streamwrapper.stream_lock(3) php man page | unix.com

STREAMWRAPPER.STREAM_LOCK(3)						 1					      STREAMWRAPPER.STREAM_LOCK(3)

streamWrapper::stream_lock - Advisory file locking

SYNOPSIS
       public bool streamWrapper::stream_lock (int  $operation)

DESCRIPTION
	This  method  is called in response to flock(3), when file_put_contents(3) (when $flags contains LOCK_EX), stream_set_blocking(3) and when
       closing the stream ( LOCK_UN).

PARAMETERS
	      o $operation
		-$operation is one of the following:

		     o LOCK_SH to acquire a shared lock (reader).

		     o LOCK_EX to acquire an exclusive lock (writer).

		     o LOCK_UN to release a lock (shared or exclusive).

		     o LOCK_NB if you don't want flock(3) to block while locking. (not supported on Windows)

RETURN VALUES
	Returns TRUE on success or FALSE on failure.

ERRORS
/EXCEPTIONS
	Emits E_WARNING if call to this method fails (i.e. not implemented).

SEE ALSO
       stream_set_blocking(3), flock(3).

PHP Documentation Group 											      STREAMWRAPPER.STREAM_LOCK(3)