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

A popular answer for displaying response headers, but OP asked about request headers.

curl -s -D - -o /dev/null http://example.com

• -s : Avoid showing progress bar
• -D - : Dump headers to a file, but - sends it to stdout
• -o /dev/null : Ignore response body

This is better than -I as it doesn't send a HEAD request, which can produce different results.

It's better than -v because you don't need so many hacks to un-verbose it.