#! /usr/bin/env bash

# abort on nonzero exitstatus
set -o errexit

# abort on unbound variable
set -o nounset

# don't hide errors within pipes
set -o pipefail

if [ $# -eq 0 ]
then
	echo "No argument supplied. Please specify the unziped Raspberry Pi OS file."
	exit 1
fi

mkdir -p /mnt/sdcard_1

# extract the start offset
sector_offset=$(fdisk --list ${1} | awk '/W95 FAT32/{print $2}')

# multiply it with the sector size
byte_offset=$((${sector_offset} * 512))

# mount the first partition
mount --options loop,offset=${byte_offset} ${1} /mnt/sdcard_1

if [ $? -eq 0 ]
then
	# create the file
	touch /mnt/sdcard_1/ssh

	if [ $? -eq 0 ]
	then
		echo "File created."
	else
		echo "Unable to create the file."
	fi

	# unmount
	umount /mnt/sdcard_1
else
	echo "Can't mount the file."
fi