Consistencely allow '-?' to get a help text.

[can-utils.git] / isotprecv.c

diff --git a/isotprecv.c b/isotprecv.c
index 7b13cf237cf6afb17bfeb07f0c8586b802aca655..9e37c86829c726964df7fa3667a95fb4b2dd26e4 100644 (file)
--- a/isotprecv.c
+++ b/isotprecv.c
@@ -94,7 +94,7 @@ int main(int argc, char **argv)
 
     addr.can_addr.tp.tx_id = addr.can_addr.tp.rx_id = NO_CAN_ID;
 
-    while ((opt = getopt(argc, argv, "s:d:x:p:P:b:m:w:l")) != -1) {
+    while ((opt = getopt(argc, argv, "s:d:x:p:P:b:m:w:l?")) != -1) {
            switch (opt) {
            case 's':
                    addr.can_addr.tp.tx_id = strtoul(optarg, (char **)NULL, 16);
@@ -148,10 +148,15 @@ int main(int argc, char **argv)
                    loop = 1;
                    break;
 
+           case '?':
+                   print_usage(basename(argv[0]));
+                   exit(0);
+                   break;
+
            default:
                    fprintf(stderr, "Unknown option %c\n", opt);
                    print_usage(basename(argv[0]));
-                   exit(0);
+                   exit(1);
                    break;
            }
     }
@@ -160,7 +165,7 @@ int main(int argc, char **argv)
        (addr.can_addr.tp.tx_id == NO_CAN_ID) ||
        (addr.can_addr.tp.rx_id == NO_CAN_ID)) {
            print_usage(basename(argv[0]));
-           exit(0);
+           exit(1);
     }
   
     if ((s = socket(PF_CAN, SOCK_DGRAM, CAN_ISOTP)) < 0) {