koutoftimer

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

jq: JSONL ↔︎ JSON conversion

Prerequisites

jq — https://jqlang.org/ — "like sed for JSON data"

There are several options available for installing jq. I prefer to use Homebrew: brew install jq
JSONL → JSON

HOWTO

Connect to Twitch.tv chat with an IRC client

Visit this website and get an OAuth Token for your Twitch account.
Add a server to your IRC client with this configuration, using your OAuth Token as the server password. Make sure it is not using SSL.

{
  address = "irc.twitch.tv";
chatnet = "Twitch";

	function die () {
	local message=$1
	[ -z "$message" ] && message="Died"
	echo "$message (at ${BASH_SOURCE[1]}:${FUNCNAME[1]} line ${BASH_LINENO[0]}.)" >&2
	exit 1
	}

	#!/bin/sh
	# Build and install Airwave64
	# https://github.com/rodlie - <ole.andre.rodlie@gmail.com>
	#

	CWD=`pwd`
	AIRWAVE_GIT="https://github.com/phantom-code/airwave"
	AIRWAVE_COMMIT="8cd3507a46c2f7809a2ef8481cbded7dcbbae8ff"
	VST_V="369_01_03_2018_build_132"

	# Set the control character to Ctrl+Spacebar (instead of Ctrl+B)
	set -g prefix C-space
	unbind-key C-b
	bind-key C-space send-prefix

	# Set new panes to open in current directory
	bind c new-window -c "#{pane_current_path}"
	bind '"' split-window -c "#{pane_current_path}"
	bind % split-window -h -c "#{pane_current_path}"

	"""
	Module implementing an enhanced string column type for SQLAlchemy
	with a support for regular expression operators in Postgres and SQLite.
	"""
	import re

	from sqlalchemy import String as _String, Text as _Text, Unicode as _Unicode, UnicodeText as _UnicodeText, event, exc
	from sqlalchemy.engine import Engine
	from sqlalchemy.ext.compiler import compiles
	from sqlalchemy.sql.expression import BinaryExpression, func, literal

	import asyncio
	from django import http
	from django.core.urlresolvers import set_script_prefix
	from django.utils.encoding import force_str
	from django.core.handlers.wsgi import get_script_name
	from django_wsgi.handler import DjangoApplication
	import logging

	import logging
	import sys

	myip() {
	curl -4 "http://icanhazip.com/"
	}

	myip6() {
	curl -6 "http://icanhazip.com/"
	}

	reverse_ipv4() {
	local ip="$1"


	function string_ends(text, ends)
	return ends == "" or string.sub(text, -string.len(ends)) == ends
	end

	function vlc_format(filename)
	-- https://wiki.videolan.org/VLC_Features_Formats#Format.2FContainer.2FMuxers
	local formats = {
	"3gp", "asf", "wmv", "au", "avi", "mka", "mkv", "flv", "mov", "mp4",
	"ogg", "ogm", "ts", "mpg", "mp3", "mp2", "msc", "msv", "nut", "ra",