In groff, the page dimensions for the formatter GNU troff
and for output devices are handled separately. See Page Layout, for
vertical manipulation of the page size, and See Line Layout, for
horizontal changes.
The papersize macro package, normally loaded by troffrc at
startup, provides an interface for configuring page dimensions by
convenient names, like ‘letter’ or ‘a4’; see
groff_tmac(5). The default used by the formatter depends on
its build configuration, but is usually one of the foregoing, as
geographically appropriate.
It is up to each macro package to respect the page dimensions configured in this way.
For each output device, the size of the output medium can be set in its
DESC file. Most output drivers also recognize a command-line
option -p to override the default dimensions and an option
-l to use landscape orientation. See DESC File Format, for
a description of the papersize keyword, which takes an argument
of the same form as -p. The output driver’s man page, such as
grops(1), may also be helpful.
groff uses the command-line option -P to pass options to
postprocessors; for example, use the following for PostScript output on
A4 paper in landscape orientation.
groff -Tps -dpaper=a4l -P-pa4 -P-l -ms foo.ms > foo.ps