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-mem-
       ory  compression  and decompression 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 com-
       pression function.  In the latter case, the  application
       must  provide more input and/or consume the output (pro-
       viding 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  cor-
       rupted 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/prod-
              ucts/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, 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.west-
              end.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  Vollant
       (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  loca-
       tions:

              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/docu-
              ments/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/arti-
              cles/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  1.2.2  Copyright (C) 1995-2004 Jean-loup Gailly
       (jloup@gzip.org)  and  Mark  Adler   (madler@alumni.cal-
       tech.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).



                         3 October 2004                 ZLIB(3)
