groff(1) General Commands Manual groff(1)
Name
groff - front end to the GNU roff document formatting system
Synopsis
groff [-abcCeEgGijklNpRsStUVXzZ] [-d ctext] [-d string=text]
[-D fallback-encoding] [-f font-family] [-F font-directory]
[-I inclusion-directory] [-K input-encoding] [-L spooler-
argument] [-m macro-package] [-M macro-directory] [-n page-
number] [-o page-list] [-P postprocessor-argument] [-r cnumeric-
expression] [-r register=numeric-expression] [-T output-device]
[-w warning-category] [-W warning-category] [file ...]
groff -h
groff --help
groff -v [option ...] [file ...]
groff --version [option ...] [file ...]
Description
groff is the primary front end to the GNU roff document formatting sys-
tem. GNU roff is a typesetting system that reads plain text input
files that include formatting commands to produce output in PostScript,
PDF, HTML, DVI, or other formats, or for display to a terminal. For-
matting commands can be low-level typesetting primitives, macros from a
supplied package, or user-defined macros. All three approaches can be
combined. If no file operands are specified, or if file is “-”, groff
reads the standard input stream.
A reimplementation and extension of the typesetter from AT&T Unix,
groff is present on most POSIX systems owing to its long association
with Unix manuals (including man pages). It and its predecessor are
notable for their production of several best-selling software engineer-
ing texts. groff is capable of producing typographically sophisticated
documents while consuming minimal system resources.
The groff command orchestrates the execution of preprocessors, the
transformation of input documents into a device-independent page de-
scription language, and the production of output from that language.
Options
-h and --help display a usage message and exit.
Because groff is intended to subsume most users' direct invocations of
the ]8;;man:troff(1)\troff(1)]8;;\ formatter, the two programs share a set of options. How-
ever, groff has some options that troff does not share, and others
which groff interprets differently. At the same time, not all valid
troff options can be given to groff.
groff-specific options
The following options either do not exist in GNU troff or are inter-
preted differently by groff.
-D enc Set fallback input encoding used by ]8;;man:preconv(1)\preconv(1)]8;;\ to enc; implies
-k.
-e Run ]8;;man:eqn(1)\eqn(1)]8;;\ preprocessor.
-g Run ]8;;man:grn(1)\grn(1)]8;;\ preprocessor.
-G Run ]8;;man:grap(1)\grap(1)]8;;\ preprocessor; implies -p.
-I dir Works as troff's option (see below), but also implies -g and -s.
It is passed to ]8;;man:soelim(1)\soelim(1)]8;;\ and the output driver, and grn is
passed an -M option with dir as its argument.
-j Run ]8;;man:chem(1)\chem(1)]8;;\ preprocessor; implies -p.
-k Run ]8;;man:preconv(1)\preconv(1)]8;;\ preprocessor. Refer to its man page for its be-
havior if neither of groff's -K or -D options is also specified.
-K enc Set input encoding used by ]8;;man:preconv(1)\preconv(1)]8;;\ to enc; implies -k.
-l Send the output to a spooler program for printing. The “print”
directive in the device description file specifies the default
command to be used; see ]8;;man:groff_font(5)\groff_font(5)]8;;\. If no such directive is
present for the output device, output is piped to ]8;;man:lpr(1)\lpr(1)]8;;\. See
options -L and -X.
-L arg Pass arg to the print spooler program. If multiple args are re-
quired, pass each with a separate -L option. groff does not
prefix an option dash to arg before passing it to the spooler
program.
-M Works as troff's option (see below), but is also passed to
]8;;man:eqn(1)\eqn(1)]8;;\, ]8;;man:grap(1)\grap(1)]8;;\, and ]8;;man:grn(1)\grn(1)]8;;\.
-N Prohibit newlines between eqn delimiters: pass -N to ]8;;man:eqn(1)\eqn(1)]8;;\.
-p Run ]8;;man:pic(1)\pic(1)]8;;\ preprocessor.
-P arg Pass arg to the postprocessor. If multiple args are required,
pass each with a separate -P option. groff does not prefix an
option dash to arg before passing it to the postprocessor.
-R Run ]8;;man:refer(1)\refer(1)]8;;\ preprocessor. No mechanism is provided for passing
arguments to refer because most refer options have equivalent
language elements that can be specified within the document.
-s Run ]8;;man:soelim(1)\soelim(1)]8;;\ preprocessor.
-S Operate in “safer” mode; see -U below for its opposite. For se-
curity reasons, safer mode is enabled by default.
-t Run ]8;;man:tbl(1)\tbl(1)]8;;\ preprocessor.
-T dev Direct troff to format the input for the output device dev.
groff then calls an output driver to convert troff's output to a
form appropriate for dev; see subsection “Output devices” below.
-U Operate in unsafe mode: pass the -U option to pic and troff.
-v
--version
Write version information for groff and all programs run by it
to the standard output stream; that is, the given command line
is processed in the usual way, passing -v to the formatter and
any pre- or postprocessors invoked.
-V Output the pipeline that groff would run to the standard output
stream, but do not execute it. If given more than once, groff
both writes and runs the pipeline.
-X Use ]8;;man:gxditview(1)\gxditview(1)]8;;\ instead of the usual postprocessor to (pre)view
a document on an X11 display. Combining this option with -Tps
uses the font metrics of the PostScript device, whereas the
-TX75 and -TX100 options use the metrics of X11 fonts.
-Z Disable postprocessing. troff output will appear on the stan-
dard output stream (unless suppressed with -z); see ]8;;man:groff_out(5)\groff_out(5)]8;;\
for a description of this format.
Transparent options
The following options are passed as-is to the formatter program
]8;;man:troff(1)\troff(1)]8;;\ and described in more detail in its man page.
-a Generate a plain text approximation of the typeset output.
-b Write a backtrace to the standard error stream on each error or
warning.
-c Start with color output disabled.
-C Enable AT&T troff compatibility mode; implies -c.
-d cs
-d name=string
Define string.
-E Inhibit troff error messages; implies -Ww.
-f fam Set default font family.
-F dir Search in directory dir for the selected output device's direc-
tory of device and font description files.
-i Process standard input after the specified input files.
-I dir Search dir for input files.
-m name
Process name.tmac before input files.
-M dir Search directory dir for macro files.
-n num Number the first page num.
-o list
Output only pages in list.
-r cnumeric-expression
-r register=numeric-expression
Define register.
-w name
-W name
Enable (-w) or inhibit (-W) emission of warnings in category
name.
-z Suppress formatted device-independent output of troff.
Usage
The architecture of the GNU roff system follows that of other device-
independent roff implementations, comprising preprocessors, macro pack-
ages, output drivers (or “postprocessors”), a suite of utilities, and
the formatter troff at its heart. See ]8;;man:roff(7)\roff(7)]8;;\ for a survey of how a
roff system works.
The front end programs available in the GNU roff system make it easier
to use than traditional roffs that required the construction of
pipelines or use of temporary files to carry a source document from
maintainable form to device-ready output. The discussion below summa-
rizes the constituent parts of the GNU roff system. It complements
]8;;man:roff(7)\roff(7)]8;;\ with groff-specific information.
Getting started
Those who prefer to learn by experimenting or are desirous of rapid
feedback from the system may wish to start with a “Hello, world!” docu-
ment.
$ echo "Hello, world!" | groff -Tascii | sed '/^$/d'
Hello, world!
We used a sed command only to eliminate the 65 blank lines that would
otherwise flood the terminal screen. (roff systems were developed in
the days of paper-based terminals with 66 lines to a page.)
Today's users may prefer output to a UTF-8-capable terminal.
$ echo "Hello, world!" | groff -Tutf8 | sed '/^$/d'
Producing PDF, HTML, or TeX's DVI is also straightforward. The hard
part may be selecting a viewer program for the output.
$ echo "Hello, world!" | groff -Tpdf > hello.pdf
$ evince hello.pdf
$ echo "Hello, world!" | groff -Thtml > hello.html
$ firefox hello.html
$ echo "Hello, world!" | groff -Tdvi > hello.dvi
$ xdvi hello.html
Using groff as a REPL
Those with a programmer's bent may be pleased to know that they can use
groff in a read-evaluate-print loop (REPL). Doing so can be handy to
verify one's understanding of the formatter's behavior and/or the syn-
tax it accepts. Turning on all warnings with -ww can aid this goal.
$ groff -ww -Tutf8
\# This is a comment. Let's define a register.
.nr a 1
\# Do integer arithmetic with operators evaluated left-to-right.
.nr b \n[a]+5/2
\# Let's get the result on the standard error stream.
.tm \n[b]
3
\# Now we'll define a string.
.ds name Leslie\" This is another form of comment.
.nr b (\n[a] + (7/2))
\# Center the next two text input lines.
.ce 2
Hi, \*[name].
Your secret number is \n[b].
\# We will see that the division rounded toward zero.
It is
\# Here's an if-else control structure.
.ie (\n[b] % 2) odd.
.el even.
\# This trick sets the page length to the current vertical
\# position, so that blank lines don't spew when we're done.
.pl \n[nl]u
<Control-D>
Hi, Leslie.
Your secret number is 4.
It is even.
Paper format
In GNU roff, the page dimensions for the formatter troff and for output
devices are handled separately. In the formatter, requests are used to
set the page length (.pl), page offset (or left margin, .po), and line
length (.ll). The right margin is not explicitly configured; the com-
bination of page offset and line length provides the information neces-
sary to derive it. The papersize macro package, automatically loaded
by troff, provides an interface for configuring page dimensions by con-
venient names, like “letter” or “A4”; see ]8;;man:groff_tmac(5)\groff_tmac(5)]8;;\. The format-
ter's default in this installation is “A4”.
It is up to each macro package to respect the page dimensions config-
ured in this way. Some offer alternative mechanisms.
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 ]8;;man:groff_font(5)\groff_font(5)]8;;\ for a description of the papersize di-
rective, which takes an argument of the same form as -p. The output
driver's man page, such as ]8;;man:grops(1)\grops(1)]8;;\, may also be helpful. groff uses
the command-line option -P to pass options to output devices; for exam-
ple, 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
Front end
The groff program is a wrapper around the ]8;;man:troff(1)\troff(1)]8;;\ program. It allows
one to specify preprocessors via command-line options and automatically
runs the appropriate postprocessor for the selected output device. Do-
ing so, the manual construction of pipelines or management of temporary
files required of users of traditional ]8;;man:roff(7)\roff(7)]8;;\ systems can be avoided.
Use the ]8;;man:grog(1)\grog(1)]8;;\ program to infer an appropriate groff command line to
format a document.
Language
Input to a roff system is in plain text interleaved with control lines
and escape sequences. The combination constitutes a document in one of
a family of languages we also call roff; see ]8;;man:roff(7)\roff(7)]8;;\ for background.
An overview of GNU roff language syntax and features, including lists
of all supported escape sequences, requests, and predefined registers,
can be found in ]8;;man:groff(7)\groff(7)]8;;\. GNU roff extensions to the AT&T troff lan-
guage, a common subset of roff dialects extant today, are detailed in
]8;;man:groff_diff(7)\groff_diff(7)]8;;\.
Preprocessors
A preprocessor interprets a domain-specific language that produces roff
language output. Frequently, such input is confined to sections or re-
gions of a roff input file (bracketed with macro calls specific to each
preprocessor), which it replaces. Preprocessors therefore often inter-
pret a subset of roff syntax along with their own language. GNU roff
provides reimplementations of most preprocessors familiar to users of
AT&T troff; these routinely have extended features and/or require GNU
troff to format their output.
tbl lays out tables;
eqn typesets mathematics;
pic draws diagrams;
refer processes bibliographic references;
soelim preprocesses “sourced” input files;
grn renders ]8;;man:gremlin(1)\gremlin(1)]8;;\ diagrams;
chem draws chemical structural formulæ using pic;
gperl populates groff registers and strings using ]8;;man:perl(1)\perl(1)]8;;\;
glilypond embeds LilyPond sheet music; and
gpinyin eases Mandarin Chinese input using Hanyu Pinyin.
A preprocessor unique to GNU roff is ]8;;man:preconv(1)\preconv(1)]8;;\, which converts various
input encodings to something GNU troff can understand. When used, it
is run before any other preprocessors.
Most preprocessors enclose content between a pair of characteristic to-
kens. Such a token must occur at the beginning of an input line and
use the dot control character. Spaces and tabs must not follow the
control character or precede the end of the input line. Deviating from
these rules defeats a token's recognition by the preprocessor. Tokens
are generally preserved in preprocessor output and interpreted as macro
calls subsequently by troff. The ideal preprocessor is not yet avail-
able in groff.
┌──────────────┬─────────────────┬────────────────┐
│ preprocessor │ starting token │ ending token │
├──────────────┼─────────────────┼────────────────┤
│ chem │ .cstart │ .cend │
│ eqn │ .EQ │ .EN │
│ grap │ .G1 │ .G2 │
│ grn │ .GS │ .GE │
│ ideal │ .IS │ .IE │
│ │ │ .IF │
│ pic │ .PS │ .PE │
│ │ │ .PF │
│ │ │ .PY │
│ refer │ .R1 │ .R2 │
│ tbl │ .TS │ .TE │
├──────────────┼─────────────────┼────────────────┤
│ glilypond │ .lilypond start │ .lilypond stop │
│ gperl │ .Perl start │ .Perl stop │
│ gpinyin │ .pinyin start │ .pinyin stop │
└──────────────┴─────────────────┴────────────────┘
Macro packages
Macro files are roff input files designed to produce no output them-
selves but instead ease the preparation of other roff documents. When
a macro file is installed at a standard location and suitable for use
by a general audience, it is termed a macro package.
Macro packages can be loaded prior to any roff input documents with the
-m option. The GNU roff system implements most well-known macro pack-
ages for AT&T troff in a compatible way and extends them. These have
one- or two-letter names arising from intense practices of naming econ-
omy in early Unix culture, a laconic approach that led to many of the
packages being identified in general usage with the nroff and troff op-
tion letter used to invoke them, sometimes to punning effect, as with
“man” (short for “manual”), and even with the option dash, as in the
case of the s package, much better known as ms or even -ms.
Macro packages serve a variety of purposes. Some are “full-service”
packages, adopting responsibility for page layout among other fundamen-
tal tasks, and defining their own lexicon of macros for document compo-
sition; each such package stands alone and a given document can use at
most one.
an is used to compose man pages in the format originating in Ver-
sion 7 Unix (1979); see ]8;;man:groff_man(7)\groff_man(7)]8;;\. It can be specified on
the command line as -man.
doc is used to compose man pages in the format originating in
4.3BSD-Reno (1990); see ]8;;man:groff_mdoc(7)\groff_mdoc(7)]8;;\. It can be specified on
the command line as -mdoc.
e is the Berkeley general-purpose macro suite, developed as an al-
ternative to AT&T's s; see ]8;;man:groff_me(7)\groff_me(7)]8;;\. It can be specified on
the command line as -me.
m implements the format used by the second-generation AT&T macro
suite for general documents, a successor to s; see ]8;;man:groff_mm(7)\groff_mm(7)]8;;\.
It can be specified on the command line as -mm.
om (invariably called “mom”) is a modern package written by Peter
Schaffter specifically for GNU roff. Consult the ]8;;file:///usr/share/doc/groff-base/html/mom/toc.html\mom HTML man-
ual]8;;\ for extensive documentation. She—for mom takes the female
pronoun—can be specified on the command line as -mom.
s is the original AT&T general-purpose document format; see
]8;;man:groff_ms(7)\groff_ms(7)]8;;\. It can be specified on the command line as -ms.
Others are supplemental. For instance, andoc is a wrapper package spe-
cific to GNU roff that recognizes whether a document uses man or mdoc
format and loads the corresponding macro package. It can be specified
on the command line as -mandoc. A ]8;;man:man(1)\man(1)]8;;\ librarian program may use
this macro file to delegate loading of the correct macro package; it is
thus unnecessary for man itself to scan the contents of a document to
decide the issue.
Many macro files augment the function of the full-service packages, or
of roff documents that do not employ such a package—the latter are
sometimes characterized as “raw”. These auxiliary packages are de-
scribed, along with details of macro file naming and placement, in
]8;;man:groff_tmac(5)\groff_tmac(5)]8;;\.
Formatters
The formatter, the program that interprets roff language input, is
]8;;man:troff(1)\troff(1)]8;;\. It provides the features of the AT&T troff and nroff pro-
grams as well as many extensions. The command-line option -C switches
troff into compatibility mode, which tries to emulate AT&T troff as
closely as is practical to enable the formatting of documents written
for the older system.
A shell script, ]8;;man:nroff(1)\nroff(1)]8;;\, emulates the behavior of AT&T nroff. It at-
tempts to correctly encode the output based on the locale, relieving
the user of the need to specify an output device with the -T option and
is therefore convenient for use with terminal output devices, described
in the next subsection.
GNU troff generates output in a device-independent, but not device-ag-
nostic, page description language detailed in ]8;;man:groff_out(5)\groff_out(5)]8;;\.
Output devices
troff output is formatted for a particular output device, typically
specified by the -T option to the formatter or a front end. If neither
this option nor the GROFF_TYPESETTER environment variable is used, the
default output device is ps. An output device may be any of the fol-
lowing.
ascii for terminals using the ISO 646 1991:IRV character set and en-
coding, also known as US-ASCII.
cp1047 for terminals using the IBM code page 1047 character set and
encoding.
dvi for TeX DVI format.
html
xhtml for HTML and XHTML output, respectively.
latin1 for terminals using the ISO Latin-1 (ISO 8859-1) character set
and encoding.
lbp for Canon CaPSL printers (LBP-4 and LBP-8 series laser print-
ers).
lj4 for HP LaserJet4-compatible (or other PCL5-compatible) print-
ers.
pdf for PDF output.
ps for PostScript output.
utf8 for terminals using the ISO 10646 (“Unicode”) character set in
UTF-8 encoding.
X75 for previewing with gxditview using 75 dpi resolution and a
10-point base type size.
X75-12 for previewing with gxditview using 75 dpi resolution and a
12-point base type size.
X100 for previewing with gxditview using 100 dpi resolution and a
10-point base type size.
X100-12 for previewing with gxditview using 100 dpi resolution and a
12-point base type size.
Postprocessors
Any program that interprets the output of GNU troff is a postprocessor.
The postprocessors provided by GNU roff are output drivers, which pre-
pare a document for viewing or printing. Postprocessors for other pur-
poses, such as page resequencing or statistical measurement of a docu-
ment, are conceivable.
An output driver supports one or more output devices, each with its own
device description file. A device determines its postprocessor with
the postpro directive in its device description file; see
]8;;man:groff_font(5)\groff_font(5)]8;;\. The -X option overrides this selection, causing
gxditview to serve as the output driver.
]8;;man:grodvi(1)\grodvi(1)]8;;\
provides dvi.
]8;;man:grohtml(1)\grohtml(1)]8;;\
provides html and xhtml.
]8;;man:grolbp(1)\grolbp(1)]8;;\
provides lbp.
]8;;man:grolj4(1)\grolj4(1)]8;;\
provides lj4.
]8;;man:gropdf(1)\gropdf(1)]8;;\
provides pdf.
]8;;man:grops(1)\grops(1)]8;;\
provides ps.
]8;;man:grotty(1)\grotty(1)]8;;\
provides ascii, cp1047, latin1, and utf8.
]8;;man:gxditview(1)\gxditview(1)]8;;\
provides X75, X75-12, X100, and X100-12, and additionally can
preview ps.
Utilities
GNU roff includes a suite of utilities.
]8;;man:gdiffmk(1)\gdiffmk(1)]8;;\
marks differences between a pair of roff input files.
]8;;man:grog(1)\grog(1)]8;;\
infers the groff command a document requires.
Several utilities prepare descriptions of fonts, enabling the formatter
to use them when producing output for a given device.
]8;;man:addftinfo(1)\addftinfo(1)]8;;\
adds information to AT&T troff font description files to enable
their use with GNU troff.
]8;;man:afmtodit(1)\afmtodit(1)]8;;\
creates font description files for PostScript Type 1 fonts.
]8;;man:pfbtops(1)\pfbtops(1)]8;;\
translates a PostScript Type 1 font in PFB (Printer Font Binary)
format to PFA (Printer Font ASCII), which can then be inter-
preted by afmtodit.
]8;;man:hpftodit(1)\hpftodit(1)]8;;\
creates font description files for the HP LaserJet 4 family of
printers.
]8;;man:tfmtodit(1)\tfmtodit(1)]8;;\
creates font description files for the TeX DVI device.
]8;;man:xtotroff(1)\xtotroff(1)]8;;\
creates font description files for X Window System core fonts.
A trio of tools transform material constructed using roff preprocessor
languages into graphical image files.
]8;;man:eqn2graph(1)\eqn2graph(1)]8;;\
converts an eqn equation into a cropped image.
]8;;man:grap2graph(1)\grap2graph(1)]8;;\
converts a grap diagram into a cropped image.
]8;;man:pic2graph(1)\pic2graph(1)]8;;\
converts a pic diagram into a cropped image.
Another set of programs works with the bibliographic data files used by
the ]8;;man:refer(1)\refer(1)]8;;\ preprocessor.
]8;;man:indxbib(1)\indxbib(1)]8;;\
makes inverted indices for bibliographic databases, speeding
lookup operations on them.
]8;;man:lkbib(1)\lkbib(1)]8;;\
searches the databases.
]8;;man:lookbib(1)\lookbib(1)]8;;\
interactively searches the databases.
Exit status
groff exits with a failure status if there was a problem parsing its
arguments and a successful status if either of the options -h or --help
was specified. Otherwise, groff runs a pipeline to process its input;
if all commands within the pipeline exit successfully, groff does like-
wise. If not, groff's exit status encodes a summary of problems en-
countered, setting bit 0 if a command exited with a failure status,
bit 1 if a command was terminated with a signal, and bit 2 if a command
could not be executed. (Thus, if all three misfortunes befell one's
pipeline, groff would exit with status 2^0 + 2^1 + 2^2 = 1+2+4 = 7.)
To troubleshoot pipeline problems, you may wish to re-run the groff
command with the -V option and break the reported pipeline down into
separate stages, inspecting the exit status of and diagnostic messages
emitted by each command.
Environment
Normally, the path separator in environment variables ending with PATH
is the colon; this may vary depending on the operating system. For ex-
ample, Windows uses a semicolon instead.
GROFF_BIN_PATH
This search path, followed by PATH, is used to locate commands
executed by groff. If it is not set, the installation directory
of the GNU roff executables, /usr/bin, is searched before PATH.
GROFF_COMMAND_PREFIX
GNU roff can be configured at compile time to apply a prefix to
the names of the programs it provides that had a counterpart in
AT&T troff, so that name collisions are avoided at run time.
The default prefix is empty.
When used, this prefix is conventionally the letter “g”. For
example, GNU troff would be installed as gtroff. Besides troff,
the prefix applies to the formatter nroff; the preprocessors
eqn, grn, pic, refer, tbl, and soelim; and the utilities indxbib
and lookbib.
GROFF_ENCODING
The value of this variable is passed to the preconv(1) pre-
processor's -e option to select the character encoding of input
files. This variable's existence implies the groff option -k.
If set but empty, groff calls preconv without an -e option.
groff's -K option overrides GROFF_ENCODING.
GROFF_FONT_PATH
Seek the selected output device's directory of device and font
description files in this list of directories. See ]8;;man:troff(1)\troff(1)]8;;\ and
]8;;man:groff_font(5)\groff_font(5)]8;;\.
GROFF_TMAC_PATH
Seek macro files in this list of directories. See ]8;;man:troff(1)\troff(1)]8;;\ and
]8;;man:groff_tmac(5)\groff_tmac(5)]8;;\.
GROFF_TMPDIR
Create temporary files in this directory. If not set, but the
environment variable TMPDIR is set, temporary files are created
there instead. On Windows systems, if neither of the foregoing
are set, the environment variables TMP and TEMP (in that order)
are checked also. Otherwise, temporary files are created in
/tmp. The ]8;;man:refer(1)\refer(1)]8;;\, ]8;;man:grohtml(1)\grohtml(1)]8;;\, and ]8;;man:grops(1)\grops(1)]8;;\ commands use tem-
porary files.
GROFF_TYPESETTER
Set the default output device. If empty or not set, ps is used.
The -T option overrides GROFF_TYPESETTER.
SOURCE_DATE_EPOCH
A time stamp (expressed as seconds since the Unix epoch) to use
as the output creation time stamp in place of the current time.
The time is converted to human-readable form using ]8;;man:gmtime(3)\gmtime(3)]8;;\ and
]8;;man:asctime(3)\asctime(3)]8;;\ when the formatter starts up and stored in registers
usable by documents and macro packages.
TZ The time zone to use when converting the current time to human-
readable form; see ]8;;man:tzset(3)\tzset(3)]8;;\. If SOURCE_DATE_EPOCH is used, it
is always converted to human-readable form using UTC.
Examples
roff systems are best known for formatting man pages. Once a ]8;;man:man(1)\man(1)]8;;\
librarian program has located a man page, it may execute a groff com-
mand much like the following.
groff -t -man -Tutf8 /usr/share/man/man1/groff.1
The librarian will also pipe the output through a pager, which might
not interpret the SGR terminal escape sequences groff emits for bold-
face, underlining, or italics; see section “Limitations” below.
To process a roff input file using the preprocessors tbl and pic and
the me macro package in the way to which AT&T troff users were accus-
tomed, one would type (or script) a pipeline.
pic foo.me | tbl | troff -me -Tutf8 | grotty
Using groff, this pipe can be shortened to an equivalent command.
groff -p -t -me -T utf8 foo.me
An even easier way to do this is to use ]8;;man:grog(1)\grog(1)]8;;\ to guess the preproces-
sor and macro options and execute the result by using the command sub-
stitution feature of the shell.
$(grog -Tutf8 foo.me)
Each command-line option to a postprocessor must be specified with any
required leading dashes “-” because groff passes the arguments as-is to
the postprocessor; this permits arbitrary arguments to be transmitted.
For example, to pass a title to the gxditview postprocessor, the shell
commands
groff -X -P -title -P 'trial run' mydoc.t
and
groff -X -Z mydoc.t | gxditview -title 'trial run' -
are equivalent.
Limitations
When paging output for the ascii, cp1047, latin1, and utf8 devices,
programs like ]8;;man:more(1)\more(1)]8;;\ and ]8;;man:less(1)\less(1)]8;;\ may require command-line options to
correctly handle some terminal escape sequences; see ]8;;man:grotty(1)\grotty(1)]8;;\.
On EBCDIC hosts such as OS/390 Unix, the output devices ascii and
latin1 aren't available. Conversely, the output device cp1047 is not
available on systems based on the ISO 646 or ISO 8859 character encod-
ing standards.
Installation directories
GNU roff installs files in varying locations depending on its compile-
time configuration. On this installation, the following locations are
used.
/etc/X11/app-defaults
Application defaults directory for ]8;;man:gxditview(1)\gxditview(1)]8;;\.
/usr/bin
Directory containing groff's executable commands.
/usr/share/groff/1.23.0/eign
List of common words for ]8;;man:indxbib(1)\indxbib(1)]8;;\.
/usr/share/groff/1.23.0
Directory for data files.
/usr/dict/papers/Ind
Default index for ]8;;man:lkbib(1)\lkbib(1)]8;;\ and ]8;;man:refer(1)\refer(1)]8;;\.
/usr/share/doc/groff-base
Documentation directory.
/usr/share/doc/groff-base/examples
Example directory.
/usr/share/groff/1.23.0/font
Font directory.
/usr/share/doc/groff-base/html
HTML documentation directory.
/usr/lib/font
Legacy font directory.
/usr/share/groff/site-font
Local font directory.
/usr/share/groff/site-tmac
Local macro package (tmac file) directory.
/usr/share/groff/1.23.0/tmac
Macro package (tmac file) directory.
/usr/share/groff/1.23.0/oldfont
Font directory for compatibility with old versions of groff; see
]8;;man:grops(1)\grops(1)]8;;\.
/usr/share/doc/groff-base/pdf
PDF documentation directory.
groff macro directory
Most macro files supplied with GNU roff are stored in /usr/share/groff/
1.23.0/tmac for the installation corresponding to this document. As a
rule, multiple directories are searched for macro files; see ]8;;man:troff(1)\troff(1)]8;;\.
For a catalog of macro files GNU roff provides, see ]8;;man:groff_tmac(5)\groff_tmac(5)]8;;\.
groff device and font description directory
Device and font description files supplied with GNU roff are stored in
/usr/share/groff/1.23.0/font for the installation corresponding to this
document. As a rule, multiple directories are searched for device and
font description files; see ]8;;man:troff(1)\troff(1)]8;;\. For the formats of these files,
see ]8;;man:groff_font(5)\groff_font(5)]8;;\.
Availability
Obtain links to groff releases for download, its source repository,
discussion mailing lists, a support ticket tracker, and further infor-
mation from the ]8;;http://www.gnu.org/software/groff\groff page of the GNU website]8;;\.
A free implementation of the grap preprocessor, written by ]8;;mailto:faber@lunabase.org\Ted Faber]8;;\,
can be found at the ]8;;http://www.lunabase.org/~faber/Vault/software/grap/\grap website]8;;\. groff supports only this grap.
Authors
groff (both the front-end command and the overall system) was primarily
written by ]8;;mailto:jjc@jclark.com\James Clark]8;;\. Contributors to this document include Clark,
Trent A. Fisher, ]8;;mailto:wl@gnu.org\Werner Lemberg]8;;\, ]8;;mailto:groff-bernd.warken-72@web.de\Bernd Warken]8;;\, and ]8;;mailto:g.branden.robinson@gmail.com\G. Branden Robinson]8;;\.
See also
Groff: The GNU Implementation of troff, by Trent A. Fisher and Werner
Lemberg, is the primary groff manual. You can browse it interactively
with “info groff”.
Introduction, history, and further reading:
]8;;man:roff(7)\roff(7)]8;;\
Viewer for groff (and AT&T device-independent troff) documents:
]8;;man:gxditview(1)\gxditview(1)]8;;\
Preprocessors:
]8;;man:chem(1)\chem(1)]8;;\, ]8;;man:eqn(1)\eqn(1)]8;;\, ]8;;man:neqn(1)\neqn(1)]8;;\, ]8;;man:glilypond(1)\glilypond(1)]8;;\, ]8;;man:grn(1)\grn(1)]8;;\, ]8;;man:preconv(1)\preconv(1)]8;;\,
]8;;man:gperl(1)\gperl(1)]8;;\, ]8;;man:pic(1)\pic(1)]8;;\, ]8;;man:gpinyin(1)\gpinyin(1)]8;;\, ]8;;man:refer(1)\refer(1)]8;;\, ]8;;man:soelim(1)\soelim(1)]8;;\, ]8;;man:tbl(1)\tbl(1)]8;;\
Macro packages and package-specific utilities:
]8;;man:groff_hdtbl(7)\groff_hdtbl(7)]8;;\, ]8;;man:groff_man(7)\groff_man(7)]8;;\, ]8;;man:groff_man_style(7)\groff_man_style(7)]8;;\, ]8;;man:groff_mdoc(7)\groff_mdoc(7)]8;;\,
]8;;man:groff_me(7)\groff_me(7)]8;;\, ]8;;man:groff_mm(7)\groff_mm(7)]8;;\, ]8;;man:groff_mmse(7)\groff_mmse(7)]8;;\ (only in Swedish lo-
cales), ]8;;man:mmroff(1)\mmroff(1)]8;;\, ]8;;man:groff_mom(7)\groff_mom(7)]8;;\, ]8;;man:pdfmom(1)\pdfmom(1)]8;;\, ]8;;man:groff_ms(7)\groff_ms(7)]8;;\,
]8;;man:groff_rfc1345(7)\groff_rfc1345(7)]8;;\, ]8;;man:groff_trace(7)\groff_trace(7)]8;;\, ]8;;man:groff_www(7)\groff_www(7)]8;;\
Bibliographic database management tools:
]8;;man:indxbib(1)\indxbib(1)]8;;\, ]8;;man:lkbib(1)\lkbib(1)]8;;\, ]8;;man:lookbib(1)\lookbib(1)]8;;\
Language, conventions, and GNU extensions:
]8;;man:groff(7)\groff(7)]8;;\, ]8;;man:groff_char(7)\groff_char(7)]8;;\, ]8;;man:groff_diff(7)\groff_diff(7)]8;;\, ]8;;man:groff_font(5)\groff_font(5)]8;;\,
]8;;man:groff_tmac(5)\groff_tmac(5)]8;;\
Intermediate output language:
]8;;man:groff_out(5)\groff_out(5)]8;;\
Formatter program:
]8;;man:troff(1)\troff(1)]8;;\
Formatter wrappers:
]8;;man:nroff(1)\nroff(1)]8;;\, ]8;;man:pdfroff(1)\pdfroff(1)]8;;\
Postprocessors for output devices:
]8;;man:grodvi(1)\grodvi(1)]8;;\, ]8;;man:grohtml(1)\grohtml(1)]8;;\, ]8;;man:grolbp(1)\grolbp(1)]8;;\, ]8;;man:grolj4(1)\grolj4(1)]8;;\, ]8;;man:gropdf(1)\gropdf(1)]8;;\,
]8;;man:grops(1)\grops(1)]8;;\, ]8;;man:grotty(1)\grotty(1)]8;;\
Font support utilities:
]8;;man:addftinfo(1)\addftinfo(1)]8;;\, ]8;;man:afmtodit(1)\afmtodit(1)]8;;\, ]8;;man:hpftodit(1)\hpftodit(1)]8;;\, ]8;;man:pfbtops(1)\pfbtops(1)]8;;\, ]8;;man:tfmtodit(1)\tfmtodit(1)]8;;\,
]8;;man:xtotroff(1)\xtotroff(1)]8;;\
Graphics conversion utilities:
]8;;man:eqn2graph(1)\eqn2graph(1)]8;;\, ]8;;man:grap2graph(1)\grap2graph(1)]8;;\, ]8;;man:pic2graph(1)\pic2graph(1)]8;;\
Difference-marking utility:
]8;;man:gdiffmk(1)\gdiffmk(1)]8;;\
“groff guess” utility:
]8;;man:grog(1)\grog(1)]8;;\
groff 1.23.0 31 March 2024 groff(1)
Generated by dwww version 1.16 on Sun Jul 12 05:23:26 CEST 2026.