README
1$Id$
2
3zlib 1.2.3 is a general purpose data compression library.
4All the code is thread safe. The data format used by the zlib library
5is described by RFCs (Request for Comments) 1950 to 1952 in the files
6ftp://ds.internic.net/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
7format) and rfc1952.txt (gzip format). These documents are also available in
8other formats from ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
9
10All functions of the compression library are documented in the file zlib.h
11(volunteer to write man pages welcome, contact jloup@gzip.org). A usage
12example of the library is given in the file example.c which also tests that
13the library is working correctly. Another example is given in the file
14minigzip.c. The compression library itself is composed of all source files
15except example.c and minigzip.c.
16
17To compile all files and run the test program, follow the instructions
18given at the top of Makefile. In short "make test; make install"
19should work for most machines. For Unix: "configure; make test; make install"
20For MSDOS, use one of the special makefiles such as Makefile.msc.
21For VMS, use Make_vms.com or descrip.mms.
22
23Questions about zlib should be sent to <zlib@quest.jpl.nasa.gov>, or to
24Gilles Vollant <info@winimage.com> for the Windows DLL version.
25The zlib home page is http://www.cdrom.com/pub/infozip/zlib/
26The official zlib ftp site is ftp://ftp.cdrom.com/pub/infozip/zlib/
27Before reporting a problem, please check those sites to verify that
28you have the latest version of zlib; otherwise get the latest version and
29check whether the problem still exists or not.
30
31Mark Nelson <markn@tiny.com> wrote an article about zlib for the Jan. 1997
32issue of Dr. Dobb's Journal; a copy of the article is available in
33http://web2.airmail.net/markn/articles/zlibtool/zlibtool.htm
34
35The changes made in version 1.1.3 are documented in the file ChangeLog.
36The main changes since 1.1.2 are:
37
38- fix "an inflate input buffer bug that shows up on rare but persistent
39 occasions" (Mark)
40- fix gzread and gztell for concatenated .gz files (Didier Le Botlan)
41- fix gzseek(..., SEEK_SET) in write mode
42- fix crc check after a gzeek (Frank Faubert)
43- fix miniunzip when the last entry in a zip file is itself a zip file
44 (J Lillge)
45- add contrib/asm586 and contrib/asm686 (Brian Raiter)
46 See http://www.muppetlabs.com/~breadbox/software/assembly.html
47- add support for Delphi 3 in contrib/delphi (Bob Dellaca)
48- add support for C++Builder 3 and Delphi 3 in contrib/delphi2 (Davide Moretti)
49- do not exit prematurely in untgz if 0 at start of block (Magnus Holmgren)
50- use macro EXTERN instead of extern to support DLL for BeOS (Sander Stoks)
51- added a FAQ file
52
53plus many changes for portability.
54
55Unsupported third party contributions are provided in directory "contrib".
56
57A Java implementation of zlib is available in the Java Development Kit 1.1
58http://www.javasoft.com/products/JDK/1.1/docs/api/Package-java.util.zip.html
59See the zlib home page http://www.cdrom.com/pub/infozip/zlib/ for details.
60
61A Perl interface to zlib written by Paul Marquess <pmarquess@bfsec.bt.co.uk>
62is in the CPAN (Comprehensive Perl Archive Network) sites, such as:
63ftp://ftp.cis.ufl.edu/pub/perl/CPAN/modules/by-module/Compress/Compress-Zlib*
64
65A Python interface to zlib written by A.M. Kuchling <amk@magnet.com>
66is available in Python 1.5 and later versions, see
67http://www.python.org/doc/lib/module-zlib.html
68
69A zlib binding for TCL written by Andreas Kupries <a.kupries@westend.com>
70is available at http://www.westend.com/~kupries/doc/trf/man/man.html
71
72An experimental package to read and write files in .zip format,
73written on top of zlib by Gilles Vollant <info@winimage.com>, is
74available at http://www.winimage.com/zLibDll/unzip.html
75and also in the contrib/minizip directory of zlib.
76
77
78Notes for some targets:
79
80- To build a Windows DLL version, include in a DLL project zlib.def, zlib.rc
81 and all .c files except example.c and minigzip.c; compile with -DZLIB_DLL
82 The zlib DLL support was initially done by Alessandro Iacopetti and is
83 now maintained by Gilles Vollant <info@winimage.com>. Check the zlib DLL
84 home page at http://www.winimage.com/zLibDll
85
86 From Visual Basic, you can call the DLL functions which do not take
87 a structure as argument: compress, uncompress and all gz* functions.
88 See contrib/visual-basic.txt for more information, or get
89 http://www.tcfb.com/dowseware/cmp-z-it.zip
90
91- For 64-bit Irix, deflate.c must be compiled without any optimization.
92 With -O, one libpng test fails. The test works in 32 bit mode (with
93 the -n32 compiler flag). The compiler bug has been reported to SGI.
94
95- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1
96 it works when compiled with cc.
97
98- on Digital Unix 4.0D (formerly OSF/1) on AlphaServer, the cc option -std1
99 is necessary to get gzprintf working correctly. This is done by configure.
100
101- zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works
102 with other compilers. Use "make test" to check your compiler.
103
104- gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
105
106- For Turbo C the small model is supported only with reduced performance to
107 avoid any far allocation; it was tested with -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
108
109- For PalmOs, see http://www.cs.uit.no/~perm/PASTA/pilot/software.html
110 Per Harald Myrvang <perm@stud.cs.uit.no>
111
112
113Acknowledgments:
114
115 The deflate format used by zlib was defined by Phil Katz. The deflate
116 and zlib specifications were written by L. Peter Deutsch. Thanks to all the
117 people who reported problems and suggested various improvements in zlib;
118 they are too numerous to cite here.
119
120Copyright notice:
121
122 (C) 1995-1998 Jean-loup Gailly and Mark Adler
123
124 This software is provided 'as-is', without any express or implied
125 warranty. In no event will the authors be held liable for any damages
126 arising from the use of this software.
127
128 Permission is granted to anyone to use this software for any purpose,
129 including commercial applications, and to alter it and redistribute it
130 freely, subject to the following restrictions:
131
132 1. The origin of this software must not be misrepresented; you must not
133 claim that you wrote the original software. If you use this software
134 in a product, an acknowledgment in the product documentation would be
135 appreciated but is not required.
136 2. Altered source versions must be plainly marked as such, and must not be
137 misrepresented as being the original software.
138 3. This notice may not be removed or altered from any source distribution.
139
140 Jean-loup Gailly Mark Adler
141 jloup@gzip.org madler@alumni.caltech.edu
142
143If you use the zlib library in a product, we would appreciate *not*
144receiving lengthy legal documents to sign. The sources are provided
145for free but without warranty of any kind. The library has been
146entirely written by Jean-loup Gailly and Mark Adler; it does not
147include third-party code.
148
149If you redistribute modified sources, we would appreciate that you include
150in the file ChangeLog history information documenting your changes.
151