#!/usr/bin/env bash
set -euo pipefail

# These optional adapters accept virtual cartridges, never device nodes.
: "${DEVICE:?DEVICE must be an existing virtual-cartridge directory}"
if [[ ! -d "${DEVICE}" || -L "${DEVICE}" ]]; then
    echo "Expected a real virtual-cartridge directory: ${DEVICE}" >&2
    exit 1
fi
device=$(realpath -- "${DEVICE}")
if [[ ! ${device##*/} =~ ^[A-Z0-9]{6}$ ]]; then
    echo "The virtual-cartridge directory name must be a six-character barcode" >&2
    exit 1
fi
printf '%s\n' "${device}"
