PHP - cURL获取响应正文

Question

如何从URL打印响应内容，因为预览为空

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); 
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_REFERER, $ref);
    curl_setopt($ch, CURLOPT_COOKIEJAR, cookie.txt');
    curl_setopt($ch, CURLOPT_COOKIEFILE, cookie.txt');
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); 
    curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/0.10.1");
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $post_fields);
    $output = curl_exec($ch);
    curl_close($ch);

照片：

Answer 1

1. 你需要回应出来的反应

   echo $output; 
   

2. 我注意到你丢失了cookie文件和cookie jar名称旁边的单引号......它们应该成为

   curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookie.txt');
   curl_setopt($ch, CURLOPT_COOKIEFILE, 'cookie.txt');