erikig

nadavrot

High-Performance Matrix Multiplication

This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).

Intro

Matrix multiplication is a mathematical operation that defines the product of

myshov

console.log(1);
(_ => console.log(2))();
eval('console.log(3);');
console.log.call(null, 4);
console.log.apply(null, [5]);
new Function('console.log(6)')();
Reflect.apply(console.log, null, [7])
Reflect.construct(function(){console.log(8)}, []);
Function.prototype.apply.call(console.log, null, [9]);
Function.prototype.call.call(console.log, null, 10);

penguinpowernz

command	args	description
status	[verbose]	get current WPA/EAPOL/EAP status
ifname		get current interface name
ping		pings wpa_supplicant
relog		re-open log-file (allow rolling logs)
note	<text>	add a note to wpa_supplicant debug log
mib		get MIB variables (dot1x, dot11)
help	[command]	show usage help
interface	[ifname]	show interfaces/select interface

atoponce

Cryptographic Best Practices

Putting cryptographic primitives together is a lot like putting a jigsaw puzzle together, where all the pieces are cut exactly the same way, but there is only one correct solution. Thankfully, there are some projects out there that are working hard to make sure developers are getting it right.

The following advice comes from years of research from leading security researchers, developers, and cryptographers. This Gist was [forked from Thomas Ptacek's Gist][1] to be more readable. Additions have been added from

dvirsky

Creating a redis Module in 15 lines of code!

A quick guide to write a very very simple "ECHO" style module to redis and load it. It's not really useful of course, but the idea is to illustrate how little boilerplate it takes.

Step 1: open your favorite editor and write/paste the following code in a file called module.c

#include "redismodule.h"
/* ECHO <string> - Echo back a string sent from the client */
int EchoCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {

m-ou-se

# Download latest archlinux bootstrap package, see https://www.archlinux.org/download/
wget 'ftp://ftp.nluug.nl/pub/os/Linux/distr/archlinux/iso/latest/archlinux-bootstrap-*-x86_64.tar.gz'

# Make sure you'll have enough entropy for pacman-key later.
apt-get install haveged

# Install the arch bootstrap image in a tmpfs.
mount -t tmpfs none /mnt
cd /mnt
tar xvf ~/archlinux-bootstrap-*-x86_64.tar.gz --strip-components=1

magnetikonline

Bash string manipulation cheatsheet

Assignment
Assign value to variable if variable is not already set, value is returned. Combine with a : no-op to discard/ignore return value.	${variable="value"} : ${variable="value"}

CAFxX

📂 Persistent "pipes" in Linux

In a project I'm working on I ran into the requirement of having some sort of persistent FIFO buffer or pipe in Linux, i.e. something file-like that could accept writes from a process and persist it to disk until a second process reads (and acknowledges) it. The persistence should be both across process restarts as well as OS restarts.

AFAICT unfortunately in the Linux world such a primitive does not exist (named pipes/FIFOs do not persist

EleotleCram

int aprintf(char *str, ...) {
	int i, j, count = 0;

	va_list argv;
	va_start(argv, str);
	for(i = 0, j = 0; str[i] != '\0'; i++) {
		if (str[i] == '%') {
			count++;

			Serial.write(reinterpret_cast<const uint8_t*>(str+j), i-j);