filter that inserts printer specific commands into print jobs

 ppdfilt is a filter program designed to be used within a filter
 script or from the command line tool to insert printer specific
 commands to a PostScript print job. This can be used to tell the printer
 to duplex or staple the print job, or tell it what paper tray to draw
 paper from. In the GNULpr printing environment, users do not call ppdfilt
 directly, but its features are accessed by using 'lpr' or 'gpr' (see)