php判断域名打不开

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

    if ($httpCode >= 200 && $httpCode < 300) {
        return true;
    } else {
        return false;
    }
}

$url = 'https://example.com';
if (checkDomain($url)) {
    echo '域名可以打开';
} else {
    echo '域名无法打开';
}
?>

<?php
function checkDomain($url) {
    $context = stream_context_create(array(
        'http' => array(
            'timeout' => 5 // 设置超时时间
        )
    ));

    $response = @file_get_contents($url, false, $context);

    if ($response !== false) {
        return true;
    } else {
        return false;
    }
}

$url = 'https://example.com';
if (checkDomain($url)) {
    echo '域名可以打开';
} else {
    echo '域名无法打开';
}
?>