Amit Kumar amit08255

RXJS CheatSheet

Basic Concept

The essential concepts in RxJS which solve async event management are:

Observable: represents the idea of an invokable collection of future values or events.
Observer: is a collection of callbacks that knows how to listen to values delivered by the Observable.
Subscription: represents the execution of an Observable, is primarily useful for cancelling the execution.
Operators: are pure functions that enable a functional programming style of dealing with collections with operations like map, filter, concat, reduce, etc.

I use GM to render thumbnails of png and jpg images.

Sadly the GM installation guide doesn't describe how to get things working on AWS EC2.

http://www.graphicsmagick.org/INSTALL-unix.html

Prepare for installing GraphicsMagick

These cheatsheet works for JSON-Generator

Using Custom Function For Final Data Result

[
  {
    data: [
      '{{repeat(15, 45)}}',
 {

Docker CheatSheet

Connect to postgreSQL using terminal

Docker compose example with postgreSQL:

version: "3"
services:
 # Postgres

Vagrant and VMWare Tech Preview on Apple M1 Pro

This document summarizes notes taken while to make the VMWare Tech preview work on Apple M1 Pro, it originated from discussions in hashicorp/vagrant-vmware-desktop#22

Created on: November 1, 2021 Updated on: September 17, 2022

Installing Rosetta

function nest_headings(headings) {
	/*
		Return an array of nested heading objects of the form:
		{
			heading: html element
			level: integer 1-6
			children: child headings
		}
	*/

const getLines = (val:string) => val.split(/\r?\n/);

const getHeadingLevel = (val: string) => {
    const tokenizer = /(#{1,6})\s*(.+)(?:\n+|$)/gm;

    const token = tokenizer.exec(val);

    if (token && token[1]) {
 return token;

Login to http://jiofi.local.html
Now go to WiFi Disk section and login to it.
On the right side section where files are being displayed, right click -> This iframe -> Open iframe in new tab.
It will open a URL like: http://jiofi.local.html/cgi-bin/en-jio-4/mSDCard.html
Create a .html file with below code:

 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">

  <head>

	// http://stackoverflow.com/questions/4787698/failure-to-override-elements-addeventlistener-in-firefox
	(function() {
	Error.stackTraceLimit = Infinity;

	var _interfaces = Object.getOwnPropertyNames(window).filter(function(i) {
	return /^HTML/.test(i);
	}).map(function(i) {
	return window[i];
	});

	function interceptFunction (object, fnName, options) {
	var noop = function () {};
	var fnToWrap = object[fnName];
	var before = options.before \|\| noop;
	var after = options.after \|\| noop;

	object[fnName] = function () {
	before.apply(this, arguments);
	var result = fnToWrap.apply(this, arguments);
	after.apply(this, arguments);