pps

#!/bin/sh
set -e

# update interval in seconds
INTERVAL="1"

_usage() {
	echo "usage: $0 DEVICE..."
	echo "  eg: $0 eth0 eth1 ..."
	echo "shows packets-per-second"
	exit 1
}
[ "$1" ] || _usage

_stat() {
	dev=$1
	stat=$2
	cat "/sys/class/net/$dev/statistics/$stat"
}

title=
for dev in "$@"; do
	title=${title:+$title+$dev}
	title=${title:-$dev}
done

while  true
do
	r1=;rd1=;rb1=;t1=;td1=;tb1=
	r2=;rd2=;rb2=;t2=;td2=;tb2=

	for dev in "$@"; do
		r1=$((r1+$(_stat "$dev" "rx_packets")))
		rd1=$((rd1+$(_stat "$dev" "rx_dropped")))
		rb1=$((rb1+$(_stat "$dev" "rx_bytes")))
		t1=$((t1+$(_stat "$dev" "tx_packets")))
		td1=$((td1+$(_stat "$dev" "tx_dropped")))
		tb1=$((tb1+$(_stat "$dev" "tx_bytes")))
	done

	sleep "$INTERVAL"

	for dev in "$@"; do
		r2=$((r2+$(_stat "$dev" "rx_packets")))
		rd2=$((rd2+$(_stat "$dev" "rx_dropped")))
		rb2=$((rb2+$(_stat "$dev" "rx_bytes")))
		t2=$((t2+$(_stat "$dev" "tx_packets")))
		td2=$((td2+$(_stat "$dev" "tx_dropped")))
		tb2=$((tb2+$(_stat "$dev" "tx_bytes")))
	done

	tx_pps=$((t2 - t1))
	tx_dropped_pps=$((td2 - td1))
	tx_bytes=$((tb2 - tb1))
	rx_pps=$((r2 - r1))
	rx_dropped_pps=$((rd2 - rd1))
	rx_bytes=$((rb2 - rb1))
	printf	"[%s] tx: %9d (dropped: %4d) pkts/s %6d Mb/s rx: %9d (dropped: %4d) pkts/s %6d Mb/s\n" \
		"$title" "$tx_pps" "$tx_dropped_pps" "$((tx_bytes*8/1000000))" \
		"$rx_pps" "$rx_dropped_pps" "$((rx_bytes*8/1000000))"
done