decode file from a series of QR code images

deqrize.go

package main

import (
	"flag"
	b64 "encoding/base64"
	"fmt"
	"github.com/clsung/grcode"
	//"github.com/maruel/natural"
	"io/ioutil"
	"os"
	//"sort"
	"strings"
)

func main() {
        image_dir := flag.String("i", "", "Directory containing the QR png images")
        filename := flag.String("f", "", "File to be created")
        verbose := flag.Bool("v", false, "verbose")
        flag.Parse()

        if flag.NFlag() < 2 {
                fmt.Println("specify the directory and the filename!")
                os.Exit(1)
        }

	original_file := *image_dir + "/" + *filename
	dump, err := os.OpenFile(original_file, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0640)
	if err != nil {
		fmt.Printf("%s", err)
	}

	files, err := ioutil.ReadDir(*image_dir)
	if err != nil {
		fmt.Println(err)
	}
	//sort.Sort(natural.StringSlice(files))

	for _, file := range files {
		filename := file.Name()
		if strings.Contains(filename, "png") {
			if *verbose {
				fmt.Printf("Processing: %s \n", filename)
			}
			results, err := grcode.GetDataFromFile(*image_dir+"/"+filename)
			if err != nil {
				fmt.Printf("%s\n", err)
                		os.Exit(1)
			}
			if len(results) == 0 {
				fmt.Printf("No qrcode detected from file: %s\n", filename)
                		os.Exit(1)
			}

			if err != nil {
				fmt.Println(err)
			}
			for _, result := range results {
				//fmt.Printf("%s\n", result)
				data, _ := b64.StdEncoding.DecodeString(result)
				_,err := dump.Write(data)
				if err != nil {
					fmt.Printf("%s\n", err)
				}
			}
		}
	}
	_ = dump.Close() 
	fmt.Printf("Done, %s created", original_file)
}