linux系统磁盘使用情况

#!/bin/bash
total_disk=`df -k | grep -v Filesystem | awk '{print int($2)}'`
available_disk=`df -k | grep -v Filesystem | awk '{print int($4)}'`
total=
available=
for t in $total_disk
do
total=$((total+t));
done
for a in $available_disk
do
available=$((available+a));
done
echo $total,$available