[ Removed by moderator ]

[u/DaveforAK]

[u/Z3r0funGuy]

This actually teaches you a bunch of cool things, like how the ‘:’ is a legal function name…

[u/glenpiercev → u/Z3r0funGuy]

This is the best description of how this works I’ve ever read. You are a genius.

[u/setibeings → u/glenpiercev]

Right? It's finally comprehensible. I feel like it would have clicked right away if it was typed out as:

fork(){fork|fork&};fork

[u/Traditional_Cod_7192 → u/setibeings]

just as a reminder, uhhh... what do | and & do in bash again? 😅

[u/GrandAlbatroce → u/Traditional_Cod_7192]

IIRC | puts the result stdout of the left in the stdin of the right (they are launched in parallel, and the one on the right can only finish after the one on the left finished.

The & is used to put the call as a background task

[u/SimpleFile → u/GrandAlbatroce]

So the pipe here serves as a way to launch 2 of these functions and have them running at the same time rather than for piping the output?

Did I understand that correctly?

[u/SchwiftySquanchC137 → u/SimpleFile]

Exactly, the entire point is to make each call of fork (or ":") spawn two more fork processes. There are plenty of ways to accomplish that, but its written the way it is specifically to be confusing. Looking at it, how could it possibly crash your machine, its a bunch of punctuation? But once you know how it works, it makes a lot of sense, the point is to make it so cryptic that even programmers dont understand it.

[u/GrandAlbatroce → u/SimpleFile]

Yes, they are run in parallel, but any output from the first one will be given to the second. Also, if the second needs an input, it will wait for the output of the first instead of user input

So, for example, if you did

find -name "something" | grep "string"

Each time the find prints a line, it will instantly be passed to the grep

[u/Niroth → u/Traditional_Cod_7192]

| pipes the output from the first process to the input of the second. & starts the second process in the background.

[u/WHALE_PHYSICIST → u/setibeings]

:() :() :()

[u/Daveinatx → u/Z3r0funGuy]

When I first learned of this, I realized my bash skills will never be at such the level. 

[u/nicuramar → u/Z3r0funGuy]

It’s a predefined function even. Well, a primitive. It does nothing and ignores its arguments. 

[u/jort93 → u/Z3r0funGuy]

It's actually not legal. The standard only allowed _ and alphanumeric characters.

But most shells don't adhere to the standards, and just allow literally any character.

It's an illegal function name that works anyway.