return nonzero returncode upon failure

watershell.c

@@ -131,7 +131,7 @@ int main(int argc, char *argv[])
         if (DEBUG) perror("ioctl SIOCGIFFLAGS");
         close(sockfd);
         free(sifreq);
-        return 0;
+        return 1;
     }
 
     //set up promisc mode if enabled