有些时候我们需要响应头的数据来做下一步的功能，比如有些api在响应头中包含了token。那么如何解析响应头数据并得到token呢？参照如下方法得到响应数据，并从中获取想要的key值。

$url = 'https://10.1pxeye.com'; // 请求地址，换成自己的。

$curl = curl_init();
curl_setopt_array($curl, array(
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => 1,
    CURLOPT_HEADER => 1,
    CURLOPT_NOBODY => 0,
    CURLOPT_POSTFIELDS => '{}',
    CURLOPT_HTTPHEADER => ['Content-Type:application/json;charset=utf-8'],
)
);
$response = curl_exec($curl);
curl_close($curl);

$header_size = curl_getinfo($curl, CURLINFO_HEADER_SIZE);
$header = substr($response, 0, $header_size);

$response_headers = [];
$line = strtok($header, "\r\n");
$status_code = trim($line);

while (($line = strtok("\r\n")) !== false) {
    if (false !== ($matches = explode(':', $line, 2))) {
        $response_headers["{$matches[0]}"] = trim($matches[1]);
    }
}

echo '<pre style="font-size:12px;line-height:1.3">';
print_r($response_headers);
echo '<pre>';

上述代码将得到如下类型数据：

Array
(
    [Date] => Fri, 22 Dec 2023 04:43:37 GMT
    [Server] => Apache
    [Link] => ; rel="https://api.w.org/", ; rel="alternate"; type="application/json", ; rel=shortlink
    [Strict-Transport-Security] => max-age=31536000; includeSubDomains;
    [Upgrade] => h2
    [Connection] => Upgrade, close
    [Cache-Control] => max-age=0
    [Vary] => Accept-Encoding
    [X-XSS-Protection] => 1; mode=block
    [X-Content-Type-Options] => nosniff
    [X-Frame-Options] => SAMEORIGIN
    [Access-Control-Allow-Origin] => https://cdn.10.1pxeye.com, https://media.1pxeye.com
    [Content-Security-Policy] => connect-src 'self' *.1pxeye.com
    [Referrer-Policy] => no-referrer-when-downgrade
    [Permissions-Policy] => microphone=(),camera=()
    [Transfer-Encoding] => chunked
    [Content-Type] => text/html; charset=UTF-8
)