Simple one-char-triggered request for confirmation

confirm

# A function to prompt/read an interactive y/n response
# Stops reading after one character, meaning only 'y' or 'Y' will return 0
# _anything_ else will return 1
confirm() {
  read -rn 1 -p "${*:-Continue} [Y/N]? "
  printf -- '%s\n' ""
  case "${REPLY}" in
    ([yY]) return 0 ;;
    (*)    return 1 ;;
  esac
}

# For a version that features a timeout:

# A function to prompt/read an interactive y/n response
# Stops reading after one character, meaning only 'y' or 'Y' will return 0
# Any other character, or an optional timeout (-t|--timeout) will return 1
confirm() {
  local confirm_args
  case "${1}" in
    (-t|--timeout)
      confirm_args=( -t "${2}" )
      set -- "${@:3}"
    ;;
  esac
  
  read "${confirm_args[@]}" -rn 1 -p "${*:-Continue} [Y/N]? "
  printf -- '%s\n' ""
  case "${REPLY}" in
    ([yY]) return 0 ;;
    (*)    return 1 ;;
  esac
}