How can I see the request headers made by curl when sending a request to the server?

Question

I want to see the request headers made by curl when I am sending a request to the server. How can I check that?

Answer 1

I think curl --verbose/-v is the easiest. It will spit out the request headers (lines prefixed with '>') without having to write to a file:

$ curl -v -I -H "Testing: Test header so you see this works" http://stackoverflow.com/
* About to connect() to stackoverflow.com port 80 (#0)
*   Trying 69.59.196.211... connected
* Connected to stackoverflow.com (69.59.196.211) port 80 (#0)
> HEAD / HTTP/1.1
> User-Agent: curl/7.16.3 (i686-pc-cygwin) libcurl/7.16.3 OpenSSL/0.9.8h zlib/1.2.3 libssh2/0.15-CVS
> Host: stackoverflow.com
> Accept: */*
> Testing: Test header so you see this works
>
< HTTP/1.0 200 OK
...