Please help with Perl program!

[94_AcCoRd_EX]

Here's all I know about the assignment:

/proc/net/dev - Identify how many ethernet devices that I have and identify which one is "upstream" by looking at the default route.

example output:
eth0 192.168.2.2
eth1 128.193.2.2 upstream


Can anyone give me a hand here? I know a few of you are experienced with networks and programming. I've never touched perl before.

Thanks