This document describes the groff program, the main front-end for the
groff document formatting system. The groff program and macro suite
is the implementation of a roff(7) system within the free software
collection GNU ⟨http://www.gnu.org⟩. The groff system has all fea‐
tures of the classical roff, but adds many extensions.
The groff program allows to control the whole groff system by command
line options. This is a great simplification in comparison to the
classical case (which uses pipes only).
The command line is parsed according to the usual GNU convention.
The whitespace between a command line option and its argument is
optional. Options can be grouped behind a single ‘-’ (minus
character). A filename of - (minus character) denotes the standard
As groff is a wrapper program for troff both programs share a set of
options. But the groff program has some additional, native options
and gives a new meaning to some troff options. On the other hand,
not all troff options can be fed into groff.
Native groff Options
The following options either do not exist for troff or are
differently interpreted by groff.
-D arg Set default input encoding used by preconv to arg. Implies
-e Preprocess with eqn.
-g Preprocess with grn.
-G Preprocess with grap. Implies -p.
-h--help Print a help message.
-I dir This option may be used to specify a directory to search for
files (both those on the command line and those named in .psbb
and .so requests, and \X'ps: import' and \X'ps: file'
escapes). The current directory is always searched first.
This option may be specified more than once; the directories
are searched in the order specified. No directory search is
performed for files specified using an absolute path. This
option implies the -s option.
-j Preprocess with chem. Implies -p.
-k Preprocess with preconv. This is run before any other
preprocessor. Please refer to preconv's manual page for its
behaviour if no -K (or -D) option is specified.
-K arg Set input encoding used by preconv to arg. Implies -k.
-l Send the output to a spooler program for printing. The
command that should be used for this is specified by the print
command in the device description file, see groff_font(5). If
this command is not present, the output is piped into the
lpr(1) program by default. See options -L and -X.
-L arg Pass arg to the spooler program. Several arguments should be
passed with a separate -L option each. Note that groff does
not prepend ‘-’ (a minus sign) to arg before passing it to the
-N Don't allow newlines within eqn delimiters. This is the same
as the -N option in eqn.
-p Preprocess with pic.
-P -option-P -option-P arg
Pass -option or -option arg to the postprocessor. The option
must be specified with the necessary preceding minus sign(s)
‘-’ or ‘--’ because groff does not prepend any dashes before
passing it to the postprocessor. For example, to pass a title
to the gxditview postprocessor, the shell command
groff -X -P -title -P 'groff it' foo
is equivalent to
groff -X -Z foo | gxditview -title 'groff it' -
-R Preprocess with refer. No mechanism is provided for passing
arguments to refer because most refer options have equivalent
language elements that can be specified within the document.
See refer(1) for more details.
-s Preprocess with soelim.
-S Safer mode. Pass the -S option to pic and disable the follow‐
ing troff requests: .open, .opena, .pso, .sy, and .pi. For
security reasons, safer mode is enabled by default.
-t Preprocess with tbl.
-T dev Set output device to dev. For this device, troff generates
the intermediate output; see groff_out(5). Then groff calls a
postprocessor to convert troff's intermediate output to its
final format. Real devices in groff are
dvi TeX DVI format (postprocessor is grodvi).
xhtml HTML and XHTML output (preprocessors are soelim
and pre-grohtml, postprocessor is post-grohtml).
lbp Canon CAPSL printers (LBP-4 and LBP-8 series
laser printers; postprocessor is grolbp).
lj4 HP LaserJet4 compatible (or other PCL5 compati‐
ble) printers (postprocessor is grolj4).
ps PostScript output (postprocessor is grops).
pdf Portable Document Format (PDF) output (postpro‐
cessor is gropdf).
For the following TTY output devices (postprocessor is always
grotty), -T selects the output encoding:
ascii 7bit ASCII.
cp1047 Latin-1 character set for EBCDIC hosts.
latin1 ISO 8859-1.
utf8 Unicode character set in UTF-8 encoding. This
mode has the most useful fonts for TTY mode, so
it is the best mode for TTY output.
The following arguments select gxditview as the ‘postproces‐
sor’ (it is rather a viewing program):
X75 75dpi resolution, 10pt document base font.
X75-12 75dpi resolution, 12pt document base font.
X100 100dpi resolution, 10pt document base font.
100dpi resolution, 12pt document base font.
The default device is ps.
-U Unsafe mode. Reverts to the (old) unsafe behaviour; see
Output version information of groff and of all programs that
are run by it; that is, the given command line is parsed in
the usual way, passing -v to all subprograms.
-V Output the pipeline that would be run by groff (as a wrapper
program) on the standard output, but do not execute it. If
given more than once, the commands are both printed on the
standard error and run.
-X Use gxditview instead of using the usual postprocessor to
(pre)view a document. The printing spooler behavior as out‐
lined with options -l and -L is carried over to gxditview(1)
by determining an argument for the -printCommand option of
gxditview(1). This sets the default Print action and the cor‐
responding menu entry to that value. -X only produces good
results with -Tps, -TX75, -TX75-12, -TX100, and -TX100-12.
The default resolution for previewing -Tps output is 75dpi;
this can be changed by passing the -resolution option to
gxditview, for example
groff -X -P-resolution -P100 -man foo.1
-z Suppress output generated by troff. Only error messages are
-Z Do not automatically postprocess groff intermediate output in
the usual manner. This will cause the troff output to appear
on standard output, replacing the usual postprocessor output;
The following options are transparently handed over to the formatter
program troff that is called by groff subsequently. These options
are described in more detail in troff(1).
-a ASCII approximation of output.
-b Backtrace on error or warning.
-c Disable color output. Please consult the grotty(1) man page
for more details.
-C Enable compatibility mode.
-d cs-d name=s
-E Disable troff error messages.
-f fam Set default font family.
-F dir Set path for font DESC files.
-i Process standard input after the specified input files.
Include macro file name.tmac (or tmac.name); see also
-M dir Path for macro files.
-n num Number the first page num.
Output only pages in list.
-r cn-r name=n
Set number register.
Enable warning name. See troff(1) for names.
disable warning name. See troff(1) for names.
The groff system implements the infrastructure of classical roff; see
roff(7) for a survey on how a roff system works in general. Due to
the front-end programs available within the groff system, using groff
is much easier than classical roff. This section gives an overview
of the parts that constitute the groff system. It complements
roff(7) with groff-specific features. This section can be regarded
as a guide to the documentation around the groff system.
The virtual paper size used by troff to format the input is
controlled globally with the requests .po, .pl, and .ll. See
groff_tmac(5) for the ‘papersize’ macro package which provides a
The physical paper size, giving the actual dimensions of the paper
sheets, is controlled by output devices like grops with the command
line options -p and -l. See groff_font(5) and the man pages of the
output devices for more details. groff uses the command line option
-P to pass options to output devices; for example, the following
selects A4 paper in landscape orientation for the PS device:
groff -Tps -P-pa4 -P-l ...
The groff program is a wrapper around the troff(1) program. It
allows to specify the preprocessors by command line options and auto‐
matically runs the postprocessor that is appropriate for the selected
device. Doing so, the sometimes tedious piping mechanism of classi‐
cal roff(7) can be avoided.
The grog(1) program can be used for guessing the correct groff com‐
mand line to format a file.
The groffer(1) program is an allround-viewer for groff files and man
The groff preprocessors are reimplementations of the classical pre‐
processors with moderate extensions. The standard preprocessors dis‐
tributed with the groff package are
eqn(1) for mathematical formulae,
grn(1) for including gremlin(1) pictures,
pic(1) for drawing diagrams,
for chemical structure diagrams,
for bibliographic references,
for including macro files from standard locations,
tbl(1) for tables.
A new preprocessor not available in classical troff is preconv(1)
which converts various input encodings to something groff can under‐
stand. It is always run first before any other preprocessor.
Besides these, there are some internal preprocessors that are auto‐
matically run with some devices. These aren't visible to the user.
Macro packages can be included by option -m. The groff system imple‐
ments and extends all classical macro packages in a compatible way
and adds some packages of its own. Actually, the following macro
packages come with groff:
man The traditional man page format; see groff_man(7). It can be
specified on the command line as -man or -m man.
mandoc The general package for man pages; it automatically recognizes
whether the documents uses the man or the mdoc format and
branches to the corresponding macro package. It can be speci‐
fied on the command line as -mandoc or -m mandoc.
mdoc The BSD-style man page format; see groff_mdoc(7). It can be
specified on the command line as -mdoc or -m mdoc.
me The classical me document format; see groff_me(7). It can be
specified on the command line as -me or -m me.
mm The classical mm document format; see groff_mm(7). It can be
specified on the command line as -mm or -m mm.
ms The classical ms document format; see groff_ms(7). It can be
specified on the command line as -ms or -m ms.
www HTML-like macros for inclusion in arbitrary groff documents;
Details on the naming of macro files and their placement can be found
in groff_tmac(5); this man page also documents some other, minor aux‐
iliary macro packages not mentioned here.
General concepts common to all roff programming languages are
described in roff(7).
The groff extensions to the classical troff language are documented
The groff language as a whole is described in the (still incomplete)
groff info file; a short (but complete) reference can be found in
The central roff formatter within the groff system is troff(1). It
provides the features of both the classical troff and nroff, as well
as the groff extensions. The command line option -C switches troff
into compatibility mode which tries to emulate classical roff as much
There is a shell script nroff(1) that emulates the behavior of clas‐
sical nroff. It tries to automatically select the proper output
encoding, according to the current locale.
The formatter program generates intermediate output; see
In roff, the output targets are called devices. A device can be a
piece of hardware, e.g., a printer, or a software file format. A
device is specified by the option -T. The groff devices are as fol‐
ascii Text output using the ascii(7) character set.
cp1047 Text output using the EBCDIC code page IBM cp1047 (e.g.,
dvi TeX DVI format.
html HTML output.
latin1 Text output using the ISO Latin-1 (ISO 8859-1) character set;
lbp Output for Canon CAPSL printers (LBP-4 and LBP-8 series laser
lj4 HP LaserJet4-compatible (or other PCL5-compatible) printers.
ps PostScript output; suitable for printers and previewers like
pdf PDF files; suitable for viewing with tools such as evince(1)
utf8 Text output using the Unicode (ISO 10646) character set with
UTF-8 encoding; see unicode(7).
xhtml XHTML output.
X75 75dpi X Window System output suitable for the previewers
xditview(1x) and gxditview(1). A variant for a 12pt document
base font is X75-12.
X100 100dpi X Window System output suitable for the previewers
xditview(1x) and gxditview(1). A variant for a 12pt document
base font is X100-12.
The postprocessor to be used for a device is specified by the postpro
command in the device description file; see groff_font(5). This can
be overridden with the -X option.
The default device is ps.
Postprocessorsgroff provides 3 hardware postprocessors:
for some Canon printers,
for printers compatible to the HP LaserJet 4 and PCL5,
for text output using various encodings, e.g., on text-ori‐
ented terminals or line-printers.
Today, most printing or drawing hardware is handled by the operating
system, by device drivers, or by software interfaces, usually accept‐
ing PostScript. Consequently, there isn't an urgent need for more
hardware device postprocessors.
The groff software devices for conversion into other document file
for the DVI format,
for HTML and XHTML formats,
Combined with the many existing free conversion tools this should be
sufficient to convert a troff document into virtually any existing
The following utility programs around groff are available.
Add information to troff font description files for use with
Create font description files for PostScript device.
Convert an eqn image into a cropped image.
Mark differences between groff, nroff, or troff files.
Convert a grap diagram into a cropped bitmap image.
General viewer program for groff files and man pages.
The groff X viewer, the GNU version of xditview.
Create font description files for lj4 device.
Make inverted index for bibliographic databases.
Search bibliographic databases.
Interactively search bibliographic databases.
Create PDF documents using groff.
Translate a PostScript font in .pfb format to ASCII.
Convert a pic diagram into a cropped image.
Create font description files for TeX DVI device.
roff viewer distributed with X window.
Convert X font metrics into GNU troff font metrics.
Normally, the path separator in the following environment variables
is the colon; this may vary depending on the operating system. For
example, DOS and Windows use a semicolon instead.
This search path, followed by $PATH, is used for commands that
are executed by groff. If it is not set then the directory
where the groff binaries were installed is prepended to PATH.
When there is a need to run different roff implementations at
the same time groff provides the facility to prepend a prefix
to most of its programs that could provoke name clashings at
run time (default is to have none). Historically, this prefix
was the character g, but it can be anything. For example,
gtroff stood for groff's troff, gtbl for the groff version of
tbl. By setting GROFF_COMMAND_PREFIX to different values, the
different roff installations can be addressed. More exactly,
if it is set to prefix xxx then groff as a wrapper program
internally calls xxxtroff instead of troff. This also applies
to the preprocessors eqn, grn, pic, refer, tbl, soelim, and to
the utilities indxbib and lookbib. This feature does not
apply to any programs different from the ones above (most
notably groff itself) since they are unique to the groff
The value of this environment value is passed to the preconv
preprocessor to select the encoding of input files. Setting
this option implies groff's command line option -k (this is,
groff actually always calls preconv). If set without a value,
groff calls preconv without arguments. An explicit -K command
line option overrides the value of GROFF_ENCODING. See
preconv(1) for details.
A list of directories in which to search for the devname
directory in addition to the default ones. See troff(1) and
groff_font(5) for more details.
A list of directories in which to search for macro files in
addition to the default directories. See troff(1) and
groff_tmac(5) for more details.
The directory in which temporary files are created. If this
is not set but the environment variable TMPDIR instead,
temporary files are created in the directory $TMPDIR. On MS-
DOS and Windows 32 platforms, the environment variables TMP
and TEMP (in that order) are searched also, after GROFF_TMPDIR
and TMPDIR. Otherwise, temporary files are created in /tmp.
The refer(1), groffer(1), grohtml(1), and grops(1) commands
use temporary files.
Preset the default device. If this is not set the ps device
is used as default. This device name is overwritten by the
The following example illustrates the power of the groff program as a
wrapper around troff.
To process a roff file using the preprocessors tbl and pic and the me
macro set, classical troff had to be called by
pic foo.me | tbl | troff -me -Tlatin1 | grotty
Using groff, this pipe can be shortened to the equivalent command
groff -p -t -me -T latin1 foo.me
An even easier way to call this is to use grog(1) to guess the pre‐
processor and macro options and execute the generated command (by
using backquotes to specify shell command substitution)
`grog -Tlatin1 foo.me`
The simplest way is to view the contents in an automated way by call‐
On EBCDIC hosts (e.g., OS/390 Unix), output devices ascii and latin1
aren't available. Similarly, output for EBCDIC code page cp1047 is
not available on ASCII based operating systems.
Report bugs to the groff mailing list ⟨firstname.lastname@example.org⟩. Include a
complete, self-contained example that allows the bug to be repro‐
duced, and say which version of groff you are using.
There are some directories in which groff installs all of its data
files. Due to different installation habits on different operating
systems, their locations are not absolutely fixed, but their function
is clearly defined and coincides on all systems.
Collection of Installation Directories
This section describes the position of all files of the groff package
after the installation — got from Makefile.comm at the top of the
groff source package.
index directory and index name
legacy font directory
directory for binary programs
system tmac directory
directory for examples
documentation directory for html files
documentation directory for pdf files
file for common words
directory for fonts
directory for old fonts
mm tmac directory
local font directory
local tmac directory
groff Macro Directory
This contains all information related to macro packages. Note that
more than a single directory is searched for those files as
documented in groff_tmac(5). For the groff installation
corresponding to this document, it is located at
/usr/local/share/groff/1.22.3/tmac. The following files contained in
the groff macro directory have a special meaning:
Initialization file for troff. This is interpreted by troff
before reading the macro sets and any input.
Final startup file for troff. It is parsed after all macro
sets have been read.
Macro file for macro package name.
groff Font Directory
This contains all information related to output devices. Note that
more than a single directory is searched for those files; see
troff(1). For the groff installation corresponding to this document,
it is located at /usr/local/share/groff/1.22.3/font. The following
files contained in the groff font directory have a special meaning:
Device description file for device name, see groff_font(5).
Font file for font F of device name.
Information on how to get groff and related information is available
at the groff GNU website ⟨http://www.gnu.org/software/groff⟩.
Three groff mailing lists are available:
for reporting bugs ⟨email@example.com⟩.
for general discussion of groff, ⟨firstname.lastname@example.org⟩.
the groff commit list ⟨email@example.com⟩, a read-only
list showing logs of commitments to the groff repository.
Details on repository access and much more can be found in the file
README at the top directory of the groff source package.
There is a free implementation of the grap preprocessor, written by
Ted Faber ⟨firstname.lastname@example.org⟩. The actual version can be found at
the grap website
⟨http://www.lunabase.org/~faber/Vault/software/grap/⟩. This is the
only grap version supported by groff.
This document is based on the original groff man page written by
James Clark ⟨email@example.com⟩. It was rewritten, enhanced, and put
under the FDL license by Bernd Warken <firstname.lastname@example.org>.
It is maintained by Werner Lemberg ⟨email@example.com⟩.
This page is part of the groff (GNU troff) project. Information
about the project can be found at
⟨http://www.gnu.org/software/groff/⟩. If you have a bug report for
this manual page, see ⟨http://www.gnu.org/software/groff/⟩. This
page was obtained from the tarball groff-1.22.3.tar.gz fetched from
⟨ftp://ftp.gnu.org/gnu/groff/⟩ on 2017-03-13. If you discover any
rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
Groff Version 1.22.3 4 November 2014 GROFF(1)