--- rfcomm/main.c	(revision 154)
+++ rfcomm/main.c	(working copy)
@@ -621,8 +621,20 @@
 	argv += optind;
 	optind = 0;
 
-	if (argc < 2)
+	if (argc == 0) {
+        show_all = 1;
+    }else if (argc == 1){
+        for(i = 0; command[i].cmd; i++) {
+		    if ((strncmp(command[i].cmd, argv[0], 4) == 0) &&
+                (strncmp(command[i].alt, argv[0], 4) == 0) )
+			    break;
+            
+            if (command[i+1].cmd == NULL)
+                usage();
+                exit(0);
+        }
 		show_all = 1;
+    }
 
 	if ((ctl = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_RFCOMM)) < 0 ) {
 		perror("Can't open RFCOMM control socket");