Kemal C. ddeveloperr

Lists all versions installed;

$ nvm ls

Lists all the available Node.js versions to download and install;

$ nvm ls-remote

Just like Ruby language has the RVM (Ruby Version Manager) to manage multiple Ruby versions, Node.js also has a manager too, the NVM (Node Version Manager). NVM is a perfect solution to test your projects in different Node.js versions. It is also useful for people that like to test unstable or latest versions. NVM has great advantages, it is practical, easy to use, it can uninstall a Node.js version with a single command and will save you time to search and install some Node.js version. It is a good alternative, especially on Linux which its native package managers are frequently outdated and invalidates a new Node.js version to be installed.

SETUP NVM

In few steps you can set up NVM into a MacOSX or Linux system, you just need to run this command:

curl https://raw.githubusercontent.com/creationix/nvm/v0.30.2/install.sh | bash

git ls-files --deleted -z | xargs -0 git rm

Details: https://stackoverflow.com/questions/492558/removing-multiple-files-from-a-git-repo-that-have-already-been-deleted-from-disk

Git Cheat Sheet

Basic commands

git init Creates a new git repository in the directory

git add <file name> Adds a specific file to staging

git add . or git add -A Adds the full directory and its contents to staging

###1. *

* { margin: 0; padding: 0; }

Let’s knock the obvious ones out, for the beginners, before we move onto the more advanced selectors. The star symbol will target every single element on the page. Many developers will use this trick to zero out the margins and padding. While this is certainly fine for quick tests, I’d advise you to never use this in production code. It adds too much weight on the browser, and is unnecessary.

You want to push your local files to remote files

git push -f <remote> <branch>

git push -f origin master

Local version has priority over the remote one!

more...

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

	[
	{
	"city": "New York",
	"growth_from_2000_to_2013": "4.8%",
	"latitude": 40.7127837,
	"longitude": -74.0059413,
	"population": "8405837",
	"rank": "1",
	"state": "New York"
	},

	class Scrape
	attr_accessor :title, :hotness, :image_url, :rating, :director,
	:genre, :runtime, :synopsis, :failure

	def scrape_new_movie
	begin
	doc = Nokogiri::HTML(open("https://www.rottentomatoes.com/m/the_martian/"))
	doc.css('script').remove
	self.title = doc.at("//h1").text.strip
	self.hotness = doc.at_css('span.meter-value').text[0, doc.at_css('span.meter-value').text.index('%')]

	Rails on Rails Cheat Sheet -- Includes updates from Rails 5.0

	1. Open terminal and check versions of Ruby and Rails against production server params or to make sure you are using the most recent stable versions.
	$ ruby -v
	$ rvm list
	$ rvm list known
	$ rvm install ruby 2.3.1
	$ rvm list
	$ ruby -v
	$ gem install rails