Austin Eschenbach eschie

ANNOUNCEMENT

I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!

\

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:
ffmpeg -i input.mp3 output.wma

You can get the list of supported formats with:
ffmpeg -formats

You can get the list of installed codecs with:

Benchmarking AngularJS performance

Things to optmize

Use one-time-bind on expressions ( {{::value}} )
Replace $scope.$apply() with $scope.$digest() whenever possible
Move filters to controllers

Measuring Watch list

To get the total watchers on the current page, you can run this script on the browser console:

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

Gmail: delete old emails automatically

Automatically deletes old emails that match the specified label.

Get started

Create a new Google Apps Script at https://script.google.com
Overwrite the placeholder with the javascript below
Update the following constants:
LABEL_TO_DELETE: the label that should be have old messages deleted

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

Motivation

You often have several docker containers and applications which work together in the locel development environment. You need the following communications:

docker container to localhost
localhost to docker container
docker container to docker container

You have a way to connect localhost-to-docker using -p (port-mapping) docker option. For instance, you can start PostgreSQL container using -p 0.0.0.0:5432:5432 and then connect like to normal PostgreSQL

	#!/usr/bin/sudo ruby

	#
	# revealer.rb -- Deobfuscate GHE .rb files.
	#
	# This is simple:
	# Every obfuscated file in the GHE VM contains the following code:
	#
	# > require "ruby_concealer.so"
	# > __ruby_concealer__ "..."

	<p th:text="${bean.field + '!' + bean.field}">Static content</p>

	th:text="'static part' + ${bean.field}"

	th:text="${'static part' + bean.field}"