Term::ReadLine::Gnu - Perl extension for the GNU Readline/History Library

FILES
EXPORTS
SEE ALSO
AUTHOR
TODO
BUGS

NAME

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
Readline Signal Handling
Completion Functions
History Functions

`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.

Examples:

    $attribs = $term->Attribs;
    $v = $attribs->{library_version};   # rl_library_version
    $v = $attribs->{history_base};      # history_base

Readline Variables

        str rl_line_buffer
        int rl_point
        int rl_end
        int rl_mark
        int rl_done
        int rl_num_chars_to_read (GRL 4.2)
        int rl_pending_input
        int rl_dispatching (GRL 4.2)
        int rl_erase_empty_line (GRL 4.0)
        str rl_prompt (read only)
        int rl_already_prompted (GRL 4.1)
        str rl_library_version (read only)
        int rl_readline_version (read only)
        int rl_gnu_readline_p (GRL 4.2)
        str rl_terminal_name
        str rl_readline_name
        filehandle rl_instream
        filehandle rl_outstream
        int rl_prefer_env_winsize (GRL 5.1)
        pfunc rl_last_func (GRL 4.2)
        pfunc rl_startup_hook
        pfunc rl_pre_input_hook (GRL 4.0)
        pfunc rl_event_hook
        pfunc rl_getc_function
        pfunc rl_redisplay_function
        pfunc rl_prep_term_function (GRL 4.2)
        pfunc rl_deprep_term_function (GRL 4.2)
        Keymap rl_executing_keymap (read only)
        Keymap rl_binding_keymap (read only)
        str rl_executing_macro (GRL 4.2)
        int rl_readline_state (GRL 4.2)
        int rl_explicit_arg (GRL 4.2)
        int rl_numeric_arg (GRL 4.2)
        int rl_editing_mode (GRL 4.2)

Signal Handling Variables

        int rl_catch_signals (GRL 4.0)
        int rl_catch_sigwinch (GRL 4.0)

Completion Variables

        pfunc rl_completion_entry_function
        pfunc rl_attempted_completion_function
        pfunc rl_filename_quoting_function
        pfunc rl_filename_dequoting_function
        pfunc rl_char_is_quoted_p
        int rl_completion_query_items
        str rl_basic_word_break_characters
        str rl_basic_quote_characters
        str rl_completer_word_break_characters
        pfunc rl_completion_word_break_hook (GRL 5.0)
        str rl_completer_quote_characters
        str rl_filename_quote_characters
        str rl_special_prefixes
        int rl_completion_append_character
        int rl_completion_suppress_append (GRL 4.3)
        int rl_completion_quote_charactor (GRL 5.0)
        int rl_completion_suppress_quote (GRL 5.0)
        int rl_completion_found_quote (GRL 5.0)
        int rl_completion_mark_symlink_dirs (GRL 4.3)
        int rl_ignore_completion_duplicates
        int rl_filename_completion_desired
        int rl_filename_quoting_desired
        int rl_attempted_completion_over (GRL 4.2)
        int rl_completion_type (GRL 4.2)
        int rl_inhibit_completion
        pfunc rl_ignore_some_completion_function
        pfunc rl_directory_completion_hook
        pfunc rl_completion_display_matches_hook (GRL 4.0)

History Variables

        int history_base
        int history_length
        int history_max_entries (called `max_input_history'. read only)
        int history_write_timestamps (GRL 5.0)
        char history_expansion_char
        char history_subst_char
        char history_comment_char
        str history_word_delimiters (GRL 4.2)
        str history_no_expand_chars
        str history_search_delimiter_chars
        int history_quotes_inhibit_expansion
        pfunc history_inhibit_expansion_function

Function References

        rl_getc
        rl_redisplay
        rl_callback_read_char
        rl_display_match_list
        rl_filename_completion_function
        rl_username_completion_function
        list_completion_function
        shadow_redisplay
        Tk_getc

Custom Completion

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>");

`Term::ReadLine::Gnu` Specific Features

Term::ReadLine::Gnu Specific Functions
Term::ReadLine::Gnu Specific Variables
Term::ReadLine::Gnu Specific Commands

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;

        ...
        $if PerlSh
        Meta-Rubout: backward-kill-word
        "\C-x\C-r": re-read-init-file
        "\e[11~": "Function Key 1"
        $endif
        ...

EXPORTS

None.

AUTHOR

Hiroo Hayashi <hiroo.hayashi@computer.org>

http://www.perl.org/CPAN/authors/Hiroo_HAYASHI/

TODO

GTK+ support in addition to Tk.

BUGS

rl_add_defun() can define up to 16 functions.

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.

newTTY() is not tested yet.

Term::ReadLine::Gnu - Perl extension for the GNU Readline/History Library