This is a Bash fork bomb, a malicious function definition that recursively calls itself:
:() — defines a function named : (yes, just a colon).
{ :|:& } — the function's body:
:|: — pipes the output of the function into another call of itself, creating two processes each time.
& — runs the call in the background, meaning it doesn’t wait for completion.
; — ends the function definition.
: — finally, this invokes the function once, starting the bomb.
The form "function(){content}" in bash defines a function called "function" that, when called by name, executes "content". This forkbomb defines a function called : (just a colon) which calls itself twice in a new subprocess (the two colons inside the curly brackets). It thus spawns more and more copies of itself until it overwhelms your processor.
It just takes all your computers CPU and RAM by making endless copies of itself. Best case your PC gets sluggish, worst it crashes. Won't do any lasting damage. It's called a "Fork Bomb"
Any modern Linux system where you didn't explicitly tell it to do otherwise will limit the amount of running processes to a safe number.
So this does nothing anymore. Same as rm -rf / which also simply triggers an error message.
I had a class about fork() on my Operating Systems course yesterday. I was going to look up the fork bomb, that the teacher didn't even tell us about >:( , but it somehow found me instead.
Breaking MacOS is easy, if the fork bomb doesn't work just create a function which recursively writes files until the disk is full. Unless they fixed it in the past 5 years, at that point even when the OS is set to delete files directly, it will still fail to delete anything. I couldn't even remove anything with sudo rm -f, that just triggered a 'not enough space to remove file' error message.
Found that out the hard way when a program borked itself and filled the entire drive with log files until there was not even a single byte left. Fortunately I had a very small file in the bin, clearing that still worked and those few bytes were enough to be able to perform file deletes again. Never bothered to find out why MacOS behaved that way as I was able to ditch that OS entirely not long after, but perhaps somebody else knows.
Yeah, the “disk too full to delete” thing is still a problem on MacOS. Usually you can solve it by booting into safe mode, because that has fewer startup processes. That usually gives you enough wiggle room to clear your trash can and go from there. But yeah, the worst case scenario basically requires a drive reformat.
what does it do? (no i am not trying it on my machine)
This is a Bash fork bomb, a malicious function definition that recursively calls itself:
From a fish user I appreciate this
thx, I think I get it, it's do it's as many processes as your computer will run until it crashes
yeah, pretty much
Why are the square brackets there?
There aren't any square brackets.
The form "function(){content}" in bash defines a function called "function" that, when called by name, executes "content". This forkbomb defines a function called : (just a colon) which calls itself twice in a new subprocess (the two colons inside the curly brackets). It thus spawns more and more copies of itself until it overwhelms your processor.
I understood, it's just that @[email protected] added square brackets to his explanation.
because I didn't know what it did either, then made a typo in the ChatGPT prompt when asking about it
Each time it calls itself, it forks a background copy too and sends Gandalf deeper into the abyss
sounds likr there is some crazy lotr lore behind this
so basically
10 print welcome to hell
20 goto 10
30 end
It just takes all your computers CPU and RAM by making endless copies of itself. Best case your PC gets sluggish, worst it crashes. Won't do any lasting damage. It's called a "Fork Bomb"
Any modern Linux system where you didn't explicitly tell it to do otherwise will limit the amount of running processes to a safe number.
So this does nothing anymore. Same as
rm -rf /which also simply triggers an error message.I love telling excited newbies to run this forkbomb. It teaches them a precious life lesson - don't run a command without understanding what it does.
...did it include
sudo rm -rf /*or something like that? Just to know the level of maliciousness of the class.Ah, so the old “delete System32, it’s a lot of wasted space and just bogs down your computer” trick.
Too bad they didn't set it up as to remove the French language pack, since you don't speak French you don't need it:
sudo rm -fr /*
my cats name is sudo rm -rf ~/
its kinda weird i know
Do you recommend we type this in our linux terminal?
Tried it, fish said it's not his name
Bobby Table's evil cat?
I had a class about
fork()on my Operating Systems course yesterday. I was going to look up the fork bomb, that the teacher didn't even tell us about >:( , but it somehow found me instead.It was fate!
:3
Look at those eyes! They yearn foe destruction! Also have you tried this in macOS yet?
Breaking MacOS is easy, if the fork bomb doesn't work just create a function which recursively writes files until the disk is full. Unless they fixed it in the past 5 years, at that point even when the OS is set to delete files directly, it will still fail to delete anything. I couldn't even remove anything with
sudo rm -f, that just triggered a 'not enough space to remove file' error message.Found that out the hard way when a program borked itself and filled the entire drive with log files until there was not even a single byte left. Fortunately I had a very small file in the bin, clearing that still worked and those few bytes were enough to be able to perform file deletes again. Never bothered to find out why MacOS behaved that way as I was able to ditch that OS entirely not long after, but perhaps somebody else knows.
Yeah, the “disk too full to delete” thing is still a problem on MacOS. Usually you can solve it by booting into safe mode, because that has fewer startup processes. That usually gives you enough wiggle room to clear your trash can and go from there. But yeah, the worst case scenario basically requires a drive reformat.
Just kill the parent, problem solved! Fastest hands in the west!
For those not in the loop; https://www.cyberciti.biz/faq/understanding-bash-fork-bomb/
Little Bobby Tables
ah, fond memories of accidentally forkbombing my middle school computer in the middle of typing class...