Make znc compile without getopt_long

If getopt_long() (GNU extension) isn't available, we use the plain old getopt()
instead. This means that long options won't work, but at least this compiles.

Tested on Solaris 9, but should also work on Irix.

Signed-off-by: Uli Schlachter <psychon@znc.in>

configure.ac

@@ -164,7 +164,7 @@ if test "$POLL" = "yes"; then
 fi
 
 AC_CHECK_LIB( gnugetopt, getopt_long,)
-AC_CHECK_FUNCS([lstat])
+AC_CHECK_FUNCS([lstat getopt_long])
 PKG_PROG_PKG_CONFIG()
 
 # ----- Check for dlopen

main.cpp

@@ -7,9 +7,28 @@
  */
 
 #include "znc.h"
-#include <getopt.h>
 #include <sys/wait.h>
 
+#ifdef HAVE_GETOPT_LONG
+#include <getopt.h>
+#else
+#define no_argument 0
+#define required_argument 1
+#define optional_argument 2
+
+struct option {
+	const char *a;
+	int opt;
+	int *flag;
+	int val;
+};
+
+static inline int getopt_long(int argc, char * const argv[], const char *optstring, const struct option *, int *)
+{
+	return getopt(argc, argv, optstring);
+}
+#endif
+
 static const struct option g_LongOpts[] = {
 	{ "help",        no_argument,       0, 'h' },
 	{ "version",     no_argument,       0, 'v' },