[socket programming] Post data error 411: Length required

[valleymannn]

hey i'm trying to send a post data with the following code

int main() {

  try {
    SocketClient s("www.site.com", 80);
    string data = "par1=value1&par2=value2";
    s.SendLine("POST /post_page.php HTTP/1.0\r\n");
    s.SendLine("Host: www.site.com\r\n");
    s.SendLine("User-Agent: Mozilla/4.0\r\n");
    s.SendLine("Content-Length: 23\r\n\r\n");
    s.SendLine("Content-Type: application/x-www-form-urlencoded\r\n");
    s.SendLine("\r\n");
    s.SendLine(data + "\r\n");
    s.SendLine("\r\n");


    while (1) {
      string l = s.ReceiveLine();
      if (l.empty()) break;
      cout << l;
      cout.flush();
    }

  }
  catch (const char* s) {
    cerr << s << endl;
  }
  catch (std::string s) {
    cerr << s << endl;
  }
  catch (...) {
    cerr << "unhandled exception\n";
  }

  return 0;
}

it returns error 411 Length required. I want to make it clear first that the SocketClient class should work properly (I tested it with a GET request) and what it does is evident by the code. I've set the Content-Length as a fixed 23 (by counting data manually) to avoid complicating the problem. So what's the problem?
Thanks,
valleyman

[valleymannn]

noone can help me??

[m4ster r0shi]

I'm not familiar with the protocol but are you sure it should be done like this:

s.SendLine("Content-Length: 23\r\n\r\n");

and not like this:

s.SendLine("23\r\n\r\n"); ???

Perhaps the other SendLine calls also need similar modification...

Anyway, google the protocol and see the proper way to communicate with the server. It shouldn't be difficult.

Take a look at this -> http://www.jmarshall.com/easy/http/#postmethod
It first sends Content-Type and then Content-Length (you do it the other way around), I don't know if it's important but I thought I should mention it.

[valleymannn]

this didn't work at any way, I followed post method specification but nothing...

[Galik]

Thi doesn't look right:

s.SendLine("Content-Length: 23\r\n\r\n");

Only the final header should have a double line end. I think it needs to be:

s.SendLine("Content-Length: 23\r\n");

Otherwise the Content-Type header will be sent as part of the data.

[Galik]

Actually, thinking about it SendLine() probably sends the line breaks itself. So I would try removing all the "\r\n" additions and try this:

    SocketClient s("www.site.com", 80);
    string data = "par1=value1&par2=value2";
    s.SendLine("POST /post_page.php HTTP/1.0");
    s.SendLine("Host: www.site.com");
    s.SendLine("User-Agent: Mozilla/4.0");
    s.SendLine("Content-Length: 23");
    s.SendLine("Content-Type: application/x-www-form-urlencoded");
    s.SendLine(""); // signal end of headers
    s.SendLine(data);