middleware

var NoArgs cli.BeforeFunc = func(ctx *cli.Context) error {

	if ctx.NArg() > 0 && ctx.App.Command(ctx.Args()[0]) == nil {
		cmdName := ctx.Command.Name
		if cmdName == "" && ctx.App.Name != "" {
			cmdName = ctx.App.Name
		}

		return fmt.Errorf("unknown command %q for %q", ctx.Args()[0], cmdName)
	}
	return nil
}