Added function for testing conf file and some comments.

src/daemon.c

@@ -64,6 +64,37 @@ int read_conf_file(void)
 	return ret;
 }
 
+/**
+ * \brief This function tries to test config file
+ */
+int test_conf_file(char *_conf_file_name)
+{
+	FILE *conf_file = NULL;
+	int ret = -1;
+
+	conf_file = fopen(_conf_file_name, "r");
+
+	if(conf_file == NULL) {
+		fprintf(stderr, "Can't read config file %s\n",
+			_conf_file_name);
+		return EXIT_FAILURE;
+	}
+
+	ret = fscanf(conf_file, "%d", &delay);
+
+	if(ret <= 0) {
+		fprintf(stderr, "Wrong config file %s\n",
+			_conf_file_name);
+	}
+
+	fclose(conf_file);
+
+	if(ret > 0)
+		return EXIT_SUCCESS;
+	else
+		return EXIT_FAILURE;
+}
+
 /**
  * \brief Callback function for handling signals.
  * \param	sig	identifier of signal
@@ -88,16 +119,19 @@ void print_help(void)
 {
 	printf("\n Usage: %s [OPTIONS]\n\n", app_name);
 	printf("  Options:\n");
-	printf("   -h --help              Print this help\n");
-	printf("   -c --confile filename  Read configuration from the file\n");
-	printf("   -l --logfile filename  Write logs to the file\n");
+	printf("   -h --help               Print this help\n");
+	printf("   -c --confile filename   Read configuration from the file\n");
+	printf("   -t --testconf filename  Test configuration file\n");
+	printf("   -l --logfile filename   Write logs to the file\n");
 	printf("\n");
 }
 
+/* Main function */
 int main(int argc, char *argv[])
 {
 	static struct option long_options[] = {
 		{"confile", required_argument, 0, 'c'},
+		{"testconf", required_argument, 0, 't'},
 		{"logfile", required_argument, 0, 'l'},
 		{"help", no_argument, 0, 'h'},
 		{NULL, 0, 0, 0}
@@ -107,18 +141,20 @@ int main(int argc, char *argv[])
 
 	app_name = argv[0];
 
-	while( (value = getopt_long(argc, argv, "c:l:h", long_options, &option_index)) != -1) {
+	/* Try to process all command line arguments */
+	while( (value = getopt_long(argc, argv, "c:l:t:h", long_options, &option_index)) != -1) {
 		switch(value) {
 			case 'c':
 				conf_file_name = strdup(optarg);
 				break;
+			case 't':
+				return test_conf_file(optarg);
 			case 'l':
 				log_file_name = strdup(optarg);
 				break;
 			case 'h':
 				print_help();
 				return EXIT_SUCCESS;
-				break;
 			case '?':
 				print_help();
 				return EXIT_FAILURE;
@@ -127,15 +163,15 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	running = 1;
-
-	openlog(argv[0], LOG_PID|LOG_CONS, LOG_USER);
-
+	/* Daemon will handle two signals */
 	signal(SIGINT, vs_handle_signal);
 	signal(SIGHUP, vs_handle_signal);
 
+	/* Open system log and write message to it */
+	openlog(argv[0], LOG_PID|LOG_CONS, LOG_USER);
 	syslog(LOG_INFO, "Started %s", app_name);
 
+	/* Try to open log file to this daemon */
 	if(log_file_name != NULL) {
 		log_stream = fopen(log_file_name, "a+");
 		if (log_stream == NULL)
@@ -149,6 +185,9 @@ int main(int argc, char *argv[])
 	/* Read configuration from config file */
 	read_conf_file();
 
+	/* This global variable can be changed in function handling signal */
+	running = 1;
+
 	/* Never ending loop of server */
 	while(running == 1) {
 		/* Debug print */
@@ -157,18 +196,22 @@ int main(int argc, char *argv[])
 		/* TODO: dome something useful here */
 
 		/* Real server should use select() or poll() for waiting at
-		 * asynchronous event */
+		 * asynchronous event. Note: sleep() is interrupted, when
+		 * signal is received. */
 		sleep(delay);
 	}
 
+	/* Close log file, when it is used. */
 	if (log_stream != stdout)
 	{
 		fclose(log_stream);
 	}
 
+	/* Write system log and close it. */
 	syslog(LOG_INFO, "Stopped %s", app_name);
 	closelog();
 
+	/* Free allocated memory */
 	if(conf_file_name != NULL) free(conf_file_name);
 	if(log_file_name != NULL) free(log_file_name);