_zimfw_run_tool() {
  local -r _zname=${1}
  if [[ -z ${_zurls[${_zname}]} ]]; then
    _zimfw_print_okay 'Skipping external module' 1
    return 0
  fi
  if (( _zfrozens[${_zname}] )); then
    _zimfw_print_okay 'Skipping frozen module' 1
    return 0
  fi
  case ${_zaction} in
    install)
      if [[ -e ${_zdirs[${_zname}]} ]]; then
        _zimfw_print_okay 'Skipping already installed module' 1
        return 0
      fi
      _zimfw_print -nR <%= clear_line %>"Installing ${_zname}<%= ellipsis %>"
      ;;
    check|update)
      if [[ ! -d ${_zdirs[${_zname}]} ]]; then
        _zimfw_print_error 'Not installed. Run %Bzimfw install%b to install.'
        return 1
      fi
      if [[ ${_zaction} == check ]]; then
        if (( _zprintlevel > 1 )) print -nR <%= clear_line %>"Checking ${_zname}<%= ellipsis %>"
      else
        _zimfw_print -nR <%= clear_line %>"Updating ${_zname}<%= ellipsis %>"
      fi
      ;;
    *)
      _zimfw_print_error "Unknown action ${_zaction}"
      return 1
      ;;
  esac
  local -r ztool=${_ztools[${_zname}]}
  case ${ztool} in
    degit|git)
      _zimfw_tool_${ztool} "${_zdirs[${_zname}]}" "${_zurls[${_zname}]}" "${_ztypes[${_zname}]}" "${_zrevs[${_zname}]}" "${_zsubmodules[${_zname}]}" "${_zonpulls[${_zname}]}"
      ;;
    *)
      _zimfw_print_error "Unknown tool ${ztool}"
      return 1
      ;;
  esac
}