#!/bin/sh

partition_slug=$(echo $1 | cut -d "/" -f 3)
sys_part="/sys/block/*/$partition_slug"
sys_disk=$(dirname $sys_part)
sector_count=$(cat $sys_part/size)
sector_size=$(cat $sys_disk/queue/hw_sector_size)
size=$(expr $sector_count / 1000000 \* $sector_size / 1000)G
if [ $size == "G" ]; then
    size=$(expr $sector_count / 1000 \* $sector_size / 1000)M
fi
echo $size