php字符串截取域名

<?php
function getDomainFromUrl($url) {
    $pattern = '/^(?:https?:\/\/)?(?:[^@\n]+@)?(?:www\.)?([^:\/\n]+)/';
    preg_match($pattern, $url, $matches);
    return $matches[1] ?? '';
}

$url = 'https://www.example.com/path/to/page?query=string';
$domain = getDomainFromUrl($url);
echo $domain; // 输出: example.com
?>

<?php
function getDomainFromUrl($url) {
    $url = parse_url($url);
    $domain = isset($url['host']) ? $url['host'] : '';
    if (strpos($domain, 'www.') === 0) {
        $domain = substr($domain, 4);
    }
    return $domain;
}

$url = 'https://www.example.com/path/to/page?query=string';
$domain = getDomainFromUrl($url);
echo $domain; // 输出: example.com
?>

<?php
$url = 'https://例子.测试';
$domain = getDomainFromUrl($url);
$asciiDomain = idn_to_ascii($domain);
echo $asciiDomain; // 输出: xn--fsq.xn--0zwm56d
?>