Er, as far as I understand the way you have it wont work. You are opening the file in overwrite mode, and since the open happens before the lock and probably that locks are advisory on your os, you just clobber the lockfile, so your follow up lock suceeds because the file you are locking is not the same one (anymore) as the one the other process has locked (which you just deleted but it is holding open anyway).

So you have to open the file with something else, maybe '>>' or maybe '+<'. Im sure the article by Dominus that was suggested will help you sort it out.

And you should know that locking semantics vary from OS to OS. On Unix they are advisory, on Win32 they are compulsary. So for instance, what you did above would work just fine on Win32, but not on Unix.


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demerphq

<Elian> And I do take a kind of perverse pleasure in having an OO assembly language...

In reply to Re: Lock Effectivity by demerphq
in thread Lock Effectivity by Gorby

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