Go program for testing DNS lookup

test-dns.go

package main

import (
	"net"
	"os"
	"fmt"
)

func main() {
	hostname := os.Args[1]
	addrs, err := net.LookupHost(hostname)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to lookup %q: %s\n", hostname, err)
		os.Exit(1)
	}

	fmt.Printf("DNS lookup of %q succeeded: %v\n", hostname, addrs)
}