Dreamplug Rollback System And UImage

#!/bin/bash
   
   function dreamplugRestoreUsage()
   {
     echo -e "usage:"
     echo -e "       $0 [ options ] " 
     echo -e "$0 restores local file system from the source via rsync"
     echo -e "       $0 -h : this help"
     echo -e "       $0 -d : performs rsync with the option '--delete'"
     echo -e "       $0 -n : performs rsync with the option '--dryRun'"
     echo -e "       $0 -v : performs rsync with the option '--verbose'"
     echo -e "       $0 -s : source device"
     echo -e "\nsetting the environment variable 'clearSystem' to a not empty value"
     echo -e "  performes the rsync with the option '--delete'"
     echo
     exit
   }
   
   function dreamplugRestoreSetSource()
   {
      source=${source:=$(basename $(cat /proc/cmdline | tr " " "\n" | grep root= | cut -d "=" -f 2 | sed -e 's/\(.*\)[1-9]/\1/'))}
      echo source: $source
   }
   
   function dreamplugRestoreChecks ()
   {
      cat /proc/cmdline | grep -q root=/dev/$target 
      if [ $? -eq 0 ]
      then 
         echo "you MUST NOT sync to the running system on /dev/$target, reboot using an external device"  
         return 1;
      fi
   }
   
   function dreamplugRestoreMounts()
   {
      for item in ${source}1 ${source}2 ${target}1 ${target}2
      do
          if [ -b /dev/${item} ];
          then 
              mkdir -p /mnt/${item} &&
              echo mounting: /dev/${item} '->' /mnt/${item} &&
              mount /dev/${item} /mnt/${item} ||
              return 1;
          else
         echo "\"/dev/$item\" is not an available (block) device"
         return 1;
          fi
      done
   }
   
   function dreamplugRestoreRsyncs()
   {
      { TIMEFORMAT=$'real\t%1lR'; 
        time { grep -q /mnt/${source}1 /etc/mtab && 
               grep -q /mnt/${target}1 /etc/mtab && 
               echo syncing: /mnt/${source}1 /mnt/${target}1"
                    rsync ${dryRun} ${verbose} --stats --one-file-system --archive --hard-links --acls --xattrs ${clearSystem} /mnt/${source}1/ /mnt/${target}1";
               eval rsync ${dryRun} ${verbose} --stats --one-file-system --archive --hard-links --acls --xattrs ${clearSystem} /mnt/${source}1/ /mnt/${target}1; 
               echo;
             } || return 1;
        echo; 
        time { grep -q /mnt/${source}2 /etc/mtab && 
               grep -q /mnt/${target}2 /etc/mtab && 
               echo syncing: /mnt/${source}2/ /mnt/${target}2"
                    rsync ${dryRun} ${verbose} --stats --one-file-system --archive --hard-links --acls --xattrs ${clearSystem} /mnt/${source}2/ /mnt/${target}2" ;
               eval rsync ${dryRun} ${verbose} --stats --one-file-system --archive --hard-links --acls --xattrs ${clearSystem} /mnt/${source}2/ /mnt/${target}2;
               echo; 
             } || return 1;
        echo;
      }
   }
   
   function dreamplugRestoreUmounts()
   {
      cd /
      for item in ${source}1 ${source}2 ${target}1 ${target}2 
      do
          if [ -d /mnt/${item} ];
          then 
        grep -q /mnt/${item} /etc/mtab &&
             echo unmounting: /mnt/${item} &&
             umount /mnt/${item}
          fi
      done
   }
   
   function dreamplugRestoreEvaluateOptions()
   {
       # evaluate options and assign
       OPTIND=1
   
       while getopts ":hs:t:dnv" arg
       do
          case $arg in
         \? | h ) Help=TRUE; ;;
         s )     source=$OPTARG;;
         d )     clearSystem=TRUE;;
         n )     dryRun=TRUE;;
         v )      verbose=TRUE;
          esac
       done
       shift $(($OPTIND - 1))
   }
   
   function dreamplugRestoreMain()
   {
       dreamplugRestoreEvaluateOptions $*
   
       # Help?
       if [ 'TRUE' = "$Help" ]; then dreamplugRestoreUsage; return 0; fi
   
       clearSystem=${clearSystem:+--delete}
       dryRun=${dryRun:+--dry-run}
       verbose=${verbose:+--verbose}
   
       echo -n -e ${clearSystem:+"NOTE: 'rsync ${clearSystem}' in use\n"}
       echo -n -e ${dryRun:+"NOTE: 'rsync ${dryRun}' in use\n"}
       echo -n -e ${verbose:+"NOTE: 'rsync ${verbose}' in use\n"}
   
       target=sda;
       echo target: $target   
   
       dreamplugRestoreSetSource $* && 
       dreamplugRestoreChecks && 
       dreamplugRestoreMounts && 
       dreamplugRestoreRsyncs 
   
       dreamplugRestoreUmounts
       unset source target
   }
   
   #main
   dreamplugRestoreMain $*
   unset main dreamplugRestoreSetSource dreamplugRestoreChecks dreamplugRestoreMounts dreamplugRestoreRsyncs dreamplugRestoreUmounts verbose dryRun clearSystem Help