ax_ext_have_lib

AX_EXT_HAVE_LIB is identical to AC_SEARCH_LIBS with the exception that will add -L<directory> when looking, and use a different variable for each directory.

Any required -L<directory> flags are added to LDFLAGS and located libraies are added to LIBS

Some libraries are unlinkable without other extra libraries, which can be specified in the 4th argument. The mysql client library needs -lz, for example.

Example:

  AX_EXT_HAVE_LIB(/lib /usr/lib /usr/local/lib /usr/lib/mysql /usr/local/mysql/lib, mysqlclient, mysql_init, [-lz])

which finds the mysql client library if succeds system when it tries with -L/usr/lib/mysql then it adds -lmysqlclient to LIBS and -L/usr/lib/mysql to LDFLAGS.

The test itself is based on the autoconf 2.53 version of AC_SEARCH_LIBS.

AC_DEFUN([AX_EXT_HAVE_LIB],
[
new_ldflags=${LDFLAGS}
new_libs=$LIBS
AC_CHECK_LIB([$2], $3, new_libs="-l$2"; ext_lib_found="yes",  ext_lib_found="no")
for dir in $1
do
if test $ext_lib_found = no
then
ext_haslib_cvdir=`echo $dir | $as_tr_sh`
AC_CACHE_CHECK([for $2 library with -L$dir], [ext_cv${ext_haslib_cvdir}_haslib_$2],
[ext_func_search_save_LIBS=$LIBS
ext_func_save_ldflags=${LDFLAGS}
LIBS="-l$2 $4 ${ext_func_search_save_LIBS}"
LDFLAGS="-L$dir ${ext_func_save_ldflags}"
AC_TRY_LINK_FUNC([$3], [eval "ext_cv${ext_haslib_cvdir}_haslib_$2"="yes"],
[eval "ext_cv${ext_haslib_cvdir}_haslib_$2"="no"])
LIBS=$ext_func_search_save_LIBS
LDFLAGS=$ext_func_save_ldflags
])
if eval `echo 'test x${'ext_cv${ext_haslib_cvdir}_haslib_$2'}' = "xyes"`; then
new_libs="-l$2 ${new_libs}"
new_ldflags="-L${dir} ${new_ldflags}"
ext_lib_found="yes"
fi
fi
done
LIBS=$new_libs
LDFLAGS=$new_ldflags
])