#!/bin/bash
NIC=$1
echo -e " In ------ Out"
while true; do
OLD_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
OLD_OUT=$(awk '$0~"'$NIC'"{print $10}' /proc/net/dev)
sleep 1
NEW_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
NEW_OUT=$(awk '$0~"'$NIC'"{print $10}' /proc/net/dev)
IN=$(printf "%.1f%s" "$((($NEW_IN-$OLD_IN)/1024))" "KB/s")
OUT=$(printf "%.1f%s" "$((($NEW_OUT-$OLD_OUT)/1024))" "KB/s")
echo "$IN $OUT"
sleep 1
done