This should work
die "a horrible death" if ( -f "lockfile");

open LOCK, ">", "lockfile" or die;
close (LOCK);

... do some stuff ...

unlink("lockfile");

[download]
Ted
--
"That which we persist in doing becomes easier, not that the task itself has become easier, but that our ability to perform it has improved."
  --Ralph Waldo Emerson

In reply to Re: self detecting script by tcf03
in thread self detecting script by InfiniteLoop

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