* We must, of course, be careful to remove the lock file by a call
* to unlock before we stop. The algorithm used here is to see if
* the lock exists, and if it does, to check its modify time. If it
* We must, of course, be careful to remove the lock file by a call
* to unlock before we stop. The algorithm used here is to see if
* the lock exists, and if it does, to check its modify time. If it