Dmitry Vorotilin route

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

Go (Golang) GOOS and GOARCH

All of the following information is based on go version go1.17.1 darwin/amd64.

GOOS Values

GOOS	Out of the Box
`aix`	✅
`android`	✅

TL;DR

Install Postgres 9.6, and then:

sudo pg_dropcluster 9.6 main --stop
sudo pg_upgradecluster 9.5 main
sudo pg_dropcluster 9.5 main

This document has moved!

It's now here, in The Programmer's Compendium. The content is the same as before, but being part of the compendium means that it's actively maintained.

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

These links no longer work. Springer have pulled the free plug.

Graduate texts in mathematics

duplicates = multiple editions

A Classical Introduction to Modern Number Theory, Kenneth Ireland Michael Rosen

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.

	# Detect underlying system.
	ifeq ($(OS),Windows_NT)
	detected_OS := Windows
	else
	detected_OS := $(shell sh -c 'uname -s 2>/dev/null \|\| echo not')
	endif

	export detected_OS

	# Set default C compiler.

	# Add this snippet to the top of your playbook.
	# It will install python2 if missing (but checks first so no expensive repeated apt updates)
	# [email protected]

	- hosts: all
	gather_facts: False

	tasks:
	- name: install python 2
	raw: test -e /usr/bin/python \|\| (apt -y update && apt install -y python-minimal)

	#include <stdio.h>
	#include <errno.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <assert.h>
	#include <string.h>
	#define streq(a, b) (!strcmp((a), (b)))

	#ifndef __USE_GNU
	#define __USE_GNU