虽然写的很烂，还是留个纪念吧。。。。
#!/bin/bash
#================================================================
#Script Name: netspeed.sh
#Description: to see every netdev's speed (B/s)
#Date: 2010.11.15
#================================================================
#----------------------------------------------------------------
#Function get the value of select netdev's special type
#$1:accounts of lines
#$2:volunm of special type value
#----------------------------------------------------------------
function getvalue()
{
local i;
for ((i=0;i<=(($1-2));i++))
do
r[$i]=`sed -n ''"$((i+3))"'p' /proc/net/dev|sed 's/^ *//g'|awk -F ': *| *' '{print $'"$2"'}'`;
t[$i]=`sed -n ''"$((i+3))"'p' /proc/net/dev|sed 's/^ *//g'|awk -F ': *| *' '{print $'"$(($2+8))"'}'`;
if [ "$j" -eq 2 ]
then
name[$i]=`sed -n ''"$((i+3))"'p' /proc/net/dev|sed 's/^ *//g'|awk -F ': *| *' '{print $1}'`
fi
done
}
i=`more /proc/net/dev|wc -l`
for ((j=2;j<=9;j++))
do
getvalue $i $j;
ro=(${ro[@]} ${r[@]});
to=(${to[@]} ${t[@]});
done
sleep 1
for ((j=2;j<=9;j++))
do
getvalue $i $j;
rn=(${rn[@]} ${r[@]});
tn=(${tn[@]} ${t[@]});
done
for ((k=0;k<((i-2))*16;k++))
do
((rn[k]=rn[k]-ro[k]))
((tn[k]=tn[k]-to[k]))
done
echo -e \\t\\t\\trecieved\\t\\t\\tsent
echo -e Interface\\tKByte/s\\t\\tpacket/s\\tKByte/s\\t\\tpacket/s
for ((j=0;j<((i-2));j++))
do
rn[$j]=`echo $"((${rn[j]}/1024))"|bc -l|cut -b1-7`
tn[$j]=`echo $"((${tn[j]}/1024))"|bc -l|cut -b1-7`
echo -e ${name[$j]}\\t\\t${rn[$j]}\\t\\t${rn[((j+i-2))]}\\t\\t${tn[$j]}\\t\\t${tn[((j+i-2))]}
done