Building a CLI in go

Creating a Command Line Interface (CLI) can be a rewarding and fun experience, especially with the powerful combination of Go and Cobra.

Here’s a brief overview of how to get started building your own CLI with cobra.

All of this is very simple, since I am a newborn gopher myself. I have not practised too much with go yet but I am planning to expand on my knowledge and keep adding features to my CLI.

Getting Started

First, I set up my Go environment and created a new project directory:

mkdir mycli
cd mycli
go mod init mycli

Installing Cobra

Cobra is a library for creating powerful CLI applications. I installed it using:

go get -u github.com/spf13/cobra/cobra

Creating the CLI

I used Cobra to initialize my CLI application:

cobra init --pkg-name mycli

This command generated the basic structure of my CLI application, including the main.go file and a cmd directory.

Adding Commands

Next, I added a simple command. For example, to add a hello command, I ran:

cobra add hello

This created a new file hello.go in the cmd directory. I edited this file to define the behavior of the hello command:

package cmd

import (
    "fmt"
    "github.com/spf13/cobra"
)

var helloCmd = &cobra.Command{
    Use:   "hello",
    Short: "Prints a greeting message",
    Run: func(cmd *cobra.Command, args []string) {
        fmt.Println("Hello, world!")
    },
}

func init() {
    rootCmd.AddCommand(helloCmd)
}

Running the CLI

Finally, I built and ran my CLI application:

go build -o mycli
./mycli hello

The output was a simple greeting: Hello, world!

Conclusion

Building a CLI with Go and Cobra was a straightforward and enjoyable process so far. With Cobra’s powerful features and Go’s performance and beautiful simplicity, I was able to create a (somewhat) useful CLI tool quickly. I look forward to expanding its functionality in the future.

Checkout Goji

If you want to see my funny little emoji generator CLI tool for yourself visit Github or the go package registry.