#!/bin/sh
# 2004-04-25 by pille <pille@struction.de>
#
# mount & sync disk to usb (sdb1)
#
# 2005-02-02
#	+ mount with -rw 
#	+ nice with -n (to be up to date)
#	+ configured for kommunist (gentoo)
#
# 2005-03-20
#	+ BACKUP_DEST	
#
# 2005-04-17
#	+ use rdiff-backup instead of rsync
#
# 2006-04-03
#	+ check for usb disk

#### CONFIGURATION ####

BACKUP_PATH="/"			# backup these files
BACKUP_PART="/dev/sdb1"		# backup to this partition
MOUNT_POINT="/mnt/usb"		# ex. dir to mount usb-disk in

BACKUP_DEST="${MOUNT_POINT}/gentoo"		# where to store the backup

RDIFF_BACKUP=`which rdiff-backup`
RDIFF_BACKUP_OPTIONS="--terminal-verbosity 2 --verbosity 5 --exclude /proc --exclude /sys"



#### FUNCTIONS ####

# checks for attached backup-disk
function check_backupdisk() 	{
    cat /proc/partitions | grep "8.*17.*78148161 sdb1"
    if [ $? == 0 ]; then
	return 1
    else
	return 0
    fi
}

# checks, wheather mountpoint is already mounted
function check_mountpoint()	{
    mount |grep "${MOUNT_POINT} "
}

#### MAIN ####

# is our backup-disk attached?
check_backupdisk
if [ $? == 0 ]; then
    echo "ERROR: backup-disk not attached"
    exit -1
fi

# is our mount-point already mounted?
check_mountpoint
if [ $? == 0 ]; then
    echo "ERROR: ${MOUNT_POINT} already mounted"
    exit -1
fi

# mount the share
echo "mounting ${BACKUP_PART} to ${MOUNT_POINT}..."
mount -rw ${BACKUP_PART} ${MOUNT_POINT} 
if [ $? != 0 ]; then
    echo "ERROR: cannot mount ${BACKUP_PART} to ${MOUNT_POINT}"
    exit -2
fi

# copy all the stuff
nice -n -19 ${RDIFF_BACKUP} ${RDIFF_BACKUP_OPTIONS} ${BACKUP_PATH} ${BACKUP_DEST} 
echo RETURN CODE: $?
df -h ${BACKUP_DEST}

# unmount the share
echo "unmounting ${BACKUP_PART} from ${MOUNT_POINT}..."
umount ${MOUNT_POINT}
if [ $? != 0 ]; then
    echo "ERROR: cannot unmount ${BACKUP_PART} from ${MOUNT_POINT}"
    exit -2
fi

# at this point everting should be fine, so the next check should never occur
# is our mount-point still mounted?
check_mountpoint
if [ $? == 0 ]; then
    echo "ERROR: ${MOUNT_POINT} still mounted (this should never happen)"
    exit -3
fi