Альтернатива vnstat

vnstat -tr 5 >> stat.txt

PATH=$PATH:/sbin
IF=$1
IF=${IF:=eth0}
echo "Using interface $IF"
oldrx=$( ifconfig $IF | awk -F ':' '{ if ($0~/RX bytes/) {print $2} }' | awk '{print $1}' )
oldtx=$( ifconfig $IF | awk -F ':' '{ if ($0~/TX bytes/) {print $3} }' | awk '{print $1}' )
while :; 
do 
  sleep 1
  newrx=$( ifconfig $IF | awk -F ':' '{ if ($0~/RX bytes/) {print $2} }' | awk '{print $1}' )
  newtx=$( ifconfig $IF | awk -F ':' '{ if ($0~/TX bytes/) {print $3} }' | awk '{print $1}' )
  printf "%s %10s RX bytes/sec %10s TX bytes/sec\n" "`date +'%F %T'`" "$(($newrx-$oldrx))" "$(($newtx-$oldtx))"
  oldrx=$newrx
  oldtx=$newtx
done