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

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

aras-p

// Just before switching jobs:
// Add one of these.
// Preferably into the same commit where you do a large merge.
//
// This started as a tweet with a joke of "C++ pro-tip: #define private public",
// and then it quickly escalated into more and more evil suggestions.
// I've tried to capture interesting suggestions here.
//
// Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_,
// @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant,

MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

xsot

Usage

sed -E -f solver.sed input where input is a file containing the maze.

For best results, resize your terminal to match the height of the maze. To disable animations, delete the lines containing p.

Maze format

The solver assumes the following:

• The maze only contains the characters # \nSE
• Every line has the same number of characters
• There is only one start (S) and end (E)

simonw

How to recover lost Python source code if it's still resident in-memory

I screwed up using git ("git checkout --" on the wrong file) and managed to delete the code I had just written... but it was still running in a process in a docker container. Here's how I got it back, using https://pypi.python.org/pypi/pyrasite/ and https://pypi.python.org/pypi/uncompyle6

Attach a shell to the docker container

Install GDB (needed by pyrasite)

apt-get update && apt-get install gdb

wacko

On Mac OS (host):

Shutdown your VM and do:

VirtualBox > Settings > Network > Add (you will get vboxnet0)

On a terminal ifconfig will show you new interface vboxnet0

VM's Settings > System > check "Enable I/O APIC." VM's Settings > Network > Adapter 2 > host-only vboxnet0

matthewhudson

A good commit message looks like this:

Header line: explaining the commit in one line

Body of commit message is a few lines of text, explaining things
in more detail, possibly giving some background about the issue
being fixed, etc etc.

The body of the commit message can be several paragraphs, and
please do proper word-wrap and keep columns shorter than about

FiloSottile

Questa è una traduzione in italiano del celebre Hacker Manifesto. Tutte quelle 
esistenti contengono grossolani errori, perlopiù dovuti ad una carente
comprensione della materia e del periodo, o in ogni caso sono poco fedeli al
contenuto e allo spirito dell'originale. Mi auguro che questa mia traduzione non
soffra degli stessi problemi. Sail strong.
                                                                  -- FiloSottile

                                     ****

Da: Phrack, Volume Uno, Issue 7, Phile 3 of 10

sr75

http://d.stavrovski.net/blog/post/how-to-install-and-setup-oracle-java-jdk-in-centos-6

# rpm
wget --no-cookies \
--no-check-certificate \
--header "Cookie: oraclelicense=accept-securebackup-cookie" \
"http://download.oracle.com/otn-pub/java/jdk/7u55-b13/jdk-7u55-linux-x64.rpm" \
-O jdk-7-linux-x64.rpm

# ubuntu