}

func runList(writer io.Writer) error {
	// Sort flag names
	keys := make([]string, len(settableFlags))
	i := 0
	for key := range settableFlags {
		keys[i] = key
		i++
	}
	sort.Strings(keys)
	w := new(tabwriter.Writer).Init(writer, 0, 8, 5, ' ', 0)
	fmt.Fprintf(w, "FLAG\tVALUE\tFROM\n")
	for _, flag := range keys {
		v := settableFlags[flag]
		fmt.Fprintf(w, "%s\t%s\t%v\n", flag, viper.GetString(flag), configSource(flag, v))
	}