The gocmdctrl package aims to make it easier to create command line
interfaces that have several commands. E.g.:

     example-cli import
     example-cli export

It includes a help command which prints information about the
available commands. A simple example that has a "help" and an "echo"
command:

    import "fmt"
    import "os"
    import "launchpad.net/gocmdtrl"

    func Echo(ctrl *gocmdctrl.CmdCtrl, args []string) int {
        for _, arg := range args {
            fmt.Fprintf(ctrl.Out, "%s ", arg)
        }
        fmt.Fprintf(ctrl.Out, "\n")
        return 0
    }

    ctrl := gocmdctrl.New(os.Args[0], os.Args[1:])
    ctrl.AddCommand(gocmdctrl.NewHelpCommand(), "help")
    ctrl.AddCommand(
        gocmdctrl.NewCommand(Echo, "Echo all arguments", "",
            []gocmdctrl.Arg{{"WORD", false, true}}),
        "hello")
    os.Exit(ctrl.Run())

A more complete example can be found in the example/ folder.

There are Out and Err io.Writer objects to use for writing information.
By default they are stdout and stderr, but they can be overridden to
make testing easier.