Viewing port changelogs

[APseudoUtopia]

Hello,

Before upgrading ports, I have made it a habit to check the changes in
the ports Makefile from the previous version. I've been using the
web-interface located at www.freebsd.org/ports/
For example, this page shows the change commit message,
http://www.freebsd.org/cgi/cvsweb.cgi/ports/mail/postfix/Makefile
and then I view the "preferred diff" for the Makefile itself.

I was wondering if there is any method to doing this from command
line? I often don't have a web-browser available to me when working on
the console. I'd be willing to write a script to display a changelog,
but I'm not even sure where to get it from in the first place, other
than that website.

Any suggestions?

Thank you!