- 
<?php
 - 
$file = “ip_data.dat”;
 - 
$duration = 30*60; //30 minutes
 - 
foreach($lines as $line) {
 - 
}
 - 
}
 - 
$ip = $_SERVER[‘REMOTE_ADDR’];
 - 
// TRUE
 - 
$was_here = TRUE;
 - 
}
 - 
} else {
 - 
$was_here = FALSE;
 - 
}
 - 
foreach($ips as $ip=>$time) {
 - 
}
 - 
if($was_here) {
 - 
echo “u was here within 30 minutes.”;
 - 
} else {
 - 
echo “u wasn\’t here within 30 minutes.”;
 - 
}
 - 
?>