Getting empty response from php curl

Question

Getting empty message as response PHP CURL

I have tried print_r, the httpcode is 200, even CURLOPT_VERBOSE shows no error. However, it is not returning any value.

curl = curl_init();
curl_setopt_array($curl, array(
  CURLOPT_URL => "http://dummy.com/xxx",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_VERBOSE=>true,
  CURLOPT_TIMEOUT => 50,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_CUSTOMREQUEST => "POST",
    CURLOPT_POSTFIELDS => $payload,
    CURLOPT_HTTPHEADER => array(
      "Authorization: Basic xxx",
    ),
  ));

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "error:" . $err;
} else {
  echo "response: ".$response;
}

I am getting

response: 
when I do CURLOPT_VERBOSE, this returned:
*   Trying xxx.xx.xx.xxx...
* TCP_NODELAY set
* Connected to xxx.xx.xx.xxx (xxx.xx.xx.xxx) port xxxx (#0)
> POST /jw/web/json/plugin/org.joget.webservices.JsonRegistrationApiService/service HTTP/1.1
Host: xxx.xx.xxx.xxx
Accept: */*
Authorization: Basic Yxxxxxx
Content-Length: 775
Expect: 100-continue
Content-Type: application/json; boundary=------------------------916024cad4258a00

< HTTP/1.1 100 
< HTTP/1.1 200 
< Set-Cookie: JSESSIONID=4ED88EE9FD9746ED9C5F345F713FDB69; Path=/jw; HttpOnly
< X-Content-Type-Options: nosniff
< Content-Type: application/json;charset=utf-8
< Content-Length: 0
< Date: Tue, 16 Apr 2019 06:19:00 GMT
< 
* Connection #0 to host xx.xx.xx.xxx left intact

Any php master care to help?

Answer 1

Content-Length: 0 means your content's length is zero.

Actually it is a good practice to return no content on POST request. So your curl code probably works fine.

The idea of this response is just to set you a session cookie. Using this cookie you can send other requests being already authorized.

Answer 2

我找到了答案，有效载荷必须是json_encode（） - ed。这是我的坏事