if test $gl_cv_socket_ipv6 = yes; then
AC_DEFINE([HAVE_IPV6], [1], [Define to 1 if <sys/socket.h> defines AF_INET6.])
fi
+])
+AC_DEFUN([gl_SOCKET_FAMILY_UNIX],
+[
+ AC_REQUIRE([gl_HEADER_SYS_SOCKET])
AC_CHECK_HEADERS_ONCE([sys/un.h])
+
AC_MSG_CHECKING([for UNIX domain sockets])
AC_CACHE_VAL([gl_cv_socket_unix],
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>