The rprint utility establishes a bidirectional raw tcp connection
to a network printer, usually on port 9100. In case of PostScript(TM)
printers, rprint may be directed to query the printer for accounting
and printer status information.

Although rprint can be used interactively, too, it is normally be
invoked by an lpd input filter program.

- Konrad Heuer
kheuer@gwdu60.gwdg.de