user2.go

package main

import (
	"fmt"
	"os"
)

func main() {
	fmt.Printf("User ID: %d\n", os.Getuid())
	fmt.Printf("Group ID: %d\n", os.Getgid())
	fmt.Printf("Effective User ID: %d\n", os.Geteuid())
	fmt.Printf("Effective Group ID: %d\n", os.Getegid())

	// Open a hnts2's file
	f, err := os.Open("test.txt")
	if err != nil {
		fmt.Println(err)
	}
	defer f.Close()
}