I know how to upload files, but I have a question. When uploading a file with PHP/Apache, does it automatically create a zero-filled file of that size, or does the size "grow" as the file is being uploaded?

I've searched long and hard for a good (and free) progress bar for multiple-file uploads (with no size limits), but I am also trying my own idea. And whether it works depends on the answer to the question...

It might be a kind of dirty solution but it should work.