"grep" username in samba or grep file owner?

[overlord]

hello forum,
I have a samba-pdf-printer.
so far so good.further have a script that calls ps2pdf to create a .pdf in PDF-Share named a few date+time parameters.
my goal is to append the username who makes the .pdf!
the shell command "logname" does not work,because samba access is via user "nobody"

so my 2 ideas:
1) log the samba-user who creates the pdf-file and grep the username
or
2) look for the owner of the pdf-file in the directory and append this username to the filename

does anybody have any (other) better ideas or corrections?
how to do? any help welcome!

greetz