go tcp c/s server client 学习笔记

server1:
package main

import (
    "fmt"
    "net"
)

func main() {
    l, err := net.Listen("tcp", "127.0.0.1:9876")
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println("服务器等待客户端连接")
    conn, err := l.Accept()
    if err != nil {
        fmt.Println(err)
    }
    defer conn.Close()
    fmt.Println("客户端建立连接 ")
    buf := make([]byte, 4096)
    n, err := conn.Read(buf)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println(string(buf[:n]))
    conn.Write(buf[:n])
}

client1:

package main

import (
    "fmt"
    "net"
)

func main() {
    conn, err := net.Dial("tcp", "127.0.0.1:9876")
    if err != nil {
        fmt.Println(err)
    }
    defer conn.Close()
    conn.Write([]byte("are you ready"))
    buf := make([]byte, 4096)
    n, err := conn.Read(buf)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Println(string(buf[:n]))
}

sever2：

package main

import (
    "fmt"
    "io"
    "net"
    "runtime"
    "strings"
)

func process(conn net.Conn) {

    // io.Copy(conn, conn)
    buf := make([]byte, 4096)
    for {
        n, err := conn.Read(buf)
        if err != nil {
            if err == io.EOF {
                fmt.Println("客户端断开连接")
                runtime.Goexit()
            } else {
                fmt.Println(err)
                runtime.Goexit()
            }
            //break
        }
        fmt.Println("接收到消息：", string(buf[:n]))
        conn.Write([]byte(strings.ToUpper(string(buf[:n]))))
        //fmt.Println(strings.ToUpper(string(buf[:n])))
    }
}

func main() {
    l, err := net.Listen("tcp", "127.0.0.1:9876")
    if err != nil {
        fmt.Println(err)
    }
    defer l.Close()

    for {
        conn, err := l.Accept()
        if err != nil {
            fmt.Println(err)
            continue
        }
        defer conn.Close()
        fmt.Println(conn.RemoteAddr())
        go process(conn)
    }
}

client2:

package main

import (
    "bufio"
    "fmt"
    "net"
    "os"
    "strings"
)

func main() {
    conn, err := net.Dial("tcp", "127.0.0.1:9876")
    if err != nil {
        fmt.Println(err)
    }
    defer conn.Close()

    for {
        //strs :=""
        // fmt.Scanln(&strs) 空格有问题
        //strs := make([]byte, 4096)

        //n, err := os.Stdin.Read(strs)
        fmt.Println("请输入要发送的消息：")
        str, err := bufio.NewReader(os.Stdin).ReadString('\n')
        if err != nil {
            fmt.Println(err)
        }
        str = strings.TrimSpace(str)

        //fmt.Println("发送前", , "展示")
        //fmt.Println("a", str, "b")
        if str == "Q" {
            fmt.Println("接收到退出命令，退出客户端")
            break
        }
        conn.Write([]byte(str))
        buf := make([]byte, 4096)
        n, err := conn.Read(buf)
        if err != nil {
            fmt.Println(err)
            break
        }
        defer conn.Close()
        fmt.Println("接收到消息：", string(buf[:n]))
    }

}