test against fake flash

test-fake.zsh

#!/usr/bin/env zsh

if test $# -ne 1; then
	echo "Tests against fake capacity flash storage. Script should print two identical checksums."
	echo "Usage: $0 /dev/sdX" >&2
	exit 1
fi

parallel --version >/dev/null 2>&1 || exit 1
hexdump --version >/dev/null 2>&1 || exit 1
xxh64sum --version >/dev/null 2>&1 || exit 1

KNAME=$(realpath $1 | rev | cut -d/ -f1 | rev)
cat /sys/block/$KNAME/size >/dev/null || exit 1
SIZE=$(cat /sys/block/$KNAME/size)

if test ! -w /dev/$KNAME; then
	echo "Device $KNAME not writeable. Are you root?" >&2
	exit 1
fi

echo "Testing device $KNAME, $SIZE sectors."
echo "Will irreparably remove all the data from the device! Hit Control-C in the next ten seconds to abort the operation."
for x in {10..1}; do
	echo -n "$x... "
	sleep 1
done
echo

fastrand() {
    parallel -q --ungroup -n1 -j2 sh -c 'openssl enc -aes-128-ctr -K '{}' -iv 00000000000000000000000000000000 < /dev/zero' ::: $(hexdump -n 16 -e '8/1 "%02x"' /dev/urandom) $(hexdump -n 16 -e '8/1 "%02x"' /dev/urandom) 2>/dev/null
}

fastrand | head -c$(( 512*$SIZE )) | tee >(xxh64sum) | dd of=/dev/$KNAME bs=4M iflag=fullblock oflag=direct status=progress
dd if=/dev/$KNAME bs=4M iflag=direct status=progress | xxh64sum

echo "If the two checksums match, your drive is OK."