Writing a line-based TCP server

In this recipe, we will look at a TCP server that works with lines instead of bytes. There are some points you need to be careful about when reading lines from a network connection, especially related to the security of the server. Just because you are expecting to read lines does not mean the client will send well-formed lines.

How to do it...

1. Use the same structure to set up the server as given in the previous section.
2. In the connection handler, use a bufio.Reader or bufio.Scanner to read lines.
3. Wrap the connection with an io.LimitedReader to limit line length.

Let’s take a look at how this can work. The following example shows how a connection handler can be implemented:

// Limit line length to 1KiB.
const MaxLineLength = 1024
func handleConnection(conn net.Conn) error {
  defer conn.Close()
  // Wrap the connection with a limited reader
  // to prevent the client from sending unbounded...