Quick base64 convertor in Go

base64.go

package main

import (
	"encoding/base64"
	"flag"
	"fmt"
	"io/ioutil"
	"mime"
	"path/filepath"
	"strings"
)

func main() {
	flag.Parse()
	args := flag.Arg(0)
	bytes, err := ioutil.ReadFile(args)
	if err != nil {
		panic(err)
	}
	fmt.Printf("data:%s;base64,%s\n", mime.TypeByExtension(filepath.Ext(args)), strings.TrimSpace(base64.StdEncoding.EncodeToString(bytes)))
}