Using Emacs as PS converter

[Angelo Graziosi <angelo.graziosi@alice.it>]

Out of curiosity, I wonder if one can use Emacs as a postscript 
converter.. Suppose I have a file foo.txt. If I visit it and the

   M-x ps-spool-buffer-with-faces

the result is in a *PostScript* buffer that I can save as foo.ps.

But what if one wants use that from command line o shell script?

I have tried this:

$ emacs --batch foo.txt -f ps-spool-buffer-with-faces --visit 
\*PostScript\* -f save-buffer

Formatting...  0%
Collecting face information...
Formatting...100%
Formatting...done
Wrote /home/angelo/work/*PostScript*


but '*PostScript*' is saved empty...

$ ls -lrt
...
... 0  1 dic 15.54 *PostScript*


Where is the error?

TIA,
  Angelo.