Go实战--实现一个简单的tcp服务端和客户端(The way to go)

生命不止，继续 go go go !!!

之前介绍了go为我们提供的net/http包，很方便的创建一些api。

今天就来点实战，写一个简单的tcp的服务端、客户端程序。

按照国际惯例，还是先介绍一点点基础知识。

* net.Listen*

Listen announces on the local network address laddr. The network net must be a stream-oriented network: “tcp”, “tcp4”, “tcp6”, “unix” or “unixpacket”. For TCP and UDP, the syntax of laddr is “host:port”, like “127.0.0.1:8080”. If host is omitted, as in “:8080”, Listen listens on all available interfaces instead of just the interface with the given host address. See Dial for more details about address syntax.

Listening on a hostname is not recommended because this creates a socket for at most one of its IP addresses.

func Listen(net, laddr string) (Listener, error)

所以我们的server端就可以这么写：

ln, _ := net.Listen("tcp", "localhost:8081")

bufio.NewReader

NewReader returns a new Reader whose buffer has the default size.

func NewReader(rd io.Reader) *Reader

Write

func (c *IPConn) Write(b []byte) (int, error)

Write implements the Conn Write method.

net.Dial

func (d *Dialer) Dial(network, address string) (Conn, error)

Dial connects to the address on the named network.

See func Dial for a description of the network and address parameters.

基础知识介绍差不多了，下面我们开始写代码了。

tcp_server.go

package main

import "net"
import "fmt"
import "bufio"
import "strings"

func main() {

fmt.Println("Launching server...")

// listen on all interfaces
ln, _ := net.Listen("tcp", "localhost:8081")

// accept connection on port
conn, _ := ln.Accept()

// run loop forever (or until ctrl-c)
for {
// will listen for message to process ending in newline (\n)
message, _ := bufio.NewReader(conn).ReadString('\n')
// output message received
fmt.Print("Message Received:", string(message))
// sample process for string received
newmessage := strings.ToUpper(message)
// send new string back to client
conn.Write([]byte(newmessage + "\n"))
}
}

tcp_client.go

package main

import "net"
import "fmt"
import "bufio"
import "os"

func main() {

// connect to this socket
conn, _ := net.Dial("tcp", "localhost:8081")
for {
// read in input from stdin
reader := bufio.NewReader(os.Stdin)
fmt.Print("Text to send: ")
text, _ := reader.ReadString('\n')
// send to socket
fmt.Fprintf(conn, text + "\n")
// listen for reply
message, _ := bufio.NewReader(conn).ReadString('\n')
fmt.Print("Message from server: "+message)
}
}