What is the right way to POST multipart/form-data using curl?

Question

I used this syntax to post a file along with some parameters:

curl -v -include --form "key1=value1" --form upload=localfilename URL

The file is around 500K in size. First of all, I see content length to be 254 on the transmit side. Later the server response's content length is 0. Where am I going wrong?

Here is the complete trace of the command.

* Couldn't find host xxx.xxx.xxx.xxx in the _netrc file; using defaults
* About to connect() to xxx.xxx.xxx.xxx port yyyy (#0)
*   Trying xxx.xxx.xxx.xxx...
* Adding handle: conn: 0x4b96a0
* Adding handle: send: 0
* Adding handle: recv: 0
* Curl_addHandleToPipeline: length: 1
* - Conn 0 (0x4b96a0) send_pipe: 1, recv_pipe: 0
* Connected to xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx) port yyyy (#0)
* POST /zzzzzz/UploadFile HTTP/1.1
* User-Agent: curl/7.32.0
* Host: xxx.xxx.xxx.xxx:yyyy
* Accept: */*
* Content-Length: 254
* Expect: 100-continue
* Content-Type: multipart/form-data; boundary=------------------------948a6137eef50079
*
* HTTP/1.1 100 Continue
* HTTP/1.1 100 Continue

* HTTP/1.1 200 OK
* HTTP/1.1 200 OK
* Server Apache-Coyote/1.1 is not blacklisted
* Server: Apache-Coyote/1.1
* Server: Apache-Coyote/1.1
* Added cookie JSESSIONID="C1D7DD042E250211D9DEA82688876F88" for domain xxx.xxx.xxx.xxx, path /zzzzz/, expire 0
* Set-Cookie: JSESSIONID=C1D7DD042E250211D9DEA82688876F88; Path=/zzzzzz/;
* HttpOnly
* Set-Cookie: JSESSIONID=C1D7DD042E250211D9DEA82688876F88; Path=/zzzzzz/; HttpOnly
* Content-Type: text/html;charset=ISO-8859-1
Content-Type: text/html;charset=ISO-8859-1
* Content-Length: 0
* Content-Length: 0
* Date: Tue, 01 Oct 2013 11:54:24 GMT
* Date: Tue, 01 Oct 2013 11:54:24 GMT
* Connection #0 to host xxx.xxx.xxx.xxx left intact

Answer 1

The following syntax fixes it for you:

curl -v -F key1=value1 -F upload=@localfilename URL