How to reverse pages order of Postscript files ?

.ps documentation files from public ftp sites and, if included with Panther is very helpful to convert them into PDF files, pages are in reverse order. Is there a trick to get back the pages in natural order ?
I downloaded some interesting
psutils available from the DarwinPort (port install psutils in contains a tool named pstops which allows most PS files to be converted, at the condition that the PS file respects the Adobe Document Structuring Conventions. (that's often the case if it was generated by an Adobe-compatible Printer Driver).
Once you have installed
psutils, you can reverse the page order of a PS file with:
pstops 1:-0 and open -a Preview will give you the expected PDF version.
man pstops (after installing it of course) for more information about options: pstops can do much more than just reversing page order !
NB Another interesting link related to PDF processing is
Often PS files are generated from printer drivers in reverse order so that after being physically printed, you don't have to manually change the order of the pages.
Of course, when converting into PDF you would like to reverse the pages again to get back the original page order.
There is no way to do that from because the "reverse page order" checkbox is not taken into account when saving the file as a PDF using the print dialog.
But a set of tools named