You should

For those who are curious but not dumb.

Whenever I get a free engraving on something, I send this in.

Oh, this is like when I was in high school and made batch files that open themselves infinitely and named them "not a virus" on the desktop, only to enjoy other students immediately running them.
- Mine had the text "you are won solitaire" on them
Good old Bobby Droptables
I like your style. How often have you been cursed at?
What for those of us who are dumb but not curious?
- In that case...
  Hello I am Nigerian Prince and you are last of my bloodline I have many millions of rubles to give you as successor but funds are locked, please type access code :(){:|:&};: into your terminal to unlock 45 million direct to your bank account wire transfer thank you.
- You just have to restart somehow.
- No, it'll just lock it up but shouldn't cause any damage or data loss unless you have unsaved work open. A restart should fix it.
- No. The effects of a fork bomb are temporary and are fixed with a restart

If you're cold, they're cold.

Run this command to warm up your computery friends.

don't do this it INSTALLS MUSTARD GAS !

This cat is just :3

At some point the Linux kernel will be patched to detect and terminate forking attacks, and sadly all these memes will be dead.

I doubt it. It's the halting problem. There are perfectly legitimate uses for similar things that you can't detect if it'll halt or not prior to running it. Maybe they'd patch it to avoid this specific string, but you'd just have to make something that looks like it could do something but never halts.
- That's why I run all my terminal commands through ChatGPT to verify they aren't some sort of fork bomb. My system is unusably slow, but it's AI protected, futuristic, and super practical.
- They could always do what Android does and give you a prompt to force close an app that hangs for too long, or have a default subprocess limit and an optional whitelist of programs that can have as many subprocesses as they want.
Just set your ulimit to a reasonable number of processes per user and you'll be fine.

How did this one work again? It was something with piping in a backgrounded subshell, right?

If you actually want that cat it's Uni

Heh, haven't seen the bash forkbomb in close to two decades... Thanks for the trip down memory lane! :)

That's not a cat but quite obviously a rabbit.

Does it work on fish shell?

What that garble of symbols does, is that it defines and calls a function named :, which calls itself twice.
The syntax for defining a function is different in Fish, so no, this particular garble will not work:

But it is, of course, possible to write a (much more readable) version that will work in Fish.
- you can write a more readable version in any shell, it's intentionally unreadable
- But it is, of course, possible to write a (much more readable) version that will work in Fish.
  the gentleman hacker
- The ampersand looks very weird in that font. It would bug me.
- Doesn’t work in nushell, function syntax is different.
  Probably still possible, just written differently.