tcp-conn

client.js

var net = require("net"); 

process.stdin.setEncoding('utf-8');

var connection = net.connect(10000, "192.168.137.1", function() {   // connect to the server we made
  console.log("client connected");

  // When receive user input data in console.
  process.stdin.on('data', function (message) {
    // If user do not input data in command line then send default message.
    if (message == null || message.length == 0) {
        message = "Hello udp server.";
    }
    // console.log("User input : " + message);
    // Create a node Buffer object to wrap message object.
    message = Buffer.from(message, 'utf-8');
    connection.write(message)
    // Send message to udp server through client socket.
  });
});

server.js

var net = require("net");       //nodejs version of imports

var server = new net.Server();  // a new raw tcp server

server.on("connection", function(client) {  // on connection event, when someone connects
    console.log("server connections: " + server.connections); // write number of connection to the command line
    client.on("data", function (data) {   //event when a client writes data to the server
        console.log("Server received data: " + data); // log what the client sent
    });
});

server.on("message", function (message) {
  process.stdout.write(output);
});

server.listen(10000, "192.168.137.1");  // listen on port 10000, localhost