sdrestore

#!/bin/bash
#--------------------------------------------------------------------------------
#  SDRestore
#  A script to decompress and restore an image onto a device such as an SD Card
#--------------------------------------------------------------------------------
#  Daniel Bull
#  daniel@neonhorizon.co.uk
#------------------------------------------------------------------------------*/


# Settings
thisapp="$(basename "$0")"
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 ! tempfolder="$(mktemp -td sdbackup.tmp.XXXXXXXX)"; then
  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

# Check the source file exists
file="$1"
if [[ ! -f "$file" ]]; then

  # Try with a .gz extension
  if [[ ! -f "$file.gz" ]]; then
    echo "Error: $1 doesnt exist?" 1>&2
    exit 1
  fi

  file+=".gz"
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 line
  declare -a devices
  declare -a sizes
  declare -a names
  device=0;
  while IFS=":" read -r -a line; do
  case "${line[0]}" in
    *"description")
      device=$((device+1))
      devices[$device]=""
      sizes[$device]=""
      names[$device]=""
      ;;
    *"logical name")
      devices[$device]="${line[1]# }"
      ;;
    *"size")
      sizes[$device]+="${line[1]# }"
      ;;
    *"product")
      names[$device]+="${line[1]# }"
      ;;
  esac
  done < <(sudo lshw -class disk 2> /dev/null)
  unset line

  # 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 ! [[ "$dev" ]]; do
    read -rp "Please select your device [$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 -rp "Restore from $file to $dev is that correct? [y/N]: " -n1 agree
if ! [[ "$agree" =~ ^[yY]$ ]]; then
  exit
fi
echo
echo

# Filenames
lockfile="/tmp/sdbackup${dev////_}.lock"
tempfile="$tempfolder/${file}_${dev////_}.tempfile"
errfile="$tempfolder/${file}_${dev////_}.error"

# 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; rm "$errfile" 2> /dev/null; rmdir "$tempfolder" 2> /dev/null' EXIT

# Clean up anything left over from a previous attempt
sudo rm "/tmp/sdbackup.tmp."*/*.tempfile 2> /dev/null
sudo rm "/tmp/sdbackup.tmp."*/*.error 2> /dev/null
sudo rmdir "/tmp/sdbackup.tmp."* 2> /dev/null

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

# See if the file needs decompressing
if file \"$file\" | grep -q 'compressed\|archive'; then
  # Decompress the file
  echo "Decompressing..."
  ucat "$file" > "$tempfile" 2> "$errfile" || { echo "Error: Cannot decompress $file" 1>&2; exit 1; }
  if [[ -s "$errfile" ]]; then
    echo "Error: Cannot decompress $file" 1>&2;
    exit 1;
  fi
  restorefile="$tempfile"
else
  # No temp file needed
  restorefile="$file"
fi

# Check its not still compressed
if file \"$restorefile\" | grep -q 'compressed\|archive'; then
  echo "Error: Cannot decompress $file" 1>&2;
  exit 1;
fi

# Restore the file
echo "Restoring $(stat -c %s "$restorefile") bytes to $dev..."
echo
sudo ddrescue --force --synchronous "$restorefile" "$dev" || exit 1;
echo
echo "Syncing the card ready for ejection..."
sync
echo "Restore complete."

# Set device as default
echo "$dev" > "$settingsfile"