dnl CF_LINK_FUNCS version: 7 updated: 2006/12/16 12:33:30
dnl -------------
dnl Most Unix systems have both link and symlink, a few don't have symlink.
dnl A few non-Unix systems implement symlink, but not link.
dnl A few non-systems implement neither (or have nonfunctional versions).
AC_DEFUN([CF_LINK_FUNCS],
[
AC_CHECK_FUNCS( \
	remove \
	unlink )

if test "$cross_compiling" = yes ; then
	AC_CHECK_FUNCS( \
		link \
		symlink )
else
	AC_CACHE_CHECK(if link/symlink functions work,cf_cv_link_funcs,[
		cf_cv_link_funcs=
		for cf_func in link symlink ; do
			AC_TRY_RUN([
#include <sys/types.h>
#include <sys/stat.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
int main()
{
	int fail = 0;
	char *src = "config.log";
	char *dst = "conftest.chk";
	struct stat src_sb;
	struct stat dst_sb;

	stat(src, &src_sb);
	fail = ($cf_func("config.log", "conftest.chk") < 0)
	    || (stat(dst, &dst_sb) < 0)
	    || (dst_sb.st_mtime != src_sb.st_mtime);
#ifdef HAVE_UNLINK
	unlink(dst);
#else
	remove(dst);
#endif
	${cf_cv_main_return:-return} (fail);
}
			],[
			cf_cv_link_funcs="$cf_cv_link_funcs $cf_func"
			eval 'ac_cv_func_'$cf_func'=yes'],[
			eval 'ac_cv_func_'$cf_func'=no'],[
			eval 'ac_cv_func_'$cf_func'=error'])
		done
		test -z "$cf_cv_link_funcs" && cf_cv_link_funcs=no
	])
	test "$ac_cv_func_link"    = yes && AC_DEFINE(HAVE_LINK)
	test "$ac_cv_func_symlink" = yes && AC_DEFINE(HAVE_SYMLINK)
fi
])dnl
