diff options
Diffstat (limited to 'src/cansequence.c')
| -rw-r--r-- | src/cansequence.c | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/src/cansequence.c b/src/cansequence.c index 9ad0b30..8395c65 100644 --- a/src/cansequence.c +++ b/src/cansequence.c @@ -30,7 +30,7 @@ enum { void print_usage(char *prg) { - fprintf(stderr, "Usage: %s <can-interface> [Options]\n" + fprintf(stderr, "Usage: %s [<can-interface>] [Options]\n" "\n" "cansequence sends CAN messages with a rising sequence number as payload.\n" "When the -r option is given, cansequence expects to receive these messages\n" @@ -58,15 +58,16 @@ void sigterm(int signo) int main(int argc, char **argv) { - int family = PF_CAN, type = SOCK_RAW, proto = CAN_RAW; - int opt; - struct sockaddr_can addr; struct can_frame frame; - int nbytes; struct ifreq ifr; + struct sockaddr_can addr; + char *interface = "can0"; + unsigned char sequence = 0; + int family = PF_CAN, type = SOCK_RAW, proto = CAN_RAW; + int loopcount = 1, infinite = 0; + int nbytes; + int opt; int receive = 0; - int loopcount = 1, infinite; - unsigned char sequence = 0; int sequence_init = 1; int verbose = 0, quit = 0; @@ -133,13 +134,11 @@ int main(int argc, char **argv) } } - if (optind == argc) { - print_usage(basename(argv[0])); - exit(0); - } + if (optind != argc) + interface = argv[optind]; printf("interface = %s, family = %d, type = %d, proto = %d\n", - argv[optind], family, type, proto); + interface, family, type, proto); s = socket(family, type, proto); if (s < 0) { @@ -148,8 +147,11 @@ int main(int argc, char **argv) } addr.can_family = family; - strncpy(ifr.ifr_name, argv[optind], sizeof(ifr.ifr_name)); - ioctl(s, SIOCGIFINDEX, &ifr); + strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name)); + if (ioctl(s, SIOCGIFINDEX, &ifr)) { + perror("ioctl"); + return 1; + } addr.can_ifindex = ifr.ifr_ifindex; if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) { |