jfarmer

true and false vs. "truthy" and "falsey" (or "falsy") in Ruby, Python, and JavaScript

Many programming languages, including Ruby, have native boolean (true and false) data types. In Ruby they're called true and false. In Python, for example, they're written as True and False. But oftentimes we want to use a non-boolean value (integers, strings, arrays, etc.) in a boolean context (if statement, &&, ||, etc.).

This outlines how this works in Ruby, with some basic examples from Python and JavaScript, too. The idea is much more general than any of these specific languages, though. It's really a question of how the people designing a programming language wants booleans and conditionals to work.

If you want to use or share this material, please see the license file, below.

Update

willurd

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

dideler

Note: I'm currently taking a break from this course to focus on my studies so I can finally graduate

Table of Contents

1. Overview
2. Introduction
3. Interactive Start
4. Linux and Server-Side Javascript
5. Linux Command Line
6. Linux Development Environment

ragingwind

Backend Architectures

Twitter

ror, scala, jetty, erlang, thrift, mongrel, comet server, my-sql, memchached, varnish, kestrel(mq), starling, gizzard, cassandra, hadoop, vertica, munin, nagios, awstats

• Introduce Gizzard of Twitter - 트위터의 새로운 분산 관리 라이브러리 Gizzard를 소개합니다.
• The Architecture Twitter Uses to Deal with 150M Active Users, 300K QPS, a 22 MB/S Firehose, and Send Tweets in Under 5 Seconds
• Scaling Twitter: Making Twitter 10000 Percent Faster

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

yunga

_________ _____ _______________       _____
\_   ___ \\    \\___________   \____ / ____\     ~/.bash/cliref.md
/    \  \/|    | |   ||       _/ __ \  __\    copy/paste from whatisdb
\     \___|__  |_|_  ||    |   \  __/|_ |   http://pastebin.com/yGmGiDQX
 \________  /_____ \_||____|_  /____  /_|     yunga.palatino@gmail.com
 20160515 \/ 1527 \/         \/     \/

---

alias CLIRef.txt='curl -s "http://pastebin.com/raw/yGmGiDQX" | less -i'

nfarrar

Learning Computer Security

About This Guide

This is an opinionated guide to learning about computer security (independently of a university or training program), starting with the absolute basics (suitable for someone without any exposure to or knowledge of computer security) and moving into progressively more difficult subject matter.

It seems that most people don't realize how much information is actually available on the internet. People love to share (especially geeks) and everything you need to become well versed in computer security is already available to you (and mostly for free). However, sometimes knowing where to start is the hardest part - which is the problem that this guide is intended to address. Therefore, this guide can accuratley be described as a 'guide to guides', with additional recommendations on effective learning and execises, based on my own experiences.

Many of the free resources are the best resources and this guide focuses on them. It is intended to provided a comprehensive

mutemule

Introduction

Everyone who runs OSSEC on a Unix system has a common problem: you want to follow and apply security udpates closely, but every time you patch, you get a flood of alerts. And this problem quickly grows: if a given package update would result in five alerts, that's fine if you only have one server. But if you have a hundred servers? Five hundred? Five thousand?

So, I've cobbled some stuff together to abuse the OSSEC's Active Response mechanism to not raise an alert when a package is upgraded properly. I've tried to emulate the workflow of a human administrator as closely as closely as possible, but there are definitely some areas that could be handled better -- see Caveats below.

Objectives

Any time I get an OSSEC alert, I'll do any number of things that generally fall into three categories:

1. Validation of automated change: make sure the file was supposed to be upgraded: check the auto-upgrade logs, verify the package that installed/upgraded the file, etc.
2. Validation of expected

yuanying

Install Vagrant

sudo su
apt-get update && apt-get install -y libvirt-dev ruby-all-dev apparmor-utils
curl -O -L https://dl.bintray.com/mitchellh/vagrant/vagrant_1.6.5_x86_64.deb
dpkg -i vagrant_1.6.5_x86_64.deb 
aa-complain /usr/lib/libvirt/virt-aa-helper # workaround
exit

Install vagrant-kvm as user

drkarl

Linux Backup Solutions

I've been looking for the best Linux backup system, and also reading lots of HN comments.

Instead of putting pros and cons of every backup system I'll just list some deal-breakers which would disqualify them.

Also I would like that you, the HN community, would add more deal breakers for these or other backup systems if you know some more and at the same time, if you have data to disprove some of the deal-breakers listed here (benchmarks, info about something being true for older releases but is fixed on newer releases), please share it so that I can edit this list accordingly.

Amanda (comments by sammcj)

• It has a lot of management overhead and that's a problem if you don't have time for a full time backup administrator.