All of that is explained in the documentation for flock().

Note that to check for a lock, you'll need to try a flock() with LOCK_NB, otherwise, if the file is already locked, the flock() will block untill the lock is released.

"What should it profit a man, if he should win a flame war, yet lose his cool?"

In reply to Re: File locking by Joost
in thread File locking by Nalina

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