[RESOLVED] Does a PHP script stop running when you leave a page?

I've been asked to check through a list of websites to make sure they are Wordpress blogs. I work for a company that hosts blog networks you see.

There's a little over 2000 blogs we have in our database. Instead of running through the list manually I thought I would create a simple PHP script that lists all the websites that are no longer Wordpress blogs. I made it look for the string '<meta name="generator" content="WordPress' to check if it's a Wordpress blog or not.

That was all good until I received a "Maximum execution time of 30 seconds exceeded" error.

I have full server access. I did look into set_time_limit(0) function. But I was worried that the script could continue running for days, especially if our clients use slow hosts. This would clog up the server, especially if this script was run a few times only my Employer, a co-worker and I will be executing it, but if we all execute it 6 times, well it's a clog-up!

So here's my questions;

Will this script continue running for a few days, even if you close the window (Disconnect from the server etc), or will Apache stop it when it detects you are no longer connected?
I'm not even sure if the server will allow the set_time_limit function to be executed (Cause I'm pretty sure it would be running in safe mode), so any alternative to this would also be appreciated?

Thanks :).