[日常] Go语言圣经-基于select的多路复用习题

func main() {
listener,err := net.Listen("tcp",":8040")
if err != nil {
log.Fatal(err)
}

    for {
            conn,err := listener.Accept()
            if err != nil {
                    log.Print(err) // e.g.,connection aborted
                    continue
            }
            go handleConn(conn) //新建goroutines处理连接
    }

}
/*
1.启动一个goroutine,for死循环让他不能断掉
select语句case判断两个channel
一个是10秒后断掉连接
另一个是接收标准输入后发送过来的channel，接收到值后，启动goroutinue输出

2.for循环接收标准输入，接收到后发送给message的channel
/
func handleConn(c net.Conn) {
input := bufio.NewScanner(c)
var wg sync.WaitGroup
var message = make(chan string)
wg.Add(1)
go func() {
defer wg.Done()
for {
select {
case <-time.After(10 time.Second):
c.Close()
case mes := <-message:
wg.Add(1)
go func(c net.Conn,shout string,delay time.Duration) {
defer wg.Done()
fmt.Fprintln(c,"t",strings.ToUpper(shout))
time.Sleep(delay)
fmt.Fprintln(c,shout)
time.Sleep(delay)
fmt.Fprintln(c,strings.ToLower(shout))
//ch<-struct{}{}

                            }(c,mes,1*time.Second)

                    }
            }
    }()
    for input.Scan() {
            text := input.Text()
            message <- text
    }

    wg.Wait()
    //cw := c.(*net.TCPConn)
    //cw.CloseWrite()

    c.Close()

}