cURL 不寫入文件獲取與使用 Cookie 的 PHP 示例

場景

某些環境（如無寫入權限、容器化部署、高併發臨時會話）不適合使用 CURLOPT_COOKIEJAR/CURLOPT_COOKIEFILE 文件存儲 Cookie。可在內存中直接提取、攜帶 Cookie 字符串。

核心代碼

<?php
/*----- 步驟 1：登錄獲取 Cookie -----*/
$url = 'https://example.com/login';
$post = "username=user&password=123456";

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HEADER, 1);           // 輸出頭部以獲取 Set-Cookie
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);   // 返回字符串
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // 測試環境忽略證書
$content = curl_exec($ch);

// 正則提取 Set-Cookie（可能有多個，取第一個或拼接）
preg_match('/Set-Cookie:\s*([^;]+)/i', $content, $matches);
$cookie = $matches[1] ?? ''; // 例：PHPSESSID=abc123
curl_close($ch);

if (!$cookie) die('登錄失敗，未獲取到 Cookie');

/*----- 步驟 2：攜帶 Cookie 訪問受保護資源 -----*/
$apiUrl = 'https://example.com/api/user/info';
$ch = curl_init($apiUrl);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_COOKIE, $cookie); // 直接設置 Cookie 字符串
$response = curl_exec($ch);
curl_close($ch);

echo $response; // {"code":0,"data":{"name":"user"}}

進階：處理多個 Cookie

若有多個 Set-Cookie 頭，需全部提取並以分號拼接：

preg_match_all('/Set-Cookie:\s*([^;]+)/i', $content, $matches);
$cookie = implode('; ', $matches[1]); // PHPSESSID=abc; token=xyz

封裝為可復用類

<?php
class CurlCookieClient {
    private $ch;
    private $cookie = '';

    public function __construct() {
        $this->ch = curl_init();
        curl_setopt($this->ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($this->ch, CURLOPT_SSL_VERIFYPEER, false);
    }

    public function post($url, $data) {
        curl_setopt($this->ch, CURLOPT_URL, $url);
        curl_setopt($this->ch, CURLOPT_POST, 1);
        curl_setopt($this->ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($this->ch, CURLOPT_HEADER, 1);
        $content = curl_exec($this->ch);
        $this->extractCookie($content);
        return $this->stripHeader($content);
    }

    public function get($url) {
        curl_setopt($this->ch, CURLOPT_URL, $url);
        curl_setopt($this->ch, CURLOPT_POST, 0);
        curl_setopt($this->ch, CURLOPT_HEADER, 0);
        if ($this->cookie) {
            curl_setopt($this->ch, CURLOPT_COOKIE, $this->cookie);
        }
        return curl_exec($this->ch);
    }

    private function extractCookie($header) {
        preg_match_all('/Set-Cookie:\s*([^;]+)/i', $header, $m);
        if ($m[1]) $this->cookie = implode('; ', $m[1]);
    }

    private function stripHeader($response) {
        list($header, $body) = explode("\r\n\r\n", $response, 2);
        return $body;
    }

    public function __destruct() {
        curl_close($this->ch);
    }
}

// 使用
$client = new CurlCookieClient();
$client->post('https://example.com/login', ['user'=>'a','pass'=>'1']);
echo $client->get('https://example.com/api/profile');

注意事項

• 安全性：Cookie 含敏感標識，內存中處理避免文件洩露，但進程內存轉儲仍可讀取，權衡場景使用。
• 有效期：Session Cookie 瀏覽器關閉即失效，服務端可能設置較短 TTL，需適時重新登錄。
• 並發：同一實例不支持並發請求（共享 Cookie 狀態），多線程/協程場景請各自實例化。