jboner

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

tarruda

Some scripts/configurations that greatly improve tmux/vim workflows. The shell scripts target zsh but should be adaptable without much effort for other unix shells.

Features:

• Transparently move between tmux panes and vim windows
• Using the shell, open files in one vim instance per project or directory
• Fully integrated copy/paste between tmux, vim and x11 using simple keybinds(need to install the xclip program)
• Easily send text to any tmux pane without breaking your edit workflow(needs slimux

'vim-tmux-move.zsh', '.vimrc' and '.tmux.conf' cooperate so you can move transparently between tmux panes and vim windows using ALT + (arrow keys or jkhl). It was based on this gist

Kartones

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

rondy

FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.

---

Effective Engineer - Notes

• By Edmond Lau
• Highly Recommended 👍
• http://www.theeffectiveengineer.com/

What's an Effective Engineer?

fatihky

const _ = require('lodash')

function genrows(groups, groupKey) {
  return _.toPairs(groups)
    .map(([key, data]) => ({[groupKey]: key, data}))
}

function gengroups(arr, iteratee, key) {
  const grouped = _.groupBy(arr, iteratee)
  return genrows(grouped, key)

wronk

Overview of Python Virtual Environments

This guide is targetted at intermediate or expert users who want low-level control over their Python environments.

When you're working on multiple coding projects, you might want a couple different version of Python and/or modules installed. This helps keep each workflow in its own sandbox instead of trying to juggle multiple projects (each with different dependencies) on your system's version of Python. The guide here covers one way to handle multiple Python versions and Python environments on your own (i.e., without a package manager like conda). See the Using the workflow section to view the end result.

h/t @sharkinsspatial for linking me to the perfect cartoon

ashrithr

#!/bin/sh
# Darkify Slack on Mac OS or Linux.

# curl https://gist.githubusercontent.com/ryanpcmcquen/8a7ddc72460eca0dc1f2dc389674dde1/raw/darkify_slack.sh | sh

if [ "`uname -s`" = "Darwin" ]; then
    SLACK_INTEROP_JS="/Applications/Slack.app/Contents/Resources/app.asar.unpacked/src/static/ssb-interop.js"
else
    SLACK_INTEROP_JS="/usr/lib/slack/resources/app.asar.unpacked/src/static/ssb-interop.js"
fi