#!/usr/bin/env zsh

gup --always
base=${2:t}
base=${base#"."}
base=${base%".chksum"}
base=${2:h}/${base}
while IFS= read -d $'\0' file; do
  if [[ -f "${file}" ]]; then
    b2sum "${file}"
  else
    echo "${file}"
  fi
done > >(gup --contents) < <(find "${base}" -print0)