// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
// For more tutorials  : https://learngoprogramming.com
// In-person training  : https://www.linkedin.com/in/inancgumus/
// Follow me on twitter: https://twitter.com/inancgumus

package main

import (
	"fmt"
	"os"
	"strings"
)

const usage = `[command] [string]

Available commands: lower, upper and title`

func main() {
	args := os.Args
	if len(args) != 3 {
		fmt.Println(usage)
		return
	}

	cmd, str := args[1], args[2]
	switch cmd {
	case "lower":
		fmt.Println(strings.ToLower(str))
	case "upper":
		fmt.Println(strings.ToUpper(str))
	case "title":
		fmt.Println(strings.Title(str))
	default:
		fmt.Printf("Unknown command: %q\n", cmd)
	}
}
