Mohammad Khanafi thekingofbandit

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

-E: will describe the underlaying queries of the \ commands (cool for learning!)
-l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

imagemagick

Nornalize all images of a folder converting them to jpgs with 90% quality (warning, removes original files):

rename 's/\.JPG$/\.jpg/' *.JPG
rename 's/\.JPEG$/\.jpg/' *.JPEG
rename 's/\.jpeg$/\.jpg/' *.jpeg
mogrify -format jpg *.png
mogrify -resize 1600x1280\> -quality 90 *.jpg
rm *.png

While attempting to explain JavaScript's reduce method on arrays, conceptually, I came up with the following - hopefully it's helpful; happy to tweak it if anyone has suggestions.

Intro

JavaScript Arrays have lots of built in methods on their prototype. Some of them mutate - ie, they change the underlying array in-place. Luckily, most of them do not - they instead return an entirely distinct array. Since arrays are conceptually a contiguous list of items, it helps code clarity and maintainability a lot to be able to operate on them in a "functional" way. (I'll also insist on referring to an array as a "list" - although in some languages, List is a native data type, in JS and this post, I'm referring to the concept. Everywhere I use the word "list" you can assume I'm talking about a JS Array) This means, to perform a single operation on the list as a whole ("atomically"), and to return a new list - thus making it much simpler to think about both the old list and the new one, what they contain, and

The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs)

This creates an archive that does the following:

rsync (Everyone seems to like -z, but it is much slower for me)

a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files.
H: preserves hard-links
A: preserves ACLs

SSH keys

Create

ssh-keygen -o

You can view the created files (one without extension and one with .pub) under ~/.ssh/. When creating several of them, you may want to rename them appropriately (e.g. work, pers...).

Add them

to the relevant github account: https://github.com/settings/ssh/new

Configuration

The configuration file for ssh is usually not created by default so we create it:

	/**
	* Axios Request Wrapper
	* ---------------------
	*
	* @author Sheharyar Naseer (@sheharyarn)
	* @license MIT
	*
	*/

	import axios from 'axios'

	<!DOCTYPE html>
	<html>
	<head>
	<meta name="description" content="[push to chart data]">
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width">
	<title>JS Bin</title>
	</head>
	<body>
	<script src="https://cdn.jsdelivr.net/lodash/4/lodash.min.js"></script>

	import React, { Component } from 'react';
	import PropTypes from 'prop-types';

	class reactClassComponentWIthMethods extends Component {
	constructor(props) {
	super(props);

	}

	componentWillMount() {

	/*****************
	* cellBlockA.js *
	*****************
	*
	* Good morning, Dr. Eval.
	*
	* It wasn't easy, but I've managed to get your computer down
	* to you. This system might be unfamiliar, but the underlying
	* code is still JavaScript. Just like we predicted.
	*