#! /bin/bash
sum=0
for mem in `ps aux |awk '{print $6}' |grep -v 'RSS' `
do
sum=$[$sum+$mem]
done
echo "The total memory is $sum""k"

也可以使用awk 一条命令计算:

ps aux | grep -v 'RSS TTY' |awk '{(sum=sum+$6)};END{print sum}'