+socket_needs_socket="no"
+AC_CHECK_FUNCS(socket, [], AC_CHECK_LIB(socket, socket, [socket_needs_socket="yes"], AC_MSG_ERROR(cannot find socket)))
+AM_CONDITIONAL(BUILD_WITH_LIBSOCKET, test "x$socket_needs_socket" = "xyes")
+
+nanosleep_needs_rt="no"
+AC_CHECK_FUNCS(nanosleep, [], AC_CHECK_LIB(rt, nanosleep, [nanosleep_needs_rt="yes"], AC_MSG_ERROR(cannot find nanosleep)))
+AM_CONDITIONAL(BUILD_WITH_LIBRT, test "x$nanosleep_needs_rt" = "xyes")
+