protohackers/cmd/smoketest/main.go

package main

import (
	"fmt"
	"io"
	"log"
	"net"
	"os"
)

const (
	connPort = "3030"
	connType = "tcp4"
)

func main() {
	l, err := net.Listen(connType, ":"+connPort)
	if err != nil {
		log.Fatalln(err)
		os.Exit(1)
	}
	defer l.Close()

	fmt.Println(fmt.Sprintf("Listening on port %s", connPort))

	for {
		conn, err := l.Accept()
		if err != nil {
			log.Fatalln(err)
		}
		go handleRequest(conn)
	}
}

func handleRequest(conn net.Conn) {
	defer conn.Close()
	if _, err := io.Copy(conn, conn); err != nil {
		log.Fatalln(err)
	}
}