PHP file lock writing example tutorial

php file lock writing

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

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);
 }
 } // bbs.it-home.org
 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 on lock, add lock_nb (set to 4 in versions prior to PHP 4.0.1) to the operation.