Simple shell script to overwrite beginning and end of block devices with zeros.

wipedev.sh

#!/bin/bash
#set -x

if [ "$(id -u)" != "0" ]; then
  echo "Sorry, you need to be root to do that."
  exit 1
fi

if [ -b "$1" ]; then
  DEVICE="$1"
  BLOCK_SIZE=$(blockdev --getss "${DEVICE}")
  COUNT=4096

  echo "This will OVERWRITE the begin and end of ${DEVICE} with 2 MB of zeroes."
  echo "ARE YOU SURE?"
  read -p "Please re-enter the device name for confirmation: " CONFIRMED_DEVICE
  if [ "${CONFIRMED_DEVICE}" != "${DEVICE}" ]; then
    echo "Device names don't match! Exiting."
    exit 1
  fi

  dd if=/dev/zero of="${DEVICE}" bs=${BLOCK_SIZE} count=${COUNT}
  dd if=/dev/zero of="${DEVICE}" bs=${BLOCK_SIZE} seek=$(( $(blockdev --getsz "${DEVICE}") - ${COUNT} )) count=${COUNT}
  echo "Done."
else
  echo "Argument needs to be an existing block device. Exiting."
  exit 1
fi