madler / zlib

ZLIB DATA COMPRESSION LIBRARY
zlib 1.3.2.1 is a general purpose data compression library. All the code is
thread safe (though see the FAQ for caveats). The data format used by the zlib
library is described by RFCs (Request for Comments) 1950 to 1952 at
https://datatracker.ietf.org/doc/html/rfc1950 (zlib format), rfc1951 (deflate
format) and rfc1952 (gzip format).
All functions of the compression library are documented in the file zlib.h
(volunteer to write man pages welcome, contact zlib@gzip.org). A usage example
of the library is given in the file test/example.c which also tests that
the library is working correctly. Another example is given in the file
test/minigzip.c. The compression library itself is composed of all source
files in the root directory.
To compile all files and run the test program, follow the instructions given at
the top of Makefile.in. In short "./configure; make test", and if that goes
well, "make install" should work for most flavors of Unix. For Windows, use
one of the special makefiles in win32/ or contrib/vstudio/ . For VMS, use
make_vms.com.
Questions about zlib should be sent to , or to Gilles Vollant
 for the Windows DLL version. The zlib home page is
https://zlib.net/ . Before reporting a problem, please check this site to
verify that you have the latest version of zlib; otherwise get the latest
version and check whether the problem still exists or not.
PLEASE read the zlib FAQ https://zlib.net/zlib_faq.html before asking for help.
Mark Nelson wrote an article about zlib for the Jan. 1997
issue of Dr. Dobb's Journal; a copy of the article is available at
https://zlib.net/nelson/ .
The changes made in version 1.3.2.1 are documented in the file ChangeLog.
Unsupported third party contributions are provided in directory contrib/ .
zlib is available in Java using the java.util.zip package. Follow the API
Documentation link at: https://docs.oracle.com/search/?q=java.util.zip .
A Perl interface to zlib and bzip2 written by Paul Marquess 
can be found at https://github.com/pmqs/IO-Compress .
A Python interface to zlib written by A.M. Kuchling is
available in Python 1.5 and later versions, see
https://docs.python.org/3/library/zlib.html .
zlib is built into tcl: https://wiki.tcl-lang.org/page/zlib .
An experimental package to read and write files in .zip format, written on top
of zlib by Gilles Vollant , is available in the
contrib/minizip directory of zlib.
Notes for some targets:
- For Windows DLL versions, please see win32/DLL_FAQ.txt
- For 64-bit Irix, deflate.c must be compiled without any optimization. With
 -O, one libpng test fails. The test works in 32 bit mode (with the -n32
 compiler flag). The compiler bug has been reported to SGI.
- zlib doesn't work with gcc 2.6.3 on a DEC 3000/300LX under OSF/1 2.1 it works
 when compiled with cc.
- On Digital Unix 4.0D (formerly OSF/1) on AlphaServer, the cc option -std1 is
 necessary to get gzprintf working correctly. This is done by configure.
- zlib doesn't work on HP-UX