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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 pro-vides provides
       vides in-memory compression and decompression functions, including integrity  checks  of  the  uncom-pressed uncompressed
       pressed 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  (providing  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  com-pressed compressed
       pressed 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 (Comprehen-
       sive Perl Archive Network) sites, including:

              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@westend.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, written on top of zlib by Gilles Vol-
       lant (info@winimage.com), is available at:

              http://www.winimage.com/zLibDll/unzip.html and also in the contrib/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 Jour-
       nal; 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  1.2.3  Copyright  (C)  1995-2005  Jean-loup   Gailly   (jloup@gzip.org)   and   Mark   Adler
       (madler@alumni.caltech.edu).

       This  software  is  provided  "as-is," without any express or implied warranty.  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).



                                                18 July 2005                                         ZLIB(3)