Force download file inside zip archive

Thanks @mwhitney. I figured out that the native php ziparchive library has the correct methods to do the job.

PHP Code:

$unzipfolder = 'media/unzipped/' . $userid;
$zf = 'example.zip';
chmod($zf,0777);
$zip = new ZipArchive;
if ($zip->open($zf) === TRUE) {
 $zip->extractTo($unzipfolder . '/');
 $zip->close();
 $z_content = directory_map($unzipfolder);
} 


In this example, I have a zip-archive called example.zip.
I'm creating a new zip object.
If this can successfully open the zipfile, it unzips (extractTo) the zipfile to a specified folder.
With the directory helper I can read the contents of that folder.