How do you display POST data with cURL?

Question

As an example, POSTing to a web server with the -v argument:

curl -v http://testserver.com/post -d "firstname=john&lastname=doe"

And the output

> POST /post HTTP/1.1
> User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 OpenSSL/0.9.8l zlib/1.2.3
> Host: testserver.com
> Accept: */*
> Content-Length: 28
> Content-Type: application/x-www-form-urlencoded
> 
< HTTP/1.1 200 OK
(etc)

There is no mention of the data that I posted.

Is there an option in cURL to display the string "firstname=john&lastname=doe" in the output?

Note: Obviously the string I want is in the command I executed, but there are several other post options such as --form and --data-ascii etc. I'd like to see the raw data being sent to the server.

Answer 1

The closest I got without using tcpdump is using the --trace-ascii option:

~ curl http://w3.org/ -d "hello=there" --trace-ascii /dev/stdout
== Info: About to connect() to w3.org port 80 (#0)
== Info:   Trying 128.30.52.45... == Info: connected
== Info: Connected to w3.org (128.30.52.45) port 80 (#0)
=> Send header, 210 bytes (0xd2)
0000: POST / HTTP/1.1
0011: User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.1
0051: 9.7 OpenSSL/0.9.8l zlib/1.2.3
0070: Host: w3.org
007e: Accept: */*
008b: Content-Length: 11
009f: Content-Type: application/x-www-form-urlencoded
00d0: 
=> Send data, 11 bytes (0xb)
0000: hello=there

Unfortunately, this doesn't work when you're posting multipart/form-data:

~ curl http://w3.org/ -F hello=there -F testing=123 --trace-ascii /dev/stdout
== Info: About to connect() to w3.org port 80 (#0)
== Info:   Trying 128.30.52.45... == Info: connected
== Info: Connected to w3.org (128.30.52.45) port 80 (#0)
=> Send header, 270 bytes (0x10e)
0000: POST / HTTP/1.1
0011: User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.1
0051: 9.7 OpenSSL/0.9.8l zlib/1.2.3
0070: Host: w3.org
007e: Accept: */*
008b: Content-Length: 244
00a0: Expect: 100-continue
00b6: Content-Type: multipart/form-data; boundary=--------------------
00f6: --------19319e4d1b79
010c: 
<= Recv header, 32 bytes (0x20)
0000: HTTP/1.1 301 Moved Permanently

Answer 2

Odd. When I use curl like so:

curl -v  -d "filename1=attach.etc" http://myurl/site.asp 

I get the posted variables appearing as the very last line in the output before the HTTP response. This is with curl 7.15.0 on Windows.