实时查看网络的流量

watch -n 1 "/sbin/ifconfig eth0 | grep bytes"
watch -n 1 "/sbin/ifconfig eth1 | grep bytes"

#!/bin/bash
while [ "1" ]
do
eth=$1
RXpre=$(cat /proc/net/dev | grep $eth | tr : " " | awk '{print $2}')
TXpre=$(cat /proc/net/dev | grep $eth | tr : " " | awk '{print $10}')
sleep 1
RXnext=$(cat /proc/net/dev | grep $eth | tr : " " | awk '{print $2}')
TXnext=$(cat /proc/net/dev | grep $eth | tr : " " | awk '{print $10}')
clear
echo  -e  "\t IN `date +%k:%M:%S` OUT"
RX=$((${RXnext}-${RXpre}))
TX=$((${TXnext}-${TXpre}))

if [[ $RX -lt 1024 ]];then
RX="${RX}B/s"
elif [[ $RX -gt 1048576 ]];then
RX=$(echo $RX | awk '{print ($1/1048576)*8 "M/s"}')
else
RX=$(echo $RX | awk '{print $1/1024 "KB/s"}')
fi

if [[ $TX -lt 1024 ]];then
TX="${TX}B/s"
elif [[ $TX -gt 1048576 ]];then
TX=$(echo $TX | awk '{print ($1/1048576)*8 "M/s"}')
else
TX=$(echo $TX | awk '{print $1/1024 "KB/s"}')
fi

echo -e "$eth \t $RX   $TX "
done