sdbackup

#!/bin/bash
#--------------------------------------------------------------------------------
#  SDBackup
#  A script to backup a device such as an SD Card to a compressed image
#--------------------------------------------------------------------------------
#  Daniel Bull
#  daniel@neonhorizon.co.uk
#------------------------------------------------------------------------------*/


# Settings
THISAPP=sdbackup
TEMPFOLDER=/tmp/sdbackup
SETTINGSFILE=~/.sdbackup
DEFAULTDEV=""

# Automatically install what we need
if [[ ! `type -P "unp"` || ! `type -P "ddrescue"` || ! `type -P "lshw"` ]]; then
  echo "It looks like this is the first time $THISAPP has been run."
  echo "Installing required packages..."
  echo
  sudo apt-get install unp gddrescue lshw || { echo "Error: Please install unp, gddrescue and lshw" 1>&2; exit 1;}
  echo "Done..."
  echo
fi

# Create the temporary folder if it doesn't already exist
if [[ ! -d "$TEMPFOLDER" ]]; then
  mkdir "$TEMPFOLDER" || { echo "Error: Cannot create temporary folder" 1>&2; exit 1; }
fi

# Check filename parameter is present
if [[ "$1" = "" ]]; then
  echo "Usage: $THISAPP <filename> [<device>]" 1>&2
  exit
fi

# Automatically add .gz extension if its not there
FILE="$1"
if ! [[ "`echo \"$FILE\" | rev | cut -c1-3`" = "zg." ]]; then
  FILE+=".gz"
fi

# Check target file doesnt already exist
if [[ -d "$FILE" ]]; then
  echo "Error: $FILE is a directory?" 1>&2
  exit 1
elif [[ -f "$FILE" ]]; then
  # Confirm overwite
  read -p "$FILE already exists, should it be deleted? [y/N]: " -n1 AGREE
  if ! [[ "$AGREE" =~ ^[yY]$ ]]; then
    exit
  fi
  echo
  rm "$FILE" || { echo "Error: Cannot delete $FILE" 1>&2; exit 1; }
  echo "Deleted $FILE"
  echo
fi

# Get a device name
if [[ "$2" != "" ]]; then
  # Supplied on CLI
  DEV="$2"
else

  # Get the default
  if [[ -f "$SETTINGSFILE" ]]; then
    DEFAULTDEV=`cat "$SETTINGSFILE"`
  fi

  # Scan for disks
  echo "Scanning drives..."
  declare -a DEVICES
  declare -a SIZES
  declare -a NAMES
  DEVICE=0;
  while read LINE; do
    if grep -q 'description: ' <<< "$LINE"; then
      DEVICE=$((DEVICE+1))
      DEVICES[$DEVICE]=""
      SIZES[$DEVICE]=""
      NAMES[$DEVICE]=""
    elif grep -q 'logical name: ' <<< "$LINE"; then
      DEVICES[$DEVICE]="`cut -d':' -f2 <<< $LINE`"
    elif grep -q 'size:' <<< "$LINE"; then
      SIZES[$DEVICE]+="`cut -d':' -f2 <<< $LINE`"
    elif grep -q 'product: ' <<< "$LINE"; then
      NAMES[$DEVICE]+="`cut -d':' -f2 <<< $LINE`"
    fi
  done < <(sudo lshw -class disk 2> /dev/null)

  # Display a list of options
  echo
  DEFAULTSELECT=0
  for I in "${!DEVICES[@]}"; do
    if [[ "${SIZES[$I]}" ]]; then
      echo "$I) ${DEVICES[$I]} ${NAMES[$I]}${SIZES[$I]}"
    else
      echo "$I) ${DEVICES[$I]} ${NAMES[$I]} (currently empty)"
    fi
    if [[ "${DEVICES[$I]:1}" = "$DEFAULTDEV" ]]; then
      DEFAULTSELECT=$I
    fi
  done
  echo "0)  Cancel"

  # Ask the user to select
  echo
  DEV=""
  while ! [[ "$DEV" ]]; do
    read -p "Please select your device [$DEFAULTSELECT]: " SELECTED
    if ! [[ "$SELECTED" ]]; then
      SELECTED=$DEFAULTSELECT
    fi
    if [[ "$SELECTED" = 0 ]]; then
      exit;
    fi
    if [[ "$SELECTED" =~ ^[01234567890]$ ]]; then
      DEV="${DEVICES["$SELECTED"]:1}"
    fi
  done

fi

# Check the device exists
if [[ ! -b "$DEV" ]]; then
  echo "Error: $DEV is not a block device?" 1>&2
  exit 1;
fi

# Confirm
read -p "Backup from $DEV to $FILE is that correct? [y/N]: " -n1 AGREE
if ! [[ "$AGREE" =~ ^[yY]$ ]]; then
  exit
fi
echo
echo

# Filenames
LOCKFILE="$TEMPFOLDER/`echo "$DEV" | tr "/" "_"`.lock"
TEMPFILE="$TEMPFOLDER/`echo "$FILE_$DEV" | tr "/" "_"`.tempfile"

# Test and create lockfile
if [[ -f $LOCKFILE ]]; then
  echo "Error: There is a `cat $LOCKFILE` currently running on $DEV" 1>&2;
  exit 1;
fi
echo $THISAPP > $LOCKFILE

# Trap for failure
trap 'rm "$LOCKFILE" 2> /dev/null; rm "$TEMPFILE" 2> /dev/null;' EXIT

# Clean up anything left over from a previous attempt
sudo rm "$TEMPFILE" 2> /dev/null

# Unmount the card
echo "Unmounting any mounted partitions..."
for PARTITION in "$DEV"*; do
  if [[ -b "$PARTITION" ]]; then
    if egrep -qs ^"$PARTITION " /proc/mounts; then
      sudo umount "$PARTITION" 2> /dev/null || { echo "Error: Cannot unmount $PARTITION" 1>&2; exit 1; }
    fi
  fi
done

# Create a temp file with our user (so we don't need sudo to delete it)
touch "$TEMPFILE"

# Back it up
echo "Copying data from $DEV..."
echo
sudo ddrescue "$DEV" "$TEMPFILE" || exit 1;
echo
echo "Zipping..."
gzip --stdout "$TEMPFILE" > "$FILE" || { echo "Error: Cannot compress the file" 1>&2; exit 1; }
echo "Backup complete."
echo "$DEV" > "$SETTINGSFILE"