Golang代码搜集-简易聊天服务器

秒速五厘米 2021-09-14 12:58 365阅读 0赞

这段代码出自《Go程序设计语言》（英文版）第254页，一段很简单的代码实现了一个简易的聊天服务器。里面涉及了tcp通讯、输入/输出、使用chan传值等。

//服务器代码
    package main
    
    import (
        "bufio"
        "fmt"
        "io"
        "log"
        "net"
    )
    
    func main() {
        listener, err := net.Listen("tcp", ":8000")
        if err != nil {
            log.Fatal(err)
        }
        fmt.Println("Server listens successfull and gets ready for acceptions")
        go broadcaster()
        for {
            conn, err := listener.Accept()
            if err != nil {
                log.Fatal(err)
            }
            fmt.Printf("[%v] connected \n", conn.RemoteAddr())
            go handleConn(conn)
        }
    }
    
    type client chan<- string
    
    var (
        entering = make(chan client)
        leaving  = make(chan client)
        message  = make(chan string)
    )
    
    func broadcaster() {
        clients := make(map[client]bool)
        for {
            select {
            case msg := <-message:
                for cli := range clients {
                    cli <- msg
                }
            case cli := <-entering:
                clients[cli] = true
            case cli := <-leaving:
                delete(clients, cli)
                close(cli)
            }
        }
    }
    func handleConn(c net.Conn) {
        defer c.Close()
        ch := make(chan string)
        go clientWriter(c, ch)
        ch <- "Welcome!\n"
        entering <- ch
        message <- fmt.Sprintf("[%v] in \n", c.RemoteAddr())
        input := bufio.NewScanner(c)
        for input.Scan() {
            message <- fmt.Sprintf("[%v] say: %v \n", c.RemoteAddr(), input.Text())
        }
        leaving <- ch
        message <- fmt.Sprintf("[%v] out \n", c.RemoteAddr())
        fmt.Printf("[%v] disconnected \n", c.RemoteAddr())
    }
    func clientWriter(c net.Conn, ch <-chan string) {
        for msg := range ch {
            io.WriteString(c, msg)
        }
    
    }

//客户端
    package main
    
    import (
        "io"
        "log"
        "net"
        "os"
    )
    
    func main() {
        conn, err := net.Dial("tcp", ":8000")
        if err != nil {
            log.Fatal(err)
        }
        go mustCopy(os.Stdout, conn)
        mustCopy(conn, os.Stdin)
    }
    func mustCopy(dest io.Writer, src io.Reader) {
        if _, err := io.Copy(dest, src); err != nil {
            log.Fatal(err)
        }
    }