http://www.perlmonks.org?node_id=240833


in reply to File Locking Tricks and Traps

Cool. I've often used flock to ensure only one instance of a program is running, but I never thought of opening $0 and locking that - consequently each of my scripts litters the filesystem with a matching .lck file.

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Re: Re: File Locking Tricks and Traps
by Limbic~Region (Chancellor) on Mar 06, 2003 at 18:02 UTC
    grantm,
    There is a better reason to use $0 then leaving the filesystem littered with lock files. I pointed out to Nitrox here that in Unix, it is possible to delete a locked file, and that he should use the process table or semaphores instead. He wanted to know if there was a way around this, and I replied with this, which is an attempt at security through obscurity.

    What Dominus is doing is beautiful. By locking $0, it can't be deleted - or rather it can be, but then there wouldn't be a program to run Dominus++.

    Cheers - L~R