title: Calculate content length POST
body: <p>How can I calculate content length for example of:</p>
  
  <pre><code>POST /Upload/ HTTP/1.1
  Host: test.lan
  User-Agent: Shockwave Flash
  Connection: Keep-Alive
  Cache-Control: no-cache
  Accept: text/*
  Content-Length: ?????
  Content-Type: multipart/form-data; boundary=----------------------------4d2179e6b3c0
  
  ------------------------------4d2179e6b3c0
  Content-Disposition: form-data; name="Filename"
  
  phpinfo.php
  ------------------------------4d2179e6b3c0
  Content-Disposition: form-data; name="ASPSESSID"
  
  6e223eb1c7561e9c599f03cc04e9444b
  ------------------------------4d2179e6b3c0
  Content-Disposition: form-data; name="Filedata"; filename="phpinfo.php"
  Content-Type: application/octet-stream
  
  &lt;? phpinfo(); ?&gt;
  ------------------------------4d2179e6b3c0
  Content-Disposition: form-data; name="Upload"
  
  Submit Query
  ------------------------------4d2179e6b3c0--
  </code></pre>