Why is the PID not being written to the file until after the script is HUPped?

I'm guessing that you have a buffering problem. There can be a substantial delay between when the script "writes" into the file, and the next event that can cause I/O buffers to be flushed. Consult your favorite reference for instructions on unbuffering (hint: it'll invole the single argument form of select() ).

You're also openning the lock file in "append" mode. Better to just truncate and rewrite.

In reply to Re: Writing to flock files in a daemon by dws
in thread Writing to flock files in a daemon by graq

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