curl登陆后模拟登陆并访问登陆后的页面

<?phpheader("content-type:textml;charset=utf-8");//采集的信息需要先登录的就要先模拟登录//设置cookie保存路径$cookie_path = './';$ch = curl_init();//组装用户名和密码$info['username'] = '141391000914';$info['password'] = '123456';$sub_url = 'http://172.27.0.200/exam/index.php?m=Index&a=login';//模拟表单提交$params[CURLOPT_URL] = $sub_url;    //请求url地址$params[CURLOPT_HEADER] = true; //是否返回响应头信息$params[CURLOPT_RETURNTRANSFER] = true; //是否将结果返回$params[CURLOPT_FOLLOWLOCATION] = true; //是否重定向$params[CURLOPT_USERAGENT] = 'Mozilla/5.0 (Windows NT 5.1; rv:9.0.1) Gecko/20100101 Firefox/9.0.1';$postfields = '';//将表单要提交的数据编程URL拼接方式foreach ($info as $key => $value){    $postfields .= urlencode($key) . '=' . urlencode($value) . '&';}$params[CURLOPT_POST] = true;$params[CURLOPT_POSTFIELDS] = $postfields;//判断是否有cookie,有的话直接使用if (isset($_COOKIE['cookie_jar'])&&($_COOKIE['cookie_jar']||is_file($_COOKIE['cookie_jar']))){    $params[CURLOPT_COOKIEFILE] = $_COOKIE['cookie_jar']; //这里判断cookie}else{    $cookie_jar = tempnam($cookie_path, 'cookie'); //产生一个cookie文件    $params[CURLOPT_COOKIEJAR] = $cookie_jar; //写入cookie信息    setcookie('cookie_jar', $cookie_jar); //保存cookie路径}curl_setopt_array($ch, $params); //传入curl参数curl_exec($ch); //执行//第一次请求是把考试平台的cookie取了过来，所以第二次请求直接请求考试平台登陆成功后的首页即可$sub_url = 'http://172.27.0.200/exam/index.php?m=Index&a=home';$params[CURLOPT_URL] = $sub_url;    //请求url地址curl_setopt_array($ch, $params); //传入curl参数$re=curl_exec($ch); //执行print_r($re);