src/zlib/README

   1 zlib 1.1.2 is a general purpose data compression library.  All the code
   2 is thread safe.  The data format used by the zlib library
   3 is described by RFCs (Request for Comments) 1950 to 1952 in the files
   4 ftp://ds.internic.net/rfc/rfc1950.txt (zlib format), rfc1951.txt (deflate
   5 format) and rfc1952.txt (gzip format). These documents are also available in
   6 other formats from ftp://ftp.uu.net/graphics/png/documents/zlib/zdoc-index.html
   7
   8 All 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
  10 example of the library is given in the file example.c which also tests that
  11 the library is working correctly. Another example is given in the file
  12 minigzip.c. The compression library itself is composed of all source files
  13 except example.c and minigzip.c.
  14
  15 To compile all files and run the test program, follow the instructions
  16 given at the top of Makefile. In short "make test; make install"
  17 should work for most machines.  For MSDOS, use one of the special
  18 makefiles such as Makefile.msc; for VMS, use Make_vms.com or descrip.mms.
  19
  20 Questions about zlib should be sent to <zlib@quest.jpl.nasa.gov> or,
  21 if this fails, to the addresses given below in the Copyright section.
  22 The zlib home page is http://www.cdrom.com/pub/infozip/zlib/
  23 The official zlib ftp site is ftp://ftp.cdrom.com/pub/infozip/zlib/
  24 Mark Nelson <markn@tiny.com> wrote an article about zlib for the Jan. 1997
  25 issue of  Dr. Dobb's Journal; a copy of the article is available in
  26 http://web2.airmail.net/markn/articles/zlibtool/zlibtool.htm
  27
  28 The changes made in version 1.1.2 are documented in the file ChangeLog.
  29 The main changes since 1.1.1 are:
  30
  31 - added contrib/minzip, mini zip and unzip based on zlib (Gilles Vollant)
  32   See http://www.winimage.com/zLibDll/unzip.html
  33 - preinitialize the inflate tables for fixed codes, to make the code
  34   completely thread safe (Mark)
  35 - some simplifications and slight speed-up to the inflate code (Mark)
  36 - fix gzeof on non-compressed files (Allan Schrum)
  37 - add -std1 option in configure for OSF1 to fix gzprintf (Martin Mokrejs)
  38 - use default value of 4K for Z_BUFSIZE for 16-bit MSDOS (Tim Wegner + Glenn)
  39 - added os2/Makefile.def and os2/zlib.def (Andrew Zabolotny)
  40 - add shared lib support for UNIX_SV4.2MP (MATSUURA Takanori)
  41 - do not wrap extern "C" around system includes (Tom Lane)
  42 - added amiga/Makefile.pup for Amiga powerUP SAS/C PPC (Andreas Kleinert)
  43 - allow "make install prefix=..." even after configure (Glenn Randers-Pehrson)
  44 - allow "configure --prefix $HOME" (Tim Mooney)
  45
  46
  47 Unsupported third party contributions are provided in directory "contrib".
  48
  49 A Java implementation of zlib is available in the Java Development Kit 1.1
  50 http://www.javasoft.com/products/JDK/1.1/docs/api/Package-java.util.zip.html
  51 See the zlib home page http://www.cdrom.com/pub/infozip/zlib/ for details.
  52
  53 A Perl interface to zlib written by Paul Marquess <pmarquess@bfsec.bt.co.uk>
  54 is in the CPAN (Comprehensive Perl Archive Network) sites, such as:
  55 ftp://ftp.cis.ufl.edu/pub/perl/CPAN/modules/by-module/Compress/Compress-Zlib*
  56
  57 A Python interface to zlib written by A.M. Kuchling <amk@magnet.com>
  58 is available from the Python Software Association sites, such as:
  59 ftp://ftp.python.org/pub/python/contrib/Encoding/zlib*.tar.gz
  60
  61 A zlib binding for TCL written by Andreas Kupries <a.kupries@westend.com>
  62 is availlable at http://www.westend.com/~kupries/doc/trf/man/man.html
  63
  64 An experimental package to read and write files in .zip format,
  65 written on top of zlib by Gilles Vollant <info@winimage.com>, is
  66 available at http://www.winimage.com/zLibDll/unzip.html
  67 and also in the contrib/minizip directory of zlib.
  68
  69
  70 Notes for some targets:
  71
  72 - To build a Windows DLL version, include in a DLL project zlib.def, zlib.rc
  73   and all .c files except example.c and minigzip.c; compile with -DZLIB_DLL
  74   The zlib DLL support was initially done by Alessandro Iacopetti and is
  75   now maintained by Gilles Vollant <info@winimage.com>. Check the zlib DLL
  76   home page at http://www.winimage.com/zLibDll
  77
  78   From Visual Basic, you can call the DLL functions which do not take
  79   a structure as argument: compress, uncompress and all gz* functions.
  80   See contrib/visual-basic.txt for more information.
  81   I don't know how to handle structures in Visual Basic, sorry.
  82
  83 - For 64-bit Irix, deflate.c must be compiled without any optimization.
  84   With -O, one libpng test fails. The test works in 32 bit mode (with
  85   the -n32 compiler flag). The compiler bug has been reported to SGI.
  86
  87 - zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1
  88   it works when compiled with cc.
  89
  90 - on Digital Unix 4.0D (formely OSF/1) on AlphaServer, the cc option -std1
  91   is necessary to get gzprintf working correctly. This is done by configure.
  92
  93 - zlib doesn't work on HP-UX 9.05 with some versions of /bin/cc. It works
  94   with other compilers. Use "make test" to check your compiler.
  95
  96 - For shared memory multiprocessors, the decompression code assumes that
  97   writes to pointers are atomic. Also the functions zalloc and zfree passed
  98   to deflateInit must be multi-threaded in this case.
  99
 100 - gzdopen is not supported on RISCOS, BEOS and by some Mac compilers.
 101
 102 - For Turbo C the small model is supported only with reduced performance to
 103   avoid any far allocation; it was tested with -DMAX_WBITS=11 -DMAX_MEM_LEVEL=3
 104
 105
 106 Acknowledgments:
 107
 108   The deflate format used by zlib was defined by Phil Katz. The deflate
 109   and zlib specifications were written by L. Peter Deutsch. Thanks to all the
 110   people who reported problems and suggested various improvements in zlib;
 111   they are too numerous to cite here.
 112
 113 Copyright notice:
 114
 115  (C) 1995-1998 Jean-loup Gailly and Mark Adler
 116
 117   This software is provided 'as-is', without any express or implied
 118   warranty.  In no event will the authors be held liable for any damages
 119   arising from the use of this software.
 120
 121   Permission is granted to anyone to use this software for any purpose,
 122   including commercial applications, and to alter it and redistribute it
 123   freely, subject to the following restrictions:
 124
 125   1. The origin of this software must not be misrepresented; you must not
 126      claim that you wrote the original software. If you use this software
 127      in a product, an acknowledgment in the product documentation would be
 128      appreciated but is not required.
 129   2. Altered source versions must be plainly marked as such, and must not be
 130      misrepresented as being the original software.
 131   3. This notice may not be removed or altered from any source distribution.
 132
 133   Jean-loup Gailly        Mark Adler
 134   jloup@gzip.org          madler@alumni.caltech.edu
 135
 136 If you use the zlib library in a product, we would appreciate *not*
 137 receiving lengthy legal documents to sign. The sources are provided
 138 for free but without warranty of any kind.  The library has been
 139 entirely written by Jean-loup Gailly and Mark Adler; it does not
 140 include third-party code.
 141
 142 If you redistribute modified sources, we would appreciate that you include
 143 in the file ChangeLog history information documenting your changes.