Duane King duaneking

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

Let's say you're using Ubuntu 13.04 (Raring Ringtail, released in April 2013) and it just went End-of-Life on you, because it's supported for only 6 months, and the deprecated packages are taken down after 12 months.

You'll probably figure this out the hard way. When you run sudo apt-get update, it will eventually report these errors:

Ign http://archive.ubuntu.com raring-updates/universe Sources/DiffIndex
Err http://security.ubuntu.com raring-security/main Sources
  404  Not Found [IP: 91.189.91.15 80]
Err http://security.ubuntu.com raring-security/universe Sources
  404  Not Found [IP: 91.189.91.15 80]

Learning Aid - Top Base64 Encodings Table

Base64 Code	Mnemonic Aid	Decoded*	Description
`JAB`	🗣 Jabber	`$.`	Variable declaration (UTF-16)
`TVq`	📺 Television	`MZ`	MZ header
`SUVY`	🚙 SUV	`IEX`	PowerShell Invoke Expression
`SQBFAF`	🐣 Squab favorite	`I.E.`	PowerShell Invoke Expression (UTF-16)
`SQBuAH`	🐣 Squab uahhh	`I.n.`	PowerShell Invoke string (UTF-16) e.g. `Invoke-Mimikatz`
`PAA`	💪 "Pah!"	`<.`	Often used by Emotet (UTF-16)

Falsehoods programmers believe about time

This is a compiled list of falsehoods programmers tend to believe about working with time.

Don't re-invent a date time library yourself. If you think you understand everything about time, you're probably doing it wrong.

Falsehoods

There are always 24 hours in a day.
February is always 28 days long.
Any 24-hour period will always begin and end in the same day (or week, or month).

Amazon Web Services (AWS) & Google Cloud Platform (GCP) explained in simple English

This guide is only representative from my point of view and it may not be accurate and you should go on the official AWS & GCP websites for accurate and detailed information. It's initially inspired by AWS in simple English and GCP for AWS professionals. The idea is to compare both services, give simple one-line explanation and examples with other software that might have similiar capabilities. Comment below for suggestions.

Category	Service	AWS	GCP	Description	It's like
Compute	IaaS	Amazon Elastic Compute Cloud (EC2)	Google Compute Engine	Type-1 virtual servers	VMware ESXi, Citrix XenServer
	PaaS	AWS Elastic Beanstalk	Google App Engine	Running your app on a platform

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

	# train_grpo.py
	import re
	import torch
	from datasets import load_dataset, Dataset
	from transformers import AutoTokenizer, AutoModelForCausalLM
	from peft import LoraConfig
	from trl import GRPOConfig, GRPOTrainer

	# Load and prep dataset

	import numpy as np
	from tqdm import trange


	def get_neighbour_matrix(x, L, R):
	dx = np.subtract.outer(x[:, 0], x[:, 0])
	dy = np.subtract.outer(x[:, 1], x[:, 1])
	dx[dx > (L / 2) 2] -= (L / 2) 2
	dy[dy > (L / 2) 2] -= (L / 2) 2
	pair_dist = dx 2 + dy 2

	D [0-9]
	L [a-zA-Z_]
	H [a-fA-F0-9]
	E ([Ee][+-]?{D}+)
	P ([Pp][+-]?{D}+)
	FS (f\|F\|l\|L)
	IS ((u\|U)\|(u\|U)?(l\|L\|ll\|LL)\|(l\|L\|ll\|LL)(u\|U))

	%{
	#include <stdio.h>

	// From http://www.tannerhelland.com/4435/convert-temperature-rgb-algorithm-code/

	// Start with a temperature, in Kelvin, somewhere between 1000 and 40000. (Other values may work,
	// but I can't make any promises about the quality of the algorithm's estimates above 40000 K.)


	function colorTemperatureToRGB(kelvin){

	var temp = kelvin / 100;