PHP域名查墙代码

<?php
function checkDomain($domain) {
    $startTime = microtime(true);
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $domain);
    curl_setopt($ch, CURLOPT_NOBODY, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_exec($ch);
    $endTime = microtime(true);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($httpCode == 403 || ($endTime - $startTime) > 5) {
        return "Domain is blocked";
    } else {
        return "Domain is accessible";
    }
}

$domain = "example.com";
$result = checkDomain($domain);
echo $result;
?>