OK, I've actually gone into this on my router now and having seen the output from ifconfig, and looked at a few guides on the web, I think I now understand the basics of grep, cut and how that's all being done. I assume the output from ifconfig is always rigidly formatted enough to rely on that then?

I'm still not sure how to get this running on the N900 though, I have not installed the thing to allow sudo gainroot yet... I'm guessing that's necessary as a first step. Where from there?