Can PHP tell when the browser goes away?

Question

If I'm generating a stream of data to send out to a browser, and the user closes the browser, can I tell within PHP that I don't need to bother generating or sending the rest of the stream? I'd like to insert something into this loop:

while (!feof($pipes[1])) {
   echo fgets($pipes[1]);
}

My fallback plan is to have the browser use a JavaScript onunload to hit another PHP page to kill the process that's generating the data, but it would be cleaner if PHP could tell when I'm echoing to nowhere.

Answer 1

By default PHP will abort the script if the user navigates away. There are however times where you don't want this to happen so php has a config you set called ignore_user_abort.
http://php.net/manual/en/misc.configuration.php