This may require a modified "quota" command that allows the httpd
server account to get quotas for other users... It requires that your
web server and user server be the same server or at least have shared
authentication and file servers (e.g. via NIS/NFS). And last, it (as
written) requires the posix php extensions.
If your quota command wraps the output onto two lines, then this module
will only work if you have a grep which supports the -A switch, and you
append an -A1 switch to your grep_path (e.g. '/bin/grep -A1').