查看網卡流量

查看網卡流量除了用iftop等工具外，我們也可以自己寫個腳本，它的優勢就是在服務器比較卡的時候查看資源不會佔用很多系統資源！

#!/bin/bash
NAME=nic_flow
PIDFILE=/var/tmp/$NAME.pid
LOGFILE=/var/tmp/$NAME.log

function start(){
    if [ -f "$PIDFILE" ]; then
        echo $PIDFILE
        exit 2
    fi
    for (( ; ; ));do
        eth=$1
        [ -z "${eth:-}" ] && eth=eth0
        time_range=$2
        [ -z "${time_range:-}" ] && time_range=1
        ifconfig  | awk '{print $1}' | grep "eth" > /dev/null
        [ $? -gt 0 ] && echo "wrong NIC device" && exit 10
        RX_1=$(cat /proc/net/dev | grep "$eth" | awk -F'[ |:]+'  '{print $4}')
        TX_1=$(cat /proc/net/dev | grep "$eth" | awk '{print $9}')
        sleep $time_range
        RX_2=$(cat /proc/net/dev | grep "$eth" | awk -F'[ |:]+'  '{print $4}')
        TX_2=$(cat /proc/net/dev | grep "$eth" | awk '{print $9}')
        clear
        echo  -e "`date +%k:%M:%S`      RX        TX" | tee -a $LOGFILE
        RX=$((${RX_2}-${RX_1}))
        TX=$((${TX_2}-${TX_1}))
        if [[ $RX -lt 1024 ]];then
            RX="${RX}B/s"
        elif [[ $RX -gt 1048576 ]];then
            RX=$(echo $RX | awk '{print $1/1048576 "MB/s"}')
        else
            RX=$(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 $1/1048576 "MB/s"}')
        else
            TX=$(echo $TX | awk '{print $1/1024 "KB/s"}')
        fi
        echo -e " $eth       $RX        $TX " | tee -a $LOGFILE
    done&
    echo $! > $PIDFILE
}
function stop(){
    [ -f $PIDFILE ] && kill `cat $PIDFILE` && rm -rf $PIDFILE
}

case "$1" in
  start)
    start $2 $3
    ;;
  stop)
    stop
    ;;
  *)
    echo $"Usage:$0  {start|stop,NIC device(eth*), time_range(s)}"
    exit 2
esac

使用

[root@localhost ~]# ./nic_flow.sh start
3:38:44      RX        TX
eth0       3B/s        138B/s
[root@localhost ~]# ./nic_flow.sh stop

這個腳本可以接受額外的兩個參數：網卡參數和時間間隔參數！

[root@localhost ~]# ./nic_flow.sh start lo 5
 5:50:05      RX        TX
 lo       2B/s        0B/s
[root@localhost tmp]# tail  /var/tmp/nic_flow.log
 5:47:04      RX        TX
 eth0       1B/s        0B/s
 5:47:05      RX        TX
 eth0       1B/s        0B/s
 5:49:55      RX        TX
 lo       0B/s        0B/s
 5:50:00      RX        TX
 lo       0B/s        0B/s
 5:50:05      RX        TX
 lo       2B/s        0B/s