I saw this command somewhere: :(){ :|:& } (fork bomb). How does it work?
First of all -- and this is important -- please do not run this command. I've actually omitted the trigger from the question above, and left only the part that sets up the function.
Here is that part, but written out in normal shell coding style, rather than rammed all together:
{{{:() {
: | : &
} }}}
What this does is create a function named : which calls itself recursively. Twice. In the background. Since the function keeps calling itself over and over (forking new processes), forever, this quickly consumes a lot of system resources. That's why it's called a "fork bomb".
If you still don't see how it works, here is an equivalent, which creates a function named bomb instead of :
{{{bomb() {
bomb | bomb &
} }}}