How can I execute PHP code on page close?

Question

I am trying to find a method to execute some PHP code once a user closes the page. In my application, once the user closes or navigates away from the page the server will st

Answer 1

Simply set ignore_user_abort(true) then enter an infinite while loop of

    while (!connection_aborted()){
      // do nothing ...
    }

//after the while loop :
some_function_to_say_that_the_user_is_offline();

but be carefull , whenever the user navigates out of the page , the function WILL be executed .

EDIT : and the progress bar of the browser will be like "downloading ..." forever ...

Edit 2 : check also http://www.php.net/manual/en/function.register-shutdown-function.php