How to display request headers with command line curl

Question

Command line curl can display response header by using -D option, but I want to see what request header it is sending. How can I do that?

Answer 1

I believe the command line switch you are looking for to pass to curl is -I.

Example usage:

$ curl -I http://heatmiser.counterhack.com/zone-5-15614E3A-CEA7-4A28-A85A-D688CC418287  
HTTP/1.1 301 Moved Permanently
Date: Sat, 29 Dec 2012 15:22:05 GMT
Server: Apache
Location: http://heatmiser.counterhack.com/zone-5-15614E3A-CEA7-4A28-A85A-D688CC418287/
Content-Type: text/html; charset=iso-8859-1

Additionally, if you encounter a response HTTP status code of 301, you might like to also pass a -L argument switch to tell curl to follow URL redirects, and, in this case, print the headers of all pages (including the URL redirects), illustrated below:

$ curl -I -L http://heatmiser.counterhack.com/zone-5-15614E3A-CEA7-4A28-A85A-D688CC418287
HTTP/1.1 301 Moved Permanently
Date: Sat, 29 Dec 2012 15:22:13 GMT
Server: Apache
Location: http://heatmiser.counterhack.com/zone-5-15614E3A-CEA7-4A28-A85A-D688CC418287/
Content-Type: text/html; charset=iso-8859-1

HTTP/1.1 302 Found
Date: Sat, 29 Dec 2012 15:22:13 GMT
Server: Apache
Set-Cookie: UID=b8c37e33defde51cf91e1e03e51657da
Location: noaccess.php
Content-Type: text/html

HTTP/1.1 200 OK
Date: Sat, 29 Dec 2012 15:22:13 GMT
Server: Apache
Content-Type: text/html