slcan: added listen-only flag

Signed-off-by: Maximilian Pachl <m@ximilian.info>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/slcan_attach.c b/slcan_attach.c
index 485cbe3776a3700099b623bf952fd184309e90f7..40bddc8c290be1b6c84dd3a995b20f8fe232a266 100644 (file)
--- a/slcan_attach.c
+++ b/slcan_attach.c
@@ -58,6 +58,7 @@ void print_usage(char *prg)
 {
        fprintf(stderr, "\nUsage: %s [options] tty\n\n", prg);
        fprintf(stderr, "Options: -o         (send open command 'O\\r')\n");
+       fprintf(stderr, "         -l         (send listen only command 'L\\r', overrides -o)\n");
        fprintf(stderr, "         -c         (send close command 'C\\r')\n");
        fprintf(stderr, "         -f         (read status flags with 'F\\r' to reset error states)\n");
        fprintf(stderr, "         -s <speed> (set CAN speed 0..8)\n");
@@ -81,6 +82,7 @@ int main(int argc, char **argv)
        int detach = 0;
        int waitkey = 0;
        int send_open = 0;
+       int send_listen = 0;
        int send_close = 0;
        int send_read_status_flags = 0;
        char *speed = NULL;
@@ -90,12 +92,8 @@ int main(int argc, char **argv)
        char *name = NULL;
        int opt;
 
-       while ((opt = getopt(argc, argv, "l:dwocfs:b:n:?")) != -1) {
+       while ((opt = getopt(argc, argv, "ldwocfs:b:n:?")) != -1) {
                switch (opt) {
-               case 'l':
-                       fprintf(stderr, "Ignored option '-l'\n");
-                       break;
-
                case 'd':
                        detach = 1;
                        break;
@@ -108,6 +106,10 @@ int main(int argc, char **argv)
                        send_open = 1;
                        break;
 
+               case 'l':
+                       send_listen = 1;
+                       break;
+
                case 'c':
                        send_close = 1;
                        break;
@@ -168,7 +170,10 @@ int main(int argc, char **argv)
                        write(fd, buf, strlen(buf));
                }
 
-               if (send_open) {
+               if (send_listen) {
+                       sprintf(buf, "L\r");
+                       write(fd, buf, strlen(buf));
+               } else if (send_open) {
                        sprintf(buf, "O\r");
                        write(fd, buf, strlen(buf));
                }