Add mechanism to restart programs

src/daemonitor/999_main.c

@@ -7,6 +7,14 @@
 
 
 
+/* DEFAULT_RESTART_INTERVAL
+ *  The default argument to --restart-interval, in seconds.
+ */
+#define DEFAULT_RESTART_INTERVAL 10
+#define DEFAULT_RESTART_INTERVAL_S "10"
+
+
+
 /* usage()
  *  Display the usage info.
  */
@@ -24,6 +32,9 @@ void usage(void)
         "                               STDERR - log to stderr (default)\n"
         "                               file path - log to file\n"
         " -p, --pidfile <path>      Write PID to file.\n"
+        " -R, --restart-interval <i>   Sets the length of time between the process\n"
+        "                              exiting and being restarted, in seconds (default\n"
+        "                              " DEFAULT_RESTART_INTERVAL_S "). May be 0 to restart immediately.\n"
     "", stderr);
 }
 
@@ -38,6 +49,7 @@ struct option options[] = {
     { "daemon", no_argument, 0, 'd' },
     { "log", required_argument, 0, 'l' },
     { "pidfile", required_argument, 0, 'p' },
+    { "restart-interval", required_argument, 0, 'R' },
     { 0, 0, 0, 0 }
 };
 
@@ -46,7 +58,7 @@ struct option options[] = {
 /* optstr
  *  The list of short commandline options for getopt(3). Sorted alphabetically, lowercase first.
  */
-const char* optstr = "dhl:p:V";
+const char* optstr = "dhl:p:R:V";
 
 
 
@@ -56,8 +68,9 @@ const char* optstr = "dhl:p:V";
  */
 int main(int argc, char* argv[])
 {
-    const char* log_argument = 0, * pidfile_argument = 0;
-    int daemon = 0;
+    char* endp;
+    const char* log_argument = 0, * pidfile_argument = 0, * restart_argument = 0;
+    int daemon = 0, restart_interval = DEFAULT_RESTART_INTERVAL;
 
     /* safety */
     close_file_descriptors(); /* leaves stdout etc. open */
@@ -72,9 +85,24 @@ int main(int argc, char* argv[])
         case 'd': ++daemon; break;
         case 'l': log_argument = optarg; break;
         case 'p': pidfile_argument = optarg; break;
+        case 'R': restart_argument = optarg; break;
         }
     }
   opts_done:
+    if(restart_argument) {
+        restart_interval = strtol(restart_argument, &endp, 0);
+        if(*endp || restart_interval < 0) {
+            LOG_ANYWHERE("Invalid --restart-interval option `%s'. Must be an integer >= 0.",
+                restart_argument);
+            return 1;
+        }
+    }
+
+    if(optind >= argc) {
+        LOG_ANYWHERE("Program not specified.");
+        return 1;
+    }
+
     /* set up logging */
     if(!log_argument || !strcmp(log_argument, "STDERR")) {
         log_destination_set(log_destination_stderr);
@@ -102,6 +130,16 @@ int main(int argc, char* argv[])
         }
     }
 
+    /* run process */
+    while(1) {
+        run_program(argv + optind, argc - optind);
+
+        if(restart_interval) {
+            LOG(LOG_NOTICE, "Sleeping for %d seconds.", restart_interval);
+            safe_sleep_fixed(restart_interval, 0);
+        }
+    }
+
     return 0;
 }