One of my archiving and backup contingencies is taking one screenshot per minute. You can also use this to get a good idea of how you spend your day, by turning it into a movie. Although with a tiling window manager like I use, it’s a headache to watch.

I send the screenshots over to another machine for storage, so they’re not cluttering my laptop. It uses up 10-20GB per year.

I’ll go over my exact setup below in case anyone is interested in doing the same:

/bin/screenlog

GPG_KEY=Zachary
TEMPLATE=/var/screenlog/%Y-%m-%d/%Y-%m-%d.%H:%M:%S.jpg
export DISPLAY=:0
export XAUTHORITY=/tmp/XAuthority

IMG=$(\date +$TEMPLATE)
mkdir -p $(dirname "$IMG")
scrot "$IMG"
gpg --encrypt -r "$GPG_KEY" "$IMG"
shred -zu "$IMG"

The script

• Prints everything to stderr if you run it manually
• Makes a per-day directory. We store everything in /var/screenlog/2022-07-10/ for the day
• Takes a screenshot. By default, crontab doesn’t have X Windows (graphics) access. To allow it, the XAuthority file which allows access needs to be somewhere my crontab can reliably access. I picked /tmp/XAuthority. It doesn’t need any unusual permissions, but the default location has some random characters in it.
• GPG-encrypts the screenshot with a public key and deletes the original. This is extra protection in case my backups somehow get shared, so I don’t literally leak all my habits, passwords, etc. I just use my standard key so I don’t lose it. It’s public-key crypto, so put the public key on your laptop. Put the private key on neither, one, or both, depending on which you want to be able to read the photos.

/etc/cron.d/screenlog

* * * * * zachary  /bin/screenlog
20  * * * * zachary  rsync --remove-source-files -r /var/screenlog/ backup-machine:/data/screenlog/laptop
30  * * * * zachary  rmdir /var/screenlog/*

That’s

• Take a screenshot once every minute. Change the first * to */5 for every 5 minutes, and so on.
• Copy over the gpg-encrypted screenshots hourly, deleting the local copy
• Also hourly, delete empty per-day folders after the contents are copied, so they don’t clutter things

~/.profile

export XAUTHORITY=/tmp/XAuthority

I mentioned /bin/screenlog needs to know where XAuthority is. In Arch Linux this is all I need to do.

I just wrote the first pass at youtube-autodl, a tool for automatically downloading youtube videos. It’s inspired by Popcorn Time, a similar program I never ended up using, for automatically pirating the latest video from a TV series coming out.

You explain what you want to download, where you want to download it to, and how to name videoes. youtube-autodl takes care of the rest, including de-duplication and downloading things ones.

The easiest way to understand it is to take a look at the example config file, which is my actual config file.

Personally, I find youtube is pushing “watch this related” video and main-page feeds more and more, to the point where they actually succeed with me. I don’t want to accidentally waste time, so I wanted a way to avoid visiting youtube.com. This is my solution.

I added an articles section to my website with all blog posts up until now.

I also fixed the very, very old archived blog from 2014.

I retired at 31, and get asked about it sometimes. I wrote an article about how the math of retirement, which explains how I retired early (and some some extent, why). And of course, how and why you might want to as well.

I want to edit my finances articles, so this one is on my website instead: https://za3k.com/finance/retire_forever

There will probably be some more finances articles to come soon.

qr-backup is a program to back up digital documents to physical paper. Restore is done with a webcam, video camera, or scanner. Someday smart phone cameras will work.

I’ve been making some progress on qr-backup v1.1. So far I’ve added:

• --restore, which does a one-step restore for you, instead of needing a bash one-line restore process
• --encrypt provides password-based encryption
• An automatic restore check that checks the generated PDF. This is mostly useful for me while maintaining qr-backup, but it also provides peace-of-mind to users.
• --instructions to give more fine-tuned control over printing instructions. There’s a “plain english” explanation of how qr-backup works that you can attach to the backup.
• --note for adding an arbitrary message to every sheet
• Base-64 encoding is now per-QR code, each QR is self-contained.
• Codes are labeled N01/50 instead of 01/50, to support more code types in the future.
• Code cleanup of QR generation process.
• Several bugfixes.

v1.1 will be released when I make qr-backup feature complete:

• Erasure coding, so you only need 70% of the QRs to do a restore.
• Improve webcam restore slightly.

v1.2 will focus on adding a GUI and support for Windows, Mac, and Android. Switching off zbar is a requirement to allow multi-platform support, and will likely improve storage density.

Year 0 – I filled 10 32-GB Kingston flash drives with random data.
Year 1 – Tested drive 1, zero bit rot. Re-wrote the drive with the same data.
Year 2 – Re-tested drive 1, zero bit rot. Tested drive 2, zero bit rot. Re-wrote both with the same data.

They have been stored in a box on my shelf, with a 1-month period in a moving van (probably below freezing) this year.

Will report back in 1 more year when I test the third 🙂

FAQs:

• Q: Why didn’t you test more kinds of drives?
  A: Because I don’t have unlimited energy, time and money :). I encourage you to!
• Q: You know you powered the drive by reading it, right?
  A: Yes, that’s why I wrote 10 drives to begin with. We want to see how something works if left unpowered for 1 year, 2 years, etc.
• Q: What drive model is this?
  A: The drive tested was “Kingston Digital DataTraveler SE9 32GB USB 2.0 Flash Drive (DTSE9H/32GBZ)” from Amazon, model DTSE9H/32GBZ, barcode 740617206432, WO# 8463411X001, ID 2364, bl 1933, serial id 206432TWUS008463411X001005. It was not used for anything previously–I bought it just for this test.
• Q: Which flash type is this model?
  A: We don’t know. If you do know, please tell me.
• Q: What data are you testing with?
  A: (Repeatable) randomly generated bits
• Q: What filesystem are you using? / Doesn’t the filesystem do error correction?
  A: I’m writing data directly to the drive using Linux’s block devices.

Here’s a list of books I read in 2021. The ones in bold I recommend.

Fiction:

Enigma by Graeme Base
City of Stairs by Robert Jackson Bennett
Look to Windward (Culture 7) by Ian Banks
Surface Detail (Culture 8) by Ian M Banks
Pump Six by Paolo Bacigalupi
Six of Crows by Leigh Bardugo
Lexicon by Max Barry
Mage Errant 1 by John Bierce
Mage Errant 2 by John Bierce
Mage Errant 3 by John Bierce
Mage Errant 4 by John Bierce
Mage Errant 5 by John Bierce
The Atlas Six by Olivie Blake
Lilith’s Brood (Xenogenesis 1) by Octavia E Butler
Elegy Beach (Change 2) by Steven Boyett
Curse of Charion by Louis Bujold
Xenocide by Orson Scott Card
Bohemian Gospel by Dan Carpenter
Convergence (Foreigner 18) by C J Cherryh
Emergence (Foreigner 19) by C J Cherryh
Convergence (Foreigner 21) by C J Cherryh
Iron Prince by Bryce O’Conner and Luke Chmilenko
Murder on the Orient Express by Agatha Christie
The Alchemist by Paulo Coelho
Artemis Fowl (Artemis Fowl 1) by Eoin Colfer
The Arctic Incident (Artemis Fowl 2) by Eoin Colfer
Eternity Code (Artemis Fowl 3) by Eoin Colfer
Opal Deception (Artemis Fowl 4) by Eoin Colfer
Space Between Worlds by J Conrad and Micaiah Johnson
Little Brother by Cory Doctrow
Homeland (Little Brother 2) by Cory Doctrow
Children of Chaos by Dave Duncan
The Alchemist’s Apprentice by Dave Duncan
The Alchemist’s Code by Dave Duncan
The Alchemist’s Pursuit by Dave Duncan
The Cutting Edge by Dave Duncan
Upland Outlaws by Dave Duncan
The Stricken Field by Dave Duncan
Queen of Blood by Sarah Beth Durst
Vita Nostra by Maryna and Serhiy Dyachenko
How Rory Thorne Destroyed the Multiverse by K. Eason
Malazan (Malazan 1) by Steven Erikson
Daughter of the Empire by Raymond Feist and Janny Wurts
Mistress of the Empire by Raymond Feist and Janny Wurts
Servant of the Empire by Raymond Feist and Janny Wurts
Dragon’s Egg (Cheela 1) by Robert L Forward
Mother of Learning by Domagoj Kurmaic/nobody103
Books of Magic by Neil Gaiman
The Midnight Library by Matt Haig
The Warehouse by Rob Hart
Forging Hephestus by Drew Hayes
Super Powereds, v1 by Drew Hayes
Super Powereds, v2 by Drew Hayes
Super Powereds, v3 by Drew Hayes
Super Powereds, v4 by Drew Hayes
Johannes Cabal by Johnathan L. Howard
The Medusa Plague by Mary Kirchoff
Six Wakes by Muir Lafferty
King of Thorns by Mark Lawrence
Emperor of Thorns by Mark Lawrence
First Contacts by Murray Leinster
Futurological Congress by Stanislaw Lem
Perfect Vacuum by Stanislaw Lem
Tuf Voyaging by George R R Martin
Memory of Empire by Arkady Martine
A Desolation Called Peace by Arkady Martine
Middlegame by Seanan McGuire
The Host by Stephanie Meyers
The city & the city by China Mieville
*The House that Made the 16 Loops of time by Tamsyn Muir
Harrow the Ninth by Tamsyn Muir
Convenience Store Woman by Sayaka Murata
A Deadly Education by Naomi Novik
The Last Graduate (Schoolomance 2) by Naomi Novik
Stiletto (Chequey, book 2) by Daniel O’Malley
Special Topics in Calamity Physics by Marisha Pessl
Carpe Jugulum by Terry Pratchett
Guards! Guards! by Terry Pratchett
Jingo by Terry Pratchett
The Last Continent by Terry Pratchett
Monsterous Regiment by Terry Pratchett
Men at Arms by Terry Pratchett
Night Watch by Terry Pratchett
Snuff by Terry Pratchett
Sourcery by Terry Pratchett
The Truth by Terry Pratchett
The Woven Ring (Sol’s Harvest 1) by M D Presley
Years of Rice + Salt by Kim Stanley Robinson
The Torch That Ignites the Stars by Andrew Rowe
Sleep Donation by Karen Russell
A Darker Shade of Magic by V E Schwab
Invisible Life of Addie LaRue by V E Schwab
Vicious by V E Schwab
Vengeance by V E Schwab
Grasshopper Jungle by Andrew Smith
Why Is This Night Different Than All Other Nights? by Lemony Snicket
Dark Storm (Rhenwars 1) by M L Spenser
Anathem by Neal Stephenson
Cryptonomicon by Neal Stephenson
Nimona by Noele Stevenson
Hunter x Hunter manga v1-36 by Yoshihiro Togashi
Worth the Candle by Alexander Wales
Educated by Tara Westover
Soulsmith (Cradle 2) by Will Wight
Blackflame (Cradle 3) by Will Wight
Skysworn (Cradle 4) by Will Wight
Ghostwater (Cradle 5) by Will Wight
Underlord (Cradle 6) by Will Wight
Uncrowned (Cradle 7) by Will Wight
Wintersteel (Cradle 8) by Will Wight
Bloodlines (Cradle 9) by Will Wight
Reaper (Cradle 10) by Will Wight
The Crimson Vault (Travelers Gate 2) by Will Wight
*Dinosaurs by Walter Jon Williams
Blind Lake by Robert Charles Wilson
Thousand Li by Tao Wong
Thousand Li 2 by Tao Wong
Thousand Li 3 by Tao Wong
Thousand Li 4 by Tao Wong
Thousand Li 5 by Tao Wong
Sorcerer’s Legacy by Janny Wurts (see also Feist)
Heretical Edge by ceruleuanscrawling
Mark of the Fool by UnstoppableJuggernaut
there is no antimemetics division by qntm
Only Villains Do That by Webbonomicon
Worm by wildbow

Nonfiction:

Compiling with Continuations by Andrew W. Appel
The Rule of Benedict by St Benedict (read the front material only)
Programming Pearls by Jon Bentley
Whole Brain Emulation Roadmap by Nick Bostrom
Data Matching by Peter Christen
Attack and Defense by James Davies and Akira Ishida
Engines of Creation by K. Eric Drexler
Class by Paul Fussell
The Food Lab by J Kenzi Lopez-Alt
Primitive Technology by John Plant
Monero whitepaper by Nicolas van Saberhagen
Secrets and Lies by Bruce Schneier
The Cuckoo’s Egg by Clifford Stoll

I downloaded all 27 million Go games from online-go.com, aka OGS, with permission. They are available on Internet Archive or here as SGF files or JSON. You can use them for whatever you like.

Recently I wrote a scraper. First, I downloaded all the HTML files. Next, I wanted to parse the content. However, real world data is pretty messy. I would run the scraper, and it would get partway though the file and fail. Then I would improve it, and it would get further and fail. I’d improve it more, and it would finish the whole file, but fail on the fifth one. Then I’d re-run things, and it would fail on file #52, #1035, and #553,956.

To make testing faster, I added a scaffold. Whenever my parser hit an error, it would print the filename (for me, the tester) and record the filename to an error log. Then, it would immediately exit. When I re-ran the parser, it would test all the files where it had hit a problem first. That way, I didn’t have to wait 20 minutes until it got to the failure case.

if __name__ == "__main__":
    if os.path.exists("failures.log"):
        # Quicker failures 
        with open("failures.log", "r") as f:
            failures = set([x.strip() for x in f])
        for path in tqdm.tqdm(failures, desc="re-checking known tricky files"):
            try:
                with open(path) as input:
                    parse_file(input)
            except Exception:
                print(path, "failed again (already failed once")
                raise

    paths = []
    for root, dirs, files in os.walk("html"):
        for file in sorted(files):
            path = os.path.join(root, file)
            paths.append(path)
    paths.sort()

    with open("output.json", "w") as out:
        for path in tqdm.tqdm(paths, desc="parse files"): # tqdm is just a progress bar. you can also use 'for path in paths:
            with open(input, "r") as input:
                try:
                    result = parse_file(input)
                except Exception:
                    print(path, "failed, adding to quick-fail test list")
                    with open("failures.log", "a") as fatal:
                        print(path, file=fatal)
                    raise
                json.dump(result, out, sort_keys=True) # my desired output is one JSON dict per line
                out.write("\n")

I was looking into building a raspberry pi based supercomputer lately. Here’s the background research I did comparing pi models. Most of this information is sourced from raspberrypi.org. I was especially interested in which boot methods worked for which models, which is very scattered, as well as prices.