Maybe I'm misunderstanding the problem. Why don't you lock one of the files or the database table you're importing into (or both)? You have a defined order in which they should be imported, so the program that gets launched to import the (defined) first file locks the file (and the table). The second program launched finds the file/table locked and just exits.

In reply to Re: Semaphore puzzle by Corion
in thread Semaphore puzzle by jerryhone

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