ax_check_zlib
=============

Synopsis
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     AX_CHECK_ZLIB([action-if-found], [action-if-not-found])

Description
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This macro searches for an installed zlib library. If nothing was specified when calling configure, it searches first in /usr/local and then in /usr, /opt/local and /sw. If the --with-zlib=DIR is specified, it will try to find it in DIR/include/zlib.h and DIR/lib/libz.a. If --without-zlib is specified, the library is not searched at all.

If either the header file (zlib.h) or the library (libz) is not found, shell commands 'action-if-not-found' is run. If 'action-if-not-found' is not specified, the configuration exits on error, asking for a valid zlib installation directory or --without-zlib.

If both header file and library are found, shell commands 'action-if-found' is run. If 'action-if-found' is not specified, the default action appends '-I${ZLIB_HOME}/include' to CPFLAGS, appends '-L$ZLIB_HOME}/lib' to LDFLAGS, prepends '-lz' to LIBS, and calls AC_DEFINE(HAVE_LIBZ). You should use autoheader to include a definition for this symbol in a config.h file. Sample usage in a C/C++ source is as follows:

       #ifdef HAVE_LIBZ
       #include <zlib.h>
       #endif /* HAVE_LIBZ */

Source Code
***********

Download the latest version of ax_check_zlib.m4 (http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_check_zlib.m4) or browse the macro's revision history (http://git.savannah.gnu.org/gitweb/?p=autoconf-archive.git;a=history;f=m4/ax_check_zlib.m4).

License
*******

Copyright © 2008 Loic Dachary loic@senga.org
 Copyright © 2010 Bastien Chevreux bach@chevreux.org

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.

As a special exception, the respective Autoconf Macro's copyright owner gives unlimited permission to copy, distribute and modify the configure scripts that are the output of Autoconf when processing the Macro. You need not follow the terms of the GNU General Public License when using or distributing such scripts, even though portions of the text of the Macro appear in them. The GNU General Public License (GPL) does govern all other use of the material that constitutes the Autoconf Macro.

This special exception to the GPL applies to versions of the Autoconf Macro released by the Autoconf Archive. When you make and distribute a modified version of the Autoconf Macro, you may extend this special exception to the GPL to apply to your modified version as well.