For the record, the example given here has an explicit command to truncate the file, however with a 'write mode' of 'w', it will do this for you automatically, so the truncate call is not needed.
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplFileObject::flock — Portable file locking
$operation
, int &$wouldBlock
= null
): boolLocks or unlocks the file in the same portable way as flock().
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 add LOCK_NB
as a bitmask to one
of the above operations, if flock() should not
block during the locking attempt.
wouldBlock
Set to true
if the lock would block (EWOULDBLOCK errno condition).
Gibt bei Erfolg true
zurück. Bei einem Fehler wird false
zurückgegeben.
Beispiel #1 SplFileObject::flock() example
<?php
$file = new SplFileObject("/tmp/lock.txt", "w");
if ($file->flock(LOCK_EX)) { // do an exclusive lock
$file->ftruncate(0); // truncate file
$file->fwrite("Write something here\n");
$file->flock(LOCK_UN); // release the lock
} else {
echo "Couldn't get the lock!";
}
?>
For the record, the example given here has an explicit command to truncate the file, however with a 'write mode' of 'w', it will do this for you automatically, so the truncate call is not needed.