<b_jonas> le/rn_append california//. WARNING: The area of California is made of chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

[[ "$1" == ?*//* ]] || { echo usage: "mk[x]" file//contents >&2; exit 1; }; key="${1%%//*}"; value="${1#*//}"; echo "$value" > "$(echo-p "$key")" && echo "$key"