encode file as QRcode image

qrize.go

package main

import (
	"flag"
	"fmt"
	b64 "encoding/base64"
	"github.com/skip2/go-qrcode"
	"math"
	"os"
	//"strconv"
	"strings"
)

func main() {

        filename := flag.String("f", "", "File to be encoded")
        verbose := flag.Bool("v", false, "verbose")
        flag.Parse()

	if flag.NFlag() == 0 {
		fmt.Println("specify a file!")
	    	os.Exit(1)
	}
	file, err := os.Open(*filename)
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}

	defer file.Close()

	fileInfo, _ := file.Stat()

	var fileSize int64 = fileInfo.Size()

	const fileChunk = 2048

	// calculate total number of parts the file will be chunked into

	totalPartsNum := uint64(math.Ceil(float64(fileSize) / float64(fileChunk)))
	
	if *verbose {
		fmt.Printf("Splitting to %d pieces.\n", totalPartsNum)
	}

	for i := uint64(0); i < totalPartsNum; i++ {

		partSize := int(math.Min(fileChunk, float64(fileSize-int64(i*fileChunk))))
		partBuffer := make([]byte, partSize)

		file.Read(partBuffer)

		// write to disk
		progressive_string := strings.Repeat("0",int(i))
		fileName := "qr_" + *filename + "_" + progressive_string + ".png"
		sEnc := b64.StdEncoding.EncodeToString(partBuffer)
		err := qrcode.WriteFile(sEnc, qrcode.Low, 256, fileName)
		if *verbose {
			fmt.Println("creating ", fileName)
		}
		if err != nil {
			fmt.Printf("%s!\n", err)
		}
	}
	fmt.Printf("Done, check the %d png images in the current directory\n",int(totalPartsNum) )
}