<oerjan> mkx bin/slashlearn//sep="/"; [[ "$0" == *//* ]] && sep="//"; [[ "$1" == ?*"$sep"* ]] || exit 1; key="$(echo "${1%%$sep*}" | lowercase)"; value="${1#*$sep}"; [ -e "wisdom/$topic" ] && verb="Relearned" || verb="Learned"; echo "$value" > "$(echo-p "wisdom/$key")" && echo "$verb \xc2\xab$key\xc2\xbb"

Cubes come in all sizes, colors and materials, but only one shape. The companion cube does not speak, however.