!/bin/bash

NIC=$l
echo -e "In ------ Out"
while true; do

OLD_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
OLD_IN=$(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 $2}' /proc/net/dev)
IN=$(printf "%.lf%s" "$((($NEW_IN-$OLD_IN)/1024))" "KB/s")
OUT=$(printf "%.lf%s" "$((($NEW_OUT-$OLD_OUT)/1024))" "KB/s")
echo "$IN $OUT"
sleep l

done