#!/bin/bash

usage="Usage: $0 [-p] DEVICE FILE
Try \`$0 --help' for more information."

help="Usage: $0 [-p] DEVICE FILE

Overwrite disk drive DEVICE with the image from FILE.  The image is
assumed to consist of the first 63 blocks of a disk device (which
covers the master boot record and any boot loader code saved before
the first partition) followed by an ntfsclone image of the first
partition (assumed to be in NTFS format), all compressed with gzip.

If the -p option is given, DEVICE refers to a partition rather than a
whole disk, and only that partition (assumed NTFS) will be written;
the MBR and boot code regions of the underlying disk device will not
be changed.  This is useful for re-imaging the main Windows partition
on computers where other partitions (e.g. Linux partitions or spare
data partitions) have been created, though care must be taken that
the MBR in such cases is compatible with the partition being written.

Examples:
$0 /dev/sda /mnt0/image.gz
$0 -p /dev/sda1 /mnt0/image.gz

Author: Stephen Thomas <flabdablet via google mail> 24-Mar-2006"

if [ -z "$1" ]
then
	echo "$usage"
	exit 1
fi

if [ "$1" == "--help" -o "$1" == "-h" ]
then
	echo "$help"
	exit 1
fi

if [ "$1" == "-p" ]
then
	mode=partition
	shift
	device="${1:-/dev/hda1}"
	dd_out=/dev/null
	ntfs_out="$device"
else
	mode=disk
	device="$1"
	dd_out="$device"
	ntfs_out="$device"1
fi
file="${2:-image.gz}"

echo "About to overwrite $mode $device with image from $file."
read -p "Is this OK? (y/n) "
if [ "${REPLY:0:1}" != y -a "${REPLY:0:1}" != Y ]
then
	exit 1
fi

zcat "$file" |
{
	dd of="$dd_out" bs=512 count=63
	if [ $mode == disk ]
	then
		sfdisk --re-read "$device"
	fi
	ntfsclone --restore-image --overwrite "$ntfs_out" -
}