talayhan

Rich Hickey on becoming a better developer

Rich Hickey • 3 years ago

Sorry, I have to disagree with the entire premise here.

A wide variety of experiences might lead to well-roundedness, but not to greatness, nor even goodness. By constantly switching from one thing to another you are always reaching above your comfort zone, yes, but doing so by resetting your skill and knowledge level to zero.

Mastery comes from a combination of at least several of the following:

talayhan

1. Clone your fork:

git clone git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git

2. Add remote from original repository in your forked repository:

cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream

talayhan

#!/usr/bin/env bash


# add repository for g++-5
sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test

# add repository for clang-3.7
sudo add-apt-repository -y "deb http://llvm.org/apt/trusty/ llvm-toolchain-trusty-3.7 main"
wget --quiet -O - http://llvm.org/apt/llvm-snapshot.gpg.key | sudo apt-key add -

talayhan

Why do compilers even bother with exploiting undefinedness signed overflow? And what are those
mysterious cases where it helps?

A lot of people (myself included) are against transforms that aggressively exploit undefined behavior, but
I think it's useful to know what compiler writers are accomplishing by this.

TL;DR: C doesn't work very well if int!=register width, but (for backwards compat) int is 32-bit on all
major 64-bit targets, and this causes quite hairy problems for code generation and optimization in some
fairly common cases. The signed overflow UB exploitation is an attempt to work around this.

talayhan

PART 1

[STEP 2] Adding a dedicated hadoop system user

check groups

$ compgen -g

talayhan

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

talayhan

#!/bin/sh

apt-get update
apt-get upgrade -y --show-upgraded
apt-get install -y sudo apt-get install libxft-dev libxinerama-dev libpango1.0-dev

wget -c https://github.com/DaveDavenport/rofi/releases/download/0.15.4/rofi-0.15.4.tar.gz
tar -xzvf rofi-0.15.4.tar.gz
cd rofi-0.15.4

talayhan

# installs to /opt/gradle
# existing versions are not overwritten/deleted
# seamless upgrades/downgrades
# $GRADLE_HOME points to latest *installed* (not released)
gradle_version=2.12
wget -N https://services.gradle.org/distributions/gradle-${gradle_version}-all.zip
sudo unzip -foq gradle-${gradle_version}-all.zip -d /opt/gradle
sudo ln -sfn gradle-${gradle_version} /opt/gradle/latest
sudo su
printf "export GRADLE_HOME=/opt/gradle/latest\nexport PATH=\$PATH:\$GRADLE_HOME/bin" > /etc/profile.d/gradle.sh

talayhan

/* $ gcc cve_2016_0728.c -o cve_2016_0728 -lkeyutils -Wall */
/* $ ./cve_2016_072 PP_KEY */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <keyutils.h>
#include <unistd.h>
#include <time.h>

talayhan

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console