README
1zlib 1.1.3 is a general purpose data compression library. All the code
2is thread safe. The data format used by the zlib library
3is described by RFCs (Request for Comments) 1950 to 1952 in the files
4ftp://ds.internic.net/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
5format) and rfc1952.txt (gzip format). These documents are also available in
6other formats from ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
7
8All functions of the compression library are documented in the file zlib.h
9(volunteer to write man pages welcome, contact jloup@gzip.org). A usage
10example of the library is given in the file example.c which also tests that
11the library is working correctly. Another example is given in the file
12minigzip.c. The compression library itself is composed of all source files
13except example.c and minigzip.c.
14
15To compile all files and run the test program, follow the instructions
16given at the top of Makefile. In short "make test; make install"
17should work for most machines. For Unix: "configure; make test; make install"
18For MSDOS, use one of the special makefiles such as Makefile.msc.
19For VMS, use Make_vms.com or descrip.mms.
20
21Questions about zlib should be sent to <zlib@quest.jpl.nasa.gov>, or to
22Gilles Vollant <info@winimage.com> for the Windows DLL version.
23The zlib home page is http://www.cdrom.com/pub/infozip/zlib/
24The official zlib ftp site is ftp://ftp.cdrom.com/pub/infozip/zlib/
25Before reporting a problem, please check those sites to verify that
26you have the latest version of zlib; otherwise get the latest version and
27check whether the problem still exists or not.
28
29Mark Nelson <markn@tiny.com> wrote an article about zlib for the Jan. 1997
30issue of Dr. Dobb's Journal; a copy of the article is available in
31http://web2.airmail.net/markn/articles/zlibtool/zlibtool.htm
32
33The changes made in version 1.1.3 are documented in the file ChangeLog.
34The main changes since 1.1.2 are:
35
36- fix "an inflate input buffer bug that shows up on rare but persistent
37 occasions" (Mark)
38- fix gzread and gztell for concatenated .gz files (Didier Le Botlan)
39- fix gzseek(..., SEEK_SET) in write mode
40- fix crc check after a gzeek (Frank Faubert)
41- fix miniunzip when the last entry in a zip file is itself a zip file
42 (J Lillge)
43- add contrib/asm586 and contrib/asm686 (Brian Raiter)
44 See http://www.muppetlabs.com/~breadbox/software/assembly.html
45- add support for Delphi 3 in contrib/delphi (Bob Dellaca)
46- add support for C++Builder 3 and Delphi 3 in contrib/delphi2 (Davide Moretti)
47- do not exit prematurely in untgz if 0 at start of block (Magnus Holmgren)
48- use macro EXTERN instead of extern to support DLL for BeOS (Sander Stoks)
49- added a FAQ file
50
51plus many changes for portability.
52
53Unsupported third party contributions are provided in directory "contrib".
54
55A Java implementation of zlib is available in the Java Development Kit 1.1
56http://www.javasoft.com/products/JDK/1.1/docs/api/Package-java.util.zip.html
57See the zlib home page http://www.cdrom.com/pub/infozip/zlib/ for details.
58
59A Perl interface to zlib written by Paul Marquess <pmarquess@bfsec.bt.co.uk>
60is in the CPAN (Comprehensive Perl Archive Network) sites, such as:
61ftp://ftp.cis.ufl.edu/pub/perl/CPAN/modules/by-module/Compress/Compress-Zlib*
62
63A Python interface to zlib written by A.M. Kuchling <amk@magnet.com>
64is available in Python 1.5 and later versions, see
65http://www.python.org/doc/lib/module-zlib.html
66
67A zlib binding for TCL written by Andreas Kupries <a.kupries@westend.com>
68is availlable at http://www.westend.com/~kupries/doc/trf/man/man.html
69
70An experimental package to read and write files in .zip format,
71written on top of zlib by Gilles Vollant <info@winimage.com>, is
72available at http://www.winimage.com/zLibDll/unzip.html
73and also in the contrib/minizip directory of zlib.
74
75
76Notes for some targets:
77
78- To build a Windows DLL version, include in a DLL project zlib.def, zlib.rc
79 and all .c files except example.c and minigzip.c; compile with -DZLIB_DLL
80 The zlib DLL support was initially done by Alessandro Iacopetti and is
81 now maintained by Gilles Vollant <info@winimage.com>. Check the zlib DLL
82 home page at http://www.winimage.com/zLibDll
83
84 From Visual Basic, you can call the DLL functions which do not take
85 a structure as argument: compress, uncompress and all gz* functions.
86 See contrib/visual-basic.txt for more information, or get
87 http://www.tcfb.com/dowseware/cmp-z-it.zip
88
89- For 64-bit Irix, deflate.c must be compiled without any optimization.
90 With -O, one libpng test fails. The test works in 32 bit mode (with
91 the -n32 compiler flag). The compiler bug has been reported to SGI.
92
93- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1
94 it works when compiled with cc.
95
96- on Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1
97 is necessary to get gzprintf working correctly. This is done by configure.
98
99- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works
100 with other compilers. Use "make test" to check your compiler.
101
102- gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
103
104- For Turbo C the small model is supported only with reduced performance to
105 avoid any far allocation; it was tested with -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
106
107- For PalmOs, see http://www.cs.uit.no/~perm/PASTA/pilot/software.html
108 Per Harald Myrvang <perm@stud.cs.uit.no>
109
110
111Acknowledgments:
112
113 The deflate format used by zlib was defined by Phil Katz. The deflate
114 and zlib specifications were written by L. Peter Deutsch. Thanks to all the
115 people who reported problems and suggested various improvements in zlib;
116 they are too numerous to cite here.
117
118Copyright notice:
119
120 (C) 1995-1998 Jean-loup Gailly and Mark Adler
121
122 This software is provided 'as-is', without any express or implied
123 warranty. In no event will the authors be held liable for any damages
124 arising from the use of this software.
125
126 Permission is granted to anyone to use this software for any purpose,
127 including commercial applications, and to alter it and redistribute it
128 freely, subject to the following restrictions:
129
130 1. The origin of this software must not be misrepresented; you must not
131 claim that you wrote the original software. If you use this software
132 in a product, an acknowledgment in the product documentation would be
133 appreciated but is not required.
134 2. Altered source versions must be plainly marked as such, and must not be
135 misrepresented as being the original software.
136 3. This notice may not be removed or altered from any source distribution.
137
138 Jean-loup Gailly Mark Adler
139 jloup@gzip.org madler@alumni.caltech.edu
140
141If you use the zlib library in a product, we would appreciate *not*
142receiving lengthy legal documents to sign. The sources are provided
143for free but without warranty of any kind. The library has been
144entirely written by Jean-loup Gailly and Mark Adler; it does not
145include third-party code.
146
147If you redistribute modified sources, we would appreciate that you include
148in the file ChangeLog history information documenting your changes.
149