hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

quiver

#!/usr/bin/env python
# http://www.rabbitmq.com/tutorials/tutorial-two-python.html
import pika
import sys

connection = pika.BlockingConnection(pika.ConnectionParameters(
        host='localhost'))
channel = connection.channel()

message = ' '.join(sys.argv[1:]) or "Hello World!"

dmytro

#!/bin/bash
# ssh-multi
# D.Kovalov
# Based on http://linuxpixies.blogspot.jp/2011/06/tmux-copy-mode-and-how-to-control.html

# a script to ssh multiple servers over multiple tmux panes


starttmux() {
    if [ -z "$HOSTS" ]; then

fabaff

#!/bin/sh

#----
# bootstrap fedora21

#release=$(cat /etc/fedora-release | awk '/^Fedora/ {print $3}')
#arch=$(arch)
release=21
arch=x86_64
ROOTFS=/var/lib/libvirt/lxc/fedora$release-$arch

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

hurricanerix

#!/usr/bin/env python
# The MIT License (MIT)
#
# Copyright (c) 2014 Richard Hawkins
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is

LeCoupa

#!/bin/bash
#####################################################
# Name: Bash CheatSheet for Mac OSX
# 
# A little overlook of the Bash basics
#
# Usage:
#
# Author: J. Le Coupanec
# Date: 2014/11/04

alexpchin

// sending to sender-client only
socket.emit('message', "this is a test");

// sending to all clients, include sender
io.emit('message', "this is a test");

// sending to all clients except sender
socket.broadcast.emit('message', "this is a test");

// sending to all clients in 'game' room(channel) except sender

mjalajel

# Example ssh config file. Usually located in ~/.ssh/config (user) or /etc/ssh/ssh_config (system)
# This works on both linux and MacOS

# Basic ssh commands converted to ssh/config file format



# Simplest format
# Run with: "ssh blog" => (equivalent to: "ssh ubuntu@example.com" and  "ssh -i ~/.ssh/id_rsa -p 22 ubuntu@example.com")
Host blog

tuxfight3r

#Install the relevant packages
dnf install -y ostree rpm-ostree git python rpm-ostree-toolbox libgsystem;

#checkout the build scripts
git clone https://github.com/CentOS/sig-atomic-buildscripts;
cd sig-atomic-buildscripts
git checkout downstream

# create and initialize repo directory
mkdir -p /srv/rpm-ostree/repo