pi@roofpi ~ $ df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs          2.0G  1.7G  149M  93% /
/dev/root       2.0G  1.7G  149M  93% /
devtmpfs         53M     0   53M   0% /dev
tmpfs            13M  232K   12M   2% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            25M     0   25M   0% /run/shm
/dev/mmcblk0p1   56M   19M   38M  34% /boot
/dev/mmcblk0p3  5.4G  1.8G  3.4G  35% /home
tmpfs            30M  8.0K   30M   1% /tmp
tmpfs            30M  108K   30M   1% /var/log
/dev/sda1        30G  1.1G   27G   4% /media
pi@roofpi ~ $ df -h /media|awk '{ print $5}'|grep "%"|sed 's/%//g'
Use
4
pi@roofpi ~ $