#!/bin/bash

for device in /sys/class/net/* ; do
	if [ ! -e $device/flags ]; then
		continue
	fi

	loop=$(($(cat $device/flags) & 0x8 && 1 || 0))
	bc=$(($(cat $device/flags) & 0x2 && 1 || 0))
	ptp=$(($(cat $device/flags) & 0x10 && 1 || 0))

	# Skip any device that is a loopback
	if [ $loop = 1 ]; then
		continue
	fi

	# Skip any device that isn't a broadcast
	# or point-to-point.
	if [ $bc = 0 ] && [ $ptp = 0 ]; then
		continue
	fi

	DEVICE="$DEVICE $(basename $device)"
done

echo $DEVICE