--- netcat-4.0.20061122/usr.bin/nc/netcat.c

+++ netcat-4.0.20061122/usr.bin/nc/netcat.c

@@ -123,6 +123,9 @@ main(int argc, char *argv[])

 	uport = NULL;

 	sv = NULL;

+	if (argc < 1)

+		usage(1);

+

 	while ((ch = getopt(argc, argv,

 	    "46Ddhi:jklnP:p:rSs:tT:Uuvw:X:x:z")) != -1) {

 		switch (ch) {

@@ -843,9 +846,9 @@ help(void)

 void

 usage(int ret)

 {

-	fprintf(stderr, "usage: nc [-46DdhklnrStUuvz] [-i interval] [-p source_port]\n");

-	fprintf(stderr, "\t  [-s source_ip_address] [-T ToS] [-w timeout] [-X proxy_version]\n");

-	fprintf(stderr, "\t  [-x proxy_address[:port]] [hostname] [port[s]]\n");

+	fprintf(stderr, "usage: netcat [-46DdhklnrStUuvz] [-i interval] [-p source_port]\n");

+	fprintf(stderr, "              [-s source_ip_address] [-w timeout] [-X proxy_version]\n");

+	fprintf(stderr, "              [-x proxy_address[:port]] [hostname] [port[s]]\n");

 	if (ret)

 		exit(1);

 }