Provided by: libterm-readline-zoid-perl_0.07-2_all 
NAME
Term::ReadLine::Zoid - another ReadLine package
SYNOPSIS
# In your app:
use Term::ReadLine;
my $term = Term::ReadLine->new("my app");
my $prompt = "eval: ";
my $OUT = $term->OUT ⎪⎪ \*STDOUT;
while ( defined ($_ = $term->readline($prompt)) ) {
# Think while (<STDIN>) {}
my $res = eval($_);
warn $@ if $@;
print $OUT $res, "\n" unless $@;
}
# In some rc file
export PERL_RL=Zoid
DESCRIPTION
This package provides a set of modules that form an interactive input buffer written in
plain perl with minimal dependencies. It features almost all key-bindings described in the
posix spec for the sh(1) utility with some extensions like multiline editing; this
includes a vi-command mode with a save-buffer (for copy-pasting) and an undo-stack.
Historically this code was part of the Zoidberg shell, but this implementation is complete
independent from zoid and uses the Term::ReadLine interface, so it can be used with other
perl programs.
( The documentation sometimes referes to 'the application', this is the program using the
ReadLine module for input. )
ENVIRONMENT
The Term::ReadLine interface module uses the "PERL_RL" variable to decide which module to
load; so if you want to use this module for all your perl applications, try something
like:
export PERL_RL=Zoid
KEY MAPPING
The function name is given between parenthesis, these can be used for privat key maps.
Default keymap
The default key mapping is as follows:
escape, ^[ (switch_mode_command)
Place the line editor in command mode, see Term::ReadLine::Zoid::ViCommand.
^C (return_empty_string)
End editing and return an empty string.
^D (delete_char_or_eof)
For a single line buffer ends editing and returns "undef" if the line is empty, else
it deletes a char. For a multiline buffer, ends editing and returns the lines to the
application if the cursor is on the last line and this line is empty, else it deletes
a char.
Note that the delete_char_or_eof function does what delete_char should do to be
compatible with GNU readline lib.
delete (delete_char)
backspace, ^H, ^? (backward_delete_char)
Delete and backspace kill the current or previous character. The key '^?' is by
default considered a backspace because most modern keyboards use this key for the
"backspace" key and an escape sequence for the "delete" key. Of course '^H' is also
considered a backspace.
tab, ^I (complete)
Try to complete the bigword on left of the cursor.
There is no default completion included in this package, so unless you define a custom
expansion it doesn't do anything. See the "completion_function" option.
Uses the PAGER environment variable to find a suitable pager when there are more
completions to be shown then would fit on the screen.
See also the "autolist" and "maxcomplete" options.
return, ^J (accept_line)
End editing and return the edit line to the application unless the newline is escaped.
If _all_ lines in the buffer end with a single '\', the newline is considered escaped
you can continue typing on the next line. This behaviour can be a bit unexpected
because this module has multiline support which historic readline implementations have
not, historically the escaping of a newline is done by the application not by the
library. The surpress this behaviour, and let the application do it's thing, disable
the "automultiline" option.
To enter the real multiline editing mode, press 'escape m', see
Term::ReadLine::Zoid::MultiLine.
^O (operate_and_get_next)
Return the current buffer to the application but remember where we are in history.
This can be used to quickly (re-)execute series of commands from history.
^K (kill_line)
Delete from cursor to the end of the line.
^L (clear_screen)
Clear entire screen. In contrast with other readline libraries, the prompt will remain
at the bottom of the screen.
^R (switch_mode_isearch)
Enter incremental search mode, see Term::ReadLine::Zoid::ISearch.
^U (unix_line_discard)
This is also known as the "kill" char. It deletes all characters on the edit line and
puts them in the save buffer. You can paste them back in later with 'escape-p'.
^V (quoted_insert)
Insert next key literally, ignoring any key-bindings.
WARNING: control or escape chars in the editline can cause unexpected results
^W (unix_word_rubout)
Delete the word before the cursor.
insert (overwrite_mode)
Toggle replace bit.
home, ^A (beginning_of_line)
Move cursor to the begin of the edit line.
end, ^E (end_of_line)
Move cursor to the end of the edit line.
left, ^B (backward_char)
right, ^F (forward_char)
These keys can be used to move the cursor in the edit line.
up, page_up, ^P (previous_history)
down, page_down, ^N (next_history)
These keys are used to rotate the history.
Multi-line keymap
The following keys are different in mutline mode, the others fall back to the default
behaviour.
return (insert_line)
Insert a newline at the current cursor position.
up (backward_line)
Move the cursor one line up.
down (forward_line)
Move the cursor one line down.
page_up (page_up)
Move the cursor one screen down, or to the bottom of the buffer.
page_down (page_down)
Move the cursor one screen up, or to the top of the buffer.
Unmapped functions
return_eof
End editing and return "undef".
return_eof_maybe
End editing and return "undef" if the buffer is completely empty.
possible_completions
Like complete but only shows the completions without actually doing them.
redraw_current_line
Redraw the current line. This is done all the time automaticly so you'll almost never
need to call this one explicitly.
ATTRIBS
The hash with options can be accessed with the "Attribs" method. These can be modified
from the rc-file (see "FILES") or can be set from the "PERL_RL" environment variable. For
example to disable the "autolist" feature you can set "PERL_RL='Zoid autolist=0'" before
you start the application.
( Also they can be altered interactively using the mini-buffer of the command mode, see
Term::ReadLine::Zoid::ViCommand. )
autohistory
If enabled lines are added to the history automaticly, subject to "MinLine". By
default enabled.
autoenv
If enabled the environment variables "COLUMNS" and "LINES" are kept up to date. By
default enabled.
autolist
If set completions are listed directly when a completion fails, if not set you need to
press "tab" twice to see a list of possible completions. By default enabled.
automultiline
See "return" for a description. By default enabled.
beat
This option can contain a CODE reference. It is called on the heartbeat event.
bell
This option can contain a CODE reference. The default is "print "\cG"", which makes
the terminal ring a bell.
comment_begin
This option can be set to a string, if the edit line starts with this string the line
is regarded to be a comment and is not returned to the application, but it will appear
in the history if 'autohistory' is also set. Defaults to "#".
When there are multiple lines in the buffer they all need to start with the comment
string for the buffer to be regarded as a comment.
completion_function
This option can contain either a code ref or the name of a function to perform
completion. For compatibility with Term::ReadLine::Perl the global scalar
$readline::rl_completion_function will be checked if this option isn't defined.
The function will get the following arguments: $word, $buffer, $start. Where $word is
the word before the cursor, while $buffer is the complete text on the command line;
$start is the offset of $word in $buffer.
The function should return a list of possible completions of $word. The completion
list is checked for double entries.
There is no default.
FIXME tell about the meta fields for advanced completion
default_mode
Specifies the mode the buffer starts in when you do a "readline()", also other modes
return to this mode if you exit them. The default is 'insert' which is the single-
line insert mode. If you always want to edit in multiline mode set this option to
'multiline'.
maxcomplete
Maximum number of completions to be displayed, when the number of completions is
bigger the user is asked before displaying them. If set to zero completions are always
displayed.
If this option is set to the string 'pager' the user is asked when the number of
completions is to big to fit on screen and a pager would be used.
minline
This option controls which lines are included in the history, lines shorter then this
number are ignored. When set to "0" all lines are included in the history, when set to
"undef" all lines are ignored. Defaults to "0".
PS2 This option can contain the prompt to be used for extra buffer lines. It defaults to
"> ".
Although the "PS1" prompt (as specified as an argument to the "readline()" method) can
contain newlines, the PS2 prompt can't.
RPS1
This option can contain a string that will be shown on the right side of the screen.
This is known as the "right prompt" and the idea is stolen from zsh(1).
title
Used to set the terminal title, defaults to the appname.
low_latency
Changes the escape sequences are read from input. If true delays evalution of the
escape key till the next char is known. By default disabled.
FILES
This module reads a rc-file on intialisation, either $HOME/.perl_rl_zoid_rc,
$HOME/.zoid/perl_rl_zoid_rc or /etc/perl_rl_zoid_rc. The rc-file is a perl script with
access to the Term::ReadLine::Zoid object through the method "current()". If you want to
have different behaviour for different applications, try to check for "$rl->{appname}".
# in for example ~/.perl_rl_zoid_rc
my $rl = Term::ReadLine::Zoid->current();
# set low latency
$rl->Attribs()->{low_latency} = 1;
# alias control-space to escape
$rl->bindchr( chr(0), 'escape' );
# create an ad hoc macro
$rl->bindkey('^P', sub { $rl->press('mplayer -vo sdl ') } );
METHODS
ReadLine api
Functions specified by the Term::ReadLine documentation.
"new($appname, $IN, $OUT)"
Simple constructor. Arguments are the application name (used for default prompt and
title string) and optional filehandles for input and output.
"ReadLine()"
Returns the name of the current ReadLine module actually used.
"readline($prompt, $preput)"
Returns a string entered by the user. The final newline is stripped, though the
string might contain newlines elsewhere.
The prompt only supports the escape "!" for the history number of the current line,
use "!!" for a literal "!". All other escapes you need to parse yourself, before
supplying the prompt. The prompt defaults to "$appname !> ".
If you want to do more with your prompt see Env::PS1.
$preput can be used to set some text on the edit line allready.
"addhistory($line)"
"AddHistory($line)"
Add a command to the history (subject to the "minline" option).
If "autohistory" is set this method will be called automaticly by "readline".
"IN()"
Returns the filehandle used for input.
"OUT()"
Returns the filehandle used for output.
"MinLine($value)"
Sets "minline" option to $value and returns old value.
"findConsole()"
TODO - what uses does this have ?
"Attribs()"
Returns a reference to the options hash.
"Features()"
Returns a reference to a hash with names of implemented features.
Be aware that the naming scheme is quite arbitrary, this module uses the same names as
Term::ReadLine::Gnu for common features.
Extended api
"SetHistory(@hist)"
"GetHistory()"
Simple acces to the history arry, the "set" function supports both a list and a
reference, the "get" function uses "wantarray". Not sure which behaviour is
compatible with T:RL::Gnu.
"TermSize()"
Returns number of columns and lines on the terminal.
"continue()"
This method can be called to continue the previous "readline()" call. Can be used to
build a custom auto-mulitline feature.
"current()"
Returns the current T:RL::Zoid object, for use in rc files, see "FILES".
"bindkey($key, $sub, $map)"
Bind a CODE reference to a key, the function gets called when the key is typed with
the key name as an argument. The $map argument is optional and can be either
"default", "command", "isearch" or "multiline".
If $sub is not a reference it is considered an alias; these aliases are not recursive.
For alphanumeric characters the name is the character itself, special characters have
long speaking names and control characters are prefixed with a '^'.
Binding combination with the meta- or alt-key is not supported (see "NOTES").
Private api
Methods for use in overload classes.
Avoid using these methods from the application.
"switch_mode($mode)"
Switch to input mode $mode; changes the key map and reblesses the object if the
"_on_switch" key returns a class name.
"reset()"
Reset all temporary attributes.
"save()"
Returns a ref with a copy of some temporary attributes. Can be used to switch between
multiple edit lines in combination with "restore".
"restore($save)"
Restores saved attributes.
"set_history($int)"
Sets history entry $int in the buffer.
"longest_match(@completion)"
Returns the longest match among the completions followed by the completions itself.
Used for completion functions.
DEVELOPMENT
FIXME minimum subroutines new mode-class
FIXME how to set up a keymap
FIXME how to add a keymap/mode
NOTES
With most modern keymappings the combination of the meta key (alt) with a letter is
identical with an escape character followed by that letter.
Some functioality may in time be moved to the ::Base package.
TODO
UTF8 support, or general charset support, would be nice but at the moment I lack the means
to test these things. If anyone has ideas or suggestions about this please contact me.
BUGS
Line wrap doesn't always displays the last character on the line right, no functional bug
though.
If the buffer size exceeds the screen size some bugs appear in the rendering.
Please mail the author if you find any other bugs.
AUTHOR
Jaap Karssenberg ⎪⎪ Pardus [Larus] <pardus@cpan.org>
Copyright (c) 2004 Jaap G Karssenberg. All rights reserved. This program is free
software; you can redistribute it and/or modify it under the same terms as Perl itself.
SEE ALSO
Term::ReadLine::Zoid::ViCommand, Term::ReadLine::Zoid::MultiLine,
Term::ReadLine::Zoid::ISearch, Term::ReadLine::Zoid::FileBrowse,
Term::ReadLine::Zoid::Base, Term::ReadLine, Env::PS1, Zoidberg