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Tom Oliver

Here's how to burn audio to a CD from the command line.

# Remove spaces from filenames
for f in *; do mv "$f" `echo $f | tr ' ' '_'`; done
# Convert all tracks to wav
for i in $( ls ); do ffmpeg -i $i $i.wav; done
# Normalize the volume across all tracks
normalize -m *.wav
# Burn to disk
sudo wodim -v -dev='/dev/cdrom' -audio -pad *.wav
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Tom Oliver

So this is one of the first times I have actually come across a hurdle when it comes to developing software on old computers. A couple days ago I started experimenting with bun, which is amazing by the way. One of the big selling points is that it is really fast, but this speed seems to come at a cost...

As I use NixOS, I installed it the usual way by adding it to my configuration.nix. But alas, life isn't always simple. It seems to install ok, but when I tried to run bun I got an error immediately:

illegal hardware instruction (core dumped)

Wow an actually hardware error! I haven't seen one of those since I was trying some overclocking! So the problem comes down to the fact that bun uses some cutting edge CPU instructions that weren't around in 2012. Now, on other Linux distributions you can simply use a bash script to install bun à la:

curl -fsSL | bash

Apparently it checks your CPU and in the event it finds something of a certain vintage it installs a baseline version of bun which I guess doesn't use any of the funky CPU instructions it would usually. Unfortunately the nix package does not at the time of writing do this. There is actually a PR open to fix this but it has not been merged yet. So for the time being you can basically just take the code from the PR, save it to a file locally and build the baseline version yourself.

  1. Download and save this file.
  2. Now to build is, run:
nix-build -E 'with import <nixpkgs> {}; callPackage ./default.nix {}'
  1. You should now be able to run bun by doing:
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Tom Oliver

I witnessed this absolute corker of a bug in the office today.

After a force reboot (its a long story), we noticed that the cursor was flickering on my colleague's Ubuntu laptop. After some googling, we realised that this flickering only happens at 200% fractional scaling. Setting to any other value like 175%, 150% etc. works perfectly fine.

Despite the link above being more than three and a half years old, it appears that even today, this bug can still be observed in the wild, in its natural habitat, on Ubuntu.

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Tom Oliver

It's taken me far too long to discover this foot-gun in express.

I started a new express project the other day and realised that my request bodies were all empty! Spent a good hour thinking it was a problem in the client or the proxy etc... but was actually just because I forgot to apply these two middlewares.

So the question is, why are these middlewares not enabled by default????

const app = express()
// this populates req.body when the payload is json
app.use(express.json({ type: "application/json" }))
// this populates req.body when the payload is urlencoded
// (e.g when a form gets submitted)
app.use(express.urlencoded({ extended: true }))

Sensible defaults are just something we don't deserve I guess...

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Tom Oliver

Optimistic VS Pessimistic Locking

Imagine you are on a plane and you need to pee. You're a stubborn guy. When you leave your seat, you are determined to pee one way or another. You must assume your fellow passengers are as least as stubborn.

Optimistic Locking

There is a single toilet located in the middle of the plane that can be accessed from multiple directions. You are sitting at the back and can only see the entrance to the toilet that is in your direct line of sight. You want to know if its ok to go to the toilet so you check the overhead light which says "vacant". Assuming that it will remain vacant for the entirety of the time it will take you to reach your destination, you get out of your seat and commit to peeing. Now one of two things are going to happen:

  1. The toilet is vacant by the time you get to it - Success
  2. Someone else has slipped into the toilet via an entrance you couldn't see during the time it took you to walk there. Since you have committed to peeing, you have no choice but to do so in a cup - Failure.

Pessimistic Locking

Due to your toilet paranoia you reserve a seat on a specially designed plane. It is designed such that each seat is directly adjacent to a toilet and has excellent visibility of all its entrances. Because of this, you are able to in a single instant, both check that a toilet is free and enter it. It is therefore guaranteed that you nor any other passenger will be forced to pee in a cup.

So obviously there is a dilemma here.

The specially designed plane will carry less passengers due to its emphasis on providing the stubborn peeing passenger peace of mind. The normal plane will be more efficient but has to account for the occasional cup of pee getting knocked over.

What have we learned?

There is no "correct" way to design a plane, only trade-offs.

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Tom Oliver

Some lesser known nice things about Japan 🗾

  • Ambulances are loud, but not too loud.
  • When Police cars do unexpected things like making a U-turn suddenly, they politely inform everyone nearby with a megaphone.
  • When large vehicles make a turn near a pedestrian they play a vocal warning "Watch out! I'm about to turn left!"
  • Dog owners carry a bottle of water to wash away any pee the dog might do on a walk.
  • There are lots of outside gyms.
  • There are lots of summer festivals which aren't exclusively an excuse to get drunk.
  • Its not okay to be ugly.
    • You better look your best if you're thinking about leaving your home.
    • Foreigners usually get the benefit of the doubt.
  • Lots of stuff made in Japan for Japanese people only. (Films, cars, appliances...)
  • There is one and only one right way to do everything.
    • If you order something in a cafe or a restaurant, chances are they'll tell you the right way to consume it.
    • e.g. You order an iced coffee creamy thing from a local cafe.
      1. First taste the top and bottom layers independently before mixing them both together with the straw...
  • There is a lot of wildlife everywhere.
    • Probably more wildlife in Tokyo than in any National park in the UK.
  • There are dry ice machines in some supermarkets.
  • Some cars have a horn? that says in a polite voice "Please watch out, a car is passing by!" to unsuspecting pedestrians that haven't noticed.
  • Relaxing background music automatically starts playing the instant your skin comes into contact with the toilet seat.
  • Safety first
    • At petrol stations there is an "anti static electricity pad" for you to touch before filling up your car.
  • The sky is big. Power cables on a hot sunny dayPower cables on a hot sunny day
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Tom Oliver

Its been a while since I did any data modelling in typescript.

// An example of a user management system
// Define user status type, just an enum
type UserAccountStatus = "ACTIVE" | "DORMANT" | "DELETED"
// Define a base type
type BaseUser = { name: string; status: UserAccountStatus }
// Create concrete types using the base type
type ActiveUser = BaseUser & { status: "ACTIVE" }
type DormantUser = BaseUser & { status: "DORMANT" }
type DeletedUser = BaseUser & { status: "DELETED" }
type User = ActiveUser | DormantUser | DeletedUser
// Create the type of function we want to implement
// Make return type a promise because we talk to the DB
type DeleteUser = (user: ActiveUser | DormantUser) => Promise<DeletedUser>
// do a temporary implementation of the function
const deleteUser: DeleteUser = (user) => {
const deletedUser: DeletedUser = { ...user, status: "DELETED" }
// define a helper that we haven't got yet
return writeUserToDB(deletedUser)
// declare the type of the helper like so:
declare function writeUserToDB<A extends User>(user: A): Promise<A>
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Tom Oliver

Bought some books with the intention of learning Chinese but yeah its pretty hard.
As long as I don't give up completely I might be ok at it in the region of say... a decade?
Which is really not too long when you think about it.
So I guess nothing to complain.

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Tom Oliver

This was super helpful for implementing webmentions on my site! Thanks!

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Tom Oliver

Oh, looks like I have to paste the link explicitly for it to work.

Anyways, here it is:

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Tom Oliver

Not as cool as this post right here am I rite m8s??? 🌳💻🎉

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Tom Oliver

So this is what shouting into the void feels like...

Hello, this is my first "note".

Probably not going to write too many until I'm sure I have web mentions all working.