CLI

A lightweight package for building CLI apps, originally implemented for fun but feel free to use it. A command can include multiple subcommands and flags, with each subcommand functioning as an independent command, enabling the same definitions to be reused. Its usage is inspired by urfave and cobra.

Features

• Minimal, testable, and simple code
• Commands with subcommands: cmd [sub-cmd [nested-sub-cmd...] ]
• Specify flags by --flag=value or --flag value
• Specify obligatory flags and default values

Examples

Command Samples

Here are a few examples of the types of commands you can create:

• ./app add 10 5
• ./app calculate multiply 7 3
• ./app greet --name user --upper-case true
• ./app [greet|goodby|echo] ...

A Greeting Application

package main

import (
	"fmt"
	"github.com/gavraz/cli"
	"log"
	"os"
	"strings"
)

func main() {
	app := cli.Command{
		Name:  "my-cli",
		Usage: "my-cli [greet]",
		Action: func(ctx cli.Flags, args []string) error {
			fmt.Println("Welcome to my cli!")
			return nil
		},
		Subcommands: []*cli.Command{
			{
				Name:        "greet",
				Usage:       "greet --name NAME",
				Description: "Outputs a greeting",
				Flags: []cli.Flag{
					cli.StringFlag{
						Name:        "name",
						Description: "Your name",
						Required:    true,
					},
					cli.BoolFlag{
						Name:        "shout",
						Description: "Shout the greeting in uppercase",
						Default:     false,
					},
				},
				Action: func(ctx cli.Flags, args []string) error {
					name := ctx.String("name")
					greeting := fmt.Sprintf("Hello, %s!", name)
					if shouldShout := ctx.Bool("shout"); shouldShout {
						greeting = strings.ToUpper(greeting)
					}
					fmt.Println(greeting)
					return nil
				},
			},
		},
	}

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

	// Input:	greet --name Taylor --shout true
	// Output:	HELLO, TAYLOR!
}

For additional examples checkout command_test.go.