Gracefully degrade to getopt if getopt_long does not exist.
diff --git a/include/config.h.in b/include/config.h.in
index a0124e6..6d03a8d 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -134,6 +134,12 @@
/* Define to 1 if you have the `getnetbyname' function. */
#undef HAVE_GETNETBYNAME
+/* Define to 1 if you have the <getopt.h> header file. */
+#undef HAVE_GETOPT_H
+
+/* Define to 1 if you have the `getopt_long' function. */
+#undef HAVE_GETOPT_LONG
+
/* Define to 1 if you have the `getpagesize' function. */
#undef HAVE_GETPAGESIZE
