Check if a website is available

available.php

<?php

ini_set("default_socket_timeout", "05");
set_time_limit(5);

$f = fopen("http://github.com", "r");
$r = fread($f, 1000);
fclose($f);

if (strlen($r) > 1) {
    echo "Online";
} else {
    echo "Offline";
}