ethagnawl

The i3-wm does not come with a keybinding to lock the screen or a preconfigured auto lockscreen. This gist describes how to setup both using i3lock and xautolock. i3lock is a minimalistic lockscreen and xautolock monitors mouse and keyboard activities to automatically lock the screen after a certain time of beiing inactive.

First get the tools if neccessary. E.g. sudo apt install i3lock xautolock.

To setup the keybinding Ctrl+Alt+l (last one is a lowercase L) to lock the screen append the following lines to the i3 configuration file located at ~/.config/i3/config.

# keybinding to lock screen

ethagnawl

In this article, I will share some of my experience on installing NVIDIA driver and CUDA on Linux OS. Here I mainly use Ubuntu as example. Comments for CentOS/Fedora are also provided as much as I can.

Table of Contents

• Install NVIDIA Graphics Driver via apt-get
• Install NVIDIA Graphics Driver via runfile
  • Remove Previous Installations (Important)
  • Download the Driver
  • Install Dependencies
  • Creat Blacklist for Nouveau Driver

• Stop lightdm/gdm/kdm

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import code; code.interact(local=dict(globals(), **locals()))

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When receiving JSON data from other resources(server API etc), we need Json.Decode to convert the JSON values into Elm values. This gist let you quickly learn how to do that.

I like to follow working example code so this is how the boilerplate will look like:

import Graphics.Element exposing (Element, show)
import Task exposing (Task, andThen)
import Json.Decode exposing (Decoder, int, string, object3, (:=))

import Http

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import com.fasterxml.jackson.annotation.JsonProperty
import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper

fun main(args: Array<String>) {
//    val mapper = ObjectMapper().registerModule(KotlinModule())
//    val mapper = ObjectMapper().registerKotlinModule()
    val mapper = jacksonObjectMapper()
    val writer = mapper.writerWithDefaultPrettyPrinter()

    val json1 = writer.writeValueAsString(Data1(1, "Foo", "Bar"))

ethagnawl

Every so often I have to restore my gpg keys and I'm never sure how best to do it. So, I've spent some time playing around with the various ways to export/import (backup/restore) keys.

Method 1

Backup the public and secret keyrings and trust database

cp ~/.gnupg/pubring.gpg /path/to/backups/
cp ~/.gnupg/secring.gpg /path/to/backups/
cp ~/.gnupg/trustdb.gpg /path/to/backups/

or, instead of backing up trustdb...

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Raspberry Pi

• Related tutorial: http://raspberrypiguide.de/
• Command Line Cheatsheet: https://gist.github.com/hofmannsven/8392477

Setup

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# Goal: Allow addition of instances to a collection in a factory-built object
# when those instances require references to the parent.
# Typically occurs in Rails when one model has_many instances of another
 
# See more at:
# http://stackoverflow.com/questions/2937326/populating-an-association-with-children-in-factory-girl
 
# Usage
# Foo has_many :bar
#

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# Crystal fork of "SEE YOU SPACE COWBOY by DANIEL REHN (danielrehn.com)"
# by @ethagnawl
# Displays a timeless message in your terminal with cosmic color effects

# Usage:
# - build with `crystal build -o ~/seeyouspacecowboy seeyouspacecowboy.cr`
# - add `~/seeyouspacecowboy; sleep 2` to ~/.bash_logout
# (adjust the sleep variable to display the message for more seconds)

class String

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PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)