in reply to Re^2: File lock demo
in thread File lock demo

Empty lock files certainly aren't wrong either. MJD's talk discusses how many problems can be solved by using a lockfile that is different from the target working files. And that's what you're doing. I mostly just didn't want someone seeing open my $fh, '>', ...; and then flock, and think this idiom will translate well to locking an output file that they intend to write to.