Andreas Steffan deas

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

Learn you a Haskell - In a nutshell

This is a summary of the "Learn You A Haskell" online book under http://learnyouahaskell.com/chapters.

1. Introduction

Haskell is a functional programming language.

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Clojure Destructuring Tutorial and Cheat Sheet

(Related blog post)

Simply put, destructuring in Clojure is a way extract values from a datastructure and bind them to symbols, without having to explicitly traverse the datstructure. It allows for elegant and concise Clojure code.

Vectors and Sequences

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

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

Introduction

I often find myself ssh'ing into my servers and checking my systemd service logs with $ journalctl -f -u {name}.service. One day I got tired of this and wanted all of my important logs in once place (Amazon AWS Cloudwatch). To my dismay, there weren't any real good tutorials on how to do so. So, voilà.

Steps

Overall, it's a fairly simple process consisting of the following few steps.

1. Modify the service file

Open the service file with $ sudo vi /lib/systemd/system/{name}.service

Modify the [Service] section:

	/*
	* object.watch polyfill
	*
	* 2012-04-03
	*
	* By Eli Grey, http://eligrey.com
	* Public Domain.
	* NO WARRANTY EXPRESSED OR IMPLIED. USE AT YOUR OWN RISK.
	*/

	#!/bin/sh

	# SPDX-FileCopyrightText: 2017-2024 SanderTheDragon <[email protected]>
	#
	# SPDX-License-Identifier: MIT

	arch=$(dpkg --print-architecture)
	echo "Detected architecture: $arch"

	case "$arch" in