tc : add timestamps to tc monitor

Support -timestamp and -tshort options for tc monitor like ip monitor.

# tc -tshort monitor
[2015-09-23T16:39:11.260555] qdisc fq 8003: dev eth0 root refcnt 2 limit
10000p flow_limit 100p buckets 1024 quantum 3028 initial_quantum 15140
refill_delay 40.0ms

Signed-off-by: Eric Dumazet <edumazet@google.com>
diff --git a/tc/tc.c b/tc/tc.c
index 46ff371..1707867 100644
--- a/tc/tc.c
+++ b/tc/tc.c
@@ -36,6 +36,7 @@
 int show_raw = 0;
 int show_pretty = 0;
 int show_graph = 0;
+int timestamp;
 
 int batch_mode = 0;
 int resolve_hosts = 0;
@@ -311,6 +312,11 @@
 				matches(argv[1], "-conf") == 0) {
 			NEXT_ARG();
 			conf_file = argv[1];
+		} else if (matches(argv[1], "-timestamp") == 0) {
+			timestamp++;
+		} else if (matches(argv[1], "-tshort") == 0) {
+			++timestamp;
+			++timestamp_short;
 		} else {
 			fprintf(stderr, "Option \"%s\" is unknown, try \"tc -help\".\n", argv[1]);
 			return -1;
diff --git a/tc/tc_monitor.c b/tc/tc_monitor.c
index cae3616..097068e 100644
--- a/tc/tc_monitor.c
+++ b/tc/tc_monitor.c
@@ -30,7 +30,7 @@
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: tc monitor\n");
+	fprintf(stderr, "Usage: tc [-timestamp [-tshort] monitor\n");
 	exit(-1);
 }
 
@@ -41,6 +41,9 @@
 {
 	FILE *fp = (FILE*)arg;
 
+	if (timestamp)
+		print_timestamp(fp);
+
 	if (n->nlmsg_type == RTM_NEWTFILTER || n->nlmsg_type == RTM_DELTFILTER) {
 		print_filter(who, n, arg);
 		return 0;