Re^4: self detecting script

[gri6507]

It's not so much that the filehand is left open when the exit event happens. Usually when the lockfiles are created the script simply writes its pid to the file and closes the filehandle to flush the file. Then when the script exists, the lockfile is deleted. However, if an unexpected exit happens, then the lockfile will still be around.

[mpeters]

Well, if you just rely on the prescence of the lock file then you open yourself up to a race condition. If you flock it, then it's prescence after the fact doesn't really matter does it? The next run of the script will be able to grab the same lock and write it's pid there if it needs to.