服務端：

package main

import (
    "fmt"
    "net"
)

type info struct {
    conn net.Conn
    name string
}

var ch chan string = make(chan string)
var infos map[string]info = make(map[string]info)

func handle(conn net.Conn) {
    defer conn.Close()

    buf := make([]byte, 100)
    n, _ :
 
= conn.Read(buf)
    name := string(buf[:n])
    var oneinfo info
    oneinfo.conn = conn
    oneinfo.name = name
    addr := conn.RemoteAddr().String()
    infos[addr] = oneinfo
    msg := name + "進入聊天室"
    ch <- msg
    fmt.Println(msg)
    for {
        n, _ := conn.Read(buf)
        
 
if n == 0 {
            fmt.Printf("%s斷開連線\n", addr)
            msg = name + "離開聊天室"
            delete(infos, addr)
            ch <- msg
            fmt.Println(msg)
            return
        }
        ch <- name + ":" + string(buf[:n])
    }
}

func send() {
    for {
        msg :
 
= <-ch
        for _, val := range infos {
            val.conn.Write([]byte(msg))
        }
    }
}
func main() {
    listener, _ := net.Listen("tcp", ":9009")
    defer listener.Close()
    go send()
    for {
        conn, _ := listener.Accept()
        fmt.Printf("%s建立連線\n", conn.RemoteAddr().String())
        go handle(conn)
    }
}

客戶端：

package main

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

func scandata(conn net.Conn) {
    var x string
    for {
        fmt.Scan(&x)
        if x == "q" {
            os.Exit(0)
        }
        conn.Write([]byte(x))
    }
}
func main() {
    conn, _ := net.Dial("tcp", "127.0.0.1:9009")
    buf := make([]byte, 1024)
    args := os.Args
    conn.Write([]byte(args[1]))
    go scandata(conn)
    for {
        n, _ := conn.Read(buf)
        fmt.Println(string(buf[:n]))
    }
}

截圖：

服務端

客戶端