I'm trying to make a php script that, when accessed, sends some data to the user, closes the connection, but keeps running after the connection is closed.

Basically, the same thing as "exit", except that the page keeps running on the server after it's called.

I can't find any command for this, is it even possible?

What you need to use is the reguster_shutdown_function() function. This will let you register a function that will be run when PHP "shuts down".

It's not working, the connection isn't closed until after the function registered is finished running....