Mac OSX Terminal – Format Disk

This process is very helpful to format a disk that has multiple partitions on it like a Raspberry Pi SD Card.

This script can be updated to allow a different type of format (JHFS+ instead of FAT32) but for now it serves my purpose.

#!/bin/sh

#  FormatSDCard.sh
#
#
#  Created by David Kittell on 6/11/19.
#

diskutil list | grep '/dev/disk' -A2

# Ask User what disk should be formatted
# say "What disk would you like to format?. Copy/Paste or type in the disk path followed by [ENTER]"
printf "What disk would you like to format?\nCopy/Paste or type in the disk path (ex. /dev/disk2) followed by [ENTER]:\n"
read sDisk
#echo "$sDisk provided"

if [ ! -z "$sDisk" ]
then
  sDiskSpace="$(diskutil list | grep $sDisk -A2 | grep -v $sDisk | grep -v 'SIZE' | tr -s " " | cut -d ' ' -f4 | sed 's|[+*]||g') $(diskutil list | grep $sDisk -A2 | grep -v $sDisk | grep -v 'SIZE' | tr -s " " | cut -d ' ' -f5)"
  echo $sDiskSpace

  clear

  # Ask User if they are sure they want to format the disk
  # say "Are you sure you want to format $sDisk ($sDiskSpace), if yes type y or if no type n followed by [ENTER]"
  printf "Are you sure you want to format $sDisk ($sDiskSpace), if yes type y or if no type n followed by [ENTER]:\n"
  read sDiskConfirm
  #echo "$sDiskConfirm"

  case $sDiskConfirm in
    [yY])

      # Ask User if they are sure they want to format the disk
      # say "Do you want to do a secure format $sDisk ($sDiskSpace), if yes type y or if no (regular format) type n followed by [ENTER]"
      printf "Do you want to do a secure format $sDisk ($sDiskSpace), if yes type y or if no (regular format) type n followed by [ENTER]:\n"
      read sDiskFormatType
      #echo "$sDiskFormatType"

      case $sDiskFormatType in
        [yY])
          sudo diskutil unmountDisk $sDisk && say "Unmount of disk completed"
          # sudo dd if=/dev/urandom of=$sDisk bs=1000000 && say "Disk Ready"
          sudo diskutil zeroDisk $sDisk && say "Disk Ready"
          sudo diskutil secureErase "ms-dos fat32" EMPTY MBRFormat $sDisk && say "Disk Is Formatted" # If you want to securely format the disk
          ;;
        [nN])
          sudo diskutil unmountDisk $sDisk && say "Unmount of disk completed"
          # sudo dd if=/dev/urandom of=$sDisk bs=1000000 && say "Disk Ready"
          sudo diskutil zeroDisk $sDisk && say "Disk Ready"
          sudo diskutil eraseDisk "ms-dos fat32" EMPTY MBRFormat $sDisk && say "Disk Is Formatted"
          ;;
        *)
          clear
          # say "You did not provide a choice. Format of $sDisk ($sDiskSpace) aborted."
          echo "You did not provide a choice\nFormat of $sDisk ($sDiskSpace) aborted."
          ;;
      esac
      ;;
    [nN])
      clear
      # say "Format of $sDisk ($sDiskSpace) aborted."
      echo "Format of $sDisk ($sDiskSpace) aborted."
      ;;
    *)
      clear
      # say "You did not confirm. Format of $sDisk ($sDiskSpace) aborted."
      echo "You did not confirm\nFormat of $sDisk ($sDiskSpace) aborted."
      ;;
  esac
else
  clear
  # say "You did not provide a disk, aborting script"
  echo "You did not provide a disk, aborting script"
fi