Bash fork bomb syntax meaning

[pgymjp]

Not that I want to actually do this, but what exactly does

:\(){ :\|:& };:

*do* to kick off a fork bomb? Just trying to better understand. I've escaped out a couple characters to prevent them from resolving as smiley faces in my post, but you get the idea of what I'm asking.

Thanks,
Jeff

[bigtomrodney]

I don't think those backslashes should be there,they're just escape characters.

The colon is an alias for the true command. This is creating a function that splits off and runs itself again. By running asynchronously it continues to multiply at a geometric rate until all of the capacity of the machine is consumed. In modern systems this is prevented through use of ulimit which limits how many processes a user can have.

[smolloy]

:(){};

Means that you're defining a function, and the function definition is between the curly braces.

The function definition,

:|:&

, means that the function first calls itself, and then passes the output to another version of itself, which is then backgrounded (that's what the & does).

After the function definition, the function is then called by using it's name, :.

The following,

forkbomb(){forkbomb|forkbomb&}; forkbomb

would do the same thing except I've called the function "forkbomb", instead of the much harder to read ":".

[greogory]

Thanks. Really works great when run by root. Now I have to break out the big hammer to get my AIX box back.