DNS Client
To create a DNS client program in Go, follow these steps:
Step 1: Initialize the Go Module
First, create a new directory for your project and initialize the Go module.
mkdir dnsclient
cd dnsclient
go mod init github.com/username/dnsclient
Step 2: Create the dnsclient.go File
Create a dnsclient.go file to handle the DNS client functionality.
// dnsclient.go
package main
import (
"fmt"
"net"
)
// ResolveDNS resolves the given hostname to its IP addresses.
func ResolveDNS(hostname string) ([]net.IP, error) {
ips, err := net.LookupIP(hostname)
if err != nil {
return nil, err
}
return ips, nil
}
Step 3: Create the main.go File
Create a main.go file to use the DNS client functionality.
// main.go
package main
import (
"fmt"
"os"
)
func main() {
if len(os.Args) != 2 {
fmt.Println("Usage: dnsclient <hostname>")
os.Exit(1)
}
hostname := os.Args[1]
ips, err := ResolveDNS(hostname)
if err != nil {
fmt.Printf("Failed to resolve DNS: %v\n", err)
os.Exit(1)
}
fmt.Printf("IP addresses for %s:\n", hostname)
for _, ip := range ips {
fmt.Println(ip)
}
}
Step 4: Run the Program
Run the program using the go run command.
go run main.go example.com
This will resolve the DNS for example.com and print its IP addresses.
Last modified: 19 December 2024