fnky

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

• Ctrl-Key: ^[
• Octal: \033
• Unicode: \u001b
• Hexadecimal: \x1B
• Decimal: 27

steven2358

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

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

ericelliott

Most configuration really isn't about the app -- it's about where the app runs, what keys it needs to communicate with third party API's, the db password and username, etc... They're just deployment details -- and there are lots of tools to help manage environment variables -- not the least handy being a simple .env file with all your settings. Simply source the appropriate env before you launch the app in the given env (you could make it part of a launch script, for instance).

env files look like this:

SOMEVAR="somevalue"
ANOTHERVAR="anothervalue"

To source it:

$ source dev.env # or staging.env, or production.env, depending on where you're deploying to

lisawolderiksen

Using Git Commit Message Templates to Write Better Commit Messages

The always enthusiastic and knowledgeable mr. @jasaltvik shared with our team an article on writing (good) Git commit messages: How to Write a Git Commit Message. This excellent article explains why good Git commit messages are important, and explains what constitutes a good commit message. I wholeheartedly agree with what @cbeams writes in his article. (Have you read it yet? If not, go read it now. I'll wait.) It's sensible stuff. So I decided to start following the

gramcha

Installing different versions of open jdk through Homebrew(assuming already installed) and already having Java 8.

We need to install a tool called jenv - Java version manager which is similar to nvm(nodeJs version manager).

brew install jenv

Export the jenv path to .bash_profile or .zshrc - whatever you are using. I am using .zshrc

rvl

Pushing to Multiple Git Repos

If a project has to have multiple git repos (e.g. Bitbucket and Github) then it's better that they remain in sync.

Usually this would involve pushing each branch to each repo in turn, but actually Git allows pushing to multiple repos in one go.

If in doubt about what git is doing when you run these commands, just

sergekukharev

Latency Comparison Numbers (~2012)

Name
L1 cache reference	0.5	ns
Branch mispredict	5	ns
L2 cachereference	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

arturmkrtchyan

|----------------------------------------------------------------------------------------|--------------------|
|                                    Object Header (64 bits)                             |        State       |
|-------------------------------------------------------|--------------------------------|--------------------|
|                  Mark Word (32 bits)                  |      Klass Word (32 bits)      |                    |
|-------------------------------------------------------|--------------------------------|--------------------|
| identity_hashcode:25 | age:4 | biased_lock:1 | lock:2 |      OOP to metadata object    |       Normal       |
|-------------------------------------------------------|--------------------------------|--------------------|
|  thread:23 | epoch:2 | age:4 | biased_lock:1 | lock:2 |      OOP to metadata object    |       Biased       |
|-------------------------------------------------------|--------------------------------|--------------------|
|               

19WAS85

# This is a super **SIMPLE** example of how to create a very basic powershell webserver
# 2019-05-18 UPDATE — Created by me and and evalued by @jakobii and the comunity.

# Http Server
$http = [System.Net.HttpListener]::new() 

# Hostname and port to listen on
$http.Prefixes.Add("http://localhost:8080/")

# Start the Http Server