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:

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

olih

Processing JSON using jq

jq is useful to slice, filter, map and transform structured json data.

Installing jq

On Mac OS

brew install jq

pksunkara

[user]
	name = Pavan Kumar Sunkara
	email = pavan.sss1991@gmail.com
	username = pksunkara
[init]
	defaultBranch = master
[core]
	editor = nvim
	whitespace = fix,-indent-with-non-tab,trailing-space,cr-at-eol
	pager = delta

jasonrudolph

# Credit http://stackoverflow.com/a/2514279
for branch in `git branch -r | grep -v HEAD`;do echo -e `git show --format="%ci %cr" $branch | head -n 1` \\t$branch; done | sort -r

shmup

Transmission Blocklist

The Transmission torrent client has an option to set a Blocklist, which helps protect you from getting caught and having the DMCA send a letter/email.

It's as simple as downloading and installing the latest client:

• https://transmissionbt.com/download/

pkuczynski

#!/bin/sh
parse_yaml() {
   local prefix=$2
   local s='[[:space:]]*' w='[a-zA-Z0-9_]*' fs=$(echo @|tr @ '\034')
   sed -ne "s|^\($s\)\($w\)$s:$s\"\(.*\)\"$s\$|\1$fs\2$fs\3|p" \
        -e "s|^\($s\)\($w\)$s:$s\(.*\)$s\$|\1$fs\2$fs\3|p"  $1 |
   awk -F$fs '{
      indent = length($1)/2;
      vname[indent] = $2;
      for (i in vname) {if (i > indent) {delete vname[i]}}

magnetikonline

AWS CLI JMESPath cheatsheet

Random query recipes of JMESPath for the AWS CLI tools that I might have written or stumbled upon.

• Examples
  • List available AWS regions
  • List Lambda functions within AWS account region
  • Test if specific Lambda function exists
  • List Route 53 record names and their type for a zone
  • List CloudWatch log groups

mcattarinussi

GPG - SSH setup

Generating the master key

Here we create the master key. We want only Certify capability: we use the master key only to create the subkeys, Sign - Encrypt - Authenticate capabilities will be assigned to the subkeys.

Run the following command to start the master key generation process. Select the set your own capabilities creation process (type 8)

  ▶ gpg --full-generate-key --expert

gpg (GnuPG) 2.2.9; Copyright (C) 2018 Free Software Foundation, Inc.

Liryna

You might want to read this to get an introduction to armel vs armhf.

If the below is too much, you can try Ubuntu-ARMv7-Qemu but note it contains non-free blobs.

Running ARM programs under linux (without starting QEMU VM!)

First, cross-compile user programs with GCC-ARM toolchain. Then install qemu-arm-static so that you can run ARM executables directly on linux