ditroff(7) - man - phpMan

DITROFF(7)                        Miscellaneous Information Manual                        DITROFF(7)



NAME
       ditroff - classical device-independent roff

DESCRIPTION
       The name ditroff refers to a historical development stage of the roff(7) text processing sys‐
       tem.  In roff systems extant today, the name troff is a synonym for ditroff.

       Early versions of roff by Joe Ossanna generated two programs from  the  same  sources,  using
       conditional  compilation to distinguish them.  nroff produced text-oriented TTY output, while
       troff generated graphical output for exactly one output device, the Wang Graphic Systems  CAT
       phototypesetter.

       In  1979,  Brian  Kernighan rewrote troff to support more devices by creating an intermediate
       output format for troff that could be fed into postprocessor programs which actually  do  the
       printout  on the device.  Kernighan's version marks what is known as “classical troff” today.
       In order to distinguish it from Ossanna's original version, it was called ditroff (device in‐
       dependent  troff)  on some systems, though this naming isn't mentioned in the classical docu‐
       mentation.

       Today, all existing roff systems are based on Kernighan's multi-device troff.   The  distinc‐
       tion  between  troff  and ditroff is no longer necessary; each modern troff provides the com‐
       plete functionality of ditroff.

       The easiest way to use ditroff is via the GNU roff system, groff.  The groff(1) program is  a
       wrapper around (di)troff that automatically handles device postprocessing.

AUTHORS
       This document was written by Bernd Warken ⟨groff-bernd.warken-72 AT web.de⟩.

SEE ALSO
       CSTR #54
              refers  to  the  1992  revision  of the Nroff/Troff User's Manual by J. F. Ossanna and
              Brian Kernighan.

       CSTR #97
              refers to A Typesetter-independent TROFF, by Brian Kernighan and is the original docu‐
              mentation of the first multi-device troff (ditroff).

       roff(7)
              provides a history and conceptual overview of roff systems.

       troff(1)
              describes the GNU implementation of (di)troff.

       groff(1)
              documents  the  GNU  roff program and includes pointers to further documentation about
              groff.

       groff_out(5)
              describes the groff version of the intermediate output language, the basis for  multi-
              device output.



groff 1.22.4                                23 March 2022                                 DITROFF(7)