In this DOS tutorial we take a look at the Path, an important concept. While the concept continues to be used in modern operating systems like Linux, in DOS you had severe limitations you always had to be conscious of. Remember that this was in the days when 640KB was enough memory for anyone.

Links:

https://www.ahuka.com/dos-lessons-for-self-study-purposes/dos-lesson-5-the-path/

Equality of structured errors

Background

In previous episode, I built a system where error codes weren't defined in one huge type. This made compilation times faster and maintenance quite a bit more easier.

Problem

I wanted to write a test to see that parameters passed to validatePatchApiPersonR are validated correctly. patchApiPersonR is used by client to do partial updates on a Person entity. There's three different cases I wanted to check:

trying to change life focus too soon (there's 5 year cooldown)

trying to select same life focus that has already been selected

trying to modify somebody else's avatar

Code is shown below and the last 2 lines are the interesting ones. There I'm using equality to compare if a given error exists in a list of errors created by validatePatchApiPersonR.

spec :: Spec

spec = do

describe "people" $ do

describe "life focus" $ do

describe "Validating requests" $ do

it "All errors are reported" $ do

forAll anyCompletelyFaultyRequest $

(userE, personE, msg, date) ->

let res = validatePatchApiPersonR (userE ^. entityKeyL, userE ^. entityValL, personE, msg, date)

newFocus = msg ^? patchPersonRequestLifeFocus . _Just . _Just

in

case res of

V.Success _ ->

expectationFailure "Invalid request was not detected"

V.Failure errs -> do

errs `shouldSatisfy` (xs -> any (x -> "CanNotChangeLifeFocusSoSoon" `isInfixOf` (pack $ show x)) xs)

errs `shouldContain` [ canNotReselectSameLifeFocus newFocus ]

errs `shouldContain` [ insufficientRights ]

Detour on equality

Equality in Haskell works slightly differently compared to for example C#. There is no built in, default implementation that gets used when the programmer hasn't written their own. If you want to compare equality, there needs to be implementation specific to your data types. This is done by making an instance of type class Eq (https://hackage.haskell.org/package/base-4.15.0.0/docs/Data-Eq.html).

class Eq a where

(==) :: a -> a -> Bool

(/=) :: a -> a -> Bool

There's two functions: == for equality and /= for inequality. You need to implement either one.

Back to problem

ECode is our structured error code type and defined as follows (this is short recap of previous episode):

data ECode where

ECode :: (ErrorCodeClass a, ToJSON a, Eq a, Show a) => a -> ECode

It can wrap anything that has correct type class instances and you will always get ECode as a result. It hides the specific type of thing being wrapped and only functions defined in type classes are available.

First try

Peel away ECode and compare what's inside and compare wrapped values:

instance Eq ECode where

ECode a == ECode b =

a == b

This will lead into a error "Couldn't match expected type ‘a’ with actual type ‘a1’. ‘a1’ is a rigid type variable bound by a pattern with constructor...". This is because ECode can wrap man

Recorded November 19 2021 quick storm. Please search Binaural on HPR for similar recordings and description of procedure, enjoy and have a glorious 2022.

Links

hpr0785 :: binaural recording

hpr0792 :: Binaural Recording

hpr2338 :: Binaural recording 2 off to work

Synopsis

In today's episode, Rho`n installs a cat door in the basement door separating the finished side of the basement from the utility side. Follow along as he learns once again that it is best to read all the instructions before starting a project, and also learns that modern, inexpensive, interior doors are not made of wood.

The following are the pictures taken during the project.

div#figures {

display: flex;

flex-direction: row;

flex-wrap: wrap;

justify-content: center;

}

div#figures figure { max-width: 492px; }

div#figures img { max-width: 50vw; padding-bottom: 0.15em }

Basement door laid out on a table with the cat door template applied

Basement door after cutting a hole through it. Showing the hole and the interior of the door.

View from the finished side of the basement showing the installed cat door.

View from the utility side of the basement showing the installed cat door.

Attribution

The transition sound used between audio clips is found on freesound.org:

Name: Harp Transition Music Cue

Author: DanJFilms

License: Creative Commons Zero

Text editors are highly subjective and highly opinionated commodities. Everyone is aware of infamous rivalry between users of Emacs and Vi/Vim. Every single text editor has its own strengths and weaknesses. At the end of the day it's the question of your personal preferences and muscle memory when it comes to default key-bindings. Both Emacs and Vim have a learning curve. Steepness of that curve depends on the person's background and interests. Hey, but today I'm not here to talk about Emacs and Vim. I'm here to talk about a simple, easy to use and almost ever present text editor called GNU nano. So what exactly is this nano text editor? Well, according to documentation available on GNU nano's website,

GNU nano was designed to be a free replacement for the Pico text editor, part of the Pine email suite from The University of Washington. It aimed to "emulate Pico as closely as is reasonable and then include extra functionality".

Pico and Pine email suites are still around so what was the need to create nano in the first place? The answer is license. Pico and Pine email suites nowadays are available under Apache-2.0 license but that always wasn't the case and this ambiguity in the original licensing terms of the Pico editor led to the creation of nano. It was first created in 1999 with the name TIP (an acronym for TIP Isn't Pico), by Chris Allegretta. The name was changed to nano on January 10th, 2000 to avoid a naming conflict with the existing Unix utility tip. The name comes from the system of SI prefixes, in which nano is 1000 times larger than pico. In February 2001, nano became a part of the GNU Project. BTW if you want to know more about SI prefixes, I'd highly recommend you to listen to HPR episode 3453 - Engineering notation by Ken Fallon.

nano is really small in footprint and is relatively easy to use compared to Emacs and Vim and perhaps this is the reason why you'd invariably find it already installed on almost all GNU/Linux distributions. If you have ever used nano before you might have noticed that it looks kinda boring; there are no line-numbers nor there is any syntax highlighting and spell-checking also seems absent. But this is not true. nano has all of these features and even some more like regex searches, indentation, multiple buffers, available at its disposal. Then why does it come across as a plain Jane? The short answer is, I honestly don't know! For some unknown and obscure reasons many of nano's cool features are disabled by default. This results in nano coming across as a plain Jane little text editor that is uncool. And as I mentioned earlier, that is not true. But worry not! It is so darn easy to unleash the true potential of nano and make it shine. Are you ready? Great! Let's do it together then!

First thing we need to to do is create a file with the name .nanorc in the $HOME directory. Open your terminal emulator and run,

touch $HOME/.nanorc

We'd also need to create a directory called Nano_Backups in our Documents directory. To do so run the following command,

mkdir -p $HOME/Documents/Nano_Backups

Next open that .nanorc file and simply paste the following content in it,

set atblanks

set autoindent

set backup

set backupdir "/home/USERNAME/Documents/Nano_Backups"

set boldtext

set constantshow

set cutfromcursor

set indicator

set linenumbers

set magic

set minibar

set mouse

set showcursor

set softwrap

set speller "aspell -x -c"

set trimblanks

s

top ten of the first unix commands

50 years after the 1st Edition of Unix was published, Ken (Fallon not Thompson) checks his unix like computer to see how many commands still exist (38) and how many are not installed by default (23).

Thanks to @bsdimp on twitter for the post. Also to @[email protected] and @[email protected] for the tip.

Packages I don't have installed

Many are available under another name but I have not installed them. Seven of the of the twenty two relates to tapes.

B -- language

bas -- basic

bcd -- binary coded decimal conversion

boot -- reboot system

chdir -- change working directory

check -- file system consistency check

db -- debug

dbppt -- dump binary paper tape

dsw -- delete interactively

dtf -- DECtape format

for -- fortran

form -- form letter generator

hup -- hang up typewriter

lbppt -- load binary paper tapes

rew -- rewind tape

rkd -- dump RK disk to tape

rkf -- format RKO3 disk pack

rkl -- reload RK disk from tape

roff -- format text

sdate -- set date and time

tap -- manipulate DECtape

tm -- provide time information

un -- undefined symbols

Top 10 most popular 50 year old commands !

1 10108 ls

2 2847 find

3 1985 rm

4 1482 mv

5 887 cat

6 649 for

7 544 mkdir

8 341 cp

9 280 rmdir

10 202 df

Using the GnuPG vim plugin to edit encrypted files.

See show hpr3476 My mutt email setup

http://www.hackerpublicradio.org/eps.php?id=3476

GnuPG Vim Plugin on vim.org

https://www.vim.org/scripts/script.php?script_id=3645

GnuPG Vim Plugin on Github

https://github.com/vim-scripts/gnupg.vim

From man 1 gpg-agent:

You should always add the following lines to your .bashrc or whatever initialization file is used for all shell invocations:

GPG_TTY=`tty`

export GPG_TTY

It is important that this environment variable always reflects the output of the tty command.

.bashrc snippet

## GPG Vim

GPG_TTY=`tty`

export GPG_TTY

export EDITOR=vim

GnuPG folder structure

[mark@fedora-lt ~]$ tree .vim

.vim

├── plugin

│ └── vim-gnupg

│ ├── autoload

│ │ └── gnupg.vim

│ ├── doc

│ │ └── gnupg.txt

│ ├── plugin

│ │ └── gnupg.vim

│ └── README.md

└── spell

├── en.utf-8.add

└── en.utf-8.add.spl

vimrc

set tabstop=2 softtabstop=0 expandtab shiftwidth=2 smarttab textwidth=80

syntax on

autocmd BufRead,BufNewFile *.log set filetype=logtalk

set spell spelllang=en_us

Generate gpg full key

gpg --full-generate-key

or just a regular one, with less options

gpg --gen-key

Encrypt the file in question, with -r as the recipient

In this case, I used part of the comment as the recipient

Picture 1

Click the thumbnail to see the full-sized image

This is more like it.

gpg -e -r test thisIsMyTestFile.txt

Now test edit the file

vim thisIsMyTestFile.txt.gpg

Picture 2

It is a good idea to shred the original text file

shred - overwrite a file to hide its contents, and optionally delete it

-u deallocate and remove file after overwriting

-v, --verbose, show progress

ringtone location: /usr/share/sounds/freedesktop/stereo

Gimp on a cellphone, for obvious reasons.

Links

wikipedia: https://en.wikipedia.org/wiki/PinePhone

Official website: https://www.pine64.org/pinephone/

PinePhone Wiki: https://wiki.pine64.org/index.php/PinePhone

http://solarbotics.net/bftgu/default.htm

https://www.bitchute.com/video/jwD4sZhnXrEk/

Hail to my Loyal Henchmen and fellow SuperVillains, welcome new recruits and greetings to the hackers of HPR.

This is Mechatroniac the mechatronics maniac with the zeroth installment of Robot Warlords of the Apocalypse, where I will talk about post apocalyptic robotics and share my projects, philosophy and future ambitions.

I am doing this podcast contribution for hacker public radio.

hackerpublicradio.org

After this has aired on HPR I will be adding video and to this presentation which will be uploaded to my channel at:

https://bitchute.com/channel/mechatroniac point youtube-dl at it and download them all.

Mechatronics is code, electronics and mechanics working together as a system. I am weak in all 3, but have built mini battlebot style robots completely from scratch, with every chassis part, every motor and wheel, and every circuit that drives them sourced for free from junk like discarded printers, dvds, tvs, computers and UPS.

I am calling this ethos and the resultant aesthetic, Post Apocalyptic Robotics, that is robots that can be built by reclaiming existing post consumer products to create something new.

Currently they are confined to smooth surfaces like battlebot arenas, but more rugged terrain bots are currently also being worked on, and I want to work towards autonomous and swarm robots as well.

The recipes I release here, can be followed by anyone to build their own robots and devices, by simply gathering the required scrap units or similar as described; then disassembling, then finally reassembling into a new meta technological device.

I hope that others will do the same, and come up with their own innovations and new recipes that can be added to our incipient swarms of meta-technological bots as they evolve ever more sophistication.

Welcome to post apocalyptic robotics.

Introduction to Post-Apocalypse Robotics Meta-technology

Tech Prepping, Building a 'battlebot' out of junk

Meteors, asteroids, comets. Cataclysmic solar flares, massive volcanic eruptions and earthquakes triggering massive tsunamis, social unrest, runaway climate change, ransomware and EMPs attacks striking electric grids, deadly viral pandemics, mass hysteria, big boats blocking waterways, obscured malware in a systemd update, management engines at the heart of CPUs providing backdoors to Intel and AMD hardware at root -3 privilege... what could go wrong there?

There are a large number of looming events which could collapse technological society as it is, wiping out most of the internet and shipping and transport and hopefully maybe even the government.

Tech Prepping is more important than food prepping

While most survivalist and prepper types concentrate on stacking cans of beans, seeds, fuel and ammo, the robot prepper will also be hoarding books on pdf, component datasheets, software libraries, breakout boards and every post EOL electronics product they can get their hands on.

In a semi apocalyptic scenario where the trucks stop rolling, a lot of people who save seeds will be able to grow food in their communities, so food won't be such a big deal.

There might even be some that figure out how to make petroleum from wood like mrteslonian channel on youtube.

But a real crux will be analog, digital electronics technology, IT and mechatronics. Those communities with working electronics, mechatronics, and information technology infrastructure, will be at a distinct competitive advantage. They will be able to leverage this in such things as automation of agriculture, from watering schedu

table td.shrink {

white-space:nowrap

}

New hosts

Welcome to our new hosts:

one_of_spoons,

dnt.

Last Month's Shows

Id

Day

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Title

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3456

Mon

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Tables

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