GNU Readline Library
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.
1 Command Line Editing
This chapter describes the basic features of the GNU
command line editing interface.
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
(see 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.
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.
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.)
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.
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.

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.
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.
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-rs 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.
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
.
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.
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 (see 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.
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.
comment-begin
- The string to insert at the beginning of the line when the
insert-comment
command is executed. The default value
is "#"
.
completion-ignore-case
- If set to
on
, Readline performs filename matching and completion
in a case-insensitive fashion.
The default value is off
.
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.
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
.
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
.
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
.
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
.
expand-tilde
- If set to
on
, tilde expansion is performed when Readline
attempts word completion. The default is off
.
If set to on
, the history code attempts to place point at the
same location on each history line retrieved with previous-history
or next-history
.
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
. 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 (see 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.
Acceptable
keymap
names are
emacs
,
emacs-standard
,
emacs-meta
,
emacs-ctlx
,
vi
,
vi-move
,
vi-command
, and
vi-insert
.
vi
is equivalent to vi-command
; emacs
is
equivalent to emacs-standard
. The default value is emacs
.
The value of the editing-mode
variable also affects the
default keymap.
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, unless the leading .
is
supplied by the user in the filename to be completed.
This variable is on
by default.
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
.
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
.
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
.
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. 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 above example, C-u is bound to the function
universal-argument
,
M-DEL is bound to the function backward-kill-word
, and
C-o is bound to run the macro
expressed on the right hand side (that is, to insert the text
> output
into the line).
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)
\x
HH
- 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\\": "\\"
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 extends to the end of the line;
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.
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
$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
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 systemwide 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
1.4 Bindable Readline 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.
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.
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.
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 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.
non-incremental-forward-search-history (M-n)
- Search forward starting at the current line and moving `down'
through the the history as necessary using a non-incremental search
for a string supplied by the user.
history-search-forward ()
- Search forward through the history for the string of characters
between the start of the current line and the point.
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. 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.
yank-last-arg (M-. or M-_)
- Insert last argument to the previous command (the last word of the
previous history entry). With an
argument, behave exactly like
yank-nth-arg
.
Successive calls to yank-last-arg
move back through the history
list, inserting the last argument of each line in turn.
1.4.3 Commands For Changing Text
delete-char (C-d)
- Delete the character at point. If point is at the
beginning of the line, there are no characters in the line, and
the last character typed was not bound to
delete-char
, then
return EOF.
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.
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.
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 to the beginning of the 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.
The word boundaries are the same as
backward-word
.

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
.
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 or minus sign, the argument count
for the next command is multiplied by four.
The argument count is initially one, so executing this function the
first time makes the argument count four, a second time makes the
argument count sixteen, and so on.
By default, this is not bound to a key.
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.
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.
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.
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.
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-uppercase-version (M-a, M-b, M-
x, ...)
- If the metafied character x is lowercase, run the command
that is bound to the corresponding uppercase character.
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.
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.
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 1003.2 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.
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.
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.
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 (see Custom Completers).
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
.
2.2.1 Readline Typedefs
For readabilty, 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 **);
-
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 non-zero value if some error occurs.
2.3 Readline Variables
These variables are available to function writers.
| char * rl_line_buffer
|
Variabele |
This is the line gathered so far. You are welcome to modify the
contents of the line, but see Allowing Undoing. The
function rl_extend_line_buffer is available to increase
the memory allocated to rl_line_buffer .
|
The offset of the current cursor position in rl_line_buffer
(the point).
|
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.
|
|
The mark (saved position) in the current line. If set, the mark
and point define a region.
|
|
Setting this to a non-zero value causes Readline to return the current
line immediately.
|
| int rl_num_chars_to_read
|
Variabele |
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 .
|
| int rl_pending_input
|
Variabele |
|
Setting this to a value makes it the next keystroke read. This is a
way to stuff a single character into the input stream.
|
| int rl_dispatching
|
Variabele |
|
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.
|
| int rl_erase_empty_line
|
Variabele |
|
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.
|
| char * rl_prompt
|
Variabele |
The prompt Readline uses. This is set from the argument to
readline() , and should not be assigned to directly.
The rl_set_prompt() function (see Redisplay) may
be used to modify the prompt string after calling readline() .
|
| int rl_already_prompted
|
Variabele |
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.
|
| const char * rl_library_version
|
Variabele |
|
The version number of this revision of the library.
|
| int rl_readline_version
|
Variabele |
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.
|
| int rl_gnu_readline_p
|
Variabele |
|
Always set to 1, denoting that this is GNU readline rather than some
emulation.
|
| const char * rl_terminal_name
|
Variabele |
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.
|
| const char * rl_readline_name
|
Variabele |
|
This variable is set to a unique name by each application using Readline.
The value allows conditional parsing of the inputrc file
(see Conditional Init Constructs).
|
| FILE * rl_instream
|
Variabele |
The stdio stream from which Readline reads input.
If NULL , Readline defaults to stdin.
|
| FILE * rl_outstream
|
Variabele |
The stdio stream to which Readline performs output.
If NULL , Readline defaults to stdout.
|
| rl_command_func_t * rl_last_func
|
Variabele |
|
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.
|
| rl_hook_func_t * rl_startup_hook
|
Variabele |
If non-zero, this is the address of a function to call just
before readline prints the first prompt.
|
| rl_hook_func_t * rl_pre_input_hook
|
Variabele |
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.
|
| rl_hook_func_t * rl_event_hook
|
Variabele |
|
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.
|
| rl_getc_func_t * rl_getc_function
|
Variabele |
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
(see Character Input).
|
| rl_voidfunc_t * rl_redisplay_function
|
Variabele |
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 (see Redisplay).
|
| rl_vintfunc_t * rl_prep_term_function
|
Variabele |
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
(see Terminal Management).
|
| rl_voidfunc_t * rl_deprep_term_function
|
Variabele |
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
(see Terminal Management).
|
| Keymap rl_executing_keymap
|
Variabele |
|
This variable is set to the keymap (see Keymaps) in which the
currently executing readline function was found.
|
| Keymap rl_binding_keymap
|
Variabele |
|
This variable is set to the keymap (see Keymaps) in which the
last key binding occurred.
|
| char * rl_executing_macro
|
Variabele |
|
This variable is set to the text of any currently-executing macro.
|
| int rl_readline_state
|
Variabele |
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 intialize.
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_DONE
- Readline has read a key sequence bound to
accept-line
and is about to return the line to the caller.
|
| int rl_explicit_arg
|
Variabele |
|
Set to a non-zero value if an explicit numeric argument was specified by
the user. Only valid in a bindable command function.
|
| int rl_numeric_arg
|
Variabele |
|
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.
|
| int rl_editing_mode
|
Variabele |
|
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.
|
2.4 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:
| int rl_add_defun (const char *name, rl_command_func_t *function, int key)
|
Functie |
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.
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.
| Keymap rl_make_bare_keymap (void)
|
Functie |
Returns a new, empty keymap. The space for the keymap is allocated with
malloc() ; the caller should free it by calling
rl_discard_keymap() when done.
|
| Keymap rl_copy_keymap (Keymap map)
|
Functie |
|
Return a new keymap which is a copy of map.
|
| Keymap rl_make_keymap (void)
|
Functie |
|
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.
|
| void rl_discard_keymap (Keymap keymap)
|
Functie |
|
Free the storage associated with keymap.
|
Readline has several internal keymaps. These functions allow you to
change which keymap is active.
| Keymap rl_get_keymap (void)
|
Functie |
|
Returns the currently active keymap.
|
| void rl_set_keymap (Keymap keymap)
|
Functie |
|
Makes keymap the currently active keymap.
|
| Keymap rl_get_keymap_by_name (const char *name)
|
Functie |
Return the keymap matching name. name is one which would
be supplied in a set keymap inputrc line (see Readline Init File).
|
| char * rl_get_keymap_name (Keymap keymap)
|
Functie |
Return the name matching keymap. name is one which would
be supplied in a set keymap inputrc line (see Readline Init File).
|
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
(see Readline Variables).
These functions manage key bindings.
| int rl_bind_key (int key, rl_command_func_t *function)
|
Functie |
|
Binds key to function in the currently active keymap.
Returns non-zero in the case of an invalid key.
|
| int rl_bind_key_in_map (int key, rl_command_func_t *function, Keymap map)
|
Functie |
|
Bind key to function in map.
Returns non-zero in the case of an invalid key.
|
| int rl_bind_key_if_unbound (int key, rl_command_func_t *function)
|
Functie |
|
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.
|
| int rl_bind_key_if_unbound_in_map (int key, rl_command_func_t *function, Keymap map)
|
Functie |
|
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.
|
| int rl_unbind_key (int key)
|
Functie |
|
Bind key to the null function in the currently active keymap.
Returns non-zero in case of error.
|
| int rl_unbind_key_in_map (int key, Keymap map)
|
Functie |
|
Bind key to the null function in map.
Returns non-zero in case of error.
|
| int rl_unbind_function_in_map (rl_command_func_t *function, Keymap map)
|
Functie |
|
Unbind all keys that execute function in map.
|
| int rl_unbind_command_in_map (const char *command, Keymap map)
|
Functie |
|
Unbind all keys that are bound to command in map.
|
| int rl_bind_keyseq (const char *keyseq, rl_command_func_t *function)
|
Functie |
|
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.
|
| int rl_bind_keyseq_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
|
Functie |
|
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.
|
| int rl_set_key (const char *keyseq, rl_command_func_t *function, Keymap map)
|
Functie |
Equivalent to rl_bind_keyseq_in_map .
|
| int rl_bind_keyseq_if_unbound (const char *keyseq, rl_command_func_t *function)
|
Functie |
|
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.
|
| int rl_bind_keyseq_if_unbound_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
|
Functie |
|
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.
|
| int rl_generic_bind (int type, const char *keyseq, char *data, Keymap map)
|
Functie |
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.
|
| int rl_parse_and_bind (char *line)
|
Functie |
Parse line as if it had been read from the inputrc file and
perform any key bindings and variable assignments found
(see Readline Init File).
|
| int rl_read_init_file (const char *filename)
|
Functie |
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.
| rl_command_func_t * rl_named_function (const char *name)
|
Functie |
|
Return the function with name name.
|
| rl_command_func_t * rl_function_of_keyseq (const char *keyseq, Keymap map, int *type)
|
Functie |
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 ).
|
| char ** rl_invoking_keyseqs (rl_command_func_t *function)
|
Functie |
|
Return an array of strings representing the key sequences used to
invoke function in the current keymap.
|
| char ** rl_invoking_keyseqs_in_map (rl_command_func_t *function, Keymap map)
|
Functie |
|
Return an array of strings representing the key sequences used to
invoke function in the keymap map.
|
| void rl_function_dumper (int readable)
|
Functie |
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.
|
| void rl_list_funmap_names (void)
|
Functie |
Print the names of all bindable Readline functions to rl_outstream .
|
| const char ** rl_funmap_names (void)
|
Functie |
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 when you are done, but not the pointers.
|
| int rl_add_funmap_entry (const char *name, rl_command_func_t *function)
|
Functie |
|
Add name to the list of bindable Readline command names, and make
function the function to be called when name is invoked.
|
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()
.
| int rl_begin_undo_group (void)
|
Functie |
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() .
|
| int rl_end_undo_group (void)
|
Functie |
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() .
|
| void rl_add_undo (enum undo_code what, int start, int end, char *text)
|
Functie |
|
Remember how to undo an event (according to what). The affected
text runs from start to end, and encompasses text.
|
| void rl_free_undo_list (void)
|
Functie |
|
Free the existing undo list.
|
| int rl_do_undo (void)
|
Functie |
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.
| int rl_modifying (int start, int end)
|
Functie |
|
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.
|
2.4.6 Redisplay
| void rl_redisplay (void)
|
Functie |
Change what's displayed on the screen to reflect the current contents
of rl_line_buffer .
|
| int rl_forced_update_display (void)
|
Functie |
|
Force the line to be updated and redisplayed, whether or not
Readline thinks the screen display is correct.
|
| int rl_on_new_line (void)
|
Functie |
|
Tell the update functions that we have moved onto a new (empty) line,
usually after ouputting a newline.
|
| int rl_on_new_line_with_prompt (void)
|
Functie |
|
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.
|
| int rl_reset_line_state (void)
|
Functie |
|
Reset the display state to a clean state and redisplay the current line
starting on a new line.
|
| int rl_crlf (void)
|
Functie |
|
Move the cursor to the start of the next screen line.
|
| int rl_show_char (int c)
|
Functie |
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.
|
| int rl_message (const char *, ...)
|
Functie |
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.
|
| int rl_clear_message (void)
|
Functie |
|
Clear the message in the echo area.
|
| void rl_save_prompt (void)
|
Functie |
Save the local Readline prompt display state in preparation for
displaying a new message in the message area with rl_message() .
|
| void rl_restore_prompt (void)
|
Functie |
Restore the local Readline prompt display state saved by the most
recent call to rl_save_prompt .
|
| int rl_expand_prompt (char *prompt)
|
Functie |
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.
|
| int rl_set_prompt (const char *prompt)
|
Functie |
Make Readline use prompt for subsequent redisplay. This calls
rl_expand_prompt() to expand the prompt and sets rl_prompt
to the result.
|
2.4.7 Modifying Text
| int rl_insert_text (const char *text)
|
Functie |
|
Insert text into the line at the current cursor position.
Returns the number of characters inserted.
|
| int rl_delete_text (int start, int end)
|
Functie |
|
Delete the text between start and end in the current line.
Returns the number of characters deleted.
|
| char * rl_copy_text (int start, int end)
|
Functie |
|
Return a copy of the text between start and end in
the current line.
|
| int rl_kill_text (int start, int end)
|
Functie |
|
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.
|
| int rl_push_macro_input (char *macro)
|
Functie |
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.
|
2.4.8 Character Input
| int rl_read_key (void)
|
Functie |
Return the next character available from Readline's current input stream.
This handles input inserted into
the input stream via rl_pending_input (see 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.
|
| int rl_getc (FILE *stream)
|
Functie |
|
Return the next character available from stream, which is assumed to
be the keyboard.
|
| int rl_stuff_char (int c)
|
Functie |
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.
|
| int rl_execute_next (int c)
|
Functie |
Make c be the next command to be executed when rl_read_key()
is called. This sets rl_pending_input.
|
| int rl_clear_pending_input (void)
|
Functie |
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() .
|
| int rl_set_keyboard_input_timeout (int u)
|
Functie |
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 . The default waiting period is
one-tenth of a second. Returns the old timeout value.
|
2.4.9 Terminal Management
| void rl_prep_terminal (int meta_flag)
|
Functie |
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.
|
| void rl_deprep_terminal (void)
|
Functie |
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() .
|
| void rl_tty_set_default_bindings (Keymap kmap)
|
Functie |
Read the operating system's terminal editing characters (as would be
displayed by stty ) to their Readline equivalents.
The bindings are performed in kmap.
|
| void rl_tty_unset_default_bindings (Keymap kmap)
|
Functie |
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.
|
| int rl_reset_terminal (const char *terminal_name)
|
Functie |
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.
|
2.4.10 Utility Functions
| void rl_replace_line (const char *text, int clear_undo)
|
Functie |
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.
|
| int rl_extend_line_buffer (int len)
|
Functie |
Ensure that rl_line_buffer has enough space to hold len
characters, possibly reallocating it if necessary.
|
| int rl_initialize (void)
|
Functie |
Initialize or re-initialize Readline's internal state.
It's not strictly necessary to call this; readline() calls it before
reading any input.
|
| int rl_ding (void)
|
Functie |
Ring the terminal bell, obeying the setting of bell-style .
|
| int rl_alphabetic (int c)
|
Functie |
|
Return 1 if c is an alphabetic character.
|
| void rl_display_match_list (char **matches, int len, int max)
|
Functie |
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 (see Readline Init File Syntax).
|
The following are implemented as macros, defined in chardefs.h
.
Applications should refrain from using them.
| int _rl_uppercase_p (int c)
|
Functie |
|
Return 1 if c is an uppercase alphabetic character.
|
| int _rl_lowercase_p (int c)
|
Functie |
|
Return 1 if c is a lowercase alphabetic character.
|
| int _rl_digit_p (int c)
|
Functie |
|
Return 1 if c is a numeric character.
|
| int _rl_to_upper (int c)
|
Functie |
|
If c is a lowercase alphabetic character, return the corresponding
uppercase character.
|
| int _rl_to_lower (int c)
|
Functie |
|
If c is an uppercase alphabetic character, return the corresponding
lowercase character.
|
| int _rl_digit_value (int c)
|
Functie |
|
If c is a number, return the value it represents.
|
2.4.11 Miscellaneous Functions
| int rl_macro_bind (const char *keyseq, const char *macro, Keymap map)
|
Functie |
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.
|
| void rl_macro_dumper (int readable)
|
Functie |
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.
|
| int rl_variable_bind (const char *variable, const char *value)
|
Functie |
Make the Readline variable variable have value.
This behaves as if the readline command
set variable value had been executed in an inputrc
file (see Readline Init File Syntax).
|
| void rl_variable_dumper (int readable)
|
Functie |
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.
|
| int rl_set_paren_blink_timeout (int u)
|
Functie |
Set the time interval (in microseconds) that Readline waits when showing
a balancing character when blink-matching-paren has been enabled.
|
| char * rl_get_termcap (const char *cap)
|
Functie |
|
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.
|
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 accomodate this need, readline can
also be invoked as a `callback' function from an event loop. There
are functions available to make this easy.
| void rl_callback_handler_install (const char *prompt, rl_vcpfunc_t *lhandler)
|
Functie |
|
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 function to call when a complete line of input has been entered.
The function takes the text of the line as an argument.
|
| void rl_callback_read_char (void)
|
Functie |
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 saved 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,
the terminal settings are modified for Readline's use again.
EOF is indicated by calling lhandler with a
NULL line.
|
| void rl_callback_handler_remove (void)
|
Functie |
Restore the terminal to its initial state and remove the line handler.
This may be called 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.
|
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);
}
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
,
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.
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.
| int rl_catch_signals
|
Variabele |
If this variable is non-zero, Readline will install signal handlers for
SIGINT , SIGQUIT , SIGTERM , SIGALRM ,
SIGTSTP , SIGTTIN , and SIGTTOU .
The default value of rl_catch_signals is 1.
|
| int rl_catch_sigwinch
|
Variabele |
If this variable is non-zero, Readline will install a signal handler for
SIGWINCH .
The default value of rl_catch_sigwinch 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.
| void rl_cleanup_after_signal (void)
|
Functie |
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 .
|
| void rl_free_line_state (void)
|
Functie |
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.
|
| void rl_reset_after_signal (void)
|
Functie |
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 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.
| void rl_resize_terminal (void)
|
Functie |
|
Update Readline's internal screen size by reading values from the kernel.
|
| void rl_set_screen_size (int rows, int cols)
|
Functie |
|
Set Readline's idea of the terminal size to rows rows and
cols columns.
|
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.
| void rl_get_screen_size (int *rows, int *cols)
|
Functie |
|
Return Readline's idea of the terminal's size in the
variables pointed to by the arguments.
|
The following functions install and remove Readline's signal handlers.
| int rl_set_signals (void)
|
Functie |
Install Readline's signal handler for SIGINT , SIGQUIT ,
SIGTERM , SIGALRM , SIGTSTP , SIGTTIN ,
SIGTTOU , and SIGWINCH , depending on the values of
rl_catch_signals and rl_catch_sigwinch .
|
| int rl_clear_signals (void)
|
Functie |
Remove all of the Readline signal handlers installed by
rl_set_signals() .
|
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.
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:
- 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.
- 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
.
- 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.
| int rl_complete (int ignore, int invoking_key)
|
Functie |
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.
|
| rl_compentry_func_t * rl_completion_entry_function
|
Variabele |
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.
|
2.6.2 Completion Functions
Here is the complete list of callable completion functions present in
Readline.
| int rl_complete_internal (int what_to_do)
|
Functie |
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.
|
| int rl_complete (int ignore, int invoking_key)
|
Functie |
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.
|
| int rl_possible_completions (int count, int invoking_key)
|
Functie |
List the possible completions. See description of rl_complete
() . This calls rl_complete_internal() with an argument of
? .
|
| int rl_insert_completions (int count, int invoking_key)
|
Functie |
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 * .
|
| int rl_completion_mode (rl_command_func_t *cfunc)
|
Functie |
Returns the apppriate 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() .
|
| char ** rl_completion_matches (const char *text, rl_compentry_func_t *entry_func)
|
Functie |
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.
|
| char * rl_filename_completion_function (const char *text, int state)
|
Functie |
|
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).
|
| char * rl_username_completion_function (const char *text, int state)
|
Functie |
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.
|
2.6.3 Completion Variables
| rl_compentry_func_t * rl_completion_entry_function
|
Variabele |
A pointer to the generator function for rl_completion_matches() .
NULL means to use rl_filename_completion_function() ,
the default filename completer.
|
| rl_completion_func_t * rl_attempted_completion_function
|
Variabele |
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.
|
| rl_quote_func_t * rl_filename_quoting_function
|
Variabele |
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.
|
| rl_dequote_func_t * rl_filename_dequoting_function
|
Variabele |
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.
|
| rl_linebuf_func_t * rl_char_is_quoted_p
|
Variabele |
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.
|
| rl_compignore_func_t * rl_ignore_some_completions_function
|
Variabele |
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.
|
| rl_icppfunc_t * rl_directory_completion_hook
|
Variabele |
|
This function, if defined, is allowed to modify the directory portion
of filenames Readline completes. 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 displayed as part of the completion, replacing
the directory portion of the pathname the user typed.
It returns an integer that should be non-zero if the function modifies
its directory argument.
It could be used to expand symbolic links or shell variables in pathnames.
|
| rl_compdisp_func_t * rl_completion_display_matches_hook
|
Variabele |
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. That
function may be called from this hook.
|
| const char * rl_basic_word_break_characters
|
Variabele |
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\"\\'`@$><=;|&{(" .
|
| const char * rl_basic_quote_characters
|
Variabele |
|
A list of quote characters which can cause a word break.
|
| const char * rl_completer_word_break_characters
|
Variabele |
The list of characters that signal a break between words for
rl_complete_internal() . The default list is the value of
rl_basic_word_break_characters .
|
| rl_cpvfunc_t * rl_completion_word_break_hook
|
Variabele |
If non-zero, this is the address of a function to call when Readline is
deciding where to separate words for word completion. It should return
a character string like rl_completer_word_break_characters to be
used to perform the current completion. The function may choose to set
rl_completer_word_break_characters itself. If the function
returns NULL , rl_completer_word_break_characters is used.
|
| const char * rl_completer_quote_characters
|
Variabele |
A list of characters which can be used to quote a substring of the line.
Completion occurs on the entire substring, and within the substring
rl_completer_word_break_characters are treated as any other character,
unless they also appear within this list.
|
| const char * rl_filename_quote_characters
|
Variabele |
|
A list of characters that cause a filename to be quoted by the completer
when they appear in a completed filename. The default is the null string.
|
| const char * rl_special_prefixes
|
Variabele |
|
The list of characters that are word break characters, but should be
left in text when it is passed to the completion function.
Programs can use this to help determine what kind of completing to do.
For instance, Bash sets this variable to "$@" so that it can complete
shell variables and hostnames.
|
| int rl_completion_query_items
|
Variabele |
|
Up to this many items will be displayed in response to a
possible-completions call. After that, we ask the user if she is sure
she wants to see them all. The default value is 100.
|
| int rl_completion_append_character
|
Variabele |
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.
|
| int rl_completion_suppress_append
|
Variabele |
|
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.
|
| int rl_completion_quote_character
|
Variabele |
|
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.
|
| int rl_completion_suppress_quote
|
Variabele |
|
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.
|
| int rl_completion_found_quote
|
Variabele |
|
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.
|
| int rl_completion_mark_symlink_dirs
|
Variabele |
|
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.
|
| int rl_ignore_completion_duplicates
|
Variabele |
|
If non-zero, then duplicates in the matches are removed.
The default is 1.
|
| int rl_filename_completion_desired
|
Variabele |
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.
|
| int rl_filename_quoting_desired
|
Variabele |
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 .
|
| int rl_attempted_completion_over
|
Variabele |
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.
|
| int rl_completion_type
|
Variabele |
Set to a character describing the type of completion Readline is currently
attempting; see the description of rl_complete_internal()
(see 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() .
|
| int rl_inhibit_completion
|
Variabele |
If this variable is non-zero, completion is inhibited. The completion
character will be inserted as any other bound to self-insert .
|
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. */
#include <stdio.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <readline/readline.h>
#include <readline/history.h>
extern char *xmalloc ();
/* The names of functions that actually do the manipulation. */
int com_list __P((char *));
int com_view __P((char *));
int com_rename __P((char *));
int com_stat __P((char *));
int com_pwd __P((char *));
int com_delete __P((char *));
int com_help __P((char *));
int com_cd __P((char *));
int com_quit __P((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 means the user is done using this program. */
int done;
char *
dupstr (s)
int 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 __P((const char *, int));
char **fileman_completion __P((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. Returnthe 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;
sprintf (syscom, "more %s", arg);
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.\n"
caller);
fprintf (stderr, "Write it yourself.\n");
}
/* 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);
}
Appendix A Copying This Manual
A.1 GNU Free Documentation License
Version 1.2, November 2002
Copyright © 2000,2001,2002 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
- 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.
- 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.
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.
- 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.
- 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.
- 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:
- 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.
- 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.
- State on the Title page the name of the publisher of the
Modified Version, as the publisher.
- Preserve all the copyright notices of the Document.
- Add an appropriate copyright notice for your modifications
adjacent to the other copyright notices.
- 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.
- Preserve in that license notice the full lists of Invariant Sections
and required Cover Texts given in the Document's license notice.
- Include an unaltered copy of this License.
- 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.
- 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.
- 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.
- 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.
- Delete any section Entitled "Endorsements". Such a section
may not be included in the Modified Version.
- Do not retitle any existing section to be Entitled "Endorsements" or
to conflict in title with any Invariant Section.
- 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.
- 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."
- 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.
- 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 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.
- 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.
- TERMINATION
You may not copy, modify, sublicense, or distribute the Document except
as expressly provided for under this License. Any other attempt to
copy, modify, sublicense or distribute the Document is void, and will
automatically terminate your rights under this License. However,
parties who have received copies, or rights, from you under this
License will not have their licenses terminated so long as such
parties remain in full compliance.
- 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.
A.1.1 ADDENDUM: How to use this License for your documents
To use this License in a document you have written, include a copy of
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 1.2
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: