availble usb devices

I suspect my problem is my lack of experience with linux..
anyway, I'm working on building a GUI version of my program that talks with my arduino. (currently it shows up as /dev/ttyACM0 ) but what I'm trying to do, get is a list of available usb devices so my program can present the list to the user to pick one. how do I generate that list? I can find tons on doing it from the command line.. but not inside a C program ..?

well, after a LOT more digging.. I came across libusb (which I couldn't get to work) then I found what libusb is based on.. LibUdev... which actually worked out pretty well!

Tutorial: How to use libudev and Sysfs in Linux