rluser.texi

android-w.song.android.widget

* Conditional Init Constructs::	Conditional key bindings in the inputrc file.

* Sample Init File::		An example inputrc file.
@end menu

@node Readline Init File Syntax
@subsection 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 @samp{#} are comments.
Lines beginning with a @samp{$} indicate conditional
constructs (@pxref{Conditional Init Constructs}).  Other lines
denote variable settings and key bindings.

@table @asis
@item Variable Settings
You can modify the run-time behavior of Readline by
altering the values of variables in Readline
using the @code{set} command within the init file.
The syntax is simple:

@example
set @var{variable} @var{value}
@end example

@noindent
Here, for example, is how to
change from the default Emacs-like key binding to use
@code{vi} line editing commands:

@example
set editing-mode vi
@end example

Variable names and values, where appropriate, are recognized without regard
to case.  Unrecognized variable names are ignored.

Boolean variables (those that can be set to on or off) are set to on if
the value is null or empty, @var{on} (case-insensitive), or 1.  Any other
value results in the variable being set to off.

@ifset BashFeatures
The @w{@code{bind -V}} command lists the current Readline variable names
and values.  @xref{Bash Builtins}.
@end ifset

A great deal of run-time behavior is changeable with the following
variables.

@cindex variables, readline
@table @code

@item bell-style
@vindex bell-style
Controls what happens when Readline wants to ring the terminal bell.
If set to @samp{none}, Readline never rings the bell.  If set to
@samp{visible}, Readline uses a visible bell if one is available.
If set to @samp{audible} (the default), Readline attempts to ring
the terminal's bell.

@item bind-tty-special-chars
@vindex bind-tty-special-chars
If set to @samp{on}, Readline attempts to bind the control characters  
treated specially by the kernel's terminal driver to their Readline
equivalents.

@item comment-begin
@vindex comment-begin
The string to insert at the beginning of the line when the
@code{insert-comment} command is executed.  The default value
is @code{"#"}.

@item completion-display-width
@vindex completion-display-width
The number of screen columns used to display possible matches
when performing completion.
The value is ignored if it is less than 0 or greater than the terminal
screen width.
A value of 0 will cause matches to be displayed one per line.
The default value is -1.

@item completion-ignore-case
@vindex completion-ignore-case
If set to @samp{on}, Readline performs filename matching and completion
in a case-insensitive fashion.
The default value is @samp{off}.

@item completion-map-case
@vindex completion-map-case
If set to @samp{on}, and @var{completion-ignore-case} is enabled, Readline
treats hyphens (@samp{-}) and underscores (@samp{_}) as equivalent when
performing case-insensitive filename matching and completion.

@item completion-prefix-display-length
@vindex completion-prefix-display-length
The length in characters of the common prefix of a list of possible
completions that is displayed without modification.  When set to a
value greater than zero, common prefixes longer than this value are
replaced with an ellipsis when displaying possible completions.

@item completion-query-items
@vindex completion-query-items
The number of possible completions that determines when the user is
asked whether the list of possibilities should be displayed.
If the number of possible completions is greater than this value,
Readline will ask the user whether or not he wishes to view
them; otherwise, they are simply listed.
This variable must be set to an integer value greater than or equal to 0.
A negative value means Readline should never ask.
The default limit is @code{100}.

@item convert-meta
@vindex convert-meta
If set to @samp{on}, Readline will convert characters with the
eighth bit set to an @sc{ascii} key sequence by stripping the eighth
bit and prefixing an @key{ESC} character, converting them to a
meta-prefixed key sequence.  The default value is @samp{on}.

@item disable-completion
@vindex disable-completion
If set to @samp{On}, Readline will inhibit word completion.
Completion  characters will be inserted into the line as if they had
been mapped to @code{self-insert}.  The default is @samp{off}.

@item editing-mode
@vindex editing-mode
The @code{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 @samp{emacs} or @samp{vi}.

@item echo-control-characters
When set to @samp{on}, on operating systems that indicate they support it,
readline echoes a character corresponding to a signal generated from the
keyboard.  The default is @samp{on}.

@item enable-keypad
@vindex enable-keypad
When set to @samp{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 @samp{off}.

@item enable-meta-key
When set to @samp{on}, Readline will try to enable any meta modifier
key the terminal claims to support when it is called.  On many terminals,
the meta key is used to send eight-bit characters.
The default is @samp{on}.

@item expand-tilde
@vindex expand-tilde
If set to @samp{on}, tilde expansion is performed when Readline
attempts word completion.  The default is @samp{off}.

@item history-preserve-point
@vindex history-preserve-point
If set to @samp{on}, the history code attempts to place the point (the
current cursor position) at the
same location on each history line retrieved with @code{previous-history}
or @code{next-history}.  The default is @samp{off}.

@item history-size
@vindex history-size
Set the maximum number of history entries saved in the history list.  If
set to zero, the number of entries in the history list is not limited.

@item horizontal-scroll-mode
@vindex horizontal-scroll-mode
This variable can be set to either @samp{on} or @samp{off}.  Setting it
to @samp{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 @samp{off}.

@item input-meta
@vindex input-meta
@vindex meta-flag
If set to @samp{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 @samp{off}.  The name @code{meta-flag} is a
synonym for this variable.

@item isearch-terminators
@vindex isearch-terminators
The string of characters that should terminate an incremental search without
subsequently executing the character as a command (@pxref{Searching}).
If this variable has not been given a value, the characters @key{ESC} and
@kbd{C-J} will terminate an incremental search.

@item keymap
@vindex keymap
Sets Readline's idea of the current keymap for key binding commands.
Acceptable @code{keymap} names are
@code{emacs},
@code{emacs-standard},
@code{emacs-meta},
@code{emacs-ctlx},
@code{vi},
@code{vi-move},
@code{vi-command}, and
@code{vi-insert}.
@code{vi} is equivalent to @code{vi-command}; @code{emacs} is
equivalent to @code{emacs-standard}.  The default value is @code{emacs}.
The value of the @code{editing-mode} variable also affects the
default keymap.

@item mark-directories
If set to @samp{on}, completed directory names have a slash
appended.  The default is @samp{on}.

@item mark-modified-lines
@vindex mark-modified-lines
This variable, when set to @samp{on}, causes Readline to display an
asterisk (@samp{*}) at the start of history lines which have been modified.
This variable is @samp{off} by default.

@item mark-symlinked-directories
@vindex mark-symlinked-directories
If set to @samp{on}, completed names which are symbolic links
to directories have a slash appended (subject to the value of
@code{mark-directories}).
The default is @samp{off}.

@item match-hidden-files
@vindex match-hidden-files
This variable, when set to @samp{on}, causes Readline to match files whose
names begin with a @samp{.} (hidden files) when performing filename
completion.
If set to @samp{off}, the leading @samp{.} must be
supplied by the user in the filename to be completed.
This variable is @samp{on} by default.

@item menu-complete-display-prefix
@vindex menu-complete-display-prefix
If set to @samp{on}, menu completion displays the common prefix of the
list of possible completions (which may be empty) before cycling through
the list.  The default is @samp{off}.

@item output-meta
@vindex output-meta
If set to @samp{on}, Readline will display characters with the
eighth bit set directly rather than as a meta-prefixed escape
sequence.  The default is @samp{off}.

@item page-completions
@vindex page-completions
If set to @samp{on}, Readline uses an internal @code{more}-like pager
to display a screenful of possible completions at a time.
This variable is @samp{on} by default.

@item print-completions-horizontally
If set to @samp{on}, Readline will display completions with matches
sorted horizontally in alphabetical order, rather than down the screen.
The default is @samp{off}.

@item revert-all-at-newline
@vindex revert-all-at-newline
If set to @samp{on}, Readline will undo all changes to history lines
before returning when @code{accept-line} is executed.  By default,
history lines may be modified and retain individual undo lists across
calls to @code{readline}.  The default is @samp{off}.

@item show-all-if-ambiguous
@vindex show-all-if-ambiguous
This alters the default behavior of the completion functions.  If
set to @samp{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 @samp{off}.

@item show-all-if-unmodified
@vindex show-all-if-unmodified
This alters the default behavior of the completion functions in
a fashion similar to @var{show-all-if-ambiguous}.
If set to @samp{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 @samp{off}.

@item skip-completed-text
@vindex skip-completed-text
If set to @samp{on}, this alters the default completion behavior when
inserting a single match into the line.  It's only active when
performing completion in the middle of a word.  If enabled, readline
does not insert characters from the completion that match characters
after point in the word being completed, so portions of the word
following the cursor are not duplicated.
For instance, if this is enabled, attempting completion when the cursor
is after the @samp{e} in @samp{Makefile} will result in @samp{Makefile}
rather than @samp{Makefilefile}, assuming there is a single possible
completion.
The default value is @samp{off}.

@item visible-stats
@vindex visible-stats
If set to @samp{on}, a character denoting a file's type
is appended to the filename when listing possible
completions.  The default is @samp{off}.

@end table

@item Key Bindings
The syntax for controlling key bindings in the init file is
simple.  First you need to find the name of the command that you
want to change.  The following sections contain tables of the command
name, the default keybinding, if any, and a short description of what
the command does.

Once you know the name of the command, simply place on a line
in the init file the name of the key
you wish to bind the command to, a colon, and then the name of the
command.
There can be no space between the key name and the colon -- that will be
interpreted as part of the key name.
The name of the key can be expressed in different ways, depending on
what you find most comfortable.

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

@ifset BashFeatures
The @w{@code{bind -p}} command displays Readline function names and
bindings in a format that can put directly into an initialization file.
@xref{Bash Builtins}.
@end ifset

@table @asis
@item @w{@var{keyname}: @var{function-name} or @var{macro}}
@var{keyname} is the name of a key spelled out in English.  For example:
@example
Control-u: universal-argument
Meta-Rubout: backward-kill-word
Control-o: "> output"
@end example

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

A number of symbolic character names are recognized while
processing this key binding syntax:
@var{DEL},
@var{ESC},
@var{ESCAPE},
@var{LFD},
@var{NEWLINE},
@var{RET},
@var{RETURN},
@var{RUBOUT},
@var{SPACE},
@var{SPC},
and