Using the flags package in Go to create sub-commands

subcommands.go

package subcommands 

import (
	"flag"
	"fmt"
	"os"
)

func main() {
	uploadCmd := flag.NewFlagSet("upload", flag.ExitOnError)
	uploadPath := uploadCmd.String("path", "", "path to file")
	uploadContainerName := uploadCmd.String("container", "", "name of azure storage container")
	uploadBlobName := uploadCmd.String("blob", "", "name of azure blob")

	downloadCmd := flag.NewFlagSet("download", flag.ExitOnError)
	downloadBlobName := downloadCmd.String("name", "", "name of azure blob to download")
	downloadContainerName := downloadCmd.String("container", "", "name of azure storage container")
	downloadFile := downloadCmd.String("file", "", "destination path for file")

	listCmd := flag.NewFlagSet("list", flag.ContinueOnError)
	listContainerName := listCmd.String("container", "", "name of azure storage container")

	deleteCmd := flag.NewFlagSet("delete", flag.ExitOnError)
	deleteBlobName := deleteCmd.String("name", "", "name of azure blob to delete")
	deleteContainerName := deleteCmd.String("container", "", "name of azure storage container")

	if len(os.Args) < 2 {
		fmt.Println("expected a subcommand")
		os.Exit(1)
	}

	switch os.Args[1] {
	case "upload":
		uploadCmd.Parse(os.Args[2:])
		// call uploadFunc
		fmt.Println("  path:", *uploadPath)
		fmt.Println("  container:", *uploadContainerName)
		fmt.Println("  blob:", *uploadBlobName)
	case "download":
		downloadCmd.Parse(os.Args[2:])
		// call downloadFunc
		fmt.Println("  name:", *downloadBlobName)
		fmt.Println("  container:", *downloadContainerName)
		fmt.Println("  file:", *downloadFile)
	case "list":
		listCmd.Parse(os.Args[2:])
		//call listFunc
		fmt.Println(" container:", *listContainerName)
	case "delete":
		deleteCmd.Parse(os.Args[2:])
		//call deleteFunc
		fmt.Println("  name:", *deleteBlobName)
		fmt.Println("  container:", &deleteContainerName)
	default:
		fmt.Println("expected 'upload' subcommand")
		os.Exit(1)
	}
}