ktdung

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

Setup Windows Subsystem 2 for Linux

Windows Subsystem 2 for Linux, Hyper, ZSH + Oh My Zsh + Powerlevel9k + plugins, FNM + VSCode (+ext) and Nerd Font

To setup native Linux, see this gist

Requirements

Setup Ubuntu Linux Dev Environment

Terminator, ZSH (+ .zshrc) + Oh My Zsh + Powerlevel9k + plugins, Rust, FNM + VSCode (+ext) and Nerd Font

To setup Linux for WSL2, see this gist

Requirements

Problem

I have two Github accounts: oanhnn (personal) and superman (for work). I want to use both accounts on same computer (without typing password everytime, when doing git push or pull).

Solution

Use ssh keys and define host aliases in ssh config file (each alias for an account).

How to?

Generate ssh key pairs for accounts and add them to GitHub accounts.

Installing Node.js with nvm to Linux & macOS & WSL

A quick guide on how to setup Node.js development environment.

Previous versions of these install instructions had been tested with:

	Service - Program which runs as a background process
	"initramfs" filesystem image contains programs and binary files that perform all actions needed to mount the proper root filesystem in RAM.
	"init" program on the root filesystem (/sbin/init) is executed. Handles the mounting and pivoting over to the final real root filesystem. If special hardware drivers are needed before the mass storage can be accessed, they must be in the initramfs image.
	The kernel runs the "/sbin/init" program. This then becomes the initial processes to get the system running.


	"parted -l" to determine the type of partition table
	"parted /dev/sda p" for listing the device node of the physical drive (/dev/sda), not a partition (/dev/sda1, /dev/sda2, etc. are partitions).
	"gdisk -l /dev/sda" Interactive GUID partition table (GPT) manipulator
	-The older startup system (SysVinit) viewed things as a serial process, divided into a series of sequential stages.

	#!/bin/bash

	# Function to display usage information
	usage() {
	echo "Usage: $0 /path/to/input.mp4 [ /path/to/output_directory ]"
	exit 1
	}

	# Check if at least one argument (input file) is provided
	if [ $# -lt 1 ]; then

	# CLI
	sudo apt update && apt install \
	git curl docker.io \
	build-essential pkg-config autoconf bison rustc cargo clang \
	libssl-dev libreadline-dev zlib1g-dev libyaml-dev libreadline-dev libncurses5-dev libffi-dev libgdbm-dev libjemalloc2 \
	libvips imagemagick libmagickwand-dev libsqlite3-0 \
	redis-server mysql-server sqlite3 libmysqlclient-dev apache2-utils \
	rbenv

	# UI apps