#!/bin/bash

# (CC) 1998 Ken Chase, math@sizone.org and others

# for freebsd, needs tweaks for linux


if [ -z "$1" ]; then
  echo "usage: $0 (interface) [delay]"
  exit
fi

d=10
if [ -n "$2" ];  then
 d=$2
fi

echo " TIME |           IN              |            OUT             |      TOTAL"
while true; do
  echo `netstat -Wnib | grep $1 | grep Link | head -1; date +%H%M%S` |
    gawk '{ print $5,$6,$7,$8,$9,$10,$12}'
                #$1 $2 $3 $4 $5 $6  $7
  sleep $d
done |
gawk '{ lasttime2=systime();
       if (lki) {
        delay=lasttime2-lasttime;
        lasttime=lasttime2;
        div=delay*1000;
        pin =int(($1-lpi)/delay);
        ein =int(($2-lei)/delay);
        kin =int(($3-lki)/div); bin =kin * 8;

        pout=int(($4-lpo)/delay);
        eout=int(($5-leo)/delay);
        kout=int(($6-lko)/div); bout=kout * 8;

        #bytes per packet
        if ($1-lpi) {
          bppi=int(($3-lki)/($1-lpi));
        } else {
          bppi="n/a"
        }
        if ($4-lpo) {
          bppo=int(($6-lko)/($4-lpo));
        } else {
          bppo="n/a"
        }

        printf("%6i|%6iKbps %5ipps %4iB/p | %6iKbps %5ipps %4iB/p | %7iKbps\n",
        $7, bin, pin, bppi, bout, pout, bppo, bin+bout)
      }
      lpi=$1;lei=$2;lki=$3; lpo=$4;leo=$5;lko=$6
    }'