Execute luacode after \end{document} to rename pdf file after creation

Question

I'm using toggle switches to create different outputs with a single tex-file. However my output PDF is always named after the producing tex-file e.g. luaexample.tex produces luaexample.pdf.

Along with the toggles I now want to create a variable

\def\fileID{Z} 

which should be appended to the filename, to get e.g. luaexampleZ.pdf.

I thought using lua would be a create option to do so, and indeed the following almost works:

\documentclass{article}
\usepackage{luacode}

\def\fileID{Z}

\begin{document}
A random number:
\begin{luacode}
tex.print(math.random())
\end{luacode}

\begin{luacode}
   os.remove("\jobname\fileID.pdf")
   os.rename("\jobname.pdf", "\jobname\fileID.pdf")
\end{luacode}

\end{document}

---

But the PDF due to rename is created after \end{document} but the lua code section appears before. If I compile the document twice, it works, but the firstly compiled PDF is renamed. I'd like to avoid this double compilation.

If I put the lua code after \end{document} it is not executed.

So, how can I execute lua code or in general latex code after \end{document}?

Answer 1

I think you can use the stop_run callback:

\documentclass{article}


\def\fileID{Z}

\begin{document}
A random number:


\directlua{
luatexbase.add_to_callback(
'stop_run',
function ()
 texio.write_nl("renaming output to " ..  "\jobname" .. "\fileID.pdf")
  os.rename("\jobname" .. ".pdf", "\jobname" .. "\fileID.pdf")
end,
"renamepdf"
)
}





\end{document}