<?php $file = “ip_data.dat”; $duration = 30*60; //30 minutes $lines = file($file); foreach($lines as $line) { list($ip, $time) = explode(“µ”, $line); if($time > time()–$duration) { $ips = trim($time); } } $ip = $_SERVER; if(@array_key_exists($ip, $ips)) { if($ips > time()–$duration) { // TRUE $ips = time(); $was_here = TRUE; } } else { $ips = time(); $was_here = FALSE; } $fp = fopen($file, “w”); foreach($ips as $ip=>$time) {...