#!/bin/bash
# please read!
# this script only backs up your $HOME directory!
# make sure you read and edit the default ~/.backup_exclude and 
#  ~/.backup_include files
#
#THIS SCRIPT IS CASE-SENSITIVE
#
#this script will back up everything to a mounted volume called 'backup'
#You need to create a disk image called 'backup' and mount it, or otherwise
#mount a writeable 'backup' volume.  If you don't know how to do this, RTFM
#for Disk Utility

#Information:
#this script will back up your home directory to a /Volumes/backup directory
#this script will also look at a recent backup and only back up newer files
#if desired.  It will do true "differential" backups in tihs way.  To do so:
# 1) create a full backup.  It does not have to be made with this script, but
#	that helps.
# 2) burn the backup to DVD.
# 3) mount the DVD.
# 4) enter the DVD name when the script asks.

#You can override some defaults below.
BACKUPDIR=$HOME/
BACKUPDEVICE="#will set later; probably /Volumes/backup/"
BACKUPIMAGE=$HOME/Desktop/backup.sparseimage
BACKUPVOLUME=backup
BACKUPSIZE=600
EXCLUDEFILE=$HOME/.backup_exclude
INCLUDEFILE=$HOME/.backup_include
LOGFILE=~/tmp/backup.log
OPTS="-vvau"

echo "Dry run? (Y/n)"
read ans
[ "$ans" = "n" ] && ans=N
[ "$ans" != "N" ] && OPTS=${OPTS}n

echo "compress? (y/N)"
read ans
[ "$ans" = "y" ] && ans=Y
[ "$ans" = "Y" ] && OPTS=${OPTS}z


echo "compare old backup? (differential backup)"
echo "some possible locations:"
ls -1  /Volumes/
echo "enter destination or leave blank"
read OLDBACKUP


[ $OLDBACKUP ] && {\
 [ -e /Volumes/$OLDBACKUP ] && { \
  echo "did you mean /Volumes/$OLDBACKUP (Y/n)?"
  echo "If this is a mounted disk, assume Y"
  read ans
   [ "$ans" = "n" ] && ans=N
   [ "$ans" != "N" ] && OLDBACKUP=/Volumes/$OLDBACKUP
  };
 [ -e $OLDBACKUP ] && COMPAREDEST="--compare-dest=$OLDBACKUP" || {\
  echo "$OLDBACKUP:no such file or directory"; exit 1; };
 };


[ -f $EXCLUDEFILE ] && EXCLUDE="--exclude-from=$EXCLUDEFILE" 
[ -f $INCLUDEFILE ] && INCLUDE="--include-from=$INCLUDEFILE"

[ -d ~/tmp ] || mkdir ~/tmp

#look for backup
[ -f $BACKUPIMAGE ] || {
echo "backup image does not exist. creating ${BACKUPIMAGE}"
hdiutil create -megabytes $BACKUPSIZE -fs HFS+ -volname $BACKUPVOLUME \
  ${BACKUPIMAGE}
}

echo "attaching device $BACKUPVOLUME"
DEVVOL=`hdiutil attach ${BACKUPIMAGE} | grep $BACKUPVOLUME | \
	 awk '{ print $1 " " $3 }' `

DEV=`echo $DEVVOL| awk '{ print $1 }'`
BACKUPDEVICE=`echo $DEVVOL | awk '{ print $2 }'`

echo "starting backup; logging on $LOGFILE"

rsync $OPTS $COMPAREDEST $INCLUDE $EXCLUDE $BACKUPDIR $BACKUPDEVICE >$LOGFILE

echo "detaching device $BACKUPVOLUME"
hdiutil detach $DEV

echo "DONE; LOGFILE IS $HOME/tmp/backup.log"
echo "logfile will be overwritten next time a backup is made"

echo "burn to disc?(y/N)"
read ans
[ "$ans" = "y" ] && ans=Y
[ "$ans" = "Y" ] && {
 TMPFILE=/tmp/backup.`jot -r 1 25555`
 hdiutil burn -list >$TMPFILE
 BURNDEV=""
 [ `wc -l $TMPFILE | awk '{ print $1 }'` -gt 2 ] && {
   echo "chose a device to burn to (by number on left)"
   grep -vn IOService $TMPFILE
   read ans
   BURNDEVID=`echo "$ans + 1" | bc`
   BURNDEV="-device \"`sed -n ${BURNDEVID}p $TMPFILE | awk '{print $1}'`\""
   }
 echo "Burning.  Ctrl-C to cancel.  Warning: cancelled burns may ruin the \
 	media"
 echo "We do not verify here to save time. \
 	make sure you verify your disk yourself"
 hdiutil burn $BURNDEV   $BACKUPIMAGE
 rm $TMPFILE
 }

 echo "Done! thanks."