Term::ReadLine::Zoid::Base(3pm) User Contributed Perl Documentation Term::ReadLine::Zoid::Base(3pm)NAME
Term::ReadLine::Zoid::Base - atomic routines
DESCRIPTION
This module contains some atomic operations used by all Term::ReadLine::Zoid objects. It is intended as a base class.
At the very least, to child class needs to define a "default()" function to handle key bindings and a "draw()" function which in turn calls
"print()". Also the attributes "IN" and "OUT" should contain valid filehandles.
METHODS
ANSI stuff
"cursor_at($x, $y)"
Positions the cursor on screen, dimensions are 1-based.
"clear_screen()"
Clear screen.
"title($string)"
Set terminal title to $string. When using for example xterm(1) this is the window name.
"print_length($string)"
Returns the printable length of $string, not counting (some) ansi sequences.
Private api
Methods for use in overload classes. Avoid using these methods from the application.
"bell()"
Notify the user of an error or limit.
"loop()"
Low level function used by readline. Calls "draw()" and "do_key()".
"beat()"
Method called by intervals while waiting for input, to be overloaded.
"read_key()"
Returns one key read from input (this is the named key, not the char when mapped).
"do_key($key)"
Execute a key, calls subroutine for a key binding or the default binding. If $key is undefined "read_key()" is called first.
"press($string)"
Do chars in $string like they were typed on the keyboard. Used for testing puposes and to make macros possible.
If you give more then one argument, these are considered individual characters, use this to press named keys.
"unread_key($string)"
Unshifts characters on the read buffer, arguments the same as "press()".
"key_name($chr)"
Returns a name for a character or character sequence.
"key_binding($key, $mode)"
Returns the keybinding for $key in $mode, mode defaults to the current one.
"bindchr($chr, $key)"
Bind a key name to a character, or a character sequence. All bindings of this kind are global (you're using only one keyboard, right
?).
"recalc_chr_map()"
Recalculates the chr map, you need to call this after deleting from %chr_names.
"print($lines, $pos)"
Low level function used by draw. Both arguments need to be array references.
BUGS
Undefined behaviour when the buffer has more lines then the terminal.
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
perl v5.8.7 2005-08-07 Term::ReadLine::Zoid::Base(3pm)
Check Out this Related Man Page
Term::ReadLine(3pm) Perl Programmers Reference Guide Term::ReadLine(3pm)NAME
Term::ReadLine - Perl interface to various "readline" packages. If no real package is found, substitutes stubs instead of basic functions.
SYNOPSIS
use Term::ReadLine;
my $term = Term::ReadLine->new('Simple Perl calc');
my $prompt = "Enter your arithmetic expression: ";
my $OUT = $term->OUT || *STDOUT;
while ( defined ($_ = $term->readline($prompt)) ) {
my $res = eval($_);
warn $@ if $@;
print $OUT $res, "
" unless $@;
$term->addhistory($_) if /S/;
}
DESCRIPTION
This package is just a front end to some other packages. It's a stub to set up a common interface to the various ReadLine implementations
found on CPAN (under the "Term::ReadLine::*" namespace).
Minimal set of supported functions
All the supported functions should be called as methods, i.e., either as
$term = Term::ReadLine->new('name');
or as
$term->addhistory('row');
where $term is a return value of Term::ReadLine->new().
"ReadLine" returns the actual package that executes the commands. Among possible values are "Term::ReadLine::Gnu", "Term::ReadLine::Perl",
"Term::ReadLine::Stub".
"new" returns the handle for subsequent calls to following functions. Argument is the name of the application. Optionally can be
followed by two arguments for "IN" and "OUT" filehandles. These arguments should be globs.
"readline" gets an input line, possibly with actual "readline" support. Trailing newline is removed. Returns "undef" on "EOF".
"addhistory"
adds the line to the history of input, from where it can be used if the actual "readline" is present.
"IN", "OUT" return the filehandles for input and output or "undef" if "readline" input and output cannot be used for Perl.
"MinLine" If argument is specified, it is an advice on minimal size of line to be included into history. "undef" means do not include
anything into history. Returns the old value.
"findConsole"
returns an array with two strings that give most appropriate names for files for input and output using conventions "<$in",
">out".
Attribs returns a reference to a hash which describes internal configuration of the package. Names of keys in this hash conform to
standard conventions with the leading "rl_" stripped.
"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.
If "Features" method reports a feature "attribs" as present, the method "Attribs" is not dummy.
Additional supported functions
Actually "Term::ReadLine" can use some other package, that will support a richer set of commands.
All these commands are callable via method interface and have names which conform to standard conventions with the leading "rl_" stripped.
The stub package included with the perl distribution allows some additional methods:
"tkRunning" makes Tk event loop run when waiting for user input (i.e., during "readline" method).
"event_loop"
Registers call-backs to wait for user input (i.e., during "readline" method). This supersedes tkRunning.
The first call-back registered is the call back for waiting. It is expected that the callback will call the current event loop
until there is something waiting to get on the input filehandle. The parameter passed in is the return value of the second
call back.
The second call-back registered is the call back for registration. The input filehandle (often STDIN, but not necessarily)
will be passed in.
For example, with AnyEvent:
$term->event_loop(sub {
my $data = shift;
$data->[1] = AE::cv();
$data->[1]->recv();
}, sub {
my $fh = shift;
my $data = [];
$data->[0] = AE::io($fh, 0, sub { $data->[1]->send() });
$data;
});
The second call-back is optional if the call back is registered prior to the call to $term->readline.
Deregistration is done in this case by calling event_loop with "undef" as its parameter:
$term->event_loop(undef);
This will cause the data array ref to be removed, allowing normal garbage collection to clean it up. With AnyEvent, that will
cause $data->[0] to be cleaned up, and AnyEvent will automatically cancel the watcher at that time. If another loop requires
more than that to clean up a file watcher, that will be up to the caller to handle.
"ornaments" makes the command line stand out by using termcap data. The argument to "ornaments" should be 0, 1, or a string of a form
"aa,bb,cc,dd". Four components of this string should be names of terminal capacities, first two will be issued to make the
prompt standout, last two to make the input line standout.
"newTTY" takes two arguments which are input filehandle and output filehandle. Switches to use these filehandles.
One can check whether the currently loaded ReadLine package supports these methods by checking for corresponding "Features".
EXPORTS
None
ENVIRONMENT
The environment variable "PERL_RL" governs which ReadLine clone is loaded. If the value is false, a dummy interface is used. If the value
is true, it should be tail of the name of the package to use, such as "Perl" or "Gnu".
As a special case, if the value of this variable is space-separated, the tail might be used to disable the ornaments by setting the tail to
be "o=0" or "ornaments=0". The head should be as described above, say
If the variable is not set, or if the head of space-separated list is empty, the best available package is loaded.
export "PERL_RL=Perl o=0" # Use Perl ReadLine sans ornaments
export "PERL_RL= o=0" # Use best available ReadLine sans ornaments
(Note that processing of "PERL_RL" for ornaments is in the discretion of the particular used "Term::ReadLine::*" package).
perl v5.18.2 2014-01-06 Term::ReadLine(3pm)