+dnl =================================================================
+dnl Mac OSX specific
+dnl =================================================================
+
+case "$host" in
+*-apple-darwin*) SPECIAL_CFLAGS="-Dunix"
+;;
+esac
+
+dnl =================================================================
+dnl OpenBSD specific
+dnl =================================================================
+
+case "$host" in
+*-openbsd*) SPECIAL_CFLAGS="$SPECIAL_CFLAGS -Dunix"
+;;
+esac
+