MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

joyrexus

A quick overview of the node.js streams interface with basic examples.

This is based on @brycebaril's presentation, Node.js Streams2 Demystified

Overview

Streams are a first-class construct in Node.js for handling data.

Think of them as as lazy evaluation applied to data.

dduvnjak

# first we download the list of IP ranges from CloudFlare
wget https://www.cloudflare.com/ips-v4

# set the security group ID
SG_ID="sg-00000000000000"

# iterate over the IP ranges in the downloaded file
# and allow access to ports 80 and 443
while read p
do

joepie91

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

• Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
• Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
• If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
• If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's

vlucas

'use strict';

const crypto = require('crypto');

const ENCRYPTION_KEY = process.env.ENCRYPTION_KEY; // Must be 256 bits (32 characters)
const IV_LENGTH = 16; // For AES, this is always 16

function encrypt(text) {
 let iv = crypto.randomBytes(IV_LENGTH);
 let cipher = crypto.createCipheriv('aes-256-cbc', Buffer.from(ENCRYPTION_KEY), iv);

coco-napky

module.exports = {
  config: {
    // default font size in pixels for all tabs
    fontSize: 12,

    // font family with optional fallbacks
    fontFamily: 'Menlo, "DejaVu Sans Mono", Consolas, "Lucida Console", monospace',

    // terminal cursor background color and opacity (hex, rgb, hsl, hsv, hwb or cmyk)
    cursorColor: 'rgba(248,28,229,0.8)',

kentoj

-- Retrieve descendants
-- ====================
-- retrieve descendants of #4
SELECT c.*
  FROM Comments AS c
    JOIN TreePaths AS t ON c.comment_id = t.descendant
 WHERE t.ancestor = 4;


-- Retrieve ancestors

xelaz

db.getCollection('fs.chunks').aggregate([
  { $lookup: { from: 'fs.files', localField: 'files_id', foreignField: '_id', as: 'file' } },
  { $unwind: { path:'$file', preserveNullAndEmptyArrays: true } },
  { $match: { file: { $exists: false } } },
  { $project: { _id: 1, files_id: 1 } },
]).forEach(function(chunk) {
  printjson(chunk);  
  // db.getCollection('fs.chunks').remove({ _id: chunk._id });
});

deejayy

import customModuleLoader = require('module');

export class CustomModuleLoader {
  public cOptions: any = require('../tsconfig.json').compilerOptions;

  public replacePaths: any = {};

  constructor() {
    Object.keys(this.cOptions.paths).forEach(alias => {
      this.replacePaths[alias.replace(/\*.?/, '(.*)')] = this.cOptions.paths[alias][0].replace(/\*.?/, '$1');

perry-mitchell

const { pbkdf2: deriveKey } = require("pbkdf2");
const crypto = require("crypto");

const DERIVATION_ROUNDS = 200000;
const HMAC_KEY_SIZE = 32;
const PASSWORD_KEY_SIZE = 32;

function pbkdf2(password, salt, rounds, bits) {
    return new Promise((resolve, reject) => {
        deriveKey(password, salt, rounds, bits / 8, "sha256", (err, key) => {