Question

I intend to write N-queens solution to a file in PHP. As the time elapsed for large N is so long, I want to place PHP code on the server, and then request for that page. Is it possible that when I close the tab in the browser, the server keep calculating and write to a file to fulfil my request ? Then later on I would check the file to see the results. If not possible, any suggestions for this problem is appreciated.

Answer 1

You can use a combination of ignore_user_abort and set_time_limit:

ignore_user_abort(true); // continue to run after client disconnects
set_time_limit(0); // infinite time limit

Rather than an infinite time limit, you could estimate the number of seconds the script will need and pad more time on to it. That way the script won’t have a chance to hang the process.