PHP Unconference Europe 2015

SplFileObject::flock

(PHP 5 >= 5.1.0)

SplFileObject::flockPortable file locking

说明

public bool SplFileObject::flock ( int $operation [, int &$wouldblock ] )

Locks 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).
  • LOCK_NB to not block while locking (not supported on Windows).

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

Example #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!";
}
?>

参见

  • flock() - 轻便的咨询文件锁定

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User Contributed Notes 1 note

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-1
digitalprecision at gmail dot com
3 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.
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