README.md

Grumble - A powerful modern CLI and SHELL

There are a handful of powerful go CLI libraries available (spf13/cobra, urfave/cli). However sometimes an integrated shell interface is a great and useful extension for the actual application. This library offers a simple API to create powerful CLI applications and automatically starts an integrated interactive shell, if the application is started without any command arguments.

Hint: The API might change slightly, until a first 1.0 release is published.

Introduction

Create a grumble APP.

var app = grumble.New(&grumble.Config{
	Name:        "app",
	Description: "short app description",

	Flags: func(f *grumble.Flags) {
		f.String("d", "directory", "DEFAULT", "set an alternative directory path")
		f.Bool("v", "verbose", false, "enable verbose mode")
	},
})

Register a top-level command. Note: Sub commands are also supported...

app.AddCommand(&grumble.Command{
    Name:      "daemon",
    Help:      "run the daemon",
    Aliases:   []string{"run"},
    Usage:     "daemon [OPTIONS]",
    AllowArgs: true,

    Flags: func(f *grumble.Flags) {
        f.Duration("t", "timeout", time.Second, "timeout duration")
    },

    Run: func(c *grumble.Context) error {
        c.App.Println("timeout:", c.Flags.Duration("timeout"))
        c.App.Println("directory:", c.Flags.String("directory"))
        c.App.Println("verbose:", c.Flags.Bool("verbose"))

        // Handle args.
        c.App.Println("args:")
        c.App.Println(strings.Join(c.Args, "\n"))

        return nil
    },
})

Run the application.

err := app.Run()

Or use the builtin grumble.Main function to handle errors automatically.

func main() {
	grumble.Main(app)
}

Shell Multiline Input

Builtin support for multiple lines.

>>> This is \
... a multi line \
... command

Samples

Check out the sample directory for some detailed examples.

The grml project uses grumble.

Additional Useful Packages

• https://github.com/AlecAivazis/survey
• https://github.com/tj/go-spin

Credits

This project is based on ideas from the great ishell library.

License

MIT