asserting filesystem structure with xpaths

Hi,

I'd like a service I'm running to be able to make an integrity check 
against a number of directory structures it depends on, to generate 
testcard/happy page on startup (and check the structure 
intermittently afterwards). I'm thinking this could be done with a 
list of XPaths asserted against a XML representation of the 
filesystem. I can't be the first person to want to have done this, 
so I was wondering if anyone here ever used XML/XPath to do such a 
thing?

Bill de hÓra