Added -d to facilitate running as a standalone daemon.

man.md

@@ -15,24 +15,22 @@ keyd [-m] [-l]
 
  **-l**: List all valid key names.
 
-# OVERVIEW
-
-keyd is intended to be run as a system wide daemon via systemd. If run
-directly it will run in the foreground and print diagnostic information to
-stderr.
+ **-d**: Fork and run in the background.
 
-Control can be exercised using the standard systemd mechanisms. E.G:
+# OVERVIEW
 
- - journalctl -fu keyd # Print diagnostic information.
- - systemctl restart keyd # Restart the daemon to effect configuration reload.
+keyd is intended to be run as system wide daemon managed by systemd. The
+default behaviour is to run the forground and print to stderr but it can also
+be run as a standalone daemon if -d is supplied, in which case log output will
+be stored in /var/log/keyd.log. 
 
 # CONFIGURATION
 
 All configuration files are stored in /etc/keyd. The name of each file should
 correspond to the device name (see `-m`) to which it is to be applied followed
 by .cfg (e.g /etc/keyd/Magic\ Keyboard.cfg). Configuration files are loaded
-upon initialization, thus restarting the daemon is necessary for changes
-to take effect.
+upon initialization thus restarting the daemon is necessary for changes
+to take effect (e.g sudo systemctl restart keyd).
 
 If no configuration file exists for a given keyboard and default.cfg is present, it is used.
 

src/main.c

@@ -43,6 +43,7 @@
 #define UINPUT_DEVICE_NAME "keyd virtual keyboard"
 #define MAX_KEYBOARDS 256
 #define LOCK_FILE "/var/lock/keyd.lock"
+#define LOG_FILE "/var/log/keyd.log" //Only used when running as a daemon.
 
 static int ufd = -1;
 
@@ -642,6 +643,24 @@ static void exit_signal_handler(int sig)
 	exit(0);
 }
 
+void daemonize()
+{
+	int fd = open(LOG_FILE, O_APPEND|O_WRONLY);
+
+	warn("Daemonizing.");
+	warn("Log output will be stored in %s", LOG_FILE);
+
+	if(fork()) exit(0);
+	if(fork()) exit(0);
+
+	close(0);
+	close(1);
+	close(2);
+
+	dup2(fd, 1);
+	dup2(fd, 2);
+}
+
 int main(int argc, char *argv[])
 {
 	if(argc > 1 && !strcmp(argv[1], "-m"))
@@ -659,6 +678,10 @@ int main(int argc, char *argv[])
 	signal(SIGINT, exit_signal_handler);
 	signal(SIGTERM, exit_signal_handler);
 
+	if(argc > 1 && !strcmp(argv[1], "-d"))
+		daemonize();
+
+	warn("Starting keyd.");
 	config_generate();
 	ufd = create_uinput_fd();