| 1 | .TH ZLIB 3 "15 Jan 2017" |
| 2 | .SH NAME |
| 3 | zlib \- compression/decompression library |
| 4 | .SH SYNOPSIS |
| 5 | [see |
| 6 | .I zlib.h |
| 7 | for full description] |
| 8 | .SH DESCRIPTION |
| 9 | The |
| 10 | .I zlib |
| 11 | library is a general purpose data compression library. |
| 12 | The code is thread safe, assuming that the standard library functions |
| 13 | used are thread safe, such as memory allocation routines. |
| 14 | It provides in-memory compression and decompression functions, |
| 15 | including integrity checks of the uncompressed data. |
| 16 | This version of the library supports only one compression method (deflation) |
| 17 | but other algorithms may be added later |
| 18 | with the same stream interface. |
| 19 | .LP |
| 20 | Compression can be done in a single step if the buffers are large enough |
| 21 | or can be done by repeated calls of the compression function. |
| 22 | In the latter case, |
| 23 | the application must provide more input and/or consume the output |
| 24 | (providing more output space) before each call. |
| 25 | .LP |
| 26 | The library also supports reading and writing files in |
| 27 | .IR gzip (1) |
| 28 | (.gz) format |
| 29 | with an interface similar to that of stdio. |
| 30 | .LP |
| 31 | The library does not install any signal handler. |
| 32 | The decoder checks the consistency of the compressed data, |
| 33 | so the library should never crash even in the case of corrupted input. |
| 34 | .LP |
| 35 | All functions of the compression library are documented in the file |
| 36 | .IR zlib.h . |
| 37 | The distribution source includes examples of use of the library |
| 38 | in the files |
| 39 | .I test/example.c |
| 40 | and |
| 41 | .IR test/minigzip.c, |
| 42 | as well as other examples in the |
| 43 | .IR examples/ |
| 44 | directory. |
| 45 | .LP |
| 46 | Changes to this version are documented in the file |
| 47 | .I ChangeLog |
| 48 | that accompanies the source. |
| 49 | .LP |
| 50 | .I zlib |
| 51 | is built in to many languages and operating systems, including but not limited to |
| 52 | Java, Python, .NET, PHP, Perl, Ruby, Swift, and Go. |
| 53 | .LP |
| 54 | An experimental package to read and write files in the .zip format, |
| 55 | written on top of |
| 56 | .I zlib |
| 57 | by Gilles Vollant (info@winimage.com), |
| 58 | is available at: |
| 59 | .IP |
| 60 | http://www.winimage.com/zLibDll/minizip.html |
| 61 | and also in the |
| 62 | .I contrib/minizip |
| 63 | directory of the main |
| 64 | .I zlib |
| 65 | source distribution. |
| 66 | .SH "SEE ALSO" |
| 67 | The |
| 68 | .I zlib |
| 69 | web site can be found at: |
| 70 | .IP |
| 71 | http://zlib.net/ |
| 72 | .LP |
| 73 | The data format used by the |
| 74 | .I zlib |
| 75 | library is described by RFC |
| 76 | (Request for Comments) 1950 to 1952 in the files: |
| 77 | .IP |
| 78 | http://tools.ietf.org/html/rfc1950 (for the zlib header and trailer format) |
| 79 | .br |
| 80 | http://tools.ietf.org/html/rfc1951 (for the deflate compressed data format) |
| 81 | .br |
| 82 | http://tools.ietf.org/html/rfc1952 (for the gzip header and trailer format) |
| 83 | .LP |
| 84 | Mark Nelson wrote an article about |
| 85 | .I zlib |
| 86 | for the Jan. 1997 issue of Dr. Dobb's Journal; |
| 87 | a copy of the article is available at: |
| 88 | .IP |
| 89 | http://marknelson.us/1997/01/01/zlib-engine/ |
| 90 | .SH "REPORTING PROBLEMS" |
| 91 | Before reporting a problem, |
| 92 | please check the |
| 93 | .I zlib |
| 94 | web site to verify that you have the latest version of |
| 95 | .IR zlib ; |
| 96 | otherwise, |
| 97 | obtain the latest version and see if the problem still exists. |
| 98 | Please read the |
| 99 | .I zlib |
| 100 | FAQ at: |
| 101 | .IP |
| 102 | http://zlib.net/zlib_faq.html |
| 103 | .LP |
| 104 | before asking for help. |
| 105 | Send questions and/or comments to zlib@gzip.org, |
| 106 | or (for the Windows DLL version) to Gilles Vollant (info@winimage.com). |
| 107 | .SH AUTHORS AND LICENSE |
| 108 | Version 1.2.11 |
| 109 | .LP |
| 110 | Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler |
| 111 | .LP |
| 112 | This software is provided 'as-is', without any express or implied |
| 113 | warranty. In no event will the authors be held liable for any damages |
| 114 | arising from the use of this software. |
| 115 | .LP |
| 116 | Permission is granted to anyone to use this software for any purpose, |
| 117 | including commercial applications, and to alter it and redistribute it |
| 118 | freely, subject to the following restrictions: |
| 119 | .LP |
| 120 | .nr step 1 1 |
| 121 | .IP \n[step]. 3 |
| 122 | The origin of this software must not be misrepresented; you must not |
| 123 | claim that you wrote the original software. If you use this software |
| 124 | in a product, an acknowledgment in the product documentation would be |
| 125 | appreciated but is not required. |
| 126 | .IP \n+[step]. |
| 127 | Altered source versions must be plainly marked as such, and must not be |
| 128 | misrepresented as being the original software. |
| 129 | .IP \n+[step]. |
| 130 | This notice may not be removed or altered from any source distribution. |
| 131 | .LP |
| 132 | Jean-loup Gailly Mark Adler |
| 133 | .br |
| 134 | jloup@gzip.org madler@alumni.caltech.edu |
| 135 | .LP |
| 136 | The deflate format used by |
| 137 | .I zlib |
| 138 | was defined by Phil Katz. |
| 139 | The deflate and |
| 140 | .I zlib |
| 141 | specifications were written by L. Peter Deutsch. |
| 142 | Thanks to all the people who reported problems and suggested various |
| 143 | improvements in |
| 144 | .IR zlib ; |
| 145 | who are too numerous to cite here. |
| 146 | .LP |
| 147 | UNIX manual page by R. P. C. Rodgers, |
| 148 | U.S. National Library of Medicine (rodgers@nlm.nih.gov). |
| 149 | .\" end of man page |