#!/bin/bash

# Get device and partition numbers/names
 # Root Partition
  PART_DEV=`findmnt / -o source -n | cut -f1 -d"["`
 
 # Remove '/dev/' from the name 
  PART_NAME=`echo $PART_DEV | cut -d "/" -f 3`
 
 # Set just the name of the device, usually mmcblk0
  DEV_NAME=`echo /sys/block/*/${PART_NAME} | cut -d "/" -f 4`

 # Add /dev/ to device name
  DEV="/dev/${DEV_NAME}"

 # Get Number of device as single digit integer
  PART_NUM=`cat /sys/block/${DEV_NAME}/${PART_NAME}/partition`

 # Get size of SDCard (final sector)
  SECTOR_SIZE=`cat /sys/block/${DEV_NAME}/size`

 # Set the ending sector that the partition should be resized too
  END_SECTOR=`expr $SECTOR_SIZE - 1`

#growpartfs $PART_DEV

# resize the partition
# parted command disabled for now. Using sfdisk instead
#parted -m $DEV u s resizepart $PART_NUM yes $END_SECTOR
echo ", +" | sfdisk --no-reread -N $PART_NUM $DEV

# reload the partitions in the kernel
#partprobe
partx -u $DEV

# resize
if [[ $(lsblk -o NAME,FSTYPE | grep $PART_NAME | awk '{print $2}') = "btrfs" ]]; then
    btrfs filesystem resize max /
else
    resize2fs $PART_DEV
fi