zlib

ZLIB(3)								      ZLIB(3)



NAME
       zlib - compression/decompression library

SYNOPSIS
       [see zlib.h for full description]

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
       1.1:

	      http://www.javasoft.com/products/JDK/1.1/docs/api/Package-
	      java.util.zip.html

       A Perl interface to zlib, written by Paul Marquess (pmqs@cpan.org), is
       available at CPAN (Comprehensive Perl Archive Network) sites,  includ-
       ing:

	      http://www.cpan.org/modules/by-module/Compress/

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

	      http://www.python.org/doc/lib/module-zlib.html

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

	      http://www.westend.com/~kupries/doc/trf/man/man.html

       An  experimental package to read and write files in .zip format, writ-
       ten on top of zlib by Gilles Vollant (info@winimage.com), is available
       at:

	      http://www.winimage.com/zLibDll/unzip.html and also in the con-
	      trib/minizip directory of the main zlib web site.

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

	      http://www.zlib.org
	      http://www.gzip.org/zlib/

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

	      http://www.ietf.org/rfc/rfc1950.txt (concerning zlib format)
	      http://www.ietf.org/rfc/rfc1951.txt (concerning deflate format)
	      http://www.ietf.org/rfc/rfc1952.txt (concerning gzip format)

       These documents are also available in other formats from:

	      ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html

       Mark Nelson (markn@ieee.org) wrote an article about zlib for the	 Jan.
       1997  issue of  Dr. Dobb’s Journal; a copy of the article is available
       at:

	      http://dogma.net/markn/articles/zlibtool/zlibtool.htm

REPORTING PROBLEMS
       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
       at:

	      http://www.gzip.org/zlib/zlib_faq.html

       before	asking	 for   help.	Send  questions	 and/or	 comments  to
       zlib@gzip.org, or (for the Windows  DLL	version)  to  Gilles  Vollant
       (info@winimage.com).

AUTHORS
       Version	  1.2.1.2    Copyright	 (C)   1995-2004   Jean-loup   Gailly
       (jloup@gzip.org) and Mark Adler (madler@alumni.caltech.edu).

       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 (rodgers@nlm.nih.gov).



			       9 September 2004			      ZLIB(3)