TCP Client & Server (ping-pong)

client.go

package main

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

func Ping(proto, addr string, out chan<- string) {
	c, err := net.Dial(proto, addr)
	if err != nil {
		log.Fatal(err)
	}
	defer c.Close()

	msg := []byte("holla!")
	_, err = c.Write(msg)
	if err != nil {
		log.Fatal(err)
	}

	buf := make([]byte, 1024)
	_, err = c.Read(buf)
	if err != nil {
		log.Fatal(err)
	}
	out <- string(buf)
}

func main() {

	start := time.Now()

	ch := make(chan string, 1)
	for i := 0; i < 100; i++ {
		go Ping("tcp", "0.0.0.0:8888", ch)
	}

	var m string
	for i := 0; i < 100; i++ {
		m = <-ch
		log.Println(i+1, m)
	}

	log.Println(time.Since(start))

}

server.go

package main

import (
	"net"
	"log"
)

func HandleConn(c net.Conn) {
	defer c.Close()

	// handle incoming data
	buffer := make([]byte, 1024)
	numBytes, err := c.Read(buffer)
	if err != nil {
		log.Fatal(err)
	}
	log.Println("received", numBytes, "bytes:", string(buffer))

	// handle reply
	msg := string(buffer[:numBytes]) + " back"
	_, err = c.Write([]byte(msg))
	if err != nil {
		log.Fatal(err)
	}
}

func main() {

	l, err := net.Listen("tcp", "0.0.0.0:8888")
	if err != nil {
		log.Fatal(err)
	}
	defer l.Close()

	for {
		// accept connection
		log.Println("Waiting for new connection...")
		conn, err := l.Accept()
		if err != nil {
			log.Fatal(err)
		}

		// handle connection
		go HandleConn(conn)
	}


}