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0003 zlib 1.2.3 is a general purpose data compression library.  All the code is
0004 thread safe.  The data format used by the zlib library is described by RFCs
0005 (Request for Comments) 1950 to 1952 in the files
0006 (zlib format), rfc1951.txt (deflate format)
0007 and rfc1952.txt (gzip format). These documents are also available in other
0008 formats from
0010 All functions of the compression library are documented in the file zlib.h
0011 (volunteer to write man pages welcome, contact A usage example
0012 of the library is given in the file example.c which also tests that the library
0013 is working correctly. Another example is given in the file minigzip.c. The
0014 compression library itself is composed of all source files except example.c and
0015 minigzip.c.
0017 To compile all files and run the test program, follow the instructions given at
0018 the top of Makefile. In short "make test; make install" should work for most
0019 machines. For Unix: "./configure; make test; make install". For MSDOS, use one
0020 of the special makefiles such as Makefile.msc. For VMS, use
0022 Questions about zlib should be sent to <>, or to Gilles Vollant
0023 <> for the Windows DLL version. The zlib home page is
0024 or Before reporting a problem,
0025 please check this site to verify that you have the latest version of zlib;
0026 otherwise get the latest version and check whether the problem still exists or
0027 not.
0029 PLEASE read the zlib FAQ before asking
0030 for help.
0032 Mark Nelson <> wrote an article about zlib for the Jan. 1997
0033 issue of  Dr. Dobb's Journal; a copy of the article is available in
0036 The changes made in version 1.2.3 are documented in the file ChangeLog.
0038 Unsupported third party contributions are provided in directory "contrib".
0040 A Java implementation of zlib is available in the Java Development Kit
0042 See the zlib home page for details.
0044 A Perl interface to zlib written by Paul Marquess <> is in the
0045 CPAN (Comprehensive Perl Archive Network) sites
0048 A Python interface to zlib written by A.M. Kuchling <> is
0049 available in Python 1.5 and later versions, see
0052 A zlib binding for TCL written by Andreas Kupries <> is
0053 availlable at
0055 An experimental package to read and write files in .zip format, written on top
0056 of zlib by Gilles Vollant <>, is available in the
0057 contrib/minizip directory of zlib.
0060 Notes for some targets:
0062 - For Windows DLL versions, please see win32/DLL_FAQ.txt
0064 - For 64-bit Irix, deflate.c must be compiled without any optimization. With
0065   -O, one libpng test fails. The test works in 32 bit mode (with the -n32
0066   compiler flag). The compiler bug has been reported to SGI.
0068 - zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
0069   when compiled with cc.
0071 - On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
0072   necessary to get gzprintf working correctly. This is done by configure.
0074 - zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
0075   other compilers. Use "make test" to check your compiler.
0077 - gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
0079 - For PalmOs, see
0081 - When building a shared, i.e. dynamic library on Mac OS X, the library must be
0082   installed before testing (do "make install" before "make test"), since the
0083   library location is specified in the library.
0086 Acknowledgments:
0088   The deflate format used by zlib was defined by Phil Katz. The deflate
0089   and zlib specifications were written by L. Peter Deutsch. Thanks to all the
0090   people who reported problems and suggested various improvements in zlib;
0091   they are too numerous to cite here.
0093 Copyright notice:
0095  (C) 1995-2004 Jean-loup Gailly and Mark Adler
0097   This software is provided 'as-is', without any express or implied
0098   warranty.  In no event will the authors be held liable for any damages
0099   arising from the use of this software.
0101   Permission is granted to anyone to use this software for any purpose,
0102   including commercial applications, and to alter it and redistribute it
0103   freely, subject to the following restrictions:
0105   1. The origin of this software must not be misrepresented; you must not
0106      claim that you wrote the original software. If you use this software
0107      in a product, an acknowledgment in the product documentation would be
0108      appreciated but is not required.
0109   2. Altered source versions must be plainly marked as such, and must not be
0110      misrepresented as being the original software.
0111   3. This notice may not be removed or altered from any source distribution.
0113   Jean-loup Gailly        Mark Adler
0116 If you use the zlib library in a product, we would appreciate *not*
0117 receiving lengthy legal documents to sign. The sources are provided
0118 for free but without warranty of any kind.  The library has been
0119 entirely written by Jean-loup Gailly and Mark Adler; it does not
0120 include third-party code.
0122 If you redistribute modified sources, we would appreciate that you include
0123 in the file ChangeLog history information documenting your changes. Please
0124 read the FAQ for more information on the distribution of modified source
0125 versions.