From: Aron Xu <aron@debian.org>
Date: Mon, 13 Feb 2012 15:38:15 +0800
Subject: verbose numeric port

---
 netcat.c |   25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

--- a/netcat.c
+++ b/netcat.c
@@ -43,6 +43,7 @@
 #include <netinet/tcp.h>
 #include <netinet/ip.h>
 #include <arpa/telnet.h>
+#include <arpa/inet.h>
 #ifdef __linux__
 # include <linux/in6.h>
 #endif
@@ -689,6 +690,21 @@ main(int argc, char *argv[])
 			}
 			if (s < 0)
 				err(1, NULL);
+
+			if (vflag && (family != AF_UNIX)) {
+				char* local;
+				if (family == AF_INET)
+					local = "0.0.0.0";
+				else if (family == AF_INET6)
+					local = "::";
+				else
+					local = "unknown";
+				fprintf(stderr, "Listening on [%s] (family %d, port %d)\n",
+					host ?: local,
+					family,
+					*uport);
+			}
+
 			if (uflag && kflag) {
 				/*
 				 * For UDP and -k, don't connect the socket,
@@ -708,20 +724,19 @@ main(int argc, char *argv[])
 				 */
 				int rv;
 				char buf[2048];
-				struct sockaddr_storage z;
 
-				len = sizeof(z);
+				len = sizeof(cliaddr);
 				rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK,
-				    (struct sockaddr *)&z, &len);
+				    (struct sockaddr *)&cliaddr, &len);
 				if (rv < 0)
 					err(1, "recvfrom");
 
-				rv = connect(s, (struct sockaddr *)&z, len);
+				rv = connect(s, (struct sockaddr *)&cliaddr, len);
 				if (rv < 0)
 					err(1, "connect");
 
 				if (vflag)
-					report_connect((struct sockaddr *)&z, len, NULL);
+					report_connect((struct sockaddr *)&cliaddr, len, NULL);
 
 # if defined(TLS)
 				readwrite(s, NULL);