davidnewhall

// Write a pid file, but first make sure it doesn't exist with a running pid.
func writePidFile(pidFile string) error {
	// Read in the pid file as a slice of bytes.
	if piddata, err := ioutil.ReadFile(pidFile); err == nil {
		// Convert the file contents to an integer.
		if pid, err := strconv.Atoi(string(piddata)); err == nil {
			// Look for the pid in the process list.
			if process, err := os.FindProcess(pid); err == nil {
				// Send the process a signal zero kill.
				if err := process.Signal(syscall.Signal(0)); err == nil {