groff - front-end for the groff document formatting system
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This document describes the groff
program, the main front-end for the
document formatting system. The groff
program and macro
suite is the implementation of a roff(7)
system within the free
software collection GNU
system has all features of the classical roff
adds many extensions.
program allows to control the whole groff
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 -
character) denotes the standard input.
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
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
- Preprocess with eqn.
- Preprocess with grn.
- Preprocess with grap. Implies -p.
- --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.
- Preprocess with chem. Implies -p.
- 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
- 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 spooler
- Don't allow newlines within eqn delimiters. This is the same as the
-N option in eqn.
- 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' -
- 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.
- Preprocess with soelim.
- Safer mode. Pass the -S option to pic and disable the
following troff requests: .open, .opena, .pso,
.sy, and .pi. For security reasons, safer mode is enabled by
- 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
- TeX DVI format (postprocessor is grodvi).
- xhtml HTML and XHTML output (preprocessors are soelim and
pre-grohtml, postprocessor is post-grohtml).
- Canon CAPSL printers (LBP-4 and LBP-8 series laser printers; postprocessor
- HP LaserJet4 compatible (or other PCL5 compatible) printers (postprocessor
- PostScript output (postprocessor is grops).
- Portable Document Format (PDF) output (postprocessor is
- For the following TTY output devices (postprocessor is always
grotty), -T selects the output encoding:
- 7bit ASCII.
- Latin-1 character set for EBCDIC hosts.
- ISO 8859-1.
- Unicode character set in UTF-8 encoding.
- The following arguments select gxditview as the `postprocessor' (it
is rather a viewing program):
- 75dpi resolution, 10pt document base font.
- 75dpi resolution, 12pt document base font.
- 100dpi resolution, 10pt document base font.
- 100dpi resolution, 12pt document base font.
- The default device is ps.
- Unsafe mode. Reverts to the (old) unsafe behaviour; see option
- --version 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.
- 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.
- Use gxditview instead of using the usual postprocessor to (pre)view
a document. The printing spooler behavior as outlined 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
corresponding 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
- Suppress output generated by troff. Only error messages are
- 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; see
The following options are transparently handed over to the formatter program
that is called by groff
subsequently. These options are
described in more detail in troff(1)
- ASCII approximation of output.
- Backtrace on error or warning.
- Disable color output. Please consult the grotty(1) man page for
- Enable compatibility mode.
- -d cs
- -d name=s Define string.
- Disable troff error messages.
- -f fam
- Set default font family.
- -F dir
- Set path for font DESC files.
- Process standard input after the specified input files.
- -m name
- Include macro file name.tmac (or tmac.name);
see also groff_tmac(5).
- -M dir
- Path for macro files.
- -n num
- Number the first page num.
- -o list
- Output only pages in list.
- -r cn
- -r name=n Set number register.
- -w name
- Enable warning name. See troff(1) for names.
- -W name
- disable warning name. See troff(1) for names.
The groff system
implements the infrastructure of classical roff; see
for a survey on how a roff
system works in general. Due
to the front-end programs available within the groff
is much easier than classical roff
. This section gives an
overview of the parts that constitute the groff
system. It complements
-specific features. This section can be
regarded as a guide to the documentation around the groff
paper size used by troff
to format the input is
controlled globally with the requests .po
, and .ll
for the `papersize' macro package which provides a
paper size, giving the actual dimensions of the paper
sheets, is controlled by output devices like grops
with the command
line options -p
. 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 ...
program is a wrapper around the troff(1)
allows to specify the preprocessors by command line options and automatically
runs the postprocessor that is appropriate for the selected device. Doing so,
the sometimes tedious piping mechanism of classical roff(7)
program can be used for guessing the correct groff
command line to format a file.
program is an allround-viewer for groff
preprocessors are reimplementations of the classical
preprocessors with moderate extensions. The standard preprocessors distributed
with the groff
- for mathematical formulæ,
- for including gremlin(1) pictures,
- for drawing diagrams,
- for chemical structure diagrams,
- for bibliographic references,
- for including macro files from standard locations,
- for tables.
A new preprocessor not available in classical troff
which converts various input encodings to something groff
understand. It is always run first before any other preprocessor.
Besides these, there are some internal preprocessors that are automatically run
with some devices. These aren't visible to the user.
Macro packages can be included by option -m
. The groff
implements and extends all classical macro packages in a compatible way and
adds some packages of its own. Actually, the following macro packages come
- The traditional man page format; see groff_man(7). It can be
specified on the command line as -man or -m man.
- 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 specified on the command line
as -mandoc or -m mandoc.
- The BSD-style man page format; see groff_mdoc(7). It can be
specified on the command line as -mdoc or
- The classical me document format; see groff_me(7). It can be
specified on the command line as -me or -m me.
- The classical mm document format; see groff_mm(7). It can be
specified on the command line as -mm or -m mm.
- The classical ms document format; see groff_ms(7). It can be
specified on the command line as -ms or -m ms.
- HTML-like macros for inclusion in arbitrary groff documents; see
Details on the naming of macro files and their placement can be found in
; this man page also documents some other, minor auxiliary
macro packages not mentioned here.
General concepts common to all roff
programming languages are described
extensions to the classical troff
documented in groff_diff(7)
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
. It provides the features of both the classical troff
, as well as the groff
extensions. The command line
into compatibility mode
tries to emulate classical roff
as much as possible.
There is a shell script nroff(1)
that emulates the behavior of classical
. It tries to automatically select the proper output encoding,
according to the current locale.
The formatter program generates intermediate output
, 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 follows.
- Text output using the ascii(7) character set.
- Text output using the EBCDIC code page IBM cp1047 (e.g., OS/390
- TeX DVI format.
- HTML output.
- Text output using the ISO Latin-1 (ISO 8859-1) character set; see
- Output for Canon CAPSL printers (LBP-4 and LBP-8 series laser
- HP LaserJet4-compatible (or other PCL5-compatible) printers.
- PostScript output; suitable for printers and previewers like
- PDF files; suitable for viewing with tools such as evince(1) and
- Text output using the Unicode (ISO 10646) character set with UTF-8
encoding; see unicode(7).
- XHTML output.
- 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.
- 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
The default device is ps
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-oriented terminals
Today, most printing or drawing hardware is handled by the operating system, by
device drivers, or by software interfaces, usually accepting PostScript.
Consequently, there isn't an urgent need for more hardware device
software devices for conversion into other document file
- for the DVI format,
- for HTML and XHTML formats,
- for PostScript.
- for PDF.
Combined with the many existing free conversion tools this should be sufficient
to convert a troff
document into virtually any existing data format.
The following utility programs around groff
- 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
- 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 package.
- 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
- 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 option -T.
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.
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
. For the groff
installation corresponding to this
document, it is located at /usr/share/groff/1.22.2/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.
- tmac.name 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
installation corresponding to this document, it is located at
. The following files contained in the
groff font directory
have a special meaning:
- Device description file for device name, see
- Font file for font F of device name.
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 the me
macro set, classical troff
had to be called by
pic foo.me | tbl | troff -me -Tlatin1 | grotty
, 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
preprocessor 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 calling
On EBCDIC hosts (e.g., OS/390 Unix), output devices ascii
aren't available. Similarly, output for EBCDIC code page
is not available on ASCII based operating systems.
Report bugs to the
groff maling list
Include a complete, self-contained example that allows
the bug to be reproduced, and say which version of groff
you are using.
Information on how to get groff
and related information is available at
The most recent released version of groff
mailing lists are available:
bugs for general
discussion of groff,
the groff commit
a read-only list showing logs of commitments to the CVS repository.
Details on CVS access and much more can be found in the file README
the top directory of the groff
There is a free implementation of the grap
preprocessor, written by
actual version can be found at the
This is the only grap version supported by groff
Copyright © 2011 Free Software Foundation, Inc.
This document is distributed under the terms of the FDL (GNU Free Documentation
License) version 1.3 or later. You should have received a copy of the FDL on
your system, it is also available on-line at the
This document is based on the original groff
man page written by
James Clark It was
rewritten, enhanced, and put under the FDL license by Bernd Warken
<email@example.com>. It is maintained by
is a GNU free software project. All parts of the groff
are protected by GNU copyleft licenses. The software files are
distributed under the terms of the GNU General Public License (GPL), while the
documentation files mostly use the GNU Free Documentation License (FDL).
The groff info file
contains all information on the groff
within a single document, providing many examples and background information.
on how to read it.
Due to its complex structure, the groff
system has many man pages. They
can be read with man(1)
- Introduction, history and further readings:
- Viewer for groff files:
- groffer(1), gxditview(1), xditview(1x).
- Wrapper programs for formatters:
- groff(1), grog(1).
- Roff preprocessors:
- eqn(1), grn(1), pic(1), chem(1),
preconv(1), refer(1), soelim(1), tbl(1),
- Roff language with the groff extensions:
- groff(7), groff_char(7), groff_diff(7),
- Roff formatter programs:
- nroff(1), troff(1), ditroff(7).
- The intermediate output language:
- Postprocessors for the output devices:
- grodvi(1), grohtml(1), grolbp(1), grolj4(1),
lj4_font(5), grops(1), gropdf(1),
- Groff macro packages and macro-specific utilities:
- groff_tmac(5), groff_man(7), groff_mdoc(7),
groff_me(7), groff_mm(7), groff_mmse(7) (only in
Swedish locales), groff_mom(7), groff_ms(7),
groff_www(7), groff_trace(7), mmroff(7).
- The following utilities are available:
- addftinfo(1), afmtodit(1), eqn2graph(1),
gdiffmk(1), grap2graph(1), groffer(1),
gxditview(1), hpftodit(1), indxbib(1),
lkbib(1), lookbib(1), pdfroff(1), pfbtops(1),
pic2graph(1), tfmtodit(1), xtotroff(1).