tcp server client

简单的tcp server

package main

import (
    "fmt"
    "net"
)

func main()  {
    
    //创建一个用于监听的套接字
    listener, err := net.Listen("tcp","127.0.0.1:8000")
    if err != nil {
        fmt.Println("net listener err:",err)
        return
    }
    defer listener.Close()

    fmt.Println("服务器等待客户端连接")
    //阻塞监听客户端连接请求，成功建立连接，返回用于通信的socket
    conn, err := listener.Accept()
    if err != nil {
        fmt.Println("listener.Accept() err:",err)
        return
    }
    fmt.Println("服务器与客户端成功建立连接")
    defer conn.Close()
    
    buf := make([]byte,4096)
    n, err := conn.Read(buf)
    if err != nil {
        fmt.Println("conn read err:",err)
        return
    }
    fmt.Println("服务器读到数据:",string(buf[:n]))

    conn.Write(buf[:n])
}

简单的tcp client

package main

import (
    "fmt"
    "net"
)

func main() {
    
    conn, err := net.Dial("tcp","127.0.0.1:8000")
    if err != nil {
        fmt.Println("net.Dial err:",err)
        return
    }
    defer conn.Close()

    conn.Write([]byte("hello"))

    buf := make([]byte, 4096)
    n, err := conn.Read(buf)
    if err != nil {
        fmt.Println("conn.Read err:",err)
        return
    }
    fmt.Println("服务器回发:",string(buf[:n]))
}

tcp server 并发

package main

import (
    "net"
    "fmt"
    "strings"
)

func HandlerConnect(conn net.Conn) {

    defer conn.Close()

    //获取连接的客户端 Addr
    addr := conn.RemoteAddr()
    fmt.Println(addr,"客户端成功连接")

    // 读取客户端数据
    buf := make([]byte,4096)
    for {
        n, err := conn.Read(buf)
        if n == 0 {
            fmt.Println("客户端",addr,"断开连接")
            return
        }
        if err != nil {
            fmt.Println("conn.Read err:",err)
            return
        }
        fmt.Println("服务器读到数据",string(buf[:n]),"=========",addr)
        
        // 小写转大写，回发给客户端
        conn.Write([]byte(strings.ToUpper(string(buf[:n]))))
    }
}

func main()  {

    listener, err := net.Listen("tcp","127.0.0.1:8001")
    if err != nil {
        fmt.Println("net.Listen err:",err)
        return
    }
    defer listener.Close()

    fmt.Println("服务器等待客户端连接")
    for {
        conn, err := listener.Accept()
        if err != nil {
            fmt.Println("listener.Accpet err:",err)
            return
        }

        go HandlerConnect(conn)
    }

}

tcp client并发

package main

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

func main()  {

    conn, err := net.Dial("tcp","127.0.0.1:8001")
    if err != nil {
        fmt.Println("net.Dial err:",err)
        return
    }
    defer conn.Close()

    // 获取用户键盘输入，发送给服务器
    go func ()  {
        str := make([]byte, 4096)
        for {
            n, err := os.Stdin.Read(str)
            if err != nil {
                fmt.Println("os.Stdin err:",err)
                continue
            }
            conn.Write(str[:n])
        }
    }()
    buf := make([]byte, 4096)
    for {
        n, err := conn.Read(buf)
        if err != nil {
            fmt.Println("conn.Read err:",err)
            return
        }
        fmt.Println("服务器回发:",string(buf[:n]))
    }
}