Detecting faked pagerank

Does anyone know how I would go about detecting faked pagerank in a php script im writing to run checks on a domain?

I understand that PR is faked when someone sets up a specific 301 redirect to a high pr domain exclusively for googlebots, but dont know how I would mimic开发者_运维百科 this to check (I guess I would need the exact user agent?)

Thanks

Use GoogleBot's UserAgent, and visit the site with a script (or even from your browser). (If from the script) check for the HTTP response code.

Google Bot UserAgent:

Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)