Manipulate an Archive in memory with PHP (without creating a temporary file on disk)

Question

I am trying to generate an archive on-the-fly in PHP and send it to the user immediately (without saving it). I figured that there would be no need to create a file on disk

Answer 1

You need to use ZipArchive::addFromString - if you use addFile() the file is not actually added until you go to close it. (Horrible bug IMHO, what if you are trying to move files into a zip and you delete them before you close the zip...)
The addFromString() method adds it to the archive immediately.