$OpenBSD: patch-viz_c,v 1.1 2007/10/26 22:00:31 ajacoutot Exp $
--- viz.c.orig	Fri Apr 14 15:30:56 1995
+++ viz.c	Fri Oct 26 23:57:18 2007
@@ -55,14 +55,17 @@
 #define VIZ_MAIN
 #include "viz.h"
 
+#ifndef _SYS_ERRNO_H_
 extern errno;
 extern int sys_nerr;
 extern char *sys_errlist[];
+#endif
 
-
+#ifndef _STDLIB_H_
 extern char *malloc();
 extern optind, opterr;
 extern char *optarg;
+#endif
 
 char *prog;
 struct Format Fmt = {