php获取url里的域名

<?php
$url = 'https://www.example.com/path/to/resource?query=string';

// 解析URL
$parsedUrl = parse_url($url);

// 获取域名
$host = $parsedUrl['host'];

echo "域名: " . $host; // 输出: 域名: www.example.com
?>

<?php
function isValidUrl($url) {
    return filter_var($url, FILTER_VALIDATE_URL);
}

$url = 'https://www.example.com/path/to/resource?query=string';

if (isValidUrl($url)) {
    $parsedUrl = parse_url($url);
    $host = $parsedUrl['host'];
    echo "域名: " . $host;
} else {
    echo "无效的URL";
}
?>

<?php
$url = 'https://www.example.com:8080/path/to/resource?query=string';

$parsedUrl = parse_url($url);
$host = $parsedUrl['host'];

// 去除端口号
if (strpos($host, ':') !== false) {
    $host = substr($host, 0, strpos($host, ':'));
}

echo "域名: " . $host; // 输出: 域名: www.example.com
?>