curl - How to get IP from "http://" or "www" in PHP? -

How do I get something in PHP / curl to capture the URL of the URL for me? This will be a simple interface that brings the URL back to me.

e.g. Enter "http://mysite.com" and then press Submit I should get mysite.com's IP back.

  $ ip_string = gethostbyname ("stackoverflow.com") ; Echo $ ip_string; // IP address return, i.e. 12.34.56.78