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<streamWrapper::stream_flushstreamWrapper::stream_metadata>
^streamWrapperLast updated: Mon, 26 Oct 2026

streamWrapper::stream_lock

(PHP 5, PHP 7, PHP 8)

streamWrapper::stream_lock — Advisory file locking

Description

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

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

Parameters

operation

operation is one of the following:

  • LOCK_SH to acquire a shared lock (reader).

  • LOCK_EX to acquire an exclusive lock (writer).

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

It is also possible to have LOCK_NB added as a bitmask to one of the above operations, if the lock should not block during the locking attempt (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


<streamWrapper::stream_flushstreamWrapper::stream_metadata>
^streamWrapperLast updated: Mon, 26 Oct 2026