wipe.sh

#!/bin/sh

which openssl > /dev/null || exit 1
which pv > /dev/null || exit 1
which sudo > /dev/null || exit 1

test -n "$1" || exit 2
disk="$1"

test -b "/dev/$disk" || exit 2

size=$(awk "\$4==\"$disk\"{print \$3}" /proc/partitions) || exit 3
size=$(($size*1024))

nice openssl enc -aes-256-ctr -pass pass:"$(dd if=/dev/urandom bs=128 count=1 2> /dev/null | base64)" -nosalt < /dev/zero | pv --progress --eta --rate --bytes --size "$size" | sudo dd of="/dev/$disk" bs=4096 || exit 4