ReadKey(3)						User Contributed Perl Documentation						ReadKey(3)

NAME

       Term::ReadKey - A perl module for simple terminal control

SYNOPSIS

	       use Term::ReadKey;
	       ReadMode 4; # Turn off controls keys
	       while (not defined ($key = ReadKey(-1))) {
		       # No key yet
	       }
	       print "Get key $key
";
	       ReadMode 0; # Reset tty mode before exiting

DESCRIPTION

       Term::ReadKey is a compiled perl module dedicated to providing simple control over terminal driver modes (cbreak, raw, cooked, etc.,)
       support for non-blocking reads, if the architecture allows, and some generalized handy functions for working with terminals. One of the
       main goals is to have the functions as portable as possible, so you can just plug in "use Term::ReadKey" on any architecture and have a
       good likelihood of it working.

       Version 2.30.01: Added handling of arrows, page up/down, home/end, insert/delete keys under Win32. These keys emit xterm-compatible
       sequences.  Works with Term::ReadLine::Perl.

       ReadMode MODE [, Filehandle]
	       Takes an integer argument, which can currently be one of the following values:

		   0	Restore original settings.
		   1	Change to cooked mode.
		   2	Change to cooked mode with echo off.
			 (Good for passwords)
		   3	Change to cbreak mode.
		   4	Change to raw mode.
		   5	Change to ultra-raw mode.
			 (LF to CR/LF translation turned off)

		   Or, you may use the synonyms:

		   restore
		   normal
		   noecho
		   cbreak
		   raw
		   ultra-raw

	       These functions are automatically applied to the STDIN handle if no other handle is supplied. Modes 0 and 5 have some special
	       properties worth mentioning: not only will mode 0 restore original settings, but it cause the next ReadMode call to save a new set
	       of default settings. Mode 5 is similar to mode 4, except no CR/LF translation is performed, and if possible, parity will be
	       disabled (only if not being used by the terminal, however. It is no different from mode 4 under Windows.)

	       If you are executing another program that may be changing the terminal mode, you will either want to say

		   ReadMode 1
		   system('someprogram');
		   ReadMode 1;

	       which resets the settings after the program has run, or:

		   $somemode=1;
		   ReadMode 0;
		   system('someprogram');
		   ReadMode 1;

	       which records any changes the program may have made, before resetting the mode.

       ReadKey MODE [, Filehandle]
	       Takes an integer argument, which can currently be one of the following values:

		   0	Perform a normal read using getc
		   -1	Perform a non-blocked read
		   >0	Perform a timed read

	       (If the filehandle is not supplied, it will default to STDIN.) If there is nothing waiting in the buffer during a non-blocked read,
	       then undef will be returned. Note that if the OS does not provide any known mechanism for non-blocking reads, then a "ReadKey -1"
	       can die with a fatal error. This will hopefully not be common.

	       If MODE is greater then zero, then ReadKey will use it as a timeout value in seconds (fractional seconds are allowed), and won't
	       return "undef" until that time expires. (Note, again, that some OS's may not support this timeout behaviour.) If MODE is less then
	       zero, then this is treated as a timeout of zero, and thus will return immediately if no character is waiting. A MODE of zero,
	       however, will act like a normal getc.

	       There are currently some limitations with this call under Windows. It may be possible that non-blocking reads will fail when
	       reading repeating keys from more then one console.

       ReadLine MODE [, Filehandle]
	       Takes an integer argument, which can currently be one of the following values:

		   0	Perform a normal read using scalar(<FileHandle>)
		   -1	Perform a non-blocked read
		   >0	Perform a timed read

	       If there is nothing waiting in the buffer during a non-blocked read, then undef will be returned. Note that if the OS does not
	       provide any known mechanism for non-blocking reads, then a "ReadLine 1" can die with a fatal error. This will hopefully not be
	       common. Note that a non-blocking test is only performed for the first character in the line, not the entire line.  This call will
	       probably not do what you assume, especially with ReadMode's higher then 1. For example, pressing Space and then Backspace would
	       appear to leave you where you started, but any timeouts would now be suspended.

	       This call is currently not available under Windows.

       GetTerminalSize [Filehandle]
	       Returns either an empty array if this operation is unsupported, or a four element array containing: the width of the terminal in
	       characters, the height of the terminal in character, the width in pixels, and the height in pixels. (The pixel size will only be
	       valid in some environments.)

	       Under Windows, this function must be called with an "output" filehandle, such as STDOUT, or a handle opened to CONOUT$.

       SetTerminalSize WIDTH,HEIGHT,XPIX,YPIX [, Filehandle]
	       Return -1 on failure, 0 otherwise. Note that this terminal size is only for informative value, and changing the size via this
	       mechanism will not change the size of the screen. For example, XTerm uses a call like this when it resizes the screen. If any of
	       the new measurements vary from the old, the OS will probably send a SIGWINCH signal to anything reading that tty or pty.

	       This call does not work under Windows.

       GetSpeeds [, Filehandle]
	       Returns either an empty array if the operation is unsupported, or a two value array containing the terminal in and out speeds, in
	       decimal. E.g, an in speed of 9600 baud and an out speed of 4800 baud would be returned as (9600,4800). Note that currently the in
	       and out speeds will always be identical in some OS's. No speeds are reported under Windows.

       GetControlChars [, Filehandle]
	       Returns an array containing key/value pairs suitable for a hash. The pairs consist of a key, the name of the control
	       character/signal, and the value of that character, as a single character. This call does nothing under Windows.

	       Each key will be an entry from the following list:

		       DISCARD
		       DSUSPEND
		       EOF
		       EOL
		       EOL2
		       ERASE
		       ERASEWORD
		       INTERRUPT
		       KILL
		       MIN
		       QUIT
		       QUOTENEXT
		       REPRINT
		       START
		       STATUS
		       STOP
		       SUSPEND
		       SWITCH
		       TIME

	       Thus, the following will always return the current interrupt character, regardless of platform.

		       %keys = GetControlChars;
		       $int = $keys{INTERRUPT};

       SetControlChars [, Filehandle]
	       Takes an array containing key/value pairs, as a hash will produce. The pairs should consist of a key that is the name of a legal
	       control character/signal, and the value should be either a single character, or a number in the range 0-255. SetControlChars will
	       die with a runtime error if an invalid character name is passed or there is an error changing the settings. The list of valid names
	       is easily available via

		       %cchars = GetControlChars();
		       @cnames = keys %cchars;

	       This call does nothing under Windows.

AUTHOR

       Kenneth Albanowski <kjahds@kjahds.com>

       Currently maintained by Jonathan Stowe <jns@gellyfish.co.uk>

       SUPPORT
	   The code is maintained at

		https://github.com/jonathanstowe/TermReadKey

	   Please feel free to fork and suggest patches.

       LICENSE
	   Prior to the 2.31 release the license statement was:

	    Copyright (C) 1994-1999 Kenneth Albanowski.
			   2001-2005 Jonathan Stowe and others

			    Unlimited distribution and/or modification is allowed as long as this
			     copyright notice remains intact.

	   And was only stated in the README file.

	   Because I believe the original author's intent was to be more open than the other commonly used licenses I would like to leave that in
	   place. However if you or your lawyers require something with some more words you can optionally choose to license this under the
	   standard Perl license:

		 This module is free software; you can redistribute it and/or modify it
		 under the terms of the Artistic License. For details, see the full
		 text of the license in the file "Artistic" that should have been provided
		 with the version of perl you are using.

		 This program is distributed in the hope that it will be useful, but
		 without any warranty; without even the implied warranty of merchantability
		 or fitness for a particular purpose.

POD ERRORS

       Hey! The above document had some coding errors, which are explained below:

       Around line 213:
	   '=item' outside of any '=over'

	   =over without closing =back

perl v5.18.2							    2013-10-26								ReadKey(3)