Go broadcast to the network

broadcast.go

package main

import (
	"log"
	"net"
	"strconv"
	"time"
)

const (
	maxDatagramSize = 1<<14
)

func main() {
	go ping()
	serveUDP(msgHandler)
}

func ping() {
	addr, err := net.ResolveUDPAddr("udp", "255.255.255.255:10001")
	if err != nil {
		log.Fatal(err)
	}
	c, err := net.DialUDP("udp", nil, addr)
	i := 0
	for {
		i++
		c.Write([]byte("hello, world! i=" + strconv.Itoa(i) + "\n"))
		time.Sleep(1 * time.Second)
	}
}

func msgHandler(src *net.UDPAddr, n int, b []byte) {
	log.Println(n, "bytes read from", src)
	log.Println(string(b[:n]))
}

func serveUDP(h func(*net.UDPAddr, int, []byte)) {
	addr, err := net.ResolveUDPAddr("udp", ":10001")
	if err != nil {
		log.Fatal(err)
	}
	l, err := net.ListenUDP("udp", addr)
	if err != nil {
		log.Fatal(err)
	}
	l.SetReadBuffer(maxDatagramSize)
	b := make([]byte, maxDatagramSize)
	for {
		n, src, err := l.ReadFromUDP(b)
		if err != nil {
			log.Fatal("ReadFromUDP failed:", err)
		}
		h(src, n, b)
	}
}