1 This directory contains the zlib package, which is not part of GCC but
2 shipped with GCC as convenience.
4 ZLIB DATA COMPRESSION LIBRARY
6 zlib 1.2.11 is a general purpose data compression library. All the code is
7 thread safe. The data format used by the zlib library is described by RFCs
8 (Request for Comments) 1950 to 1952 in the files
9 http://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) and
10 rfc1952 (gzip format).
12 All functions of the compression library are documented in the file zlib.h
13 (volunteer to write man pages welcome, contact zlib@gzip.org). A usage example
14 of the library is given in the file test/example.c which also tests that
15 the library is working correctly. Another example is given in the file
16 test/minigzip.c. The compression library itself is composed of all source
17 files in the root directory.
19 To compile all files and run the test program, follow the instructions given at
20 the top of Makefile.in. In short "./configure; make test", and if that goes
21 well, "make install" should work for most flavors of Unix. For Windows, use
22 one of the special makefiles in win32/ or contrib/vstudio/ . For VMS, use
25 Questions about zlib should be sent to <zlib@gzip.org>, or to Gilles Vollant
26 <info@winimage.com> for the Windows DLL version. The zlib home page is
27 http://zlib.net/ . Before reporting a problem, please check this site to
28 verify that you have the latest version of zlib; otherwise get the latest
29 version and check whether the problem still exists or not.
31 PLEASE read the zlib FAQ http://zlib.net/zlib_faq.html before asking for help.
33 Mark Nelson <markn@ieee.org> wrote an article about zlib for the Jan. 1997
34 issue of Dr. Dobb's Journal; a copy of the article is available at
35 http://marknelson.us/1997/01/01/zlib-engine/ .
37 The changes made in version 1.2.11 are documented in the file ChangeLog.
39 Unsupported third party contributions are provided in directory contrib/ .
41 zlib is available in Java using the java.util.zip package, documented at
42 http://java.sun.com/developer/technicalArticles/Programming/compression/ .
44 A Perl interface to zlib written by Paul Marquess <pmqs@cpan.org> is available
45 at CPAN (Comprehensive Perl Archive Network) sites, including
46 http://search.cpan.org/~pmqs/IO-Compress-Zlib/ .
48 A Python interface to zlib written by A.M. Kuchling <amk@amk.ca> is
49 available in Python 1.5 and later versions, see
50 http://docs.python.org/library/zlib.html .
52 zlib is built into tcl: http://wiki.tcl.tk/4610 .
54 An experimental package to read and write files in .zip format, written on top
55 of zlib by Gilles Vollant <info@winimage.com>, is available in the
56 contrib/minizip directory of zlib.
59 Notes for some targets:
61 - For Windows DLL versions, please see win32/DLL_FAQ.txt
63 - For 64-bit Irix, deflate.c must be compiled without any optimization. With
64 -O, one libpng test fails. The test works in 32 bit mode (with the -n32
65 compiler flag). The compiler bug has been reported to SGI.
67 - zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
68 when compiled with cc.
70 - On Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1 is
71 necessary to get gzprintf working correctly. This is done by configure.
73 - zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works with
74 other compilers. Use "make test" to check your compiler.
76 - gzdopen is not supported on RISCOS or BEOS.
78 - For PalmOs, see http://palmzlib.sourceforge.net/
83 The deflate format used by zlib was defined by Phil Katz. The deflate and
84 zlib specifications were written by L. Peter Deutsch. Thanks to all the
85 people who reported problems and suggested various improvements in zlib; they
86 are too numerous to cite here.
90 (C) 1995-2017 Jean-loup Gailly and Mark Adler
92 This software is provided 'as-is', without any express or implied
93 warranty. In no event will the authors be held liable for any damages
94 arising from the use of this software.
96 Permission is granted to anyone to use this software for any purpose,
97 including commercial applications, and to alter it and redistribute it
98 freely, subject to the following restrictions:
100 1. The origin of this software must not be misrepresented; you must not
101 claim that you wrote the original software. If you use this software
102 in a product, an acknowledgment in the product documentation would be
103 appreciated but is not required.
104 2. Altered source versions must be plainly marked as such, and must not be
105 misrepresented as being the original software.
106 3. This notice may not be removed or altered from any source distribution.
108 Jean-loup Gailly Mark Adler
109 jloup@gzip.org madler@alumni.caltech.edu
111 If you use the zlib library in a product, we would appreciate *not* receiving
112 lengthy legal documents to sign. The sources are provided for free but without
113 warranty of any kind. The library has been entirely written by Jean-loup
114 Gailly and Mark Adler; it does not include third-party code.
116 If you redistribute modified sources, we would appreciate that you include in
117 the file ChangeLog history information documenting your changes. Please read
118 the FAQ for more information on the distribution of modified source versions.