Alexzanderk

const useFocus = (count: number) => {
    const refsArr: Array<React.RefObject<HTMLInputElement>> = [];

    for (let index = 0; index < count; index++) {
        const htmlElRef: React.RefObject<HTMLInputElement> = useRef(null);
        refsArr[index] = htmlElRef;
    }

    const setFocus = (index: number): void => {
        refsArr[index].current && refsArr[index].current.focus();

Alexzanderk

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Run ts-mocha File",
            "type": "node",
            "request": "launch",
            "runtimeExecutable": "${workspaceRoot}/node_modules/.bin/ts-mocha",
            "runtimeArgs": [
                "${file}"

Alexzanderk

app.get('/video', function(req, res) {
  const path = 'assets/sample.mp4'
  const stat = fs.statSync(path)
  const fileSize = stat.size
  const range = req.headers.range
  if (range) {
    const parts = range.replace(/bytes=/, "").split("-")
    const start = parseInt(parts[0], 10)
    const end = parts[1] 
      ? parseInt(parts[1], 10)

Alexzanderk

import cluster from "cluster";
import { cpus } from "os";

const NUM_WORKERS = cpus().length;
const PATH_TO_SERVER_APP = __dirname + '/app.ts';

cluster.setupMaster({
    execArgv: ['-r', 'tsconfig-paths/register', '-r', 'ts-node/register'],
    exec: PATH_TO_SERVER_APP
} as cluster.ClusterSettings)

Alexzanderk

// Nodejs encryption with GCM
// Does not work with nodejs v0.10.31
// Part of https://github.com/chris-rock/node-crypto-examples

var crypto = require('crypto'),
  algorithm = 'aes-256-gcm',
  password = '3zTvzr3p67VC61jmV54rIYu1545x4TlY',
  // do not use a global iv for production, 
  // generate a new one for each encryption
  iv = '60iP0h6vJoEa'

Alexzanderk

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "type": "node",
            "request": "launch",
            "name": "Launch Program",

Alexzanderk

var net = require('net');

var client = new net.Socket();
client.connect(1337, '127.0.0.1', function() {
	console.log('Connected');
	client.write('Hello, server! Love, Client.');
});

client.on('data', function(data) {
	console.log('Received: ' + data);

Alexzanderk

#!/bin/bash
for branch in `git branch -a | grep remotes | grep -v HEAD | grep -v master `; do
   git branch --track ${branch#remotes/origin/} $branch
done

Alexzanderk

var fs = require('fs'); 
var readStream = fs.createReadStream('bigfilelogs.txt');  

var stream = require('stream'); 
var xtream = new stream.Transform( { objectMode: true } );

xtream._transform = function(chunk, encoding, done) {
	var strData = chunk.toString();

	if (this._invalidLine) {

Alexzanderk

// Log incoming traffic
var metricStore = new Map();

/**
 *
 * @param {string} key
 * @returns {void}
 */
const getCount = (key) => metricStore.has(key) ? metricStore.get(key) + 1 : 1;