Golang Changing permissions, ownership, and timestamps

package main
 
import (
	"log"
	"os"
	"time"
)
 
func main() {
	// Test File existence.
	_, err := os.Stat("test.txt")
	if err != nil {
		if os.IsNotExist(err) {
			log.Fatal("File does not exist.")
		}
	}
	log.Println("File exist.")
 
	// Change permissions Linux.
	err = os.Chmod("test.txt", 0777)
	if err != nil {
		log.Println(err)
	}
 
	// Change file ownership.
	err = os.Chown("test.txt", os.Getuid(), os.Getgid())
	if err != nil {
		log.Println(err)
	}
 
	// Change file timestamps.
	addOneDayFromNow := time.Now().Add(24 * time.Hour)
	lastAccessTime := addOneDayFromNow
	lastModifyTime := addOneDayFromNow
	err = os.Chtimes("test.txt", lastAccessTime, lastModifyTime)
	if err != nil {
		log.Println(err)
	}
}