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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

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;; 12.4 Rearranging words

;; a 'word' is either 
;; 1 - empty, or 
;; 2 - (cons a w) where a is a symbol 
;; ('a, 'b,..., 'z) and w is a word

;; examples:
(define noword empty)
(define red (cons 'r (cons 'e (cons 'd empty))))

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After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install postgresql@9.6
brew unlink postgresql@9.6
brew link postgresql