System Resource Usage

[Mmcdermo]

Hi there,
   I'm working on a function that determines what percentage of basic 
resources (CPU, memory, etc) the calling application is using (on *NIX, 
but eventually for windows as well). So far the best solution I've come 
up with is to use the ps utility, but I'm not sure what method I should 
use to retrieve the output. I could have it output to file or pipe the 
output somewhere, but all of this seems extremely awkward for such a 
simple task. Are there some libraries out there that could assist me 
with this, or is there at least a simple way to retrieve the output from 
  ps?

  Thank you very much for your time,
   ~Morgan McDermott