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   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 compres-
       sion 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 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  exam-
       ples  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.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  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/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/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; other-
       wise,  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  soft-
       ware.   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 sug-
       gested 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)