# BandWidth Usage
# Federico Zanco

IFACE=eth0
TIMEOUT=10
RX="1"
TX="1"
TRAFFIC="FALSE"
UNIT="KiB"
VERBOSE=

show_help () {
echo
echo "usage: bwusage [-h|--help] [-i|--interface ] [--rx-only]"
echo " [--tx-only] [--traffic] [-t|--timeout ]"
echo " [-u|--unit [-v|--verbose]"
echo
}

change_unit () {
case "$UNIT" in

"KiB")
[ "$1" = "RX" ] && RX=`echo "$RX"|awk '{printf "%0.4f", $1 / 1024}'`
[ "$1" = "TX" ] && TX=`echo "$TX"|awk '{printf "%0.4f", $1 / 1024}'`
;;

"MiB")
[ "$1" = "RX" ] && RX=`echo "$RX"|awk '{printf "%0.4f", $1 / 1048576}'`
[ "$1" = "TX" ] && TX=`echo "$TX"|awk '{printf "%0.4f", $1 / 1048576}'`
;;

esac
}

TEMP=`getopt -q -o hi:t:u:v --long help,interface,rx-only,tx-only,traffic,timeout,unit,verbose -- "$@"`

eval set -- "$TEMP"

while true ; do
case "$1" in

-h|--help)
show_help
exit 0
;;

-i|--interface)
IFACE=$2
shift 2
;;

--rx-only)
TX=
shift
;;

--tx-only)
RX=
shift
;;

--traffic)
TRAFFIC="TRUE"
shift
;;

-t|--timeout)
TIMEOUT=$2
shift 2
;;

-u|--unit)
[ "$2" != "B" -a "$2" != "KiB" -a "$2" != "MiB" ] && echo && echo "ERROR: unit $2 not valid" && show_help && exit 1
UNIT=$2
shift 2
;;

-v|--verbose)
VERBOSE="1"
shift
;;

*)
# [ "--" != "$1" ] && echo && echo "ERROR: $1 unknown option" && show_help && exit 1
break
;;
esac
done

[ -z "$(ifconfig -s )|grep $IFACE" ] && echo && echo "ERROR: $IFACE not up or not valid" && exit 1

[ -n "$VERBOSE" ] && echo
[ -n "$VERBOSE" ] && echo "IFACE=$IFACE"
[ -n "$VERBOSE" ] && echo "TIMEOUT=$TIMEOUT s"
[ -n "$VERBOSE" ] && echo "TRAFFIC=$TRAFFIC"
[ -n "$VERBOSE" ] && echo "UNIT=$UNIT"
[ -n "$VERBOSE" ] && echo
[ -n "$VERBOSE" ] && echo "... please wait $TIMEOUT seconds ..."
[ -n "$VERBOSE" ] && echo

[ -n "$RX" ] && rx1=`/sbin/ifconfig $IFACE|tr -s ' '|grep -e "RX bytes:"|cut -d' ' -f3|cut -d: -f2`
[ -n "$TX" ] && tx1=`/sbin/ifconfig $IFACE|tr -s ' '|grep -e "RX bytes:"|cut -d' ' -f7|cut -d: -f2`

sleep $TIMEOUT

[ -n "$RX" ] && rx2=`/sbin/ifconfig $IFACE|tr -s ' '|grep -e "RX bytes:"|cut -d' ' -f3|cut -d: -f2`
[ -n "$TX" ] && tx2=`/sbin/ifconfig $IFACE|tr -s ' '|grep -e "RX bytes:"|cut -d' ' -f7|cut -d: -f2`

if [ -n "$RX" ]
then
RX=`echo "$rx2 - $rx1"|bc`
[ "$TRAFFIC" = "FALSE" ] && RX=`echo "$RX $TIMEOUT"|awk '{printf "%0.4f", $1 / $2 }'`
change_unit "RX"
[ -n "$VERBOSE" ] && echo -n "RX: "
echo "$RX"|awk '{printf "%0.2f", $1 }'
[ -n "$VERBOSE" ] && echo -n " $UNIT" && [ "$TRAFFIC" = "FALSE" ] && echo -n "/s"
fi

[ -n "$RX" ] && [ -n "$TX" ] && echo -n " "

if [ -n "$TX" ]
then
TX=`echo "$tx2 - $tx1"|bc`
[ "$TRAFFIC" = "FALSE" ] && TX=`echo "$TX $TIMEOUT"|awk '{printf "%0.4f", $1 / $2 }'`
change_unit "TX"
[ -n "$VERBOSE" ] && echo -n "TX: "
echo "$TX"| awk '{printf "%0.2f", $1 }'
[ -n "$VERBOSE" ] && echo -n " $UNIT" && [ "$TRAFFIC" = "FALSE" ] && echo -n "/s"
fi