udp sample

main.go

package main

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

func main() {
	// Check if at least 3 arguments are passed
	if len(os.Args) < 4 {
		fmt.Println("Usage: ./udp [--broadcast] <IP> <Port> <Message>")
		return
	}

	// Determine if broadcasting is needed
	broadcast := false
	args := os.Args[1:]

	if args[0] == "--broadcast" {
		broadcast = true
		args = args[1:] // Shift arguments if broadcast flag is present
	}

	// Extract IP, port, and message from command line arguments
	ip := args[0]
	port := args[1]
	message := args[2]

	// Resolve the UDP address
	address := net.JoinHostPort(ip, port)
	udpAddr, err := net.ResolveUDPAddr("udp", address)
	if err != nil {
		fmt.Println("Error resolving address:", err)
		return
	}

	// Dial the UDP connection
	conn, err := net.DialUDP("udp", nil, udpAddr)
	if err != nil {
		fmt.Println("Error dialing UDP connection:", err)
		return
	}
	defer conn.Close()

	// TODO: broadcast
	_ = broadcast

	// Send the message
	_, err = conn.Write([]byte(message))
	if err != nil {
		fmt.Println("Error sending message:", err)
		return
	}

	fmt.Println("Message sent to", address)

	// Set a 10-second timeout for the response
	conn.SetReadDeadline(time.Now().Add(10 * time.Second))

	// Buffer to hold the response
	buffer := make([]byte, 1024)

	// Read the response
	n, addr, err := conn.ReadFromUDP(buffer)
	if err != nil {
		fmt.Println("No response received within 10 seconds or an error occurred:", err)
		return
	}

	fmt.Printf("Received response from %s: %s\n", addr, string(buffer[:n]))
}