php取二级域名

<?php
function getSecondLevelDomain($url) {
    $host = parse_url($url, PHP_URL_HOST);
    $parts = explode('.', $host);
    
    // 假设顶级域名是.com
    if (count($parts) > 2 && $parts[count($parts) - 2] == 'com') {
        return $parts[count($parts) - 3];
    }
    
    // 其他顶级域名的处理
    return $parts[count($parts) - 2];
}

$url = 'http://blog.example.com/path';
$secondLevelDomain = getSecondLevelDomain($url);
echo "二级域名是: " . $secondLevel.php
?>

<?php
function getSecondLevelDomain($url) {
    $host = parse_url($url, PHP_URL_HOST);
    if (empty($host)) {
        throw new Exception("无法解析主机名");
    }
    
    $parts = explode('.', $host);
    if (count($parts) < 3) {
        throw new Exception("主机名格式不正确");
    }
    
    // 假设顶级域名是.com
    if ($parts[count($parts) - 1] == 'com') {
        return $parts[count($parts) - 3];
    }
    
    // 其他顶级域名的处理
    return $parts[count($parts) - 2];
}

$url = 'http://blog.example.com/path';
try {
    $secondLevelDomain = getSecondLevelDomain($url);
    echo "二级域名是: " . $secondLevelDomain;
} catch (Exception $e) {
    echo "错误: " . $e->getMessage();
}
?>