如何在PHP中检测站点是否支持HTTP/2

<?php
$url = 'https://example.com';
$ch = curl_init($url);

curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HEADER => true,
    CURLOPT_NOBODY => true,
    CURLOPT_SSL_VERIFYPEER => false, // 注意：在生产环境中应设置为true
    CURLOPT_SSL_VERIFYHOST => false, // 注意：在生产环境中应设置为2
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_2_0,
]);

$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$protocol_version = curl_getinfo($ch, CURLINFO_PROTOCOL_VERSION);

curl_close($ch);

if ($protocol_version === 'HTTP/2.0') {
    echo '站点支持HTTP/2';
} else {
    echo '站点不支持HTTP/2';
}
?>

<?php
$url = 'https://example.com';
$headers = get_headers($url);

if (strpos(implode("\n", $headers), 'HTTP/2') !== false) {
    echo '站点支持HTTP/2';
} else {
    echo '站点不支持HTTP/2';
}
?>

composer require guzzlehttp/guzzle

<?php
require 'vendor/autoload.php';

use GuzzleHttp\Client;

$client = new Client(['http2' => true]);
$response = $client->head('https://example.com');

if ($response->getProtocolVersion() === '2.0') {
    echo '站点支持HTTP/2';
} else {
    echo '站点不支持HTTP/2';
}
?>