for k, v := range combineFiles {
				if err := combine(v, k); err != nil {
					fmt.Println("ERROR:", err)
				}
			}
		}

		return nil
	}
	err := app.Run(os.Args)
	if err != nil {
		log.Fatal(err)
	}
}

var (
	// XL header specifies the format
	xlHeader = [4]byte{'X', 'L', '2', ' '}

	// Current version being written.
	xlVersionCurrent [4]byte
)

const (