php正则匹配主域名

<?php
function matchMainDomain($url) {
    // 正则表达式匹配主域名
    $pattern = '/(?:https?:\/\/)?(?:www\.)?([^\/]+)/';
    preg_match($pattern, $url, $matches);
    
    if (isset($matches[1])) {
        return $matches[1];
    } else {
        return false;
    }
}

$url = "https://www.example.com/path/to/page";
$mainDomain = matchMainDomain($url);
if ($mainDomain) {
    echo "主域名是: " . $mainDomain;
} else {
    echo "未找到主域名";
}
?>

<?php
function matchMainDomainComplex($url) {
    // 正则表达式匹配主域名，考虑更多URL变体
    $pattern = '/(?:https?:\/\/)?(?:www\.)?((?:[a-zA-Z0-9-]+\.)+[a-zA-Z]{2,})/';
    preg_match($pattern, $url, $matches);
    
    if (isset($matches[1])) {
        return $matches[1];
    } else {
        return false;
    }
}

$url = "https://subdomain.example.com:8080/path/to/page?query=param";
$mainDomain = matchMainDomainComplex($url);
if ($mainDomain) {
    echo "主域名是: " . $mainDomain;
} else {
    echo "未找到主域名";
}
?>