Run external program in background

[eluser]eroy4u[/eluser]
[quote author="TheFuzzy0ne" date="1209594896"]For Winblows-based systems, I believe appending /B to the end of the command should do it. Please bear in mind that in both cases (using & or /B), you're code won't be portable.

What do you mean by "new thread"? PHP works on a single thread. Are you looking for a way to keep the PHP thread open, but disconnect the script from the browser, so the PHP script keeps running and can do stuff when the process finishes, but the user doesn't end up having to stay on the same constantly loading page for 30 minutes?[/quote]
Yes it is what i mean. Is it possible?