Function defaultUsageFunc

command.go:1974–2040

defaultUsageFunc is equivalent to executing defaultUsageTemplate. The two should be changed in sync.

(w io.Writer, in interface{})

// defaultUsageFunc is equivalent to executing defaultUsageTemplate. The two should be changed in sync.
func defaultUsageFunc(w io.Writer, in interface{}) error {
	c := in.(*Command)
	fmt.Fprint(w, "Usage:")
	if c.Runnable() {
		fmt.Fprintf(w, "\n  %s", c.UseLine())
	}
	if c.HasAvailableSubCommands() {
		fmt.Fprintf(w, "\n  %s [command]", c.CommandPath())
	}
	if len(c.Aliases) > 0 {
		fmt.Fprintf(w, "\n\nAliases:\n")
		fmt.Fprintf(w, "  %s", c.NameAndAliases())
	}
	if c.HasExample() {
		fmt.Fprintf(w, "\n\nExamples:\n")
		fmt.Fprintf(w, "%s", c.Example)
	}
	if c.HasAvailableSubCommands() {
		cmds := c.Commands()
		if len(c.Groups()) == 0 {
			fmt.Fprintf(w, "\n\nAvailable Commands:")
			for _, subcmd := range cmds {
				if subcmd.IsAvailableCommand() || subcmd.Name() == helpCommandName {
					fmt.Fprintf(w, "\n  %s %s", rpad(subcmd.Name(), subcmd.NamePadding()), subcmd.Short)
				}
			}
		} else {
			for _, group := range c.Groups() {
				fmt.Fprintf(w, "\n\n%s", group.Title)
				for _, subcmd := range cmds {
					if subcmd.GroupID == group.ID && (subcmd.IsAvailableCommand() || subcmd.Name() == helpCommandName) {
						fmt.Fprintf(w, "\n  %s %s", rpad(subcmd.Name(), subcmd.NamePadding()), subcmd.Short)
					}
				}
			}
			if !c.AllChildCommandsHaveGroup() {
				fmt.Fprintf(w, "\n\nAdditional Commands:")
				for _, subcmd := range cmds {
					if subcmd.GroupID == "" && (subcmd.IsAvailableCommand() || subcmd.Name() == helpCommandName) {
						fmt.Fprintf(w, "\n  %s %s", rpad(subcmd.Name(), subcmd.NamePadding()), subcmd.Short)
					}
				}
			}
		}
	}
	if c.HasAvailableLocalFlags() {
		fmt.Fprintf(w, "\n\nFlags:\n")
		fmt.Fprint(w, trimRightSpace(c.LocalFlags().FlagUsages()))
	}
	if c.HasAvailableInheritedFlags() {
		fmt.Fprintf(w, "\n\nGlobal Flags:\n")
		fmt.Fprint(w, trimRightSpace(c.InheritedFlags().FlagUsages()))
	}
	if c.HasHelpSubCommands() {
		fmt.Fprintf(w, "\n\nAdditional help topics:")
		for _, subcmd := range c.Commands() {
			if subcmd.IsAdditionalHelpTopicCommand() {
				fmt.Fprintf(w, "\n  %s %s", rpad(subcmd.CommandPath(), subcmd.CommandPathPadding()), subcmd.Short)