Gabriel Laskar GabrielL

This article is now published on my website: Prefer Subshells for Context.

Pub/Sub pattern with PostgreSQL's LISTEN/NOTIFY command

This is a simple chat-like program using pub-sub pattern, backed by PostgreSQL's LISTEN/NOTIFY command.

Publish

publish message to foo channel from user nickname.

$ python pub.py foo nickname
PUBLISH to channel #foo

I want to write software that helps kill people.

Please, before you call the police and get my github account put on lockdown, allow me a moment to explain. What I really want to do is work on projects that advance the human condition and improve people's lives. I've been in a mad dash to learn how to program for the past four or five years exactly because I realized how much good I could do for the world with a computer.

a simple git branching model (written in 2013)

This is a very simple git workflow. It (and variants) is in use by many people. I settled on it after using it very effectively at Athena. GitHub does something similar; Zach Holman mentioned it in this talk.

Update: Woah, thanks for all the attention. Didn't expect this simple rant to get popular.

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

To remove a submodule you need to:

Delete the relevant section from the .gitmodules file.
Stage the .gitmodules changes git add .gitmodules
Delete the relevant section from .git/config.
Run git rm --cached path_to_submodule (no trailing slash).
Run rm -rf .git/modules/path_to_submodule (no trailing slash).
Commit git commit -m "Removed submodule "
Delete the now untracked submodule files rm -rf path_to_submodule

	#!/usr/bin/env python
	import MySQLdb

	import os, sys
	import pprint
	pp = pprint.PrettyPrinter()

	mysql_host = "localhost"
	mysql_user = "dbusername"
	mysql_pass = "dbpassword"

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	VERSION=0.20.6

	sudo apt-get update
	sudo apt-get install openjdk-6-jdk

	wget https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-$VERSION.deb
	sudo dpkg -i elasticsearch-$VERSION.deb

	# be sure you add "action.disable_delete_all_indices" : true to the config!!

	# /etc/acpi/events/thinkpad-dock
	# This is called when the Thinkpad docks in a series 3 docking station

	event=ibm/hotkey HKEY 00000080 00004010
	action=/etc/acpi/thinkpad-dock.sh