Simple Go program to download xkcd images to local disk

xkcd.go

package main
import (
	"fmt"
	"net/http"
	"encoding/json"
	"strconv"
	"os"
	"log"
	"io"
)
var ComicURL string = "http://xkcd.com/"

type Comic struct {
	Year 		string `json:"year"`
	SafeTitle 	string `json:"safe_title"`
	Transcript 	string `json:"transcript"`
	Image		string `json:"img"`
}

func main() {
	for i:=1; i < 50; i++ {
		result, err := GetComic(ComicURL + strconv.Itoa(i) + "/info.0.json")
		if err != nil {
			fmt.Errorf("Error %v", err)
		}

		extension := result.Image[len(result.Image)-4 : ]
		img, err := os.Create("./xkcd/" + result.SafeTitle + extension)
		if err != nil {
			log.Fatal(err)
		}

		resp, err := http.Get(result.Image)
		if err != nil {
			log.Fatal(err)
		}
		defer resp.Body.Close()

		_, err = io.Copy(img,resp.Body)
		if err != nil {
			log.Fatal(err)
		}

		defer img.Close()
		fmt.Printf("URL : %s\n", result.Image)
	}

}

func GetComic(url string)(*Comic, error) {
	resp, err := http.Get(url)

	if err != nil {
		defer resp.Body.Close()
		return nil, err
	}

	if resp.StatusCode != http.StatusOK {
		fmt.Println("ERROR")
		defer resp.Body.Close()
		fmt.Errorf("Error trying to access the provided URL: %s", resp.Status)
		return nil, err
	}

	var comicBlock Comic
	result := json.NewDecoder(resp.Body).Decode(&comicBlock)

	if result != nil {
		defer resp.Body.Close()
		return nil, err
	}

	defer resp.Body.Close()

	return &comicBlock, nil
}