rluser.texinfo

这个是LINUX下的GDB调度工具的源码

@end ifclear

@end ftable

@node Readline vi Mode
@section Readline vi Mode

While the Readline library does not have a full set of @code{vi}
editing functions, it does contain enough to allow simple editing
of the line.  The Readline @code{vi} mode behaves as specified in
the @sc{posix} 1003.2 standard.

@ifset BashFeatures
In order to switch interactively between @code{emacs} and @code{vi}
editing modes, use the @samp{set -o emacs} and @samp{set -o vi}
commands (@pxref{The Set Builtin}).
@end ifset
@ifclear BashFeatures
In order to switch interactively between @code{emacs} and @code{vi}
editing modes, use the command @kbd{M-C-j} (bound to emacs-editing-mode
when in @code{vi} mode and to vi-editing-mode in @code{emacs} mode).
@end ifclear
The Readline default is @code{emacs} mode.

When you enter a line in @code{vi} mode, you are already placed in
`insertion' mode, as if you had typed an @samp{i}.  Pressing @key{ESC}
switches you into `command' mode, where you can edit the text of the
line with the standard @code{vi} movement keys, move to previous
history lines with @samp{k} and subsequent lines with @samp{j}, and
so forth.

@ifset BashFeatures
@node Programmable Completion
@section Programmable Completion
@cindex programmable completion

When word completion is attempted for an argument to a command for
which a completion specification (a @var{compspec}) has been defined
using the @code{complete} builtin (@pxref{Programmable Completion Builtins}),
the programmable completion facilities are invoked. 

First, the command name is identified.
If a compspec has been defined for that command, the
compspec is used to generate the list of possible completions for the word.
If the command word is a full pathname, a compspec for the full
pathname is searched for first.
If no compspec is found for the full pathname, an attempt is made to
find a compspec for the portion following the final slash.

Once a compspec has been found, it is used to generate the list of
matching words.
If a compspec is not found, the default Bash completion
described above (@pxref{Commands For Completion}) is performed.

First, the actions specified by the compspec are used.
Only matches which are prefixed by the word being completed are
returned.
When the @option{-f} or @option{-d} option is used for filename or
directory name completion, the shell variable @env{FIGNORE} is
used to filter the matches.
@xref{Bash Variables}, for a description of @env{FIGNORE}.

Any completions specified by a filename expansion pattern to the
@option{-G} option are generated next.
The words generated by the pattern need not match the word being completed.
The @env{GLOBIGNORE} shell variable is not used to filter the matches,
but the @env{FIGNORE} shell variable is used.

Next, the string specified as the argument to the @option{-W} option
is considered.
The string is first split using the characters in the @env{IFS}
special variable as delimiters.
Shell quoting is honored.
Each word is then expanded using
brace expansion, tilde expansion, parameter and variable expansion,
command substitution, arithmetic expansion, and pathname expansion,
as described above (@pxref{Shell Expansions}).
The results are split using the rules described above
(@pxref{Word Splitting}).
The results of the expansion are prefix-matched against the word being
completed, and the matching words become the possible completions.

After these matches have been generated, any shell function or command
specified with the @option{-F} and @option{-C} options is invoked.
When the command or function is invoked, the @env{COMP_LINE} and
@env{COMP_POINT} variables are assigned values as described above
(@pxref{Bash Variables}).
If a shell function is being invoked, the @env{COMP_WORDS} and
@env{COMP_CWORD} variables are also set.
When the function or command is invoked, the first argument is the
name of the command whose arguments are being completed, the
second argument is the word being completed, and the third argument
is the word preceding the word being completed on the current command line.
No filtering of the generated completions against the word being completed
is performed; the function or command has complete freedom in generating
the matches.

Any function specified with @option{-F} is invoked first.
The function may use any of the shell facilities, including the
@code{compgen} builtin described below
(@pxref{Programmable Completion Builtins}), to generate the matches.
It must put the possible completions in the @env{COMPREPLY} array
variable.

Next, any command specified with the @option{-C} option is invoked
in an environment equivalent to command substitution.
It should print a list of completions, one per line, to
the standard output.
Backslash may be used to escape a newline, if necessary.

After all of the possible completions are generated, any filter
specified with the @option{-X} option is applied to the list.
The filter is a pattern as used for pathname expansion; a @samp{&}
in the pattern is replaced with the text of the word being completed.
A literal @samp{&} may be escaped with a backslash; the backslash
is removed before attempting a match.
Any completion that matches the pattern will be removed from the list.
A leading @samp{!} negates the pattern; in this case any completion
not matching the pattern will be removed.

Finally, any prefix and suffix specified with the @option{-P} and @option{-S}
options are added to each member of the completion list, and the result is
returned to the Readline completion code as the list of possible
completions.

If the previously-applied actions do not generate any matches, and the
@option{-o dirnames} option was supplied to @code{complete} when the
compspec was defined, directory name completion is attempted. 

By default, if a compspec is found, whatever it generates is returned to
the completion code as the full set of possible completions.
The default Bash completions are not attempted, and the Readline default
of filename completion is disabled.
If the @option{-o default} option was supplied to @code{complete} when the
compspec was defined, Readline's default completion will be performed
if the compspec generates no matches.

When a compspec indicates that directory name completion is desired,
the programmable completion functions force Readline to append a slash
to completed names which are symbolic links to directories, subject to
the value of the @var{mark-directories} Readline variable, regardless
of the setting of the @var{mark-symlinked-directories} Readline variable.

@node Programmable Completion Builtins
@section Programmable Completion Builtins
@cindex completion builtins

Two builtin commands are available to manipulate the programmable completion
facilities.

@table @code
@item compgen
@btindex compgen
@example
@code{compgen [@var{option}] [@var{word}]}
@end example

Generate possible completion matches for @var{word} according to
the @var{option}s, which may be any option accepted by the
@code{complete}
builtin with the exception of @option{-p} and @option{-r}, and write
the matches to the standard output.
When using the @option{-F} or @option{-C} options, the various shell variables
set by the programmable completion facilities, while available, will not
have useful values.

The matches will be generated in the same way as if the programmable
completion code had generated them directly from a completion specification
with the same flags.
If @var{word} is specified, only those completions matching @var{word}
will be displayed.

The return value is true unless an invalid option is supplied, or no
matches were generated.

@item complete
@btindex complete
@example
@code{complete [-abcdefgjksuv] [-o @var{comp-option}] [-A @var{action}] [-G @var{globpat}] [-W @var{wordlist}]
[-P @var{prefix}] [-S @var{suffix}] [-X @var{filterpat}] [-F @var{function}]
[-C @var{command}] @var{name} [@var{name} @dots{}]}
@code{complete -pr [@var{name} @dots{}]}
@end example

Specify how arguments to each @var{name} should be completed.
If the @option{-p} option is supplied, or if no options are supplied, existing
completion specifications are printed in a way that allows them to be
reused as input.
The @option{-r} option removes a completion specification for
each @var{name}, or, if no @var{name}s are supplied, all
completion specifications.

The process of applying these completion specifications when word completion
is attempted is described above (@pxref{Programmable Completion}).

Other options, if specified, have the following meanings.
The arguments to the @option{-G}, @option{-W}, and @option{-X} options
(and, if necessary, the @option{-P} and @option{-S} options)
should be quoted to protect them from expansion before the
@code{complete} builtin is invoked.


@table @code
@item -o @var{comp-option}
The @var{comp-option} controls several aspects of the compspec's behavior
beyond the simple generation of completions.
@var{comp-option} may be one of: 

@table @code

@item default
Use Readline's default filename completion if the compspec generates
no matches.

@item dirnames
Perform directory name completion if the compspec generates no matches.

@item filenames
Tell Readline that the compspec generates filenames, so it can perform any
filename\-specific processing (like adding a slash to directory names or
suppressing trailing spaces).  This option is intended to be used with
shell functions specified with @option{-F}.

@item nospace
Tell Readline not to append a space (the default) to words completed at
the end of the line.
@end table

@item -A @var{action}
The @var{action} may be one of the following to generate a list of possible
completions:

@table @code
@item alias
Alias names.  May also be specified as @option{-a}.

@item arrayvar
Array variable names.

@item binding
Readline key binding names (@pxref{Bindable Readline Commands}).

@item builtin
Names of shell builtin commands.  May also be specified as @option{-b}.

@item command
Command names.  May also be specified as @option{-c}.

@item directory
Directory names.  May also be specified as @option{-d}.

@item disabled
Names of disabled shell builtins.

@item enabled
Names of enabled shell builtins.

@item export
Names of exported shell variables.  May also be specified as @option{-e}.

@item file
File names.  May also be specified as @option{-f}.

@item function
Names of shell functions.

@item group
Group names.  May also be specified as @option{-g}.

@item helptopic
Help topics as accepted by the @code{help} builtin (@pxref{Bash Builtins}).

@item hostname
Hostnames, as taken from the file specified by the
@env{HOSTFILE} shell variable (@pxref{Bash Variables}).

@item job
Job names, if job control is active.  May also be specified as @option{-j}.

@item keyword
Shell reserved words.  May also be specified as @option{-k}.

@item running
Names of running jobs, if job control is active.

@item service
Service names.  May also be specified as @option{-s}.

@item setopt
Valid arguments for the @option{-o} option to the @code{set} builtin
(@pxref{The Set Builtin}).

@item shopt
Shell option names as accepted by the @code{shopt} builtin
(@pxref{Bash Builtins}).

@item signal
Signal names.

@item stopped
Names of stopped jobs, if job control is active.

@item user
User names.  May also be specified as @option{-u}.

@item variable
Names of all shell variables.  May also be specified as @option{-v}.
@end table

@item -G @var{globpat}
The filename expansion pattern @var{globpat} is expanded to generate
the possible completions.

@item -W @var{wordlist}
The @var{wordlist} is split using the characters in the
@env{IFS} special variable as delimiters, and each resultant word
is expanded.
The possible completions are the members of the resultant list which
match the word being completed.

@item -C @var{command}
@var{command} is executed in a subshell environment, and its output is
used as the possible completions.

@item -F @var{function}
The shell function @var{function} is executed in the current shell
environment.
When it finishes, the possible completions are retrieved from the value
of the @env{COMPREPLY} array variable.

@item -X @var{filterpat}
@var{filterpat} is a pattern as used for filename expansion.
It is applied to the list of possible completions generated by the
preceding options and arguments, and each completion matching
@var{filterpat} is removed from the list.
A leading @samp{!} in @var{filterpat} negates the pattern; in this
case, any completion not matching @var{filterpat} is removed.

@item -P @var{prefix}
@var{prefix} is added at the beginning of each possible completion
after all other options have been applied.

@item -S @var{suffix}
@var{suffix} is appended to each possible completion
after all other options have been applied.
@end table

The return value is true unless an invalid option is supplied, an option
other than @option{-p} or @option{-r} is supplied without a @var{name}
argument, an attempt is made to remove a completion specification for
a @var{name} for which no specification exists, or
an error occurs adding a completion specification.

@end table
@end ifset