<?php require_once 'xmlHandler.php'; $datasize = $_POST["datasize"]; // set the execution time limit for this php session to 60 seconds (default is in php.ini) set_time_limit(60); // create the chatroom xml file handler $xmlh = new xmlHandler("chatroom.xml"); // check if the chatroom XML data file exists if (!$xmlh->fileExist()) { // create new XML file $xmlh->openFile(); // create a 'chatroom' element, as root element $root = $xmlh->addRootElement("chatroom"); // create a 'messages' element for the set of messages $xmlh->addElement($root, "users"); $xmlh->addElement($root, "messages"); // save the XML file $xmlh->saveFile(); } $start = gettimeofday(); while (1) { // if the file size of chatroom.xml is changed, that means new message has been added if ($xmlh->fileExist()) { // if data size is changed, // stop running this while loop to send messages to user if ($_POST["datasize"] != filesize("chatroom.xml")) { break; } } // clear the internal cache of file system functions from php