/*

A chat client in node.js.

Connects to a TCP socket server. Sends anything

typed on the keyboard to the server. If the server sends an

'end' event, the program stops.

To start it, give it a server address and a port number

created 25 Jan 2015

modified 7 Sept 2017

by Tom Igoe

*/

// make an instance of the net library:

const net = require('net');

// make a new instance of the socket class:

var client = new net.Socket();

// input string from the keyboard (STDIN):

var input = '';

// get the server address from the command line:

var serverAddress = process.argv[2];

// get the port number from the command line

var portNumber = process.argv[3];

// make sure the server address, and the port number are filled in:

if (!serverAddress || !portNumber) {

console.log("To run this program, you need to give the server IP address and the port number, like so:\n");

console.log("node serialSocketClient.js <ipAddress> <portNumber>\n\n");

process.exit(0);

}

var stdin = process.openStdin(); // enable input from the keyboard

stdin.setEncoding('utf8'); // encode everything typed as a string

client.setEncoding('utf8'); // encode everything sent by the client as a string

client.connect(portNumber, serverAddress, login); // connect to the server

// client event handlers:

client.on('data', printIncoming); // if there's incoming data in the socket

client.on('end', endClient); // if the socket ends from the remote side

client.on('close', endClient); // if the socket ends from the local side

// this function runs when the client successfully connects:

function login() {

console.log('Connected');

client.write('Hello ' + client.localAddress); // send a hello and your address

}

// this function runs if there's input from the keyboard.

// you need to hit enter to generate this event.

stdin.on('data', function(data) {

client.write(data); // send it to the server

});

// this function runs if there's incoming data from the socket:

function printIncoming(data) {

data = data.trim(); // trim any whitespace from the string

console.log('Server said: ' + data); // print the message

}

// this function runs if the socket is closed:

function endClient() {

console.log('Connection closed');

process.exit(0);

}