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ZLIB(3)								       ZLIB(3)

       zlib - compression/decompression	library

       [see zlib.h for full description]

       The  zlib  library  is a	general	purpose	data compression library.  The
       code is thread safe.  It	provides in-memory compression and  decompres-
       sion  functions,	 including  integrity checks of	the uncompressed data.
       This version of	the  library  supports	only  one  compression	method
       (deflation)  but	other algorithms will be added later and will have the
       same stream interface.

       Compression can be done in a single  step  if  the  buffers  are	 large
       enough  (for  example  if  an input file	is mmap'ed), or	can be done by
       repeated	calls of the compression function.  In the  latter  case,  the
       application  must provide more input and/or consume the output (provid-
       ing more	output space) before each call.

       The library also	supports reading and writing files  in	gzip(1)	 (.gz)
       format with an interface	similar	to that	of stdio.

       The  library  does  not install any signal handler.  The	decoder	checks
       the consistency of the compressed data, so  the	library	 should	 never
       crash even in case of corrupted input.

       All  functions  of  the	compression library are	documented in the file
       zlib.h.	The distribution  source  includes  examples  of  use  of  the
       library in the files example.c and minigzip.c.

       Changes	to  this  version  are	documented  in the file	ChangeLog that
       accompanies the source, and are concerned primarily with	bug fixes  and
       portability enhancements.

       A  Java implementation of zlib is available in the Java Development Kit

       A  Perl interface to zlib, written by Paul Marquess (, is
       available at CPAN (Comprehensive	Perl Archive Network)  sites,  includ-

       A  Python interface to zlib, written by A.M. Kuchling (,
       is available in Python 1.5 and later versions:

       A zlib binding for tcl(1), written by Andreas Kupries  (a.kupries@west-, is availlable at:

       An experimental package to read and write files in .zip format, written
       on top of zlib by Gilles	Vollant	(, is	available at: and also in the  con-
	      trib/minizip directory of	the main zlib web site.

       The zlib	web site can be	found at either	of these locations:

       The  data  format used by the zlib library is described by RFC (Request
       for Comments) 1950 to 1952 in the files: (concerning zlib format) (concerning deflate format) (concerning gzip format)

       These documents are also	available in other formats from:

       Mark Nelson ( wrote an article about zlib	for  the  Jan.
       1997  issue  of	Dr. Dobb's Journal; a copy of the article is available

       Before reporting	a problem, please check	the zlib web  site  to	verify
       that  you have the latest version of zlib; otherwise, obtain the	latest
       version and see if the problem still exists.  Please read the zlib  FAQ

       before	asking	 for   help.	Send   questions  and/or  comments  to, or (for the  Windows  DLL	 version)  to  Gilles  Vollant

       Version 1.2.3 Copyright (C) 1995-2005 Jean-loup Gailly (
       and Mark	Adler (

       This software is	provided "as-is," without any express or implied  war-
       ranty.	In  no	event  will the	authors	be held	liable for any damages
       arising from the	use of this software.  See the distribution  directory
       with  respect  to  requirements	governing redistribution.  The deflate
       format used by zlib was defined by Phil Katz.   The  deflate  and  zlib
       specifications  were  written  by  L. Peter Deutsch.  Thanks to all the
       people who reported problems  and  suggested  various  improvements  in
       zlib; who are too numerous to cite here.

       UNIX manual page	by R. P. C. Rodgers, U.S. National Library of Medicine

				 18 July 2005			       ZLIB(3)


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