rl_message', call
'rl_restore_prompt' before calling this function.
-- Function: void rl_save_prompt (void)
Save the local Readline prompt display state in preparation for
displaying a new message in the message area with 'rl_message()'.
-- Function: void rl_restore_prompt (void)
Restore the local Readline prompt display state saved by the most
recent call to 'rl_save_prompt'. if 'rl_save_prompt' was called to
save the prompt before a call to 'rl_message', this function should
be called before the corresponding call to 'rl_clear_message'.
-- Function: int rl_expand_prompt (char *prompt)
Expand any special character sequences in PROMPT and set up the
local Readline prompt redisplay variables. This function is called
by 'readline()'. It may also be called to expand the primary
prompt if the 'rl_on_new_line_with_prompt()' function or
'rl_already_prompted' variable is used. It returns the number of
visible characters on the last line of the (possibly multi-line)
prompt. Applications may indicate that the prompt contains
characters that take up no physical screen space when displayed by
bracketing a sequence of such characters with the special markers
'RL_PROMPT_START_IGNORE' and 'RL_PROMPT_END_IGNORE' (declared in
'readline.h'). This may be used to embed terminal-specific escape
sequences in prompts.
-- Function: int rl_set_prompt (const char *prompt)
Make Readline use PROMPT for subsequent redisplay. This calls
'rl_expand_prompt()' to expand the prompt and sets 'rl_prompt' to
the result.

File: readline.info, Node: Modifying Text, Next: Character Input, Prev: Redisplay, Up: Readline Convenience Functions
2.4.7 Modifying Text
--------------------
-- Function: int rl_insert_text (const char *text)
Insert TEXT into the line at the current cursor position. Returns
the number of characters inserted.
-- Function: int rl_delete_text (int start, int end)
Delete the text between START and END in the current line. Returns
the number of characters deleted.
-- Function: char * rl_copy_text (int start, int end)
Return a copy of the text between START and END in the current
line.
-- Function: int rl_kill_text (int start, int end)
Copy the text between START and END in the current line to the kill
ring, appending or prepending to the last kill if the last command
was a kill command. The text is deleted. If START is less than
END, the text is appended, otherwise prepended. If the last
command was not a kill, a new kill ring slot is used.
-- Function: int rl_push_macro_input (char *macro)
Cause MACRO to be inserted into the line, as if it had been invoked
by a key bound to a macro. Not especially useful; use
'rl_insert_text()' instead.

File: readline.info, Node: Character Input, Next: Terminal Management, Prev: Modifying Text, Up: Readline Convenience Functions
2.4.8 Character Input
---------------------
-- Function: int rl_read_key (void)
Return the next character available from Readline's current input
stream. This handles input inserted into the input stream via
RL_PENDING_INPUT (*note Readline Variables::) and
'rl_stuff_char()', macros, and characters read from the keyboard.
While waiting for input, this function will call any function
assigned to the 'rl_event_hook' variable.
-- Function: int rl_getc (FILE *stream)
Return the next character available from STREAM, which is assumed
to be the keyboard.
-- Function: int rl_stuff_char (int c)
Insert C into the Readline input stream. It will be "read" before
Readline attempts to read characters from the terminal with
'rl_read_key()'. Up to 512 characters may be pushed back.
'rl_stuff_char' returns 1 if the character was successfully
inserted; 0 otherwise.
-- Function: int rl_execute_next (int c)
Make C be the next command to be executed when 'rl_read_key()' is
called. This sets RL_PENDING_INPUT.
-- Function: int rl_clear_pending_input (void)
Unset RL_PENDING_INPUT, effectively negating the effect of any
previous call to 'rl_execute_next()'. This works only if the
pending input has not already been read with 'rl_read_key()'.
-- Function: int rl_set_keyboard_input_timeout (int u)
While waiting for keyboard input in 'rl_read_key()', Readline will
wait for U microseconds for input before calling any function
assigned to 'rl_event_hook'. U must be greater than or equal to
zero (a zero-length timeout is equivalent to a poll). The default
waiting period is one-tenth of a second. Returns the old timeout
value.

File: readline.info, Node: Terminal Management, Next: Utility Functions, Prev: Character Input, Up: Readline Convenience Functions
2.4.9 Terminal Management
-------------------------
-- Function: void rl_prep_terminal (int meta_flag)
Modify the terminal settings for Readline's use, so 'readline()'
can read a single character at a time from the keyboard. The
META_FLAG argument should be non-zero if Readline should read
eight-bit input.
-- Function: void rl_deprep_terminal (void)
Undo the effects of 'rl_prep_terminal()', leaving the terminal in
the state in which it was before the most recent call to
'rl_prep_terminal()'.
-- Function: void rl_tty_set_default_bindings (Keymap kmap)
Read the operating system's terminal editing characters (as would
be displayed by 'stty') to their Readline equivalents. The
bindings are performed in KMAP.
-- Function: void rl_tty_unset_default_bindings (Keymap kmap)
Reset the bindings manipulated by 'rl_tty_set_default_bindings' so
that the terminal editing characters are bound to 'rl_insert'. The
bindings are performed in KMAP.
-- Function: int rl_tty_set_echoing (int value)
Set Readline's idea of whether or not it is echoing output to its
output stream (RL_OUTSTREAM). If VALUE is 0, Readline does not
display output to RL_OUTSTREAM; any other value enables output.
The initial value is set when Readline initializes the terminal
settings. This function returns the previous value.
-- Function: int rl_reset_terminal (const char *terminal_name)
Reinitialize Readline's idea of the terminal settings using
TERMINAL_NAME as the terminal type (e.g., 'vt100'). If
TERMINAL_NAME is 'NULL', the value of the 'TERM' environment
variable is used.

File: readline.info, Node: Utility Functions, Next: Miscellaneous Functions, Prev: Terminal Management, Up: Readline Convenience Functions
2.4.10 Utility Functions
------------------------
-- Function: int rl_save_state (struct readline_state *sp)
Save a snapshot of Readline's internal state to SP. The contents
of the READLINE_STATE structure are documented in 'readline.h'.
The caller is responsible for allocating the structure.
-- Function: int rl_restore_state (struct readline_state *sp)
Restore Readline's internal state to that stored in SP, which must
have been saved by a call to 'rl_save_state'. The contents of the
READLINE_STATE structure are documented in 'readline.h'. The
caller is responsible for freeing the structure.
-- Function: void rl_free (void *mem)
Deallocate the memory pointed to by MEM. MEM must have been
allocated by 'malloc'.
-- Function: void rl_replace_line (const char *text, int clear_undo)
Replace the contents of 'rl_line_buffer' with TEXT. The point and
mark are preserved, if possible. If CLEAR_UNDO is non-zero, the
undo list associated with the current line is cleared.
-- Function: void rl_extend_line_buffer (int len)
Ensure that 'rl_line_buffer' has enough space to hold LEN
characters, possibly reallocating it if necessary.
-- Function: int rl_initialize (void)
Initialize or re-initialize Readline's internal state. It's not
strictly necessary to call this; 'readline()' calls it before
reading any input.
-- Function: int rl_ding (void)
Ring the terminal bell, obeying the setting of 'bell-style'.
-- Function: int rl_alphabetic (int c)
Return 1 if C is an alphabetic character.
-- Function: void rl_display_match_list (char **matches, int len, int
max)
A convenience function for displaying a list of strings in columnar
format on Readline's output stream. 'matches' is the list of
strings, in argv format, such as a list of completion matches.
'len' is the number of strings in 'matches', and 'max' is the
length of the longest string in 'matches'. This function uses the
setting of 'print-completions-horizontally' to select how the
matches are displayed (*note Readline Init File Syntax::). When
displaying completions, this function 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.
The following are implemented as macros, defined in 'chardefs.h'.
Applications should refrain from using them.
-- Function: int _rl_uppercase_p (int c)
Return 1 if C is an uppercase alphabetic character.
-- Function: int _rl_lowercase_p (int c)
Return 1 if C is a lowercase alphabetic character.
-- Function: int _rl_digit_p (int c)
Return 1 if C is a numeric character.
-- Function: int _rl_to_upper (int c)
If C is a lowercase alphabetic character, return the corresponding
uppercase character.
-- Function: int _rl_to_lower (int c)
If C is an uppercase alphabetic character, return the corresponding
lowercase character.
-- Function: int _rl_digit_value (int c)
If C is a number, return the value it represents.

File: readline.info, Node: Miscellaneous Functions, Next: Alternate Interface, Prev: Utility Functions, Up: Readline Convenience Functions
2.4.11 Miscellaneous Functions
------------------------------
-- Function: int rl_macro_bind (const char *keyseq, const char *macro,
Keymap map)
Bind the key sequence KEYSEQ to invoke the macro MACRO. The
binding is performed in MAP. When KEYSEQ is invoked, the MACRO
will be inserted into the line. This function is deprecated; use
'rl_generic_bind()' instead.
-- Function: void rl_macro_dumper (int readable)
Print the key sequences bound to macros and their values, using the
current keymap, to 'rl_outstream'. If READABLE is non-zero, the
list is formatted in such a way that it can be made part of an
'inputrc' file and re-read.
-- Function: int rl_variable_bind (const char *variable, const char
*value)
Make the Readline variable VARIABLE have VALUE. This behaves as if
the readline command 'set VARIABLE VALUE' had been executed in an
'inputrc' file (*note Readline Init File Syntax::).
-- Function: char * rl_variable_value (const char *variable)
Return a string representing the value of the Readline variable
VARIABLE. For boolean variables, this string is either 'on' or
'off'.
-- Function: void rl_variable_dumper (int readable)
Print the readline variable names and their current values to
'rl_outstream'. If READABLE is non-zero, the list is formatted in
such a way that it can be made part of an 'inputrc' file and
re-read.
-- Function: int rl_set_paren_blink_timeout (int u)
Set the time interval (in microseconds) that Readline waits when
showing a balancing character when 'blink-matching-paren' has been
enabled.
-- Function: char * rl_get_termcap (const char *cap)
Retrieve the string value of the termcap capability CAP. Readline
fetches the termcap entry for the current terminal name and uses
those capabilities to move around the screen line and perform other
terminal-specific operations, like erasing a line. Readline does
not use all of a terminal's capabilities, and this function will
return values for only those capabilities Readline uses.
-- Function: void rl_clear_history (void)
Clear the history list by deleting all of the entries, in the same
manner as the History library's 'clear_history()' function. This
differs from 'clear_history' because it frees private data Readline
saves in the history list.

File: readline.info, Node: Alternate Interface, Next: A Readline Example, Prev: Miscellaneous Functions, Up: Readline Convenience Functions
2.4.12 Alternate Interface
--------------------------
An alternate interface is available to plain 'readline()'. Some
applications need to interleave keyboard I/O with file, device, or
window system I/O, typically by using a main loop to 'select()' on
various file descriptors. To accommodate this need, readline can also
be invoked as a 'callback' function from an event loop. There are
functions available to make this easy.
-- Function: void rl_callback_handler_install (const char *prompt,
rl_vcpfunc_t *lhandler)
Set up the terminal for readline I/O and display the initial
expanded value of PROMPT. Save the value of LHANDLER to use as a
handler function to call when a complete line of input has been
entered. The handler function receives the text of the line as an
argument. As with 'readline()', the handler function should 'free'
the line when it it finished with it.
-- Function: void rl_callback_read_char (void)
Whenever an application determines that keyboard input is
available, it should call 'rl_callback_read_char()', which will
read the next character from the current input source. If that
character completes the line, 'rl_callback_read_char' will invoke
the LHANDLER function installed by 'rl_callback_handler_install' to
process the line. Before calling the LHANDLER function, the
terminal settings are reset to the values they had before calling
'rl_callback_handler_install'. If the LHANDLER function returns,
and the line handler remains installed, the terminal settings are
modified for Readline's use again. 'EOF' is indicated by calling
LHANDLER with a 'NULL' line.
-- Function: void rl_callback_sigcleanup (void)
Clean up any internal state the callback interface uses to maintain
state between calls to rl_callback_read_char (e.g., the state of
any active incremental searches). This is intended to be used by
applications that wish to perform their own signal handling;
Readline's internal signal handler calls this when appropriate.
-- Function: void rl_callback_handler_remove (void)
Restore the terminal to its initial state and remove the line
handler. You may call this function from within a callback as well
as independently. If the LHANDLER installed by
'rl_callback_handler_install' does not exit the program, either
this function or the function referred to by the value of
'rl_deprep_term_function' should be called before the program exits
to reset the terminal settings.

File: readline.info, Node: A Readline Example, Next: Alternate Interface Example, Prev: Alternate Interface, Up: Readline Convenience Functions
2.4.13 A Readline Example
-------------------------
Here is a function which changes lowercase characters to their uppercase
equivalents, and uppercase characters to lowercase. If this function
was bound to 'M-c', then typing 'M-c' would change the case of the
character under point. Typing 'M-1 0 M-c' would change the case of the
following 10 characters, leaving the cursor on the last character
changed.
/* Invert the case of the COUNT following characters. */
int
invert_case_line (count, key)
int count, key;
{
register int start, end, i;
start = rl_point;
if (rl_point >= rl_end)
return (0);
if (count < 0)
{
direction = -1;
count = -count;
}
else
direction = 1;
/* Find the end of the range to modify. */
end = start + (count * direction);
/* Force it to be within range. */
if (end > rl_end)
end = rl_end;
else if (end < 0)
end = 0;
if (start == end)
return (0);
if (start > end)
{
int temp = start;
start = end;
end = temp;
}
/* Tell readline that we are modifying the line,
so it will save the undo information. */
rl_modifying (start, end);
for (i = start; i != end; i++)
{
if (_rl_uppercase_p (rl_line_buffer[i]))
rl_line_buffer[i] = _rl_to_lower (rl_line_buffer[i]);
else if (_rl_lowercase_p (rl_line_buffer[i]))
rl_line_buffer[i] = _rl_to_upper (rl_line_buffer[i]);
}
/* Move point to on top of the last character changed. */
rl_point = (direction == 1) ? end - 1 : start;
return (0);
}

File: readline.info, Node: Alternate Interface Example, Prev: A Readline Example, Up: Readline Convenience Functions
2.4.14 Alternate Interface Example
----------------------------------
Here is a complete program that illustrates Readline's alternate
interface. It reads lines from the terminal and displays them,
providing the standard history and TAB completion functions. It
understands the EOF character or "exit" to exit the program.
/* Standard include files. stdio.h is required. */
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <locale.h>
/* Used for select(2) */
#include <sys/types.h>
#include <sys/select.h>
#include <signal.h>
#include <stdio.h>
/* Standard readline include files. */
#include <readline/readline.h>
#include <readline/history.h>
static void cb_linehandler (char *);
static void sighandler (int);
int running;
int sigwinch_received;
const char *prompt = "rltest$ ";
/* Handle SIGWINCH and window size changes when readline is not active and
reading a character. */
static void
sighandler (int sig)
{
sigwinch_received = 1;
}
/* Callback function called for each line when accept-line executed, EOF
seen, or EOF character read. This sets a flag and returns; it could
also call exit(3). */
static void
cb_linehandler (char *line)
{
/* Can use ^D (stty eof) or `exit' to exit. */
if (line == NULL || strcmp (line, "exit") == 0)
{
if (line == 0)
printf ("\n");
printf ("exit\n");
/* This function needs to be called to reset the terminal settings,
and calling it from the line handler keeps one extra prompt from
being displayed. */
rl_callback_handler_remove ();
running = 0;
}
else
{
if (*line)
add_history (line);
printf ("input line: %s\n", line);
free (line);
}
}
int
main (int c, char **v)
{
fd_set fds;
int r;
/* Set the default locale values according to environment variables. */
setlocale (LC_ALL, "");
/* Handle window size changes when readline is not active and reading
characters. */
signal (SIGWINCH, sighandler);
/* Install the line handler. */
rl_callback_handler_install (prompt, cb_linehandler);
/* Enter a simple event loop. This waits until something is available
to read on readline's input stream (defaults to standard input) and
calls the builtin character read callback to read it. It does not
have to modify the user's terminal settings. */
running = 1;
while (running)
{
FD_ZERO (&fds);
FD_SET (fileno (rl_instream), &fds);
r = select (FD_SETSIZE, &fds, NULL, NULL, NULL);
if (r < 0 && errno != EINTR)
{
perror ("rltest: select");
rl_callback_handler_remove ();
break;
}
if (sigwinch_received)
{
rl_resize_terminal ();
sigwinch_received = 0;
}
if (r < 0)
continue;
if (FD_ISSET (fileno (rl_instream), &fds))
rl_callback_read_char ();
}
printf ("rltest: Event loop has exited\n");
return 0;
}

File: readline.info, Node: Readline Signal Handling, Next: Custom Completers, Prev: Readline Convenience Functions, Up: Programming with GNU Readline
2.5 Readline Signal Handling
============================
Signals are asynchronous events sent to a process by the Unix kernel,
sometimes on behalf of another process. They are intended to indicate
exceptional events, like a user pressing the interrupt key on his
terminal, or a network connection being broken. There is a class of
signals that can be sent to the process currently reading input from the
keyboard. Since Readline changes the terminal attributes when it is
called, it needs to perform special processing when such a signal is
received in order to restore the terminal to a sane state, or provide
application writers with functions to do so manually.
Readline contains an internal signal handler that is installed for a
number of signals ('SIGINT', 'SIGQUIT', 'SIGTERM', 'SIGHUP', 'SIGALRM',
'SIGTSTP', 'SIGTTIN', and 'SIGTTOU'). When one of these signals is
received, the signal handler will reset the terminal attributes to those
that were in effect before 'readline()' was called, reset the signal
handling to what it was before 'readline()' was called, and resend the
signal to the calling application. If and when the calling
application's signal handler returns, Readline will reinitialize the
terminal and continue to accept input. When a 'SIGINT' is received, the
Readline signal handler performs some additional work, which will cause
any partially-entered line to be aborted (see the description of
'rl_free_line_state()' below).
There is an additional Readline signal handler, for 'SIGWINCH', which
the kernel sends to a process whenever the terminal's size changes (for
example, if a user resizes an 'xterm'). The Readline 'SIGWINCH' handler
updates Readline's internal screen size information, and then calls any
'SIGWINCH' signal handler the calling application has installed.
Readline calls the application's 'SIGWINCH' signal handler without
resetting the terminal to its original state. If the application's
signal handler does more than update its idea of the terminal size and
return (for example, a 'longjmp' back to a main processing loop), it
_must_ call 'rl_cleanup_after_signal()' (described below), to restore
the terminal state.
When an application is using the callback interface (*note Alternate
Interface::), Readline installs signal handlers only for the duration of
the call to 'rl_callback_read_char'. Applications using the callback
interface should be prepared to clean up Readline's state if they wish
to handle the signal before the line handler completes and restores the
terminal state.
If an application using the callback interface wishes to have
Readline install its signal handlers at the time the application calls
'rl_callback_handler_install' and remove them only when a complete line
of input has been read, it should set the
'rl_persistent_signal_handlers' variable to a non-zero value. This
allows an application to defer all of the handling of the signals
Readline catches to Readline. Applications should use this variable
with care; it can result in Readline catching signals and not acting on
them (or allowing the application to react to them) until the
application calls 'rl_callback_read_char'. This can result in an
application becoming less responsive to keyboard signals like SIGINT. If
an application does not want or need to perform any signal handling, or
does not need to do any processing between calls to
'rl_callback_read_char', setting this variable may be desirable.
Readline provides two variables that allow application writers to
control whether or not it will catch certain signals and act on them
when they are received. It is important that applications change the
values of these variables only when calling 'readline()', not in a
signal handler, so Readline's internal signal state is not corrupted.
-- Variable: int rl_catch_signals
If this variable is non-zero, Readline will install signal handlers
for 'SIGINT', 'SIGQUIT', 'SIGTERM', 'SIGHUP', 'SIGALRM', 'SIGTSTP',
'SIGTTIN', and 'SIGTTOU'.
The default value of 'rl_catch_signals' is 1.
-- Variable: int rl_catch_sigwinch
If this variable is set to a non-zero value, Readline will install
a signal handler for 'SIGWINCH'.
The default value of 'rl_catch_sigwinch' is 1.
-- Variable: int rl_persistent_signal_handlers
If an application using the callback interface wishes Readline's
signal handlers to be installed and active during the set of calls
to 'rl_callback_read_char' that constitutes an entire single line,
it should set this variable to a non-zero value.
The default value of 'rl_persistent_signal_handlers' is 0.
-- Variable: int rl_change_environment
If this variable is set to a non-zero value, and Readline is
handling 'SIGWINCH', Readline will modify the LINES and COLUMNS
environment variables upon receipt of a 'SIGWINCH'
The default value of 'rl_change_environment' is 1.
If an application does not wish to have Readline catch any signals,
or to handle signals other than those Readline catches ('SIGHUP', for
example), Readline provides convenience functions to do the necessary
terminal and internal state cleanup upon receipt of a signal.
-- Function: int rl_pending_signal (void)
Return the signal number of the most recent signal Readline
received but has not yet handled, or 0 if there is no pending
signal.
-- Function: void rl_cleanup_after_signal (void)
This function will reset the state of the terminal to what it was
before 'readline()' was called, and remove the Readline signal
handlers for all signals, depending on the values of
'rl_catch_signals' and 'rl_catch_sigwinch'.
-- Function: void rl_free_line_state (void)
This will free any partial state associated with the current input
line (undo information, any partial history entry, any
partially-entered keyboard macro, and any partially-entered numeric
argument). This should be called before
'rl_cleanup_after_signal()'. The Readline signal handler for
'SIGINT' calls this to abort the current input line.
-- Function: void rl_reset_after_signal (void)
This will reinitialize the terminal and reinstall any Readline
signal handlers, depending on the values of 'rl_catch_signals' and
'rl_catch_sigwinch'.
If an application wants to force Readline to handle any signals that
have arrived while it has been executing, 'rl_check_signals()' will call
Readline's internal signal handler if there are any pending signals.
This is primarily intended for those applications that use a custom
'rl_getc_function' (*note Readline Variables::) and wish to handle
signals received while waiting for input.
-- Function: void rl_check_signals (void)
If there are any pending signals, call Readline's internal signal
handling functions to process them. 'rl_pending_signal()' can be
used independently to determine whether or not there are any
pending signals.
If an application does not wish Readline to catch 'SIGWINCH', it may
call 'rl_resize_terminal()' or 'rl_set_screen_size()' to force Readline
to update its idea of the terminal size when a 'SIGWINCH' is received.
-- Function: void rl_echo_signal_char (int sig)
If an application wishes to install its own signal handlers, but
still have readline display characters that generate signals,
calling this function with SIG set to 'SIGINT', 'SIGQUIT', or
'SIGTSTP' will display the character generating that signal.
-- Function: void rl_resize_terminal (void)
Update Readline's internal screen size by reading values from the
kernel.
-- Function: void rl_set_screen_size (int rows, int cols)
Set Readline's idea of the terminal size to ROWS rows and COLS
columns. If either ROWS or COLUMNS is less than or equal to 0,
Readline's idea of that terminal dimension is unchanged.
If an application does not want to install a 'SIGWINCH' handler, but
is still interested in the screen dimensions, Readline's idea of the
screen size may be queried.
-- Function: void rl_get_screen_size (int *rows, int *cols)
Return Readline's idea of the terminal's size in the variables
pointed to by the arguments.
-- Function: void rl_reset_screen_size (void)
Cause Readline to reobtain the screen size and recalculate its
dimensions.
The following functions install and remove Readline's signal
handlers.
-- Function: int rl_set_signals (void)
Install Readline's signal handler for 'SIGINT', 'SIGQUIT',
'SIGTERM', 'SIGHUP', 'SIGALRM', 'SIGTSTP', 'SIGTTIN', 'SIGTTOU',
and 'SIGWINCH', depending on the values of 'rl_catch_signals' and
'rl_catch_sigwinch'.
-- Function: int rl_clear_signals (void)
Remove all of the Readline signal handlers installed by
'rl_set_signals()'.

File: readline.info, Node: Custom Completers, Prev: Readline Signal Handling, Up: Programming with GNU Readline
2.6 Custom Completers
=====================
Typically, a program that reads commands from the user has a way of
disambiguating commands and data. If your program is one of these, then
it can provide completion for commands, data, or both. The following
sections describe how your program and Readline cooperate to provide
this service.
* Menu:
* How Completing Works:: The logic used to do completion.
* Completion Functions:: Functions provided by Readline.
* Completion Variables:: Variables which control completion.
* A Short Completion Example:: An example of writing completer subroutines.

File: readline.info, Node: How Completing Works, Next: Completion Functions, Up: Custom Completers
2.6.1 How Completing Works
--------------------------
In order to complete some text, the full list of possible completions
must be available. That is, it is not possible to accurately expand a
partial word without knowing all of the possible words which make sense
in that context. The Readline library provides the user interface to
completion, and two of the most common completion functions: filename
and username. For completing other types of text, you must write your
own completion function. This section describes exactly what such
functions must do, and provides an example.
There are three major functions used to perform completion:
1. The user-interface function 'rl_complete()'. This function is
called with the same arguments as other bindable Readline
functions: COUNT and INVOKING_KEY. It isolates the word to be
completed and calls 'rl_completion_matches()' to generate a list of
possible completions. It then either lists the possible
completions, inserts the possible completions, or actually performs
the completion, depending on which behavior is desired.
2. The internal function 'rl_completion_matches()' uses an
application-supplied "generator" function to generate the list of
possible matches, and then returns the array of these matches. The
caller should place the address of its generator function in
'rl_completion_entry_function'.
3. The generator function is called repeatedly from
'rl_completion_matches()', returning a string each time. The
arguments to the generator function are TEXT and STATE. TEXT is
the partial word to be completed. STATE is zero the first time the
function is called, allowing the generator to perform any necessary
initialization, and a positive non-zero integer for each subsequent
call. The generator function returns '(char *)NULL' to inform
'rl_completion_matches()' that there are no more possibilities
left. Usually the generator function computes the list of possible
completions when STATE is zero, and returns them one at a time on
subsequent calls. Each string the generator function returns as a
match must be allocated with 'malloc()'; Readline frees the strings
when it has finished with them. Such a generator function is
referred to as an "application-specific completion function".
-- Function: int rl_complete (int ignore, int invoking_key)
Complete the word at or before point. You have supplied the
function that does the initial simple matching selection algorithm
(see 'rl_completion_matches()'). The default is to do filename
completion.
-- Variable: rl_compentry_func_t * rl_completion_entry_function
This is a pointer to the generator function for
'rl_completion_matches()'. If the value of
'rl_completion_entry_function' is 'NULL' then the default filename
generator function, 'rl_filename_completion_function()', is used.
An "application-specific completion function" is a function whose
address is assigned to 'rl_completion_entry_function' and whose
return values are used to generate possible completions.

File: readline.info, Node: Completion Functions, Next: Completion Variables, Prev: How Completing Works, Up: Custom Completers
2.6.2 Completion Functions
--------------------------
Here is the complete list of callable completion functions present in
Readline.
-- Function: int rl_complete_internal (int what_to_do)
Complete the word at or before point. WHAT_TO_DO says what to do
with the completion. A value of '?' means list the possible
completions. 'TAB' means do standard completion. '*' means insert
all of the possible completions. '!' means to display all of the
possible completions, if there is more than one, as well as
performing partial completion. '@' is similar to '!', but possible
completions are not listed if the possible completions share a
common prefix.
-- Function: int rl_complete (int ignore, int invoking_key)
Complete the word at or before point. You have supplied the
function that does the initial simple matching selection algorithm
(see 'rl_completion_matches()' and 'rl_completion_entry_function').
The default is to do filename completion. This calls
'rl_complete_internal()' with an argument depending on
INVOKING_KEY.
-- Function: int rl_possible_completions (int count, int invoking_key)
List the possible completions. See description of 'rl_complete
()'. This calls 'rl_complete_internal()' with an argument of '?'.
-- Function: int rl_insert_completions (int count, int invoking_key)
Insert the list of possible completions into the line, deleting the
partially-completed word. See description of 'rl_complete()'.
This calls 'rl_complete_internal()' with an argument of '*'.
-- Function: int rl_completion_mode (rl_command_func_t *cfunc)
Returns the appropriate value to pass to 'rl_complete_internal()'
depending on whether CFUNC was called twice in succession and the
values of the 'show-all-if-ambiguous' and 'show-all-if-unmodified'
variables. Application-specific completion functions may use this
function to present the same interface as 'rl_complete()'.
-- Function: char ** rl_completion_matches (const char *text,
rl_compentry_func_t *entry_func)
Returns an array of strings which is a list of completions for
TEXT. If there are no completions, returns 'NULL'. The first
entry in the returned array is the substitution for TEXT. The
remaining entries are the possible completions. The array is
terminated with a 'NULL' pointer.
ENTRY_FUNC is a function of two args, and returns a 'char *'. The
first argument is TEXT. The second is a state argument; it is zero
on the first call, and non-zero on subsequent calls. ENTRY_FUNC
returns a 'NULL' pointer to the caller when there are no more
matches.
-- Function: char * rl_filename_completion_function (const char *text,
int state)
A generator function for filename completion in the general case.
TEXT is a partial filename. The Bash source is a useful reference
for writing application-specific completion functions (the Bash
completion functions call this and other Readline functions).
-- Function: char * rl_username_completion_function (const char *text,
int state)
A completion generator for usernames. TEXT contains a partial
username preceded by a random character (usually '~'). As with all
completion generators, STATE is zero on the first call and non-zero
for subsequent calls.

File: readline.info, Node: Completion Variables, Next: A Short Completion Example, Prev: Completion Functions, Up: Custom Completers
2.6.3 Completion Variables
--------------------------
-- Variable: rl_compentry_func_t * rl_completion_entry_function
A pointer to the generator function for 'rl_completion_matches()'.
'NULL' means to use 'rl_filename_completion_function()', the
default filename completer.
-- Variable: rl_completion_func_t * rl_attempted_completion_function
A pointer to an alternative function to create matches. The
function is called with TEXT, START, and END. START and END are
indices in 'rl_line_buffer' defining the boundaries of TEXT, which
is a character string. If this function exists and returns 'NULL',
or if this variable is set to 'NULL', then 'rl_complete()' will
call the value of 'rl_completion_entry_function' to generate
matches, otherwise the array of strings returned will be used. If
this function sets the 'rl_attempted_completion_over' variable to a
non-zero value, Readline will not perform its default completion
even if this function returns no matches.
-- Variable: rl_quote_func_t * rl_filename_quoting_function
A pointer to a function that will quote a filename in an
application-specific fashion. This is called if filename
completion is being attempted and one of the characters in
'rl_filename_quote_characters' appears in a completed filename.
The function is called with TEXT, MATCH_TYPE, and QUOTE_POINTER.
The TEXT is the filename to be quoted. The MATCH_TYPE is either
'SINGLE_MATCH', if there is only one completion match, or
'MULT_MATCH'. Some functions use this to decide whether or not to
insert a closing quote character. The QUOTE_POINTER is a pointer
to any opening quote character the user typed. Some functions
choose to reset this character.
-- Variable: rl_dequote_func_t * rl_filename_dequoting_function
A pointer to a function that will remove application-specific
quoting characters from a filename before completion is attempted,
so those characters do not interfere with matching the text against
names in the filesystem. It is called with TEXT, the text of the
word to be dequoted, and QUOTE_CHAR, which is the quoting character
that delimits the filename (usually ''' or '"'). If QUOTE_CHAR is
zero, the filename was not in an embedded string.
-- Variable: rl_linebuf_func_t * rl_char_is_quoted_p
A pointer to a function to call that determines whether or not a
specific character in the line buffer is quoted, according to
whatever quoting mechanism the program calling Readline uses. The
function is called with two arguments: TEXT, the text of the line,
and INDEX, the index of the character in the line. It is used to
decide whether a character found in
'rl_completer_word_break_characters' should be used to break words
for the completer.
-- Variable: rl_compignore_func_t * rl_ignore_some_completions_function
This function, if defined, is called by the completer when real
filename completion is done, after all the matching names have been
generated. It is passed a 'NULL' terminated array of matches. The
first element ('matches[0]') is the maximal substring common to all
matches. This function can re-arrange the list of matches as
required, but each element deleted from the array must be freed.
-- Variable: rl_icppfunc_t * rl_directory_completion_hook
This function, if defined, is allowed to modify the directory
portion of filenames Readline completes. It could be used to
expand symbolic links or shell variables in pathnames. It is
called with the address of a string (the current directory name) as
an argument, and may modify that string. If the string is replaced
with a new string, the old value should be freed. Any modified
directory name should have a trailing slash. The modified value
will be used as part of the completion, replacing the directory
portion of the pathname the user typed. At the least, even if no
other expansion is performed, this function should remove any quote
characters from the directory name, because its result will be
passed directly to 'opendir()'.
The directory completion hook returns an integer that should be
non-zero if the function modifies its directory argument. The
function should not modify the directory argument if it returns 0.
-- Variable: rl_icppfunc_t * rl_directory_rewrite_hook;
If non-zero, this is the address of a function to call when
completing a directory name. This function takes the address of
the directory name to be modified as an argument. Unlike
'rl_directory_completion_hook', it only modifies the directory name
used in 'opendir', not what is displayed when the possible
completions are printed or inserted. It is called before
rl_directory_completion_hook. At the least, even if no other
expansion is performed, this function should remove any quote
characters from the directory name, because its result will be
passed directly to 'opendir()'.
The directory rewrite hook returns an integer that should be
non-zero if the function modfies its directory argument. The
function should not modify the directory argument if it returns 0.
-- Variable: rl_icppfunc_t * rl_filename_stat_hook
If non-zero, this is the address of a function for the completer to
call before deciding which character to append to a completed name.
This function modifies its filename name argument, and the modified
value is passed to 'stat()' to determine the file's type and
characteristics. This function does not need to remove quote
characters from the filename.
The stat hook returns an integer that should be non-zero if the
function modfies its directory argument. The function should not
modify the directory argument if it returns 0.
-- Variable: rl_dequote_func_t * rl_filename_rewrite_hook
If non-zero, this is the address of a function called when reading
directory entries from the filesystem for completion and comparing
them to the partial word to be completed. The function should
perform any necessary application or system-specific conversion on
the filename, such as converting between character sets or
converting from a filesystem format to a character input format.
The function takes two arguments: FNAME, the filename to be
converted, and FNLEN, its length in bytes. It must either return
its first argument (if no conversion takes place) or the converted
filename in newly-allocated memory. The converted form is used to
compare against the word to be completed, and, if it matches, is
added to the list of matches. Readline will free the allocated
string.
-- Variable: rl_compdisp_func_t * rl_completion_display_matches_hook
If non-zero, then this is the address of a function to call when
completing a word would normally display the list of possible
matches. This function is called in lieu of Readline displaying
the list. It takes three arguments: ('char **'MATCHES, 'int'
NUM_MATCHES, 'int' MAX_LENGTH) where MATCHES is the array of
matching strings, NUM_MATCHES is the number of strings in that
array, and MAX_LENGTH is the length of the longest string in that
array. Readline provides a convenience function,
'rl_display_match_list', that takes care of doing the display to
Readline's output stream. You may call that function from this
hook.
-- Variable: const char * rl_basic_word_break_characters
The basic list of characters that signal a break between words for
the completer routine. The default value of this variable is the
characters which break words for completion in Bash: '"
\t\n\"\\'`@$><=;|&{("'.
-- Variable: const char * rl_basic_quote_characters
A list of quote characters which can cause a word break.
-- Variable: const char * rl_completer_word_break_characters
The list of characters that signal a break between words for
'rl_complete_internal()'. The default list is the value of
'rl_basic_word_break_characters'.
-- Variable: rl_cpvfunc_t * rl_completion_word_break_hook
If non-zero, this is the address of a function to call when
Readline is deciding where to separate words for word completion.
It should return a character string like
'rl_completer_word_break_characters' to be used to perform the
current completion. The function may choose to set
'rl_completer_word_break_characters' itself. If the function
returns 'NULL', 'rl_completer_word_break_characters' is used.
-- Variable: const char * rl_completer_quote_characters
A list of characters which can be used to quote a substring of the
line. Completion occurs on the entire substring, and within the
substring 'rl_completer_word_break_characters' are treated as any
other character, unless they also appear within this list.
-- Variable: const char * rl_filename_quote_characters
A list of characters that cause a filename to be quoted by the
completer when they appear in a completed filename. The default is
the null string.
-- Variable: const char * rl_special_prefixes
The list of characters that are word break characters, but should
be left in TEXT when it is passed to the completion function.
Programs can use this to help determine what kind of completing to
do. For instance, Bash sets this variable to "$@" so that it can
complete shell variables and hostnames.
-- Variable: int rl_completion_query_items
Up to this many items will be displayed in response to a
possible-completions call. After that, readline asks the user if
she is sure she wants to see them all. The default value is 100.
A negative value indicates that Readline should never ask the user.
-- Variable: int rl_completion_append_character
When a single completion alternative matches at the end of the
command line, this character is appended to the inserted completion
text. The default is a space character (' '). Setting this to the
null character ('\0') prevents anything being appended
automatically. This can be changed in application-specific
completion functions to provide the "most sensible word separator
character" according to an application-specific command line syntax
specification. It is set to the default before any
application-specific completion function is called, and may only be
changed within such a function.
-- Variable: int rl_completion_suppress_append
If non-zero, RL_COMPLETION_APPEND_CHARACTER is not appended to
matches at the end of the command line, as described above. It is
set to 0 before any application-specific completion function is
called, and may only be changed within such a function.
-- Variable: int rl_completion_quote_character
When Readline is completing quoted text, as delimited by one of the
characters in RL_COMPLETER_QUOTE_CHARACTERS, it sets this variable
to the quoting character found. This is set before any
application-specific completion function is called.
-- Variable: int rl_completion_suppress_quote
If non-zero, Readline does not append a matching quote character
when performing completion on a quoted string. It is set to 0
before any application-specific completion function is called, and
may only be changed within such a function.
-- Variable: int rl_completion_found_quote
When Readline is completing quoted text, it sets this variable to a
non-zero value if the word being completed contains or is delimited
by any quoting characters, including backslashes. This is set
before any application-specific completion function is called.
-- Variable: int rl_completion_mark_symlink_dirs
If non-zero, a slash will be appended to completed filenames that
are symbolic links to directory names, subject to the value of the
user-settable MARK-DIRECTORIES variable. This variable exists so
that application-specific completion functions can override the
user's global preference (set via the MARK-SYMLINKED-DIRECTORIES
Readline variable) if appropriate. This variable is set to the
user's preference before any application-specific completion
function is called, so unless that function modifies the value, the
user's preferences are honored.
-- Variable: int rl_ignore_completion_duplicates
If non-zero, then duplicates in the matches are removed. The
default is 1.
-- Variable: int rl_filename_completion_desired
Non-zero means that the results of the matches are to be treated as
filenames. This is _always_ zero when completion is attempted, and
can only be changed within an application-specific completion
function. If it is set to a non-zero value by such a function,
directory names have a slash appended and Readline attempts to
quote completed filenames if they contain any characters in
'rl_filename_quote_characters' and 'rl_filename_quoting_desired' is
set to a non-zero value.
-- Variable: int rl_filename_quoting_desired
Non-zero means that the results of the matches are to be quoted
using double quotes (or an application-specific quoting mechanism)
if the completed filename contains any characters in
'rl_filename_quote_chars'. This is _always_ non-zero when
completion is attempted, and can only be changed within an
application-specific completion function. The quoting is effected
via a call to the function pointed to by
'rl_filename_quoting_function'.
-- Variable: int rl_attempted_completion_over
If an application-specific completion function assigned to
'rl_attempted_completion_function' sets this variable to a non-zero
value, Readline will not perform its default filename completion
even if the application's completion function returns no matches.
It should be set only by an application's completion function.
-- Variable: int rl_sort_completion_matches
If an application sets this variable to 0, Readline will not sort
the list of completions (which implies that it cannot remove any
duplicate completions). The default value is 1, which means that
Readline will sort the completions and, depending on the value of
'rl_ignore_completion_duplicates', will attempt to remove duplicate
matches.
-- Variable: int rl_completion_type
Set to a character describing the type of completion Readline is
currently attempting; see the description of
'rl_complete_internal()' (*note Completion Functions::) for the
list of characters. This is set to the appropriate value before
any application-specific completion function is called, allowing
such functions to present the same interface as 'rl_complete()'.
-- Variable: int rl_completion_invoking_key
Set to the final character in the key sequence that invoked one of
the completion functions that call 'rl_complete_internal()'. This
is set to the appropriate value before any application-specific
completion function is called.
-- Variable: int rl_inhibit_completion
If this variable is non-zero, completion is inhibited. The
completion character will be inserted as any other bound to
'self-insert'.

File: readline.info, Node: A Short Completion Example, Prev: Completion Variables, Up: Custom Completers
2.6.4 A Short Completion Example
--------------------------------
Here is a small application demonstrating the use of the GNU Readline
library. It is called 'fileman', and the source code resides in
'examples/fileman.c'. This sample application provides completion of
command names, line editing features, and access to the history list.
/* fileman.c -- A tiny application which demonstrates how to use the
GNU Readline library. This application interactively allows users
to manipulate files and their modes. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <sys/types.h>
#ifdef HAVE_SYS_FILE_H
# include <sys/file.h>
#endif
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#if defined (HAVE_STRING_H)
# include <string.h>
#else /* !HAVE_STRING_H */
# include <strings.h>
#endif /* !HAVE_STRING_H */
#ifdef HAVE_STDLIB_H
# include <stdlib.h>
#endif
#include <time.h>
#include <readline/readline.h>
#include <readline/history.h>
extern char *xmalloc PARAMS((size_t));
/* The names of functions that actually do the manipulation. */
int com_list PARAMS((char *));
int com_view PARAMS((char *));
int com_rename PARAMS((char *));
int com_stat PARAMS((char *));
int com_pwd PARAMS((char *));
int com_delete PARAMS((char *));
int com_help PARAMS((char *));
int com_cd PARAMS((char *));
int com_quit PARAMS((char *));
/* A structure which contains information on the commands this program
can understand. */
typedef struct {
char *name; /* User printable name of the function. */
rl_icpfunc_t *func; /* Function to call to do the job. */
char *doc; /* Documentation for this function. */
} COMMAND;
COMMAND commands[] = {
{ "cd", com_cd, "Change to directory DIR" },
{ "delete", com_delete, "Delete FILE" },
{ "help", com_help, "Display this text" },
{ "?", com_help, "Synonym for `help'" },
{ "list", com_list, "List files in DIR" },
{ "ls", com_list, "Synonym for `list'" },
{ "pwd", com_pwd, "Print the current working directory" },
{ "quit", com_quit, "Quit using Fileman" },
{ "rename", com_rename, "Rename FILE to NEWNAME" },
{ "stat", com_stat, "Print out statistics on FILE" },
{ "view", com_view, "View the contents of FILE" },
{ (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL }
};
/* Forward declarations. */
char *stripwhite ();
COMMAND *find_command ();
/* The name of this program, as taken from argv[0]. */
char *progname;
/* When non-zero, this global means the user is done using this program. */
int done;
char *
dupstr (s)
char *s;
{
char *r;
r = xmalloc (strlen (s) + 1);
strcpy (r, s);
return (r);
}
main (argc, argv)
int argc;
char **argv;
{
char *line, *s;
progname = argv[0];
initialize_readline (); /* Bind our completer. */
/* Loop reading and executing lines until the user quits. */
for ( ; done == 0; )
{
line = readline ("FileMan: ");
if (!line)
break;
/* Remove leading and trailing whitespace from the line.
Then, if there is anything left, add it to the history list
and execute it. */
s = stripwhite (line);
if (*s)
{
add_history (s);
execute_line (s);
}
free (line);
}
exit (0);
}
/* Execute a command line. */
int
execute_line (line)
char *line;
{
register int i;
COMMAND *command;
char *word;
/* Isolate the command word. */
i = 0;
while (line[i] && whitespace (line[i]))
i++;
word = line + i;
while (line[i] && !whitespace (line[i]))
i++;
if (line[i])
line[i++] = '\0';
command = find_command (word);
if (!command)
{
fprintf (stderr, "%s: No such command for FileMan.\n", word);
return (-1);
}
/* Get argument to command, if any. */
while (whitespace (line[i]))
i++;
word = line + i;
/* Call the function. */
return ((*(command->func)) (word));
}
/* Look up NAME as the name of a command, and return a pointer to that
command. Return a NULL pointer if NAME isn't a command name. */
COMMAND *
find_command (name)
char *name;
{
register int i;
for (i = 0; commands[i].name; i++)
if (strcmp (name, commands[i].name) == 0)
return (&commands[i]);
return ((COMMAND *)NULL);
}
/* Strip whitespace from the start and end of STRING. Return a pointer
into STRING. */
char *
stripwhite (string)
char *string;
{
register char *s, *t;
for (s = string; whitespace (*s); s++)
;
if (*s == 0)
return (s);
t = s + strlen (s) - 1;
while (t > s && whitespace (*t))
t--;
*++t = '\0';
return s;
}
/* **************************************************************** */
/* */
/* Interface to Readline Completion */
/* */
/* **************************************************************** */
char *command_generator PARAMS((const char *, int));
char **fileman_completion PARAMS((const char *, int, int));
/* Tell the GNU Readline library how to complete. We want to try to complete
on command names if this is the first word in the line, or on filenames
if not. */
initialize_readline ()
{
/* Allow conditional parsing of the ~/.inputrc file. */
rl_readline_name = "FileMan";
/* Tell the completer that we want a crack first. */
rl_attempted_completion_function = fileman_completion;
}
/* Attempt to complete on the contents of TEXT. START and END bound the
region of rl_line_buffer that contains the word to complete. TEXT is
the word to complete. We can use the entire contents of rl_line_buffer
in case we want to do some simple parsing. Return the array of matches,
or NULL if there aren't any. */
char **
fileman_completion (text, start, end)
const char *text;
int start, end;
{
char **matches;
matches = (char **)NULL;
/* If this word is at the start of the line, then it is a command
to complete. Otherwise it is the name of a file in the current
directory. */
if (start == 0)
matches = rl_completion_matches (text, command_generator);
return (matches);
}
/* Generator function for command completion. STATE lets us know whether
to start from scratch; without any state (i.e. STATE == 0), then we
start at the top of the list. */
char *
command_generator (text, state)
const char *text;
int state;
{
static int list_index, len;
char *name;
/* If this is a new word to complete, initialize now. This includes
saving the length of TEXT for efficiency, and initializing the index
variable to 0. */
if (!state)
{
list_index = 0;
len = strlen (text);
}
/* Return the next name which partially matches from the command list. */
while (name = commands[list_index].name)
{
list_index++;
if (strncmp (name, text, len) == 0)
return (dupstr(name));
}
/* If no names matched, then return NULL. */
return ((char *)NULL);
}
/* **************************************************************** */
/* */
/* FileMan Commands */
/* */
/* **************************************************************** */
/* String to pass to system (). This is for the LIST, VIEW and RENAME
commands. */
static char syscom[1024];
/* List the file(s) named in arg. */
com_list (arg)
char *arg;
{
if (!arg)
arg = "";
sprintf (syscom, "ls -FClg %s", arg);
return (system (syscom));
}
com_view (arg)
char *arg;
{
if (!valid_argument ("view", arg))
return 1;
#if defined (__MSDOS__)
/* more.com doesn't grok slashes in pathnames */
sprintf (syscom, "less %s", arg);
#else
sprintf (syscom, "more %s", arg);
#endif
return (system (syscom));
}
com_rename (arg)
char *arg;
{
too_dangerous ("rename");
return (1);
}
com_stat (arg)
char *arg;
{
struct stat finfo;
if (!valid_argument ("stat", arg))
return (1);
if (stat (arg, &finfo) == -1)
{
perror (arg);
return (1);
}
printf ("Statistics for `%s':\n", arg);
printf ("%s has %d link%s, and is %d byte%s in length.\n",
arg,
finfo.st_nlink,
(finfo.st_nlink == 1) ? "" : "s",
finfo.st_size,
(finfo.st_size == 1) ? "" : "s");
printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime));
printf (" Last access at: %s", ctime (&finfo.st_atime));
printf (" Last modified at: %s", ctime (&finfo.st_mtime));
return (0);
}
com_delete (arg)
char *arg;
{
too_dangerous ("delete");
return (1);
}
/* Print out help for ARG, or for all of the commands if ARG is
not present. */
com_help (arg)
char *arg;
{
register int i;
int printed = 0;
for (i = 0; commands[i].name; i++)
{
if (!*arg || (strcmp (arg, commands[i].name) == 0))
{
printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
printed++;
}
}
if (!printed)
{
printf ("No commands match `%s'. Possibilties are:\n", arg);
for (i = 0; commands[i].name; i++)
{
/* Print in six columns. */
if (printed == 6)
{
printed = 0;
printf ("\n");
}
printf ("%s\t", commands[i].name);
printed++;
}
if (printed)
printf ("\n");
}
return (0);
}
/* Change to the directory ARG. */
com_cd (arg)
char *arg;
{
if (chdir (arg) == -1)
{
perror (arg);
return 1;
}
com_pwd ("");
return (0);
}
/* Print out the current working directory. */
com_pwd (ignore)
char *ignore;
{
char dir[1024], *s;
s = getcwd (dir, sizeof(dir) - 1);
if (s == 0)
{
printf ("Error getting pwd: %s\n", dir);
return 1;
}
printf ("Current directory is %s\n", dir);
return 0;
}
/* The user wishes to quit using this program. Just set DONE non-zero. */
com_quit (arg)
char *arg;
{
done = 1;
return (0);
}
/* Function which tells you that you can't do this. */
too_dangerous (caller)
char *caller;
{
fprintf (stderr,
"%s: Too dangerous for me to distribute. Write it yourself.\n",
caller);
}
/* Return non-zero if ARG is a valid argument for CALLER, else print
an error message and return zero. */
int
valid_argument (caller, arg)
char *caller, *arg;
{
if (!arg || !*arg)
{
fprintf (stderr, "%s: Argument required.\n", caller);
return (0);
}
return (1);
}

File: readline.info, Node: GNU Free Documentation License, Next: Concept Index, Prev: Programming with GNU Readline, Up: Top
Appendix A GNU Free Documentation License
*****************************************
Version 1.3, 3 November 2008
Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
<http://fsf.org/>
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or
noncommercially. Secondarily, this License preserves for the
author and publisher a way to get credit for their work, while not
being considered responsible for modifications made by others.
This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense.
It complements the GNU General Public License, which is a copyleft
license designed for free software.
We have designed this License in order to use it for manuals for
free software, because free software needs free documentation: a
free program should come with manuals providing the same freedoms
that the software does. But this License is not limited to
software manuals; it can be used for any textual work, regardless
of subject matter or whether it is published as a printed book. We
recommend this License principally for works whose purpose is
instruction or reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium,
that contains a notice placed by the copyright holder saying it can
be distributed under the terms of this License. Such a notice
grants a world-wide, royalty-free license, unlimited in duration,
to use that work under the conditions stated herein. The
"Document", below, refers to any such manual or work. Any member
of the public is a licensee, and is addressed as "you". You accept
the license if you copy, modify or distribute the work in a way
requiring permission under copyright law.
A "Modified Version" of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.
A "Secondary Section" is a named appendix or a front-matter section
of the Document that deals exclusively with the relationship of the
publishers or authors of the Document to the Document's overall
subject (or to related matters) and contains nothing that could
fall directly within that overall subject. (Thus, if the Document
is in part a textbook of mathematics, a Secondary Section may not
explain any mathematics.) The relationship could be a matter of
historical connection with the subject or with related matters, or
of legal, commercial, philosophical, ethical or political position
regarding them.
The "Invariant Sections" are certain Secondary Sections whose
titles are designated, as being those of Invariant Sections, in the
notice that says that the Document is released under this License.
If a section does not fit the above definition of Secondary then it
is not allowed to be designated as Invariant. The Document may
contain zero Invariant Sections. If the Document does not identify
any Invariant Sections then there are none.
The "Cover Texts" are certain short passages of text that are
listed, as Front-Cover Texts or Back-Cover Texts, in the notice
that says that the Document is released under this License. A
Front-Cover Text may be at most 5 words, and a Back-Cover Text may
be at most 25 words.
A "Transparent" copy of the Document means a machine-readable copy,
represented in a format whose specification is available to the
general public, that is suitable for revising the document
straightforwardly with generic text editors or (for images composed
of pixels) generic paint programs or (for drawings) some widely
available drawing editor, and that is suitable for input to text
formatters or for automatic translation to a variety of formats
suitable for input to text formatters. A copy made in an otherwise
Transparent file format whose markup, or absence of markup, has
been arranged to thwart or discourage subsequent modification by
readers is not Transparent. An image format is not Transparent if
used for any substantial amount of text. A copy that is not
"Transparent" is called "Opaque".
Examples of suitable formats for Transparent copies include plain
ASCII without markup, Texinfo input format, LaTeX input format,
SGML or XML using a publicly available DTD, and standard-conforming
simple HTML, PostScript or PDF designed for human modification.
Examples of transparent image formats include PNG, XCF and JPG.
Opaque formats include proprietary formats that can be read and
edited only by proprietary word processors, SGML or XML for which
the DTD and/or processing tools are not generally available, and
the machine-generated HTML, PostScript or PDF produced by some word
processors for output purposes only.
The "Title Page" means, for a printed book, the title page itself,
plus such following pages as are needed to hold, legibly, the
material this License requires to appear in the title page. For
works in formats which do not have any title page as such, "Title
Page" means the text near the most prominent appearance of the
work's title, preceding the beginning of the body of the text.
The "publisher" means any person or entity that distributes copies
of the Document to the public.
A section "Entitled XYZ" means a named subunit of the Document
whose title either is precisely XYZ or contains XYZ in parentheses
following text that translates XYZ in another language. (Here XYZ
stands for a specific section name mentioned below, such as
"Acknowledgements", "Dedications", "Endorsements", or "History".)
To "Preserve the Title" of such a section when you modify the
Document means that it remains a section "Entitled XYZ" according
to this definition.
The Document may include Warranty Disclaimers next to the notice
which states that this License applies to the Document. These
Warranty Disclaimers are considered to be included by reference in
this License, but only as regards disclaiming warranties: any other
implication that these Warranty Disclaimers may have is void and
has no effect on the meaning of this License.
2. VERBATIM COPYING
You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License
applies to the Document are reproduced in all copies, and that you
add no other conditions whatsoever to those of this License. You
may not use technical measures to obstruct or control the reading
or further copying of the copies you make or distribute. However,
you may accept compensation in exchange for copies. If you
distribute a large enough number of copies you must also follow the
conditions in section 3.
You may also lend copies, under the same conditions stated above,
and you may publicly display copies.
3. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly
have printed covers) of the Document, numbering more than 100, and
the Document's license notice requires Cover Texts, you must
enclose the copies in covers that carry, clearly and legibly, all
these Cover Texts: Front-Cover Texts on the front cover, and
Back-Cover Texts on the back cover. Both covers must also clearly
and legibly identify you as the publisher of these copies. The
front cover must present the full title with all words of the title
equally prominent and visible. You may add other material on the
covers in addition. Copying with changes limited to the covers, as
long as they preserve the title of the Document and satisfy these
conditions, can be treated as verbatim copying in other respects.
If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto
adjacent pages.
If you publish or distribute Opaque copies of the Document
numbering more than 100, you must either include a machine-readable
Transparent copy along with each Opaque copy, or state in or with
each Opaque copy a computer-network location from which the general
network-using public has access to download using public-standard
network protocols a complete Transparent copy of the Document, free
of added material. If you use the latter option, you must take
reasonably prudent steps, when you begin distribution of Opaque
copies in quantity, to ensure that this Transparent copy will
remain thus accessible at the stated location until at least one
year after the last time you distribute an Opaque copy (directly or
through your agents or retailers) of that edition to the public.
It is requested, but not required, that you contact the authors of
the Document well before redistributing any large number of copies,
to give them a chance to provide you with an updated version of the
Document.
4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document
under the conditions of sections 2 and 3 above, provided that you
release the Modified Version under precisely this License, with the
Modified Version filling the role of the Document, thus licensing
distribution and modification of the Modified Version to whoever
possesses a copy of it. In addition, you must do these things in
the Modified Version:
A. Use in the Title Page (and on the covers, if any) a title
distinct from that of the Document, and from those of previous
versions (which should, if there were any, be listed in the
History section of the Document). You may use the same title
as a previous version if the original publisher of that
version gives permission.
B. List on the Title Page, as authors, one or more persons or
entities responsible for authorship of the modifications in
the Modified Version, together with at least five of the
principal authors of the Document (all of its principal
authors, if it has fewer than five), unless they release you
from this requirement.
C. State on the Title page the name of the publisher of the
Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license
notice giving the public permission to use the Modified
Version under the terms of this License, in the form shown in
the Addendum below.
G. Preserve in that license notice the full lists of Invariant
Sections and required Cover Texts given in the Document's
license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled "History", Preserve its Title,
and add to it an item stating at least the title, year, new
authors, and publisher of the Modified Version as given on the
Title Page. If there is no section Entitled "History" in the
Document, create one stating the title, year, authors, and
publisher of the Document as given on its Title Page, then add
an item describing the Modified Version as stated in the
previous sentence.
J. Preserve the network location, if any, given in the Document
for public access to a Transparent copy of the Document, and
likewise the network locations given in the Document for
previous versions it was based on. These may be placed in the
"History" section. You may omit a network location for a work
that was published at least four years before the Document
itself, or if the original publisher of the version it refers
to gives permission.
K. For any section Entitled "Acknowledgements" or "Dedications",
Preserve the Title of the section, and preserve in the section
all the substance and tone of each of the contributor
acknowledgements and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document, unaltered
in their text and in their titles. Section numbers or the
equivalent are not considered part of the section titles.
M. Delete any section Entitled "Endorsements". Such a section
may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled
"Endorsements" or to conflict in title with any Invariant
Section.
O. Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no
material copied from the Document, you may at your option designate
some or all of these sections as invariant. To do this, add their
titles to the list of Invariant Sections in the Modified Version's
license notice. These titles must be distinct from any other
section titles.
You may add a section Entitled "Endorsements", provided it contains
nothing but endorsements of your Modified Version by various
parties--for example, statements of peer review or that the text
has been approved by an organization as the authoritative
definition of a standard.
You may add a passage of up to five words as a Front-Cover Text,
and a passage of up to 25 words as a Back-Cover Text, to the end of
the list of Cover Texts in the Modified Version. Only one passage
of Front-Cover Text and one of Back-Cover Text may be added by (or
through arrangements made by) any one entity. If the Document
already includes a cover text for the same cover, previously added
by you or by arrangement made by the same entity you are acting on
behalf of, you may not add another; but you may replace the old
one, on explicit permission from the previous publisher that added
the old one.
The author(s) and publisher(s) of the Document do not by this
License give permission to use their names for publicity for or to
assert or imply endorsement of any Modified Version.
5. COMBINING DOCUMENTS
You may combine the Document with other documents released under
this License, under the terms defined in section 4 above for
modified versions, provided that you include in the combination all
of the Invariant Sections of all of the original documents,
unmodified, and list them all as Invariant Sections of your
combined work in its license notice, and that you preserve all
their Warranty Disclaimers.
The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy. If there are multiple Invariant Sections with the same name
but different contents, make the title of each such section unique
by adding at the end of it, in parentheses, the name of the
original author or publisher of that section if known, or else a
unique number. Make the same adjustment to the section titles in
the list of Invariant Sections in the license notice of the
combined work.
In the combination, you must combine any sections Entitled
"History" in the various original documents, forming one section
Entitled "History"; likewise combine any sections Entitled
"Acknowledgements", and any sections Entitled "Dedications". You
must delete all sections Entitled "Endorsements."
6. COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy
that is included in the collection, provided that you follow the
rules of this License for verbatim copying of each of the documents
in all other respects.
You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert
a copy of this License into the extracted document, and follow this
License in all other respects regarding verbatim copying of that
document.
7. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other
separate and independent documents or works, in or on a volume of a
storage or distribution medium, is called an "aggregate" if the
copyright resulting from the compilation is not used to limit the
legal rights of the compilation's users beyond what the individual
works permit. When the Document is included in an aggregate, this
License does not apply to the other works in the aggregate which
are not themselves derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half
of the entire aggregate, the Document's Cover Texts may be placed
on covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic
form. Otherwise they must appear on printed covers that bracket
the whole aggregate.
8. TRANSLATION
Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section
4. Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections. You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also
include the original English version of this License and the
original versions of those notices and disclaimers. In case of a
disagreement between the translation and the original version of
this License or a notice or disclaimer, the original version will
prevail.
If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to
Preserve its Title (section 1) will typically require changing the
actual title.
9. TERMINATION
You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense, or distribute it is void,
and will automatically terminate your rights under this License.
However, if you cease all violation of this License, then your
license from a particular copyright holder is reinstated (a)
provisionally, unless and until the copyright holder explicitly and
finally terminates your license, and (b) permanently, if the
copyright holder fails to notify you of the violation by some
reasonable means prior to 60 days after the cessation.
Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from
that copyright holder, and you cure the violation prior to 30 days
after your receipt of the notice.
Termination of your rights under this section does not terminate
the licenses of parties who have received copies or rights from you
under this License. If your rights have been terminated and not
permanently reinstated, receipt of a copy of some or all of the
same material does not give you any rights to use it.
10. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of
the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See
<http://www.gnu.org/copyleft/>.
Each version of the License is given a distinguishing version
number. If the Document specifies that a particular numbered
version of this License "or any later version" applies to it, you
have the option of following the terms and conditions either of
that specified version or of any later version that has been
published (not as a draft) by the Free Software Foundation. If the
Document does not specify a version number of this License, you may
choose any version ever published (not as a draft) by the Free
Software Foundation. If the Document specifies that a proxy can
decide which future versions of this License can be used, that
proxy's public statement of acceptance of a version permanently
authorizes you to choose that version for the Document.
11. RELICENSING
"Massive Multiauthor Collaboration Site" (or "MMC Site") means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works. A
public wiki that anybody can edit is an example of such a server.
A "Massive Multiauthor Collaboration" (or "MMC") contained in the
site means any set of copyrightable works thus published on the MMC
site.
"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.
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in part, as part of another Document.
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incorporated in whole or in part into the MMC, (1) had no cover
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ADDENDUM: How to use this License for your documents
====================================================
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the License in the document and put the following copyright and license
notices just after the title page:
Copyright (C) YEAR YOUR NAME.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled ``GNU
Free Documentation License''.
If you have Invariant Sections, Front-Cover Texts and Back-Cover
Texts, replace the "with...Texts." line with this:
with the Invariant Sections being LIST THEIR TITLES, with
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File: readline.info, Node: Concept Index, Next: Function and Variable Index, Prev: GNU Free Documentation License, Up: Top
Concept Index
*************
�[index�]
* Menu:
* application-specific completion functions: Custom Completers.
(line 6)
* command editing: Readline Bare Essentials.
(line 6)
* editing command lines: Readline Bare Essentials.
(line 6)
* initialization file, readline: Readline Init File. (line 6)
* interaction, readline: Readline Interaction. (line 6)
* kill ring: Readline Killing Commands.
(line 18)
* killing text: Readline Killing Commands.
(line 6)
* notation, readline: Readline Bare Essentials.
(line 6)
* readline, function: Basic Behavior. (line 12)
* variables, readline: Readline Init File Syntax.
(line 34)
* yanking text: Readline Killing Commands.
(line 6)

File: readline.info, Node: Function and Variable Index, Prev: Concept Index, Up: Top
Function and Variable Index
***************************
�[index�]
* Menu:
* _rl_digit_p: Utility Functions. (line 64)
* _rl_digit_value: Utility Functions. (line 75)
* _rl_lowercase_p: Utility Functions. (line 61)
* _rl_to_lower: Utility Functions. (line 71)
* _rl_to_upper: Utility Functions. (line 67)
* _rl_uppercase_p: Utility Functions. (line 58)
* abort (C-g): Miscellaneous Commands.
(line 10)
* accept-line (Newline or Return): Commands For History.
(line 6)
* backward-char (C-b): Commands For Moving. (line 15)
* backward-delete-char (Rubout): Commands For Text. (line 17)
* backward-kill-line (C-x Rubout): Commands For Killing.
(line 9)
* backward-kill-word (M-<DEL>): Commands For Killing.
(line 24)
* backward-word (M-b): Commands For Moving. (line 22)
* beginning-of-history (M-<): Commands For History.
(line 19)
* beginning-of-line (C-a): Commands For Moving. (line 6)
* bell-style: Readline Init File Syntax.
(line 35)
* bind-tty-special-chars: Readline Init File Syntax.
(line 42)
* blink-matching-paren: Readline Init File Syntax.
(line 47)
* bracketed-paste-begin (): Commands For Text. (line 36)
* call-last-kbd-macro (C-x e): Keyboard Macros. (line 13)
* capitalize-word (M-c): Commands For Text. (line 64)
* character-search (C-]): Miscellaneous Commands.
(line 42)
* character-search-backward (M-C-]): Miscellaneous Commands.
(line 47)
* clear-screen (C-l): Commands For Moving. (line 40)
* colored-completion-prefix: Readline Init File Syntax.
(line 52)
* colored-stats: Readline Init File Syntax.
(line 59)
* comment-begin: Readline Init File Syntax.
(line 65)
* complete (<TAB>): Commands For Completion.
(line 6)
* completion-display-width: Readline Init File Syntax.
(line 70)
* completion-ignore-case: Readline Init File Syntax.
(line 77)
* completion-map-case: Readline Init File Syntax.
(line 82)
* completion-prefix-display-length: Readline Init File Syntax.
(line 88)
* completion-query-items: Readline Init File Syntax.
(line 95)
* convert-meta: Readline Init File Syntax.
(line 105)
* copy-backward-word (): Commands For Killing.
(line 49)
* copy-forward-word (): Commands For Killing.
(line 54)
* copy-region-as-kill (): Commands For Killing.
(line 45)
* delete-char (C-d): Commands For Text. (line 12)
* delete-char-or-list (): Commands For Completion.
(line 39)
* delete-horizontal-space (): Commands For Killing.
(line 37)
* digit-argument (M-0, M-1, ... M--): Numeric Arguments. (line 6)
* disable-completion: Readline Init File Syntax.
(line 113)
* do-lowercase-version (M-A, M-B, M-X, ...): Miscellaneous Commands.
(line 14)
* downcase-word (M-l): Commands For Text. (line 60)
* dump-functions (): Miscellaneous Commands.
(line 70)
* dump-macros (): Miscellaneous Commands.
(line 82)
* dump-variables (): Miscellaneous Commands.
(line 76)
* echo-control-characters: Readline Init File Syntax.
(line 118)
* editing-mode: Readline Init File Syntax.
(line 123)
* emacs-editing-mode (C-e): Miscellaneous Commands.
(line 88)
* emacs-mode-string: Readline Init File Syntax.
(line 129)
* enable-bracketed-paste: Readline Init File Syntax.
(line 139)
* enable-keypad: Readline Init File Syntax.
(line 147)
* end-kbd-macro (C-x )): Keyboard Macros. (line 9)
* end-of-file (usually C-d): Commands For Text. (line 6)
* end-of-history (M->): Commands For History.
(line 22)
* end-of-line (C-e): Commands For Moving. (line 9)
* exchange-point-and-mark (C-x C-x): Miscellaneous Commands.
(line 37)
* expand-tilde: Readline Init File Syntax.
(line 158)
* forward-backward-delete-char (): Commands For Text. (line 21)
* forward-char (C-f): Commands For Moving. (line 12)
* forward-search-history (C-s): Commands For History.
(line 30)
* forward-word (M-f): Commands For Moving. (line 18)
* history-preserve-point: Readline Init File Syntax.
(line 162)
* history-search-backward (): Commands For History.
(line 52)
* history-search-forward (): Commands For History.
(line 46)
* history-size: Readline Init File Syntax.
(line 168)
* history-substring-search-backward (): Commands For History.
(line 64)
* history-substring-search-forward (): Commands For History.
(line 58)
* horizontal-scroll-mode: Readline Init File Syntax.
(line 177)
* input-meta: Readline Init File Syntax.
(line 184)
* insert-comment (M-#): Miscellaneous Commands.
(line 61)
* insert-completions (M-*): Commands For Completion.
(line 18)
* isearch-terminators: Readline Init File Syntax.
(line 192)
* keymap: Readline Init File Syntax.
(line 199)
* kill-line (C-k): Commands For Killing.
(line 6)
* kill-region (): Commands For Killing.
(line 41)
* kill-whole-line (): Commands For Killing.
(line 15)
* kill-word (M-d): Commands For Killing.
(line 19)
* mark-modified-lines: Readline Init File Syntax.
(line 229)
* mark-symlinked-directories: Readline Init File Syntax.
(line 234)
* match-hidden-files: Readline Init File Syntax.
(line 239)
* menu-complete (): Commands For Completion.
(line 22)
* menu-complete-backward (): Commands For Completion.
(line 34)
* menu-complete-display-prefix: Readline Init File Syntax.
(line 246)
* meta-flag: Readline Init File Syntax.
(line 184)
* next-history (C-n): Commands For History.
(line 16)
* next-screen-line (): Commands For Moving. (line 33)
* non-incremental-forward-search-history (M-n): Commands For History.
(line 40)
* non-incremental-reverse-search-history (M-p): Commands For History.
(line 34)
* output-meta: Readline Init File Syntax.
(line 251)
* overwrite-mode (): Commands For Text. (line 68)
* page-completions: Readline Init File Syntax.
(line 257)
* possible-completions (M-?): Commands For Completion.
(line 11)
* prefix-meta (<ESC>): Miscellaneous Commands.
(line 19)
* previous-history (C-p): Commands For History.
(line 12)
* previous-screen-line (): Commands For Moving. (line 26)
* print-last-kbd-macro (): Keyboard Macros. (line 17)
* quoted-insert (C-q or C-v): Commands For Text. (line 26)
* re-read-init-file (C-x C-r): Miscellaneous Commands.
(line 6)
* readline: Basic Behavior. (line 12)
* redraw-current-line (): Commands For Moving. (line 44)
* reverse-search-history (C-r): Commands For History.
(line 26)
* revert-all-at-newline: Readline Init File Syntax.
(line 267)
* revert-line (M-r): Miscellaneous Commands.
(line 26)
* rl_add_defun: Function Naming. (line 18)
* rl_add_funmap_entry: Associating Function Names and Bindings.
(line 54)
* rl_add_undo: Allowing Undoing. (line 39)
* rl_alphabetic: Utility Functions. (line 38)
* rl_already_prompted: Readline Variables. (line 63)
* rl_attempted_completion_function: Completion Variables.
(line 11)
* rl_attempted_completion_over: Completion Variables.
(line 255)
* rl_basic_quote_characters: Completion Variables.
(line 143)
* rl_basic_word_break_characters: Completion Variables.
(line 137)
* rl_begin_undo_group: Allowing Undoing. (line 28)
* rl_binding_keymap: Readline Variables. (line 184)
* rl_bind_key: Binding Keys. (line 21)
* rl_bind_keyseq: Binding Keys. (line 57)
* rl_bind_keyseq_if_unbound: Binding Keys. (line 75)
* rl_bind_keyseq_if_unbound_in_map: Binding Keys. (line 81)
* rl_bind_keyseq_in_map: Binding Keys. (line 64)
* rl_bind_key_if_unbound: Binding Keys. (line 30)
* rl_bind_key_if_unbound_in_map: Binding Keys. (line 36)
* rl_bind_key_in_map: Binding Keys. (line 25)
* rl_callback_handler_install: Alternate Interface. (line 13)
* rl_callback_handler_remove: Alternate Interface. (line 42)
* rl_callback_read_char: Alternate Interface. (line 22)
* rl_callback_sigcleanup: Alternate Interface. (line 35)
* rl_catch_signals: Readline Signal Handling.
(line 69)
* rl_catch_sigwinch: Readline Signal Handling.
(line 76)
* rl_change_environment: Readline Signal Handling.
(line 90)
* rl_char_is_quoted_p: Completion Variables.
(line 45)
* rl_check_signals: Readline Signal Handling.
(line 133)
* rl_cleanup_after_signal: Readline Signal Handling.
(line 107)
* rl_clear_history: Miscellaneous Functions.
(line 49)
* rl_clear_message: Redisplay. (line 51)
* rl_clear_pending_input: Character Input. (line 29)
* rl_clear_signals: Readline Signal Handling.
(line 179)
* rl_clear_visible_line: Redisplay. (line 25)
* rl_complete: How Completing Works.
(line 46)
* rl_complete <1>: Completion Functions.
(line 19)
* rl_completer_quote_characters: Completion Variables.
(line 160)
* rl_completer_word_break_characters: Completion Variables.
(line 146)
* rl_complete_internal: Completion Functions.
(line 9)
* rl_completion_append_character: Completion Variables.
(line 184)
* rl_completion_display_matches_hook: Completion Variables.
(line 124)
* rl_completion_entry_function: How Completing Works.
(line 52)
* rl_completion_entry_function <1>: Completion Variables.
(line 6)
* rl_completion_found_quote: Completion Variables.
(line 214)
* rl_completion_invoking_key: Completion Variables.
(line 278)
* rl_completion_mark_symlink_dirs: Completion Variables.
(line 220)
* rl_completion_matches: Completion Functions.
(line 43)
* rl_completion_mode: Completion Functions.
(line 36)
* rl_completion_query_items: Completion Variables.
(line 178)
* rl_completion_quote_character: Completion Variables.
(line 202)
* rl_completion_suppress_append: Completion Variables.
(line 196)
* rl_completion_suppress_quote: Completion Variables.
(line 208)
* rl_completion_type: Completion Variables.
(line 270)
* rl_completion_word_break_hook: Completion Variables.
(line 151)
* rl_copy_keymap: Keymaps. (line 16)
* rl_copy_text: Modifying Text. (line 14)
* rl_crlf: Redisplay. (line 33)
* rl_delete_text: Modifying Text. (line 10)
* rl_deprep_terminal: Terminal Management. (line 12)
* rl_deprep_term_function: Readline Variables. (line 174)
* rl_ding: Utility Functions. (line 35)
* rl_directory_completion_hook: Completion Variables.
(line 63)
* rl_directory_rewrite_hook;: Completion Variables.
(line 81)
* rl_discard_keymap: Keymaps. (line 25)
* rl_dispatching: Readline Variables. (line 40)
* rl_display_match_list: Utility Functions. (line 41)
* rl_display_prompt: Readline Variables. (line 58)
* rl_done: Readline Variables. (line 27)
* rl_do_undo: Allowing Undoing. (line 47)
* rl_echo_signal_char: Readline Signal Handling.
(line 143)
* rl_editing_mode: Readline Variables. (line 281)
* rl_empty_keymap: Keymaps. (line 33)
* rl_end: Readline Variables. (line 18)
* rl_end_undo_group: Allowing Undoing. (line 34)
* rl_erase_empty_line: Readline Variables. (line 46)
* rl_event_hook: Readline Variables. (line 123)
* rl_execute_next: Character Input. (line 25)
* rl_executing_key: Readline Variables. (line 191)
* rl_executing_keymap: Readline Variables. (line 180)
* rl_executing_keyseq: Readline Variables. (line 195)
* rl_executing_macro: Readline Variables. (line 188)
* rl_expand_prompt: Redisplay. (line 66)
* rl_explicit_arg: Readline Variables. (line 272)
* rl_extend_line_buffer: Utility Functions. (line 26)
* rl_filename_completion_desired: Completion Variables.
(line 235)
* rl_filename_completion_function: Completion Functions.
(line 57)
* rl_filename_dequoting_function: Completion Variables.
(line 36)
* rl_filename_quote_characters: Completion Variables.
(line 166)
* rl_filename_quoting_desired: Completion Variables.
(line 245)
* rl_filename_quoting_function: Completion Variables.
(line 23)
* rl_filename_rewrite_hook: Completion Variables.
(line 109)
* rl_filename_stat_hook: Completion Variables.
(line 97)
* rl_forced_update_display: Redisplay. (line 10)
* rl_free: Utility Functions. (line 17)
* rl_free_keymap: Keymaps. (line 29)
* rl_free_line_state: Readline Signal Handling.
(line 113)
* rl_free_undo_list: Allowing Undoing. (line 44)
* rl_function_dumper: Associating Function Names and Bindings.
(line 38)
* rl_function_of_keyseq: Associating Function Names and Bindings.
(line 13)
* rl_function_of_keyseq_len: Associating Function Names and Bindings.
(line 22)
* rl_funmap_names: Associating Function Names and Bindings.
(line 48)
* rl_generic_bind: Binding Keys. (line 87)
* rl_getc: Character Input. (line 14)
* rl_getc_function: Readline Variables. (line 128)
* rl_get_keymap: Keymaps. (line 40)
* rl_get_keymap_by_name: Keymaps. (line 46)
* rl_get_keymap_name: Keymaps. (line 51)
* rl_get_screen_size: Readline Signal Handling.
(line 162)
* rl_get_termcap: Miscellaneous Functions.
(line 41)
* rl_gnu_readline_p: Readline Variables. (line 82)
* rl_ignore_completion_duplicates: Completion Variables.
(line 231)
* rl_ignore_some_completions_function: Completion Variables.
(line 55)
* rl_inhibit_completion: Completion Variables.
(line 284)
* rl_initialize: Utility Functions. (line 30)
* rl_input_available_hook: Readline Variables. (line 140)
* rl_insert_completions: Completion Functions.
(line 31)
* rl_insert_text: Modifying Text. (line 6)
* rl_instream: Readline Variables. (line 96)
* rl_invoking_keyseqs: Associating Function Names and Bindings.
(line 29)
* rl_invoking_keyseqs_in_map: Associating Function Names and Bindings.
(line 33)
* rl_key_sequence_length: Readline Variables. (line 199)
* rl_kill_text: Modifying Text. (line 18)
* rl_last_func: Readline Variables. (line 109)
* rl_library_version: Readline Variables. (line 72)
* rl_line_buffer: Readline Variables. (line 8)
* rl_list_funmap_names: Associating Function Names and Bindings.
(line 44)
* rl_macro_bind: Miscellaneous Functions.
(line 6)
* rl_macro_dumper: Miscellaneous Functions.
(line 13)
* rl_make_bare_keymap: Keymaps. (line 11)
* rl_make_keymap: Keymaps. (line 19)
* rl_mark: Readline Variables. (line 23)
* rl_message: Redisplay. (line 42)
* rl_modifying: Allowing Undoing. (line 56)
* rl_named_function: Associating Function Names and Bindings.
(line 10)
* rl_numeric_arg: Readline Variables. (line 276)
* rl_num_chars_to_read: Readline Variables. (line 31)
* rl_on_new_line: Redisplay. (line 14)
* rl_on_new_line_with_prompt: Redisplay. (line 18)
* rl_outstream: Readline Variables. (line 100)
* rl_parse_and_bind: Binding Keys. (line 95)
* rl_pending_input: Readline Variables. (line 36)
* rl_pending_signal: Readline Signal Handling.
(line 102)
* rl_persistent_signal_handlers: Readline Signal Handling.
(line 82)
* rl_point: Readline Variables. (line 14)
* rl_possible_completions: Completion Functions.
(line 27)
* rl_prefer_env_winsize: Readline Variables. (line 104)
* rl_prep_terminal: Terminal Management. (line 6)
* rl_prep_term_function: Readline Variables. (line 167)
* rl_pre_input_hook: Readline Variables. (line 118)
* rl_prompt: Readline Variables. (line 52)
* rl_push_macro_input: Modifying Text. (line 25)
* rl_readline_name: Readline Variables. (line 91)
* rl_readline_state: Readline Variables. (line 202)
* rl_readline_version: Readline Variables. (line 75)
* rl_read_init_file: Binding Keys. (line 100)
* rl_read_key: Character Input. (line 6)
* rl_redisplay: Redisplay. (line 6)
* rl_redisplay_function: Readline Variables. (line 161)
* rl_replace_line: Utility Functions. (line 21)
* rl_reset_after_signal: Readline Signal Handling.
(line 121)
* rl_reset_line_state: Redisplay. (line 29)
* rl_reset_screen_size: Readline Signal Handling.
(line 166)
* rl_reset_terminal: Terminal Management. (line 34)
* rl_resize_terminal: Readline Signal Handling.
(line 149)
* rl_restore_prompt: Redisplay. (line 60)
* rl_restore_state: Utility Functions. (line 11)
* rl_save_prompt: Redisplay. (line 56)
* rl_save_state: Utility Functions. (line 6)
* rl_set_key: Binding Keys. (line 71)
* rl_set_keyboard_input_timeout: Character Input. (line 34)
* rl_set_keymap: Keymaps. (line 43)
* rl_set_keymap_name: Keymaps. (line 56)
* rl_set_paren_blink_timeout: Miscellaneous Functions.
(line 36)
* rl_set_prompt: Redisplay. (line 80)
* rl_set_screen_size: Readline Signal Handling.
(line 153)
* rl_set_signals: Readline Signal Handling.
(line 173)
* rl_show_char: Redisplay. (line 36)
* rl_signal_event_hook: Readline Variables. (line 136)
* rl_sort_completion_matches: Completion Variables.
(line 262)
* rl_special_prefixes: Completion Variables.
(line 171)
* rl_startup_hook: Readline Variables. (line 114)
* rl_stuff_char: Character Input. (line 18)
* rl_terminal_name: Readline Variables. (line 86)
* rl_tty_set_default_bindings: Terminal Management. (line 17)
* rl_tty_set_echoing: Terminal Management. (line 27)
* rl_tty_unset_default_bindings: Terminal Management. (line 22)
* rl_unbind_command_in_map: Binding Keys. (line 53)
* rl_unbind_function_in_map: Binding Keys. (line 49)
* rl_unbind_key: Binding Keys. (line 41)
* rl_unbind_key_in_map: Binding Keys. (line 45)
* rl_username_completion_function: Completion Functions.
(line 64)
* rl_variable_bind: Miscellaneous Functions.
(line 19)
* rl_variable_dumper: Miscellaneous Functions.
(line 30)
* rl_variable_value: Miscellaneous Functions.
(line 25)
* self-insert (a, b, A, 1, !, ...): Commands For Text. (line 33)
* set-mark (C-@): Miscellaneous Commands.
(line 33)
* show-all-if-ambiguous: Readline Init File Syntax.
(line 273)
* show-all-if-unmodified: Readline Init File Syntax.
(line 279)
* show-mode-in-prompt: Readline Init File Syntax.
(line 288)
* skip-completed-text: Readline Init File Syntax.
(line 294)
* skip-csi-sequence (): Miscellaneous Commands.
(line 52)
* start-kbd-macro (C-x (): Keyboard Macros. (line 6)
* tab-insert (M-<TAB>): Commands For Text. (line 30)
* tilde-expand (M-~): Miscellaneous Commands.
(line 30)
* transpose-chars (C-t): Commands For Text. (line 45)
* transpose-words (M-t): Commands For Text. (line 51)
* undo (C-_ or C-x C-u): Miscellaneous Commands.
(line 23)
* universal-argument (): Numeric Arguments. (line 10)
* unix-filename-rubout (): Commands For Killing.
(line 32)
* unix-line-discard (C-u): Commands For Killing.
(line 12)
* unix-word-rubout (C-w): Commands For Killing.
(line 28)
* upcase-word (M-u): Commands For Text. (line 56)
* vi-cmd-mode-string: Readline Init File Syntax.
(line 307)
* vi-editing-mode (M-C-j): Miscellaneous Commands.
(line 92)
* vi-ins-mode-string: Readline Init File Syntax.
(line 318)
* visible-stats: Readline Init File Syntax.
(line 329)
* yank (C-y): Commands For Killing.
(line 59)
* yank-last-arg (M-. or M-_): Commands For History.
(line 79)
* yank-nth-arg (M-C-y): Commands For History.
(line 70)
* yank-pop (M-y): Commands For Killing.
(line 62)

Tag Table:
Node: Top865
Node: Command Line Editing1590
Node: Introduction and Notation2242
Node: Readline Interaction3866
Node: Readline Bare Essentials5058
Node: Readline Movement Commands6842
Node: Readline Killing Commands7803
Node: Readline Arguments9722
Node: Searching10767
Node: Readline Init File12920
Node: Readline Init File Syntax14074
Node: Conditional Init Constructs34233
Node: Sample Init File38430
Node: Bindable Readline Commands41548
Node: Commands For Moving42603
Node: Commands For History44170
Node: Commands For Text48435
Node: Commands For Killing51877
Node: Numeric Arguments54044
Node: Commands For Completion55184
Node: Keyboard Macros57153
Node: Miscellaneous Commands57841
Node: Readline vi Mode61763
Node: Programming with GNU Readline63580
Node: Basic Behavior64566
Node: Custom Functions68249
Node: Readline Typedefs69732
Node: Function Writing71366
Node: Readline Variables72680
Node: Readline Convenience Functions85352
Node: Function Naming86424
Node: Keymaps87686
Node: Binding Keys90765
Node: Associating Function Names and Bindings95313
Node: Allowing Undoing98092
Node: Redisplay100642
Node: Modifying Text104666
Node: Character Input105913
Node: Terminal Management107811
Node: Utility Functions109634
Node: Miscellaneous Functions112962
Node: Alternate Interface115551
Node: A Readline Example118293
Node: Alternate Interface Example120232
Node: Readline Signal Handling123764
Node: Custom Completers132813
Node: How Completing Works133533
Node: Completion Functions136840
Node: Completion Variables140414
Node: A Short Completion Example156205
Node: GNU Free Documentation License168984
Node: Concept Index194158
Node: Function and Variable Index195679

End Tag Table