X-Git-Url: http://git.subgeniuskitty.com/icmpmonitor/.git/blobdiff_plain/fc42886b5ccafa67847a2ccad623b237333bfd4d..f52e475dfcc6b825cc7b4c0cbe13cfc467e3e679:/icmpmonitor.c

diff --git a/icmpmonitor.c b/icmpmonitor.c
index f7e4a47..76404c2 100644
--- a/icmpmonitor.c
+++ b/icmpmonitor.c
@@ -133,8 +133,8 @@ pinger(int ignore) /* Dummy parameter since this function registers as a signal
             if (verbose) printf("INFO: Host %s stopped responding. Executing DOWN command.\n", host->name);
             host->host_up = false;
             if (!fork()) {
-                system(host->down_cmd);
-                exit(EXIT_SUCCESS);
+                int sys_ret = system(host->down_cmd);
+                exit(sys_ret);
             }
         }
 
@@ -201,8 +201,8 @@ read_icmp_data(struct host_entry * host)
             if (verbose) printf("INFO: Host %s started responding. Executing UP command.\n", host->name);
             host->host_up = true;
             if (!fork()) {
-                system(host->up_cmd);
-                exit(EXIT_SUCCESS);
+                int sys_ret = system(host->up_cmd);
+                exit(sys_ret);
             }
         }
     } else {
@@ -432,6 +432,7 @@ parse_params(int argc, char ** argv)
     }
     if (first_host_in_list == NULL) {
         fprintf(stderr, "ERROR: Unable to parse a config file.\n");
+        print_usage(argv);
         exit(EXIT_FAILURE);
     }
 }
@@ -439,14 +440,22 @@ parse_params(int argc, char ** argv)
 int
 main(int argc, char ** argv)
 {
+    /* Parse the command line options, load and parse the config file. */
     parse_params(argc, argv);
 
+    /* Process config for each host, generating/verifying any necessary information. */
     init_hosts();
 
+    /* Make sure initialization left us with something useful. */
+    assert(first_host_in_list);
+
+    /* Pings are sent asynchronously. */
     signal(SIGALRM, pinger);
     alarm(TIMER_RESOLUTION);
 
+    /* The main program loop listens for ping responses. */
     get_response();
 
+    /* Should be unreachable. */
     exit(EXIT_SUCCESS);
 }