Welcome back!

In the last article, we did foundational work on minipak, our ELF packer.

It is now able to receive command-line arguments, environment variables, and auxiliary vectors. It can parse those command-line arguments into a set of options. It can make an ELF file smaller using the LZ4 compression algorithm, and pack it together with stage1, our launcher.

What’s next? Well… poppler is the library Inkscape uses to import PDFs.

Turns out, poppler comes with a bunch of CLI tools, including pdftocairo!

I’ve been working on the itch.io desktop app for about a year now, so I thought I’d make a quick recap:

At the time of this writing, the app has been downloaded about 460K times (including updates). Not counting the back-end, the app and its various components are made up of around 100K lines of code (mostly javascript and golang), most of which is open-source.

In the two years since I’ve posted I want off Mr Golang’s Wild Ride, it’s made the rounds time and time again, on Reddit, on Lobste.rs, on HackerNews, and elsewhere.

And every time, it elicits the same responses:

• You talk about Windows: that’s not what Go is good at! (Also, who cares?)
• This is very one-sided: you’re not talking about the good sides of Go!

So you want to do live streams. Are you sure? Okay. Let’s talk about it.

Let’s talk numbers

Being a “content creator” (sorry for those who hate that term) is a job, for sure, and many people do it, successfully, full-time, they pay rent with it etc.

Platforms like Twitch & YouTube would have you think that, if you put in enough effort, you can grow your channel from nothing to 🎉 profitable ✨ in just a few short years.

With the previous part’s VM still running, let’s try connecting to our machine over SSH.

Network addresses, loopback and IP nets

Normally, to connect to a machine, you’d find its IP address. On Linux, a decade ago, you would’ve used ifconfig. Nowadays you can use ip addr:

The loopback interface (lo) is local, so it’s not useful to reach the box from the outside: you can see it can be accessed over IPv4 at address 127.0.0.1 but not just! What we’re reading here is 127.0.0.1/8, which corresponds to the range 127.0.0.1 - 127.255.255.255

The end of Advent of Code 2020 is fast approaching, and we’re nowhere near done. Time to do Day 6!

The problem statement here is a little contrived, as uh, as the days that came before it, but that won’t stop us.

Basically, the input looks like this:

abc a b c ab ac a a a a b

Each line represents one person, and “groups of persons” are separated by blank lines.

Alright! The day 12 puzzle involves path finding, and it seems like a good time to lean more heavily on the WASM embeds I’ve set up for the previous parts.

Let’s start by setting up the types we’ll want!

Types and parsing

Our input is a heightmap, like so:

Sabqponm abcryxxl accszExk acctuvwj abdefghi

Where 'a'..='z' is a square with a given elevation (from lowest to highest), S is the start, and E is the end.

I wanted to take some time to write about a piece of software I’ve been working on lately, just so you know how I’ve been spending the last few weeks.

Rationale

A few years ago, I designed a programming language: ooc. Even though I’ve done my fair share of Java, C, Ruby, JavaScript, and even some Perl, Scala, Python, PHP, etc., I still find myself going back to ooc because it gives me access to C libs, relatively high-level constructs, and it forces me to write code that’s not too smart.