从go中的tcp连接读取数据是否需要for循环？

Question

There's a func to handle tcp connection:

for {
    select {
    case conn := <-listen:
        go handleClient(conn)
    ...
}

func handleClient(client net.Conn) {
    for {
       // ...read from conn
       // at some point return
       return
    }
}

My question is , if you use for loop, you must write return or it will be a dead loop. If it returns, this handleClient function will execute only once. So for is not necessary here, right? We can still read all of the data Without for , is this the right way to think ?

Answer 1

A common pattern for a server handling connections might be

func handleClient(conn net.Conn) {
    r := bufio.NewReader(conn)
    for {
        line, err := r.ReadBytes(byte('
'))
        switch err {
        case nil:
            break
        case io.EOF:
        default:
            fmt.Println("ERROR", err)
        }
        // do something with the data, in this case echo it back
        conn.Write(line)
    }
}

The for {} loop is necessary to read multiple lines of data from the connection.

If the handleClient can read the input all in one chunk then a loop isn't necessary

So, yes you are right the for {} is not always necessary but it depends what data is being read. Often a loop like this is the best way to read the data