#!/bin/bash

false
while [ $? -ne 0 ]; do sudo true; done

SEC=false

for ARG in "$@"; do
  case "${ARG}" in
    "--secure") SEC=true        ;;
             *) [[ -b "${ARG}" ]] && DVC+=("${ARG}") || ( echo "${ARG} is not a block device"; exit 1 ) ;;
  esac
done

echo -n "Filling ${DVC[@]} with "
${SEC} && echo "random data" || echo "zeros"

for DEV in "${DVC[@]}"; do
  echo "${DEV}:"
  ${SEC} && openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64)" -nosalt </dev/zero | sudo dd of=${DEV} bs=4M status=progress
  ${SEC} || sudo dd if=/dev/zero of=${DEV} bs=4M status=progress
done