golang copy folder

package main

import (
	"fmt"
	"io"
	"log"
	"os"
)

var target_path string
var source_path string

func main() {

	source_path = os.Args[1]
	target_path = os.Args[2]

	err := copy_folder(source_path, target_path)
	if err != nil {
		log.Fatal(err)
	} else {
		fmt.Print("copy finish")
	}

}

func copy_folder(source string, dest string) (err error) {

	sourceinfo, err := os.Stat(source)
	if err != nil {
		return err
	}

	err = os.MkdirAll(dest, sourceinfo.Mode())
	if err != nil {
		return err
	}

	directory, _ := os.Open(source)

	objects, err := directory.Readdir(-1)
	
	if err != nil {
		fmt.Println(err)
	}

	for _, obj := range objects {

		sourcefilepointer := source + "/" + obj.Name()

		destinationfilepointer := dest + "/" + obj.Name()

		if obj.IsDir() {
			err = copy_folder(sourcefilepointer, destinationfilepointer)
			if err != nil {
				fmt.Println(err)
			}
		} else {
			err = copy_file(sourcefilepointer, destinationfilepointer)
			if err != nil {
				fmt.Println(err)
			}
		}

	}
	return
}

func copy_file(source string, dest string) (err error) {
	sourcefile, err := os.Open(source)
	if err != nil {
		return err
	}

	defer sourcefile.Close()

	destfile, err := os.Create(dest)
	if err != nil {
		return err
	}

	defer destfile.Close()

	_, err = io.Copy(destfile, sourcefile)
	if err == nil {
		sourceinfo, err := os.Stat(source)
		if err == nil {
			err = os.Chmod(dest, sourceinfo.Mode())
		}

	}

	return
}