通过/proc/net/dev分析网络包量，流量，错包，丢包
!/bin/bash
NIC=$l
echo -e "In ------ Out"
while true; do
OLD_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
OLD_IN=$(awk '$0~"'$NIC'"{print $10}' /proc/net/dev)
sleep 1
NEW_IN=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
NEW_OUT=$(awk '$0~"'$NIC'"{print $2}' /proc/net/dev)
IN=$(printf "%.lf%s" "$((($NEW_IN-$OLD_IN)/1024))" "KB/s")
OUT=$(printf "%.lf%s" "$((($NEW_OUT-$OLD_OUT)/1024))" "KB/s")
echo "$IN $OUT"
sleep ldone