linux - How to see HTTP request header by curl?

I can see HTTP header response by curl -I command.

Is there any option to see the HTTP request header sent?

curl -I www.google.com
HTTP/1.1 200 OK
Date: Sat, 31 Dec 2011 00:55:53 GMT
Expires: -1
Cache-Control: private, max-age=0
Content-Type: text/html; charset=ISO-8859-1
Server: gws
Transfer-Encoding: chunked

Answer

From the curl man page:

   -v/--verbose
          Makes the fetching more verbose/talkative. Mostly useful for debugging. A line  starting
          with '>' means "header data" sent by curl, '<' means "header data" received by curl that
          is hidden in normal cases, and a line starting with '*' means additional  info  provided
          by curl.