php file lock write

PHP file writing method, coping with multi-threaded writing:

Php code

function file_write($file_name, $text, $mode='a', $timeout=30){  
    $handle = fopen($file_name, $mode);  
    while($timeout>0){  
        if ( flock($handle, LOCK_EX) ) {  
            $timeout--;  
            sleep(1);  
        }  
    }  
    if ( $timeout > 0 ){  
        fwrite($handle, $text.'\n');  
        flock($handle, LOCK_UN);  
        fclose($handle);  
        return true;  
    }  
    return false;  
}

The handle operated by flock(int $handle, int $operation) function must be an open file pointer.

operation can be one of the following values:

To obtain a shared lock (reading program), set operation to LOCK_SH (set to 1 in versions prior to PHP 4.0.1).

To obtain an exclusive lock (writing program), set operation to LOCK_EX (set to 2 in versions prior to PHP 4.0.1).

To release a lock (whether shared or exclusive), set operation to LOCK_UN (set to 3 in versions prior to PHP 4.0.1).

If you don’t want flock() to block when locked, add LOCK_NB to operation (set to 4 in versions before PHP 4.0.1).