| 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. |