Term::ReadLine::Gnu - Perl extension for the GNU Readline/History Library
SYNOPSIS
use Term::ReadLine;
$term = new Term::ReadLine 'ProgramName';
while ( defined ($_ = $term->readline('prompt>')) ) {
...
}
DESCRIPTION
Overview
This is an implementation of Term::ReadLine using the GNU
Readline/History Library.
For basic functions object oriented interface is provided. These are
described in the section ``Standard Methods'' and
""Term::ReadLine::Gnu" Functions".
This package also has the interface with the almost all functions and
variables which are documented in the GNU Readline/History Library
Manual. They are documented in the section
""Term::ReadLine::Gnu" Functions"
and
""Term::ReadLine::Gnu" Variables"
briefly. For more detail of the GNU Readline/History Library, see
'GNU Readline Library Manual' and 'GNU History Library Manual'.
The sample programs under "eg/" directory and test programs under
"t/" directory in the "Term::ReadLine::Gnu" distribution include
many example of this module.
Standard Methods
These methods are standard methods defined by Term::ReadLine.
ReadLine
returns the actual package that executes the commands. If you have
installed this package, possible value is "Term::ReadLine::Gnu".
new(NAME,[IN[,OUT]])
returns the handle for subsequent calls to following functions.
Argument is the name of the application. Optionally can be followed
by two arguments for "IN" and "OUT" file handles. These arguments
should be globs.
readline(PROMPT[,PREPUT])
gets an input line, with actual "GNU Readline" support. Trailing
newline is removed. Returns "undef" on "EOF". "PREPUT" is an
optional argument meaning the initial value of input.
The optional argument "PREPUT" is granted only if the value "preput"
is in "Features".
"PROMPT" may include some escape sequences. Use
"RL_PROMPT_START_IGNORE" to begin a sequence of non-printing
characters, and "RL_PROMPT_END_IGNORE" to end of such a sequence.
AddHistory(LINE1, LINE2, ...)
adds the lines to the history of input, from where it can be used if
the actual "readline" is present.
IN, OUT
return the file handles for input and output or "undef"
if
"readline" input and output cannot be used for Perl.
MinLine([MAX])
If argument "MAX" is specified, it is an advice on minimal size of
line to be included into history. "undef" means do not include
anything into history. Returns the old value.
findConsole
returns an array with two strings that give most appropriate names for
files for input and output using conventions "<$in", ">$out".
Attribs
returns a reference to a hash which describes internal configuration
(variables) of the package. Names of keys in this hash conform to
standard conventions with the leading "rl_" stripped.
See section ``Variables'' for supported variables.
Features
Returns a reference to a hash with keys being features present in
current implementation. Several optional features are used in the
minimal interface: "appname" should be present if the first argument
to "new" is recognized, and "minline" should be present if
"MinLine" method is not dummy. "autohistory" should be present if
lines are put into history automatically (maybe subject to
"MinLine"), and "addHistory" if "AddHistory" method is not dummy.
"preput" means the second argument to "readline" method is processed.
"getHistory" and "setHistory" denote that the corresponding methods are
present. "tkRunning" denotes that a Tk application may run while ReadLine
is getting input.
Term::ReadLine::Gnu Functions
All these GNU Readline/History Library functions are callable via
method interface and have names which conform to standard conventions
with the leading "rl_" stripped.
Almost methods have lower level functions in
"Term::ReadLine::Gnu::XS" package. To use them full qualified name
is required. Using method interface is preferred.
Readline Convenience Functions
Naming Function
add_defun(NAME, FUNC [,KEY=-1])
Add name to the Perl function "FUNC". If optional argument "KEY" is
specified, bind it to the "FUNC". Returns reference to
"FunctionPtr".
Example:
# name name `reverse-line' to a function reverse_line(),
# and bind it to "\C-t"
$term->add_defun('reverse-line', \&reverse_line, ord "\ct");
Selecting a Keymap
make_bare_keymap
Keymap rl_make_bare_keymap()
copy_keymap(MAP)
Keymap rl_copy_keymap(Keymap|str map)
make_keymap
Keymap rl_make_keymap()
discard_keymap(MAP)
Keymap rl_discard_keymap(Keymap|str map)
get_keymap
Keymap rl_get_keymap()
set_keymap(MAP)
Keymap rl_set_keymap(Keymap|str map)
get_keymap_by_name(NAME)
Keymap rl_get_keymap_by_name(str name)
get_keymap_name(MAP)
str rl_get_keymap_name(Keymap map)
Binding Keys
bind_key(KEY, FUNCTION [,MAP])
int rl_bind_key(int key, FunctionPtr|str function,
Keymap|str map = rl_get_keymap())
Bind "KEY" to the "FUNCTION". "FUNCTION" is the name added by the
"add_defun" method. If optional argument "MAP" is specified, binds
in "MAP". Returns non-zero in case of error.
unbind_key(KEY [,MAP])
int rl_unbind_key(int key, Keymap|str map = rl_get_keymap())
Bind "KEY" to the null function. Returns non-zero in case of error.
unbind_function(FUNCTION [,MAP])
int rl_unbind_function(FunctionPtr|str function,
Keymap|str map = rl_get_keymap())
unbind_command(COMMAND [,MAP])
int rl_unbind_command(str command,
Keymap|str map = rl_get_keymap())
set_key(KEYSEQ, FUNCTION [,MAP])
int rl_set_key(str keyseq, FunctionPtr|str function,
Keymap|str map = rl_get_keymap())
Parse "LINE" as if it had been read from the ~/.inputrc file and
perform any key bindings and variable assignments found. For more
detail see 'GNU Readline Library Manual'.
read_init_file([FILENAME])
int rl_read_init_file(str filename = '~/.inputrc')
Associating Function Names and Bindings
named_function(NAME)
FunctionPtr rl_named_function(str name)
get_function_name(FUNCTION)
str rl_get_function_name(FunctionPtr function)
function_of_keyseq(KEYMAP [,MAP])
(FunctionPtr|Keymap|str data, int type)
rl_function_of_keyseq(str keyseq,
Keymap|str map = rl_get_keymap())
str rl_filename_completion_function(str text, int state)
username_completion_function(TEXT, STATE)
str rl_username_completion_function(str text, int state)
list_completion_function(TEXT, STATE)
str list_completion_function(str text, int state)
History Functions
Initializing History and State Management
using_history
void using_history()
History List Management
addhistory(STRING[, STRING, ...])
void add_history(str string)
StifleHistory(MAX)
int stifle_history(int max|undef)
stifles the history list, remembering only the last "MAX" entries.
If "MAX" is undef, remembers all entries. This is a replacement
of unstifle_history().
unstifle_history
int unstifle_history()
This is equivalent with 'stifle_history(undef)'.
SetHistory(LINE1 [, LINE2, ...])
sets the history of input, from where it can be used if the actual
"readline" is present.
remove_history(WHICH)
str remove_history(int which)
replace_history_entry(WHICH, LINE)
str replace_history_entry(int which, str line)
clear_history
void clear_history()
history_is_stifled
int history_is_stifled()
Information About the History List
where_history
int where_history()
current_history
str current_history()
history_get(OFFSET)
str history_get(offset)
history_total_bytes
int history_total_bytes()
GetHistory
returns the history of input as a list, if actual "readline" is present.
Moving Around the History List
history_set_pos(POS)
int history_set_pos(int pos)
previous_history
str previous_history()
next_history
str next_history()
Searching the History List
history_search(STRING [,DIRECTION])
int history_search(str string, int direction = -1)
history_search_prefix(STRING [,DIRECTION])
int history_search_prefix(str string, int direction = -1)
history_search_pos(STRING [,DIRECTION [,POS]])
int history_search_pos(str string,
int direction = -1,
int pos = where_history())
Managing the History File
ReadHistory([FILENAME [,FROM [,TO]]])
int read_history(str filename = '~/.history',
int from = 0, int to = -1)
int read_history_range(str filename = '~/.history',
int from = 0, int to = -1)
adds the contents of "FILENAME" to the history list, a line at a
time. If "FILENAME" is false, then read from ~/.history. Start
reading at line "FROM" and end at "TO". If "FROM" is omitted or
zero, start at the beginning. If "TO" is omitted or less than
"FROM", then read until the end of the file. Returns true if
successful, or false if not. "read_history()" is an aliase of
"read_history_range()".
WriteHistory([FILENAME])
int write_history(str filename = '~/.history')
writes the current history to "FILENAME", overwriting "FILENAME" if
necessary. If "FILENAME" is false, then write the history list to
~/.history. Returns true if successful, or false if not.
append_history(NELEMENTS [,FILENAME])
int append_history(int nelements, str filename = '~/.history')
history_truncate_file([FILENAME [,NLINES]])
int history_truncate_file(str filename = '~/.history',
int nlines = 0)
Note that this function returns "expansion" in scalar context.
get_history_event(STRING, CINDEX [,QCHAR])
(str text, int cindex) = get_history_event(str string,
int cindex,
char qchar = '\0')
history_tokenize(LINE)
(@str) history_tokenize(str line)
history_arg_extract(LINE, [FIRST [,LAST]])
str history_arg_extract(str line, int first = 0, int last = '$')
Term::ReadLine::Gnu Variables
Following GNU Readline/History Library variables can be accessed from
Perl program. See 'GNU Readline Library Manual' and ' GNU History
Library Manual' for each variable. You can access them with
"Attribs" methods. Names of keys in this hash conform to standard
conventions with the leading "rl_" stripped.
In this section variables and functions for custom completion is
described with examples.
Most of descriptions in this section is cited from GNU Readline
Library manual.
rl_completion_entry_function
This variable holds reference refers to a generator function for
"completion_matches()".
A generator function is called repeatedly from
"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. When the generator function returns "undef" this signals
"completion_matches()" that there are no more possibilities left.
If the value is undef, built-in "filename_completion_function" is
used.
A sample generator function, "list_completion_function", is defined
in Gnu.pm. You can use it as follows;
use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
$attribs->{completion_entry_function} =
$attribs->{list_completion_function};
...
$attribs->{completion_word} =
[qw(reference to a list of words which you want to use for completion)];
$term->readline("custom completion>");
See also "completion_matches".
rl_attempted_completion_function
A reference to an alternative function to create matches.
The function is called with "TEXT", "LINE_BUFFER", "START", and
"END". "LINE_BUFFER" is a current input buffer string. "START"
and "END" are indices in "LINE_BUFFER" saying what the boundaries of
"TEXT" are.
If this function exists and returns null list or "undef", or if this
variable is set to "undef", then an internal function
"rl_complete()" will call the value of
$rl_completion_entry_function to generate matches, otherwise the
array of strings returned will be used.
The default value of this variable is "undef". You can use it as follows;
use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
sub sample_completion {
my ($text, $line, $start, $end) = @_;
# If first word then username completion, else filename completion
if (substr($line, 0, $start) =~ /^\s*$/) {
return $term->completion_matches($text,
$attribs->{'username_completion_function'});
} else {
return ();
}
}
...
$attribs->{attempted_completion_function} = \&sample_completion;
completion_matches(TEXT, ENTRY_FUNC)
Returns an array of strings which is a list of completions for
"TEXT". If there are no completions, returns "undef". The first
entry in the returned array is the substitution for "TEXT". The
remaining entries are the possible completions.
"ENTRY_FUNC" is a generator function which has two arguments, and
returns a string. 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 "undef" to the caller when
there are no more matches.
If the value of "ENTRY_FUNC" is undef, built-in
"filename_completion_function" is used.
"completion_matches" is a Perl wrapper function of an internal
function "completion_matches()". See also
$rl_completion_entry_function.
completion_function
A variable whose content is a reference to a function which returns a
list of candidates to complete.
This variable is compatible with "Term::ReadLine::Perl" and very easy
to use.
use Term::ReadLine;
...
my $term = new Term::ReadLine 'sample';
my $attribs = $term->Attribs;
...
$attribs->{completion_function} = sub {
my ($text, $line, $start) = @_;
return qw(a list of candidates to complete);
}
list_completion_function(TEXT, STATE)
A sample generator function defined by "Term::ReadLine::Gnu".
Example code at "rl_completion_entry_function" shows how to use this
function.
Term::ReadLine::Gnu Specific Features
Term::ReadLine::Gnu Specific Functions
CallbackHandlerInstall(PROMPT, LHANDLER)
This method provides the function "rl_callback_handler_install()"
with the following addtional feature compatible with "readline"
method; ornament feature, "Term::ReadLine::Perl" compatible
completion function, histroy expansion, and addition to history
buffer.
call_function(FUNCTION, [COUNT [,KEY]])
int rl_call_function(FunctionPtr|str function, count = 1, key = -1)
rl_get_all_function_names
Returns a list of all function names.
shadow_redisplay
A redisplay function for password input. You can use it as follows;
Returns candidates of filename to complete. This function can be used
with "completion_function" and is implemented for the compatibility
with "Term::ReadLine::Perl".
list_completion_function
See the description of section ``Custom Completion''.
Term::ReadLine::Gnu Specific Variables
do_expand
When true, the history expansion is enabled. By default false.
completion_function
See the description of section ``Custom Completion''.
completion_word
A reference to a list of candidates to complete for
"list_completion_function".
Term::ReadLine::Gnu Specific Commands
history-expand-line
The equivalent of the Bash "history-expand-line" editing command.
operate-and-get-next
The equivalent of the Korn shell "operate-and-get-next-history-line"
editing command and the Bash "operate-and-get-next".
This command is bound to "\C-o" by default for the compatibility with
the Bash and "Term::ReadLine::Perl".
display-readline-version
Shows the version of "Term::ReadLine::Gnu" and the one of the GNU
Readline Library.
change-ornaments
Change ornaments interactively.
FILES
~/.inputrc
Readline init file. Using this file it is possible that you would
like to use a different set of key bindings. When a program which
uses the Readline library starts up, the init file is read, and the
key bindings are set.
Conditional key binding is also available. The program name which is
specified by the first argument of "new" method is used as the
application construct.
For example, when your program call "new" method like this;
...
$term = new Term::ReadLine 'PerlSh';
...
your ~/.inputrc can define key bindings only for it as follows;
SPP (Synopsys Plus Perl) is a Perl module that wraps around Synopsys'
shell programs. SPP is inspired by the original dc_perl written by
Steve Golson, but it's an entirely new implementation. Why is it
called SPP and not dc_perl? Well, SPP was written to wrap around any
of Synopsys' shells.
soundgrab is designed to help you slice up a big long raw audio file
(by default 44.1 kHz 2 channel signed sixteen bit little endian) and
save your favorite sections to other files. It does this by providing
you with a cassette player like command line interface.
PDL (``Perl Data Language'') gives standard Perl the ability to
compactly store and speedily manipulate the large N-dimensional data
arrays which are the bread and butter of scientific computing.
PIQT is an interactive query tool using the Perl DBI database
interface. It supports ReadLine, provides a built in scripting language
with a Lisp like syntax, an online help system, and uses wrappers to
interface to the DBD modules.
It provides a friendly way to play with the Ghostscript interpreter,
including command history and auto-completion of Postscript font names
and reserved words.
If you know any other works which can be listed here, please let me
know.
Ornament feature works only on prompt strings. It requires very hard
hacking of "display.c:rl_redisplay()" in GNU Readline library to
ornament input line.