1 ZLIB DATA COMPRESSION LIBRARY
3 zlib 1.2.11 is a general purpose data compression library. All the code is
4 thread safe. The data format used by the zlib library is described by RFCs
5 (Request for Comments) 1950 to 1952 in the files
6 http://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) and
9 All functions of the compression library are documented in the file zlib.h
10 (volunteer to write man pages welcome, contact zlib@gzip.org). A usage example
11 of the library is given in the file test/example.c which also tests that
12 the library is working correctly. Another example is given in the file
13 test/minigzip.c. The compression library itself is composed of all source
14 files in the root directory.
16 To compile all files and run the test program, follow the instructions given at
17 the top of Makefile.in. In short "./configure; make test", and if that goes
18 well, "make install" should work for most flavors of Unix. For Windows, use
19 one of the special makefiles in win32/ or contrib/vstudio/ . For VMS, use
22 Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant
23 <info@winimage.com> for the Windows DLL version. The zlib home page is
24 http://zlib.net/ . Before reporting a problem, please check this site to
25 verify that you have the latest version of zlib; otherwise get the latest
26 version and check whether the problem still exists or not.
28 PLEASE read the zlib FAQ http://zlib.net/zlib_faq.html before asking for help.
30 Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan. 1997
31 issue of Dr. Dobb's Journal; a copy of the article is available at
32 http://marknelson.us/1997/01/01/zlib-engine/ .
34 The changes made in version 1.2.11 are documented in the file ChangeLog.
36 Unsupported third party contributions are provided in directory contrib/ .
38 zlib is available in Java using the java.util.zip package, documented at
39 http://java.sun.com/developer/technicalArticles/Programming/compression/ .
41 A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is available
42 at CPAN (Comprehensive Perl Archive Network) sites, including
43 http://search.cpan.org/~pmqs/IO-Compress-Zlib/ .
45 A Python interface to zlib written by A.M. Kuchling <amk@amk.ca> is
46 available in Python 1.5 and later versions, see
47 http://docs.python.org/library/zlib.html .
49 zlib is built into tcl: http://wiki.tcl.tk/4610 .
51 An experimental package to read and write files in .zip format, written on top
52 of zlib by Gilles Vollant <info@winimage.com>, is available in the
53 contrib/minizip directory of zlib.
56 Notes for some targets:
58 - For Windows DLL versions, please see win32/DLL_FAQ.txt
60 - For 64-bit Irix, deflate.c must be compiled without any optimization. With
61 -O, one libpng test fails. The test works in 32 bit mode (with the -n32
62 compiler flag). The compiler bug has been reported to SGI.
64 - zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
65 when compiled with cc.
67 - On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
68 necessary to get gzprintf working correctly. This is done by configure.
70 - zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
71 other compilers. Use "make test" to check your compiler.
73 - gzdopen is not supported on RISCOS or BEOS.
75 - For PalmOs, see http://palmzlib.sourceforge.net/
80 The deflate format used by zlib was defined by Phil Katz. The deflate and
81 zlib specifications were written by L. Peter Deutsch. Thanks to all the
82 people who reported problems and suggested various improvements in zlib; they
83 are too numerous to cite here.
87 (C) 1995-2017 Jean-loup Gailly and Mark Adler
89 This software is provided 'as-is', without any express or implied
90 warranty. In no event will the authors be held liable for any damages
91 arising from the use of this software.
93 Permission is granted to anyone to use this software for any purpose,
94 including commercial applications, and to alter it and redistribute it
95 freely, subject to the following restrictions:
97 1. The origin of this software must not be misrepresented; you must not
98 claim that you wrote the original software. If you use this software
99 in a product, an acknowledgment in the product documentation would be
100 appreciated but is not required.
101 2. Altered source versions must be plainly marked as such, and must not be
102 misrepresented as being the original software.
103 3. This notice may not be removed or altered from any source distribution.
105 Jean-loup Gailly Mark Adler
106 jloup@gzip.org madler@alumni.caltech.edu
108 If you use the zlib library in a product, we would appreciate *not* receiving
109 lengthy legal documents to sign. The sources are provided for free but without
110 warranty of any kind. The library has been entirely written by Jean-loup
111 Gailly and Mark Adler; it does not include third-party code.
113 If you redistribute modified sources, we would appreciate that you include in
114 the file ChangeLog history information documenting your changes. Please read
115 the FAQ for more information on the distribution of modified source versions.