| .TH ZLIB 3 "27 Mar 2022" |
| .SH NAME |
| zlib \- compression/decompression library |
| .SH SYNOPSIS |
| [see |
| .I zlib.h |
| for full description] |
| .SH DESCRIPTION |
| The |
| .I zlib |
| library is a general purpose data compression library. |
| The code is thread safe, assuming that the standard library functions |
| used are thread safe, such as memory allocation routines. |
| It provides in-memory compression and decompression functions, |
| including integrity checks of the uncompressed data. |
| This version of the library supports only one compression method (deflation) |
| but other algorithms may be added later |
| with the same stream interface. |
| .LP |
| Compression can be done in a single step if the buffers are large enough |
| or can be done by repeated calls of the compression function. |
| In the latter case, |
| the application must provide more input and/or consume the output |
| (providing more output space) before each call. |
| .LP |
| The library also supports reading and writing files in |
| .IR gzip (1) |
| (.gz) format |
| with an interface similar to that of stdio. |
| .LP |
| The library does not install any signal handler. |
| The decoder checks the consistency of the compressed data, |
| so the library should never crash even in the case of corrupted input. |
| .LP |
| All functions of the compression library are documented in the file |
| .IR zlib.h . |
| The distribution source includes examples of use of the library |
| in the files |
| .I test/example.c |
| and |
| .IR test/minigzip.c, |
| as well as other examples in the |
| .IR examples/ |
| directory. |
| .LP |
| Changes to this version are documented in the file |
| .I ChangeLog |
| that accompanies the source. |
| .LP |
| .I zlib |
| is built in to many languages and operating systems, including but not limited to |
| Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go. |
| .LP |
| An experimental package to read and write files in the .zip format, |
| written on top of |
| .I zlib |
| by Gilles Vollant (info@winimage.com), |
| is available at: |
| .IP |
| http://www.winimage.com/zLibDll/minizip.html |
| and also in the |
| .I contrib/minizip |
| directory of the main |
| .I zlib |
| source distribution. |
| .SH "SEE ALSO" |
| The |
| .I zlib |
| web site can be found at: |
| .IP |
| http://zlib.net/ |
| .LP |
| The data format used by the |
| .I zlib |
| library is described by RFC |
| (Request for Comments) 1950 to 1952 in the files: |
| .IP |
| http://tools.ietf.org/html/rfc1950 (for the zlib header and trailer format) |
| .br |
| http://tools.ietf.org/html/rfc1951 (for the deflate compressed data format) |
| .br |
| http://tools.ietf.org/html/rfc1952 (for the gzip header and trailer format) |
| .LP |
| Mark Nelson wrote an article about |
| .I zlib |
| for the Jan. 1997 issue of Dr. Dobb's Journal; |
| a copy of the article is available at: |
| .IP |
| http://marknelson.us/1997/01/01/zlib-engine/ |
| .SH "REPORTING PROBLEMS" |
| Before reporting a problem, |
| please check the |
| .I zlib |
| web site to verify that you have the latest version of |
| .IR zlib ; |
| otherwise, |
| obtain the latest version and see if the problem still exists. |
| Please read the |
| .I zlib |
| FAQ at: |
| .IP |
| http://zlib.net/zlib_faq.html |
| .LP |
| before asking for help. |
| Send questions and/or comments to zlib@gzip.org, |
| or (for the Windows DLL version) to Gilles Vollant (info@winimage.com). |
| .SH AUTHORS AND LICENSE |
| Version 1.2.12 |
| .LP |
| Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler |
| .LP |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| .LP |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| .LP |
| .nr step 1 1 |
| .IP \n[step]. 3 |
| The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| .IP \n+[step]. |
| Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| .IP \n+[step]. |
| This notice may not be removed or altered from any source distribution. |
| .LP |
| Jean-loup Gailly Mark Adler |
| .br |
| jloup@gzip.org madler@alumni.caltech.edu |
| .LP |
| The deflate format used by |
| .I zlib |
| was defined by Phil Katz. |
| The deflate and |
| .I zlib |
| specifications were written by L. Peter Deutsch. |
| Thanks to all the people who reported problems and suggested various |
| improvements in |
| .IR zlib ; |
| who are too numerous to cite here. |
| .LP |
| UNIX manual page by R. P. C. Rodgers, |
| U.S. National Library of Medicine (rodgers@nlm.nih.gov). |
| .\" end of man page |