Quick 'n' dirty script to recover a disk image and write to a drive.

recover_disk_img.sh

#!/usr/bin/env bash
#
# Automatically recover a backup to a destination drive.
# NOTE: Must be run as root.
#
# DEPENDENCIES
#
#	Lziprecover - for decompressing possibly corrupted lzip archives.
#	pv - for status of writing image to drive
#	smartmontools - for printing out drive info, used as safety measure to
#		allow user to confirm selection
# TODO
#
#	Auto-suggest valid files and drives when the user hits tab after an arg.
#	Auto-detect archive file type to determine which decompressor to use.
#	Verify a file is actually a file.
#		Might not be necessary if the user is output simply to a file to be 
#		created.
#	Print out drive smartctl and 


function uncompressed_size {
	# Calculate the uncompressed byte size of the archive.
	#
	#	Usage: uncompressed_size <archive.file.lz>
	if [ "$#" -ne 1 ]
	then
		echo "Illegal number of parameters: uncompressed_size <archive.file.lz>"
		exit 1
	fi
	# The uncompressed size of the file is extracted from the output of
	# 	lziprecover --list.
	#
	#	e.g. $ lziprecover --list archive.tar.lz
	#		>>   /absolute/path/to/archive.tar.lz: 15.986:1,  0.500 bits/byte, 93.74% saved.  decompressed size 256060514304, compressed size 16018250608.
	#		                                                                                field to extract:  |------------|
	# This output is split by spaces.
	# Because the file might have spaces, the size is extracted by started from
	#	the end and counting backwards.
	ARCHIVE_FILE="$1"
	UNCOMPRESSED_SIZE=$(\
		lziprecover --list "$ARCHIVE_FILE" \
		| rev \
		| cut --delimiter=' ' --field=4 \
		| rev \
		| tr --delete ,)
	echo $UNCOMPRESSED_SIZE
}


# Recover a disk image and write to a drive.
#
#	Usage: recover_sisk_img.sh <archive.file.lz> </dev/hdd>
INCORRECT_ARG_COUNT=$( test "$#" -ne 2 )
if [ $INCORRECT_ARG_COUNT ]
then
	echo "Illegal number of parameters. Aborting."
	echo "Usage: # bash recover_sisk_img.sh <archive.file.lz> </dev/hdd>"
	exit 1
fi

# notify user of all errors
#if blah or blah or blah or blah:
#then
#	echo "The following errors were encountered. Execution will be aborted."
#	if $INCORRECT_ARG_COUNT
#	then
#		echo "Illegal number of parameters. Aborting."
#	fi
#	exit 1
#fi

ARCHIVE_FILE="$1"
DRIVE="$2"
echo "Archive:           $ARCHIVE_FILE"
echo "Drive:             $DRIVE"

# calculate byte size of uncompressed archive
UNCOMPRESSED_SIZE=$(uncompressed_size "$ARCHIVE_FILE")
echo "Bytes to write:    $UNCOMPRESSED_SIZE"

# Decompress the archived image and write it to the drive.
echo '-------------------------------------------------------------------------------'
lziprecover --decompress --stdout "$ARCHIVE_FILE" | pv -s $UNCOMPRESSED_SIZE >"$DRIVE"
#echo 'pv -s ' $UNCOMPRESSED_SIZE 'lziprecover --decompress --stdout ' "$COMPRESSED_FILE" "$DRIVE"