SplFileObject::flock
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplFileObject::flock — Portable file locking
说明
public SplFileObject::flock
( int
$operation
, int &$wouldblock
= ?
) : boolLocks or unlocks the file in the same portable way as flock().
参数
-
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).
返回值
成功时返回 true
, 或者在失败时返回 false
。
范例
示例 #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!";
}
?>