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Awesome Open Source

Grumble - A powerful modern CLI and SHELL

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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: We do not guarantee 100% backwards compatiblity between minor versions (1.x). However, the API is mostly stable and should not change much.



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...

    Name:      "daemon",
    Help:      "run the daemon",
    Aliases:   []string{"run"},

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

    Args: func(a *grumble.Args) {
        a.String("service", "which service to start", grumble.Default("server"))

    Run: func(c *grumble.Context) error {
        // Parent Flags.
        c.App.Println("directory:", c.Flags.String("directory"))
        c.App.Println("verbose:", c.Flags.Bool("verbose"))
        // Flags.
        c.App.Println("timeout:", c.Flags.Duration("timeout"))
        // Args.
        c.App.Println("service:", c.Args.String("service"))
        return nil

Run the application.

err := app.Run()

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

func main() {

Shell Multiline Input

Builtin support for multiple lines.

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


Check out the sample directory for some detailed examples.

The grml project uses grumble.

Additional Useful Packages


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



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