Need help with detecting wireless interfaces

Hey,

I've been a lurker here for sometime and am confident that someone will be able to help me (with all your knowledge :))

I'm doing a little program for general unix and unix-like environments in C and wanted to know if there is any way I could find out which network interfaces on my system are wireless?

I can easily enough find all of the interfaces using ifconfig -a (or ifconfig -l if it supports it) but that doesn't show if it is wireless or not.

Is there any guarenteed (or at least common?) way I can find which interfaces are wireless?

Heck at this point I'm willing to take a specific-to-one-platform method just to get it working. (Linux or BSD etc I've got a few systems to play with)

Thanks a million! ;)