sockets - 从 go 中的套接字读取时遇到问题

Question

我正在尝试学习 go 语言，并且正在编写一个简单的 echo 服务器。不过，我很难让它发挥作用。

func listen(server string) {
    var buf []byte

    listener, ok := net.Listen("tcp", server)
    if ok != nil {
        fmt.Fprintf(os.Stderr, "Could not listen on socket: %s\n", ok.String())
        return
    }
    conn, ok := listener.Accept()
    if ok != nil {
        fmt.Fprintf(os.Stderr, "Could not accept connection on socket: %s\n", ok.String())
        return
    }

    writelen, ok := conn.Write(strings.Bytes("Ready to receive\n"))
    if ok != nil {
        fmt.Fprintf(os.Stderr, "Could not write to socket: %s\n", ok.String())
    } else {
        fmt.Printf("Wrote %d bytes to socket\n", writelen)
    }

    for ;; {
        readlen, ok := conn.Read(buf)
        if ok != nil {
            fmt.Fprintf(os.Stderr, "Error when reading from socket: %s\n", ok.String())
            return
        }
        if readlen == 0 {
            fmt.Printf("Connection closed by remote host\n")
            return
        }

        fmt.Printf("Client at %s says '%s'\n", conn.RemoteAddr().String(), buf)
    }
}

我从这个函数得到以下输出:

[nathan@ebisu ~/src/go/echo_server] ./6.out 1234
Using port 1234
Wrote 17 bytes to socket
Error when reading from socket: EOF

这是我在客户端看到的:

[nathan@ebisu ~] telnet 127.0.0.1 1234
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Ready to receive
Connection closed by foreign host.

我们将不胜感激(或指向资源的指针；关于套接字 API 的 go 文档还有一些不足之处)。

谢谢，

内森

Answer 1

在您的示例中，buf 需要具有确定的大小。您已将其声明为长度为 0 的 slice 。

声明为:

var buf = make([]byte, 1024)