Node.js client and server game using Telnet

Question

I'm trying to create a basic game (only text) using Node.js, and it's 'net' library.
I'm hitting a bit of a wall. I can't seem to figure out how to prompt the user to enter some information, and wait for the user to enter said information.

Here's the code I have so far. It's fairly basic, and will print out 2 lines for you when you run the client, and then hang. It's at that point I want the user to be able to enter information. I'm unsure of a few things here:
1. How do I enable the user to type? (more specifically, is it client or server side)
2. How do I send that data to the server when enter is pressed?

I have read up on some documentation as far as Telnet goes, and it leads me to my last question: is the Telnet module in Node really the right one for this, or is there a better alternative for client/server creation and communication?

Client Code:

var connect = require('net');

var client = connect.connect('80', 'localhost');
console.log('Connection Success!\n\n');
client.on('data', function(data) {
  // Log the response from the HTTP server.
  console.log('' + data);
}).on('connect', function() {
  // Manually write an HTTP request.
  //I'm assuming I could send data at this point here, on connect?
}).on('end', function() {
  console.log('Disconnected');
});

Server Code:

var net = require('net');

var sockets = [];

function cleanInput(data) {
    return data.toString().replace(/(\r\n|\n|\r)/gm,"");
}

function receiveData(socket, data) {
    var cleanData = cleanInput(data);
    if(cleanData === "quit") {
        socket.end('Goodbye!\n');
    }
    else {
        for(var i = 0; i<sockets.length; i++) {
            if (sockets[i] !== socket) {
                sockets[i].write(data);
            }
        }
    }
}

function closeSocket(socket) {
    var i = sockets.indexOf(socket);
    if (i != -1) {
        sockets.splice(i, 1);
    }
}

function newSocket(socket) {
    sockets.push(socket);
    socket.write('Welcome to the Battleship Server!\n\n');
    socket.write('Please enter a username: ');
    socket.on('data', function(data) {
        receiveData(socket, data);
    })
    socket.on('end', function() {
        closeSocket(socket);
    })
}


var server = net.createServer(newSocket);
server.listen(80);

Thanks in advance!

Answer 1

• you want to use process.stdin and process.stdout to interact with input/output from/to the terminal. Have a look here.
• You can send data to the server when enter is pressed with process.stdin.once('data', function(data){ /* ... */ }). The .once method ensures that the callback is called just once when the user hits enter.

The client code should look like:

var connect = require('net');

var client = connect.connect('80', 'localhost');
client.on('data', function(data) {
  console.log('' + data);
  process.stdin.once('data', function (chunk) {
    client.write(chunk.toString());
  });
}).on('connect', function() {
  client.write('Hello');
}).on('end', function() {
  console.log('Disconnected');
});