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SplFileObject::flockPortable file locking


public SplFileObject::flock(int $operation, int &$wouldBlock = null): bool

Locks or unlocks the file in the same portable way as flock().

Bağımsız Değişkenler


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.


Set to true if the lock would block (EWOULDBLOCK errno condition).

Dönen Değerler

Başarı durumunda true, başarısızlık durumunda false döner.


Örnek 1 SplFileObject::flock() example

= 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 {
"Couldn't get the lock!";

Ayrıca Bakınız

  • flock() - Öneri niteliğinde taşınabilir dosya kilitleme

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User Contributed Notes 2 notes

digitalprecision at gmail dot com
11 years ago
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.
Ahmed Rain
3 months ago
@digitalprecision What you said is not completely true, ftruncate(0); is needed if there was a write to the file before the lock is acquired. You also may need fseek(0); to move back the file pointer to the beginning of the file

= new SplFileObject("/tmp/lock.txt", "w");
$file->fwrite("xxxxx"); // write something before the lock is acquired
sleep(5); // wait for 5 seconds

if ($file->flock(LOCK_EX)) { // do an exclusive lock
$file->fwrite("Write something here\n");
$file->flock(LOCK_UN);   // release the lock   
} else {
"Couldn't get the lock!";

"lock.txt" content:

xxxxxWrite something here
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