How can I execute remaining php code after calling "exit"?

Question

How can a client send a request to a server just to trigger an execution, where the server immediately sends a response then executes the requested code? Similar to this:

echo 'the execution is starting';
exit;
execution_function(); // <--- is it possible to this function being executed after exit 

I want the response to be immediate so the client can do other things while the server executes the request.

Answer 1

Thanks to this question I figured out the way to insert and execute code at the end of script. Usefull when you're debugging a website.

function shutdown($var){
    echo '<pre>';
    var_export($var);
    echo '</pre>';
}
// pass get_included_files()
register_shutdown_function('shutdown',get_included_files());
// or something else
register_shutdown_function('shutdown',get_defined_vars());

note: shutdown is executed after script execution finishes or exit() is called.