#!/bin/bash
interface="$1"
metric="$2"
case "$metric" in
	rx)
		cat /proc/net/dev | grep "$interface" | awk '{print $2}'
		;;
	tx)
		cat /proc/net/dev | grep "$interface" | awk '{print $10}'
		;;
	*)
		echo "Usage: $0 <interface> {rx|tx}"
		exit 1
		;;
esac