mfuerstenau

  ZigZag-Encoding
  ---------------
  
  Maps negative values to positive values while going back and
  forth (0 = 0, -1 = 1, 1 = 2, -2 = 3, 2 = 4, -3 = 5, 3 = 6 ...)

  (i >> bitlength-1) ^ (i << 1)

  with "i" being the number to be encoded, "^" being
  XOR-operation and ">>" would be arithemtic shifting-operation

Khoulaiz

Here are several different ways to test a TCP port without telnet.

BASH (man page)

$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C

$ cat &lt; /dev/tcp/127.0.0.1/23

MikeNGarrett

# Changed to use content-type flag instead of header: -H 'Content-Type: application/json'
siege -c50 -t60S --content-type "application/json" 'http://domain.com/path/to/json.php POST {"ids": ["1","2","3"]}'

zeusdeux

Flamegraphs for your node processes on OS X

This document will help you generate flamegraphs for your node processes on OS X.

You can read about the various types of flamegraphs and how they are useful
in Brendan Gregg's wonderful write up here.

By the end of this document, you should have a flamegraph for you node app to play with.

azam

convert -density 256x256 -background transparent favicon.svg -define icon:auto-resize -colors 256 favicon.ico

addyosmani

CSS Layout Debugger

A tweet-sized debugger for visualizing your CSS layouts. Outlines every DOM element on your page a random (valid) CSS hex color.

One-line version to paste in your DevTools

Use $$ if your browser aliases it:

~ 108 byte version

XVilka

THIS GIST WAS MOVED TO TERMSTANDARD/COLORS REPOSITORY.

PLEASE ASK YOUR QUESTIONS OR ADD ANY SUGGESTIONS AS A REPOSITORY ISSUES OR PULL REQUESTS INSTEAD!

afair

==========================================          ==========================================
             TMUX COMMAND                                        WINDOW (TAB)
==========================================          ==========================================

List    tmux ls                                     List         ^b w
New          new -s <session>                       Create       ^b c
Attach       att -t <session>                       Rename       ^b , <name>
Rename       rename-session -t <old> <new>          Last         ^b l               (lower-L)
Kill         kill-session -t <session>              Close        ^b &

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

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