A Much simpler and easier approach is to use:

 curl -X HEAD -I http://www.google.com

Order can be changed for example: 

 curl http://www.google.com -X HEAD -I

This is useful if you are grabbing curl request from chrome inspector.

`Note:` Some incorrectly configured/programmed web servers might response different then the post because it is a HEAD request not POST. But works most of the time