Prakhar Srivastav prakhar1989

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

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

Why?

There is a long standing issue in Ruby where the net/http library by default does not check the validity of an SSL certificate during a TLS handshake. Rather than deal with the underlying problem (a missing certificate authority, a self-signed certificate, etc.) one tends to see bad hacks everywhere. This can lead to problems down the road.

From what I can see the OpenSSL library that Rails Installer delivers has no certificate authorities defined. So, let's go fetch some from the curl website. And since this is for ruby, why don't we download and install the file with a ruby script?

	<html>
	<head>
	<title>I'm learning</title>
	<link rel="stylesheet" href="http://code.leafletjs.com/leaflet-0.3.1/leaflet.css" />
	<script src="http://code.leafletjs.com/leaflet-0.3.1/leaflet.js"></script>
	<script src="http://zeptojs.com/zepto.js" type="text/javascript"></script>
	<script src="map.js" type="text/javascript"></script>
	<style>
	body {margin: 0; padding: 0; text-align: center;}
	#button { -webkit-transition: -webkit-transform 3s ease-in; box-shadow: 0 0 25px #EFEF4D; margin: auto; margin-top: 15px; padding: 3px 6px; height: 20px; width: 200px;}

	/* Exercise: Loops and Functions #43 */
	package main

	import (
	"fmt"
	"math"
	)

	func Sqrt(x float64) float64 {
	z := float64(2.)

	-- This is a Hive program. Hive is an SQL-like language that compiles
	-- into Hadoop Map/Reduce jobs. It's very popular among analysts at
	-- Facebook, because it allows them to query enormous Hadoop data
	-- stores using a language much like SQL.

	-- Our logs are stored on the Hadoop Distributed File System, in the
	-- directory /logs/randomhacks.net/access. They're ordinary Apache
	-- logs in *.gz format.
	--
	-- We want to pretend that these gzipped log files are a database table,

	package main

	import (
	"bytes"
	"exec"
	"log"
	"os"
	)

	// Pipeline strings together the given exec.Cmd commands in a similar fashion


	" Port of my favorite theme Made of Code by Mark Dodwell
	" For Textmate Theme visit - http://madeofcode.com/posts/29-photo-my-new-textmate-theme-8220-made-of-code-8221-mdash-download-9-feb-2010-update-t
	" Vim color file

	set background=dark
	highlight clear

	if exists("syntax_on")
	syntax reset

Prakhar Srivastav prakhar1989

tmux shortcuts & cheatsheet

Latency numbers every programmer should know

Why?

Installation

The Ruby Way! (Fun)

	#! /usr/bin/env python

	""" Convert values between RGB hex codes and xterm-256 color codes.

	Nice long listing of all 256 colors and their codes. Useful for
	developing console color themes, or even script output schemes.

	Resources:
	* http://en.wikipedia.org/wiki/8-bit_color
	* http://en.wikipedia.org/wiki/ANSI_escape_code