Small modification to trace_dump.

It can now be used to make a dump from a trace stream on stdin.
Nice for taking a quick look at traces which were dumped to disk first.

common/trace/trace_dump.c

@@ -87,27 +87,47 @@ static void handler_value(struct trace *trace,
 	}
 }
 
+
+void usage(void)
+{
+	printf("Usage:\n\n");
+	printf("trace_dump [host] [port] [trace] <interval>\n");
+	
+	exit(0);
+}
+
 int main(int argc, char **argv)
 {
 	struct trace *trace;
 	struct trace_pkt *pkt;
 	int interval = 1;
 	uint64_t nsec_interval;
+	bool fromstdin = false;
 
-	if (argc < 4) {
-		printf("Usage:\n\n");
-		printf("%s [host] [port] [trace] <interval>\n", argv[0]);
-		return 0;
+	if (argc < 2) {
+		usage();
+	}
+	if (!strcmp(argv[1], "-")) {
+		fromstdin = true;
+	}
+	if (!fromstdin && argc < 4) {
+		usage();
 	}
 
+	if (!fromstdin) {
 		tracename = argv[3];
 
-	trace = trace_open(argv[1], atoi(argv[2]));
-
 		if (argc >= 5) {
 			interval = atoi(argv[4]);
 		}
 	
+		trace = trace_open(argv[1], atoi(argv[2]));
+
+	} else {
+		trace = trace_alloc();
+		trace_initialize_fd(trace, 0);
+	}
+	
 	trace->handler_interval = handler_interval;
 	trace->handler_value = handler_value;
 	trace->handler_timestamp = handler_timestamp;
@@ -125,6 +145,7 @@ int main(int argc, char **argv)
 		trace_handle(trace, &fdrx);
 	}
 	
+	if (!fromstdin) {
 		printf("Connection ready for tracing\n");
 	
 		if (interval) {
@@ -147,6 +168,7 @@ int main(int argc, char **argv)
 		trace_packet_name_set(pkt, tracename);
 		trace_packet_write(trace, pkt);
 		trace_packet_put(pkt);
+	}
 
 	printf("Wait for data\n");