padolsey

// ----------------------------------------------------------
// A short snippet for detecting versions of IE in JavaScript
// without resorting to user-agent sniffing
// ----------------------------------------------------------
// If you're not in IE (or IE version is less than 5) then:
//     ie === undefined
// If you're in IE (>=5) then you can determine which version:
//     ie === 7; // IE7
// Thus, to detect IE:
//     if (ie) {}

sstephenson

$ sudo su -
# mkdir /etc/resolver
# cat > /etc/resolver/test
nameserver 127.0.0.1
port 2155
^D
^D
$ brew install dnsmasq
$ dnsmasq --port=2155 --no-resolv --address=/.test/127.0.0.1
$ ping foo.test

pjkix

#!/bin/bash

## v1.0.6
## this script will gernerate css stats

### example output

# CSS STATS
# ----------
# Floats:  132

acdha

#!/bin/bash
#
# Report time to first byte for the provided URL using a cache buster to ensure
# that we're measuring full cold-cache performance

while (($#)); do
    echo $1
    curl -so /dev/null -H "Pragma: no-cache" -H "Cache-Control: no-cache" \
        -w "%{http_code}\tPre-Transfer: %{time_pretransfer}\tStart Transfer: %{time_starttransfer}\tTotal: %{time_total}\tSize: %{size_download}\n" \
        "$1?`date +%s`"

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

balupton

Debugging & Profiling Node.js - Moved! Click here to be redirected to the new location.

dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

jashkenas

# MAC manipulators
alias random_mac='sudo ifconfig en0 ether `openssl rand -hex 6 | sed "s/\(..\)/\1:/g; s/.$//"`'
alias restore_mac='sudo ifconfig en0 ether YOUR_ORIGINAL_MAC_ADDRESS_GOES_HERE'

tskaggs

Convert MOV to GIF using FFmpeg and ImageMagick

I tried a few different techniques to make a GIF via command-line and the following gives me the best control of quality and size. Once you're all setup, you'll be pumping out GIFs in no time!

Preparation

Install FFmpeg

• $ brew install ffmpeg [all your options]
  • Example: $ brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-frei0r --with-libass --with-libvo-aacenc --with-libvorbis --with-libvpx --with-opencore-amr --with-openjpeg --with-opus --with-rtmpdump --with-schroedinger --with-speex --with-theora --with-tools

Install ImageMagick

ShawnMilo

from uuid import UUID

def validate_uuid4(uuid_string):

    """
    Validate that a UUID string is in
    fact a valid uuid4.

    Happily, the uuid module does the actual
    checking for us.