```bash

readarray -d '' FILES < <(
  git ls-files -z \
    ':(exclude)po' \
    ':(exclude)shared/c-rbtree' \
    ':(exclude)shared/c-list' \
    ':(exclude)shared/c-siphash' \
    ':(exclude)shared/c-stdaux' \
    ':(exclude)shared/n-acd' \
    ':(exclude)shared/n-dhcp4' \
    ':(exclude)src/systemd/src' \
    ':(exclude)shared/systemd/src' \
    ':(exclude)m4' \
    ':(exclude)COPYING*'
  )

sed \
  -e 's/^\(--\|#\| \*\) *\(([cC]) *\)\?Copyright \+\(\(([cC])\) \+\)\?\(\(20\|19\)[0-9][0-9]\) *[-–] *\(\(20\|19\)[0-9][0-9]\) \+\([^ ].*\)$/\1 C1pyright#\5 - \7#\9/' \
  -e 's/^\(--\|#\| \*\) *\(([cC]) *\)\?Copyright \+\(\(([cC])\) \+\)\?\(\(20\|19\)[0-9][0-9]\) *[,] *\(\(20\|19\)[0-9][0-9]\) \+\([^ ].*\)$/\1 C2pyright#\5, \7#\9/' \
  -e 's/^\(--\|#\| \*\) *\(([cC]) *\)\?Copyright \+\(\(([cC])\) \+\)\?\(\(20\|19\)[0-9][0-9]\) \+\([^ ].*\)$/\1 C3pyright#\5#\7/' \
  -e 's/^Copyright \(\(20\|19\)[0-9][0-9]\) \+\([^ ].*\)$/C4pyright#\1#\3/' \
  -i \
  "${FILES[@]}"

echo ">>> untouched Copyright lines"
git grep Copyright "${FILES[@]}"

echo ">>> Copyright lines with unusual extra"
git grep '\<C[0-9]pyright#' "${FILES[@]}" | grep -i reserved

sed \
  -e 's/\<C[0-9]pyright#\([^#]*\)#\(.*\)$/Copyright (C) \1 \2/' \
  -i \
  "${FILES[@]}"

```

!298