This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php
(PHP 5 >= 5.3.0, PHP 7, PHP 8)
stream_supports_lock — Tells whether the stream supports locking
Tells whether the stream supports locking through flock().
stream
The stream to check.
Gibt bei Erfolg true
zurück. Bei einem Fehler wird false
zurückgegeben.
This method returns TRUE on custom wrappers by default if you don't implement the stream_lock() method inside the wrapper : http://php.net/manual/en/streamwrapper.stream-lock.php