To do

<?php $fp = fopen(“/tmp/lock.txt”, “w+”); if (flock($fp, LOCK_EX)) { // do an exclusive lock fwrite($fp, “Write something heren”); flock($fp, LOCK_UN); // release the lock } else { echo “Couldn’t lock the file !”; } fclose($fp); ?> http://us3.php.net/flock read – write Berkeley DB Response handling in response.c