charlesroper

How to setup a practically free CDN using Backblaze B2 and Cloudflare

⚠️ Note 2023-01-21
Some things have changed since I originally wrote this in 2016. I have updated a few minor details, and the advice is still broadly the same, but there are some new Cloudflare features you can (and should) take advantage of. In particular, pay attention to Trevor Stevens' comment here from 22 January 2022, and Matt Stenson's useful caching advice. In addition, Backblaze, with whom Cloudflare are a Bandwidth Alliance partner, have published their own guide detailing how to use Cloudflare's Web Workers to cache content from B2 private buckets. That is worth reading,

JoeyBurzynski

58 bytes of CSS to look great nearly everywhere

When making this website, i wanted a simple, reasonable way to make it look good on most displays. Not counting any minimization techniques, the following 58 bytes worked well for me:

main {
  max-width: 38rem;
  padding: 2rem;
  margin: auto;
}

shafik

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

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

rain-1

WannaCry|WannaDecrypt0r NSA-Cyberweapon-Powered Ransomware Worm

• Virus Name: WannaCrypt, WannaCry, WanaCrypt0r, WCrypt, WCRY
• Vector: All Windows versions before Windows 10 are vulnerable if not patched for MS-17-010. It uses EternalBlue MS17-010 to propagate.
• Ransom: between $300 to $600. There is code to 'rm' (delete) files in the virus. Seems to reset if the virus crashes.
• Backdooring: The worm loops through every RDP session on a system to run the ransomware as that user. It also installs the DOUBLEPULSAR backdoor. It corrupts shadow volumes to make recovery harder. (source: malwarebytes)
• Kill switch: If the website www.iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com is up the virus exits instead of infecting the host. (source: malwarebytes). This domain has been sinkholed, stopping the spread of the worm. Will not work if proxied (source).

update: A minor variant of the viru

nicowilliams

I recently happened upon a very interesting implementation of popen() (different API, same idea) called popen-noshell using clone(2), and so I opened an issue requesting use of vfork(2) or posix_spawn() for portability. It turns out that on Linux there's an important advantage to using clone(2). I think I should capture the things I wrote there in a better place. A gist, a blog, whatever.

This is not a paper. I assume reader familiarity with fork() in particular and Unix in general, though, of course, I link to relevant wiki pages, so if the unfamiliar reader is willing to go down the rabbit hole, they should be able to come ou

skratchdot

Math Cheatsheets

http://www.eeweb.com/tools/math-sheets/images/algebra.png

http://www.eeweb.com/tools/math-sheets/images/trigonometry-definition.png

http://www.eeweb.com/tools/math-sheets/images/trigonometry-laws-and-identities.png

alibo

bkaradzic

Orthodox C++

What is Orthodox C++?

Orthodox C++ (sometimes referred as C+) is minimal subset of C++ that improves C, but avoids all unnecessary things from so called Modern C++. It's exactly opposite of what Modern C++ suppose to be.

Why not Modern C++?

mathiasbynens

#!/usr/bin/env bash

# https://code.google.com/p/chromium/issues/detail?id=226801
url='https://chromium.googlesource.com/chromium/src/net/+/master/http/transport_security_state_static.json?format=TEXT';
curl -#s "${url}" | \
	base64 --decode | \
	sed '/^ *\/\// d' | \
	sed '/^\s*$/d' > hsts.json;