groff(1) — Linux manual page

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groff(1)                 General Commands Manual                groff(1)

Name         top

       groff - front end to the GNU roff document formatting system

Synopsis         top

       groff [-abcegijklpstzCEGNRSUVXZ] [-d cs] [-D enc] [-f fam]
             [-F dir] [-I dir] [-K enc] [-L arg] [-m name] [-M dir]
             [-n num] [-o list] [-P arg] [-r cn] [-T dev] [-w name]
             [-W name] [file ...]

       groff -h
       groff --help

       groff -v [option ...] [file ...]
       groff --version [option ...] [file ...]

Description         top

       groff is the primary front end to the GNU roff document
       formatting system.  The groff command orchestrates the execution
       of preprocessors, the loading of macro packages, the formatting
       of input documents, and the production of output appropriate to a
       variety of hardware devices and file formats.

Options         top

       -h and --help display a usage message and exit.

       Because groff is intended to subsume most users' direct
       invocations of the troff(1) formatter, the two programs share a
       set of options.  However, groff has some options specific to it,
       some of which 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 for troff or are
       interpreted differently by groff.

       -D enc Set default input encoding used by preconv(1) to enc.
              Implies -k.

       -e     Run eqn(1) preprocessor.

       -g     Run grn(1) preprocessor.

       -G     Run grap(1) preprocessor; implies -p.

       -I dir Works as troff's option (see below), but also implies -s
              and passes the -I options to soelim(1).

       -j     Run chem(1) preprocessor; implies -p.

       -k     Run preconv(1), which is run before any other
              preprocessor.  Please refer to preconv's manual page for
              its behavior if neither of groff's -K or -D options is
              also specified.

       -K enc Set input encoding used by preconv(1) 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 groff_font(5).  If no
              such directive is present for the output device, output is
              piped to lpr(1).  See options -L and -X.

       -L arg Pass arg to the print spooler program.  If multiple args
              are required, each should be passed with a separate -L
              option each.  groff does not prepend “-” (a minus sign) to
              arg before passing it to the spooler program.

       -N     Don't allow newlines within eqn delimiters.  This is the
              same as the -N option in eqn(1).

       -p     Run pic(1) preprocessor.

       -P arg
       -P -option
       -P -option -P arg
              Pass arguments to the postprocessor.

              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 command
                     groff -X -P -title -P 'trial run' mydoc.t
              is equivalent to
                     groff -X -Z mydoc.t | gxditview -title 'trial run' -

       -R     Run refer(1) 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; see refer(1).

       -s     Run soelim(1) preprocessor.

       -S     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
              default.

       -t     Run tbl(1) preprocessor.

       -T dev Prepare output for the device type dev; troff generates
              “intermediate output” (groff_out(5)) appropriate to the
              device.  groff then calls a postprocessor to convert
              troff's output to a form appropriate for dev.  Real
              devices in groff are

                     dvi    TeX DVI format (postprocessor is grodvi(1)).

                     html
                     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(1)).

                     lj4    HP LaserJet4-compatible (or other
                            PCL5-compatible) printers (postprocessor is
                            grolj4(1)).

                     ps     PostScript output (postprocessor is
                            grops(1)).

                     pdf    Portable Document Format (PDF) output
                            (postprocessor is gropdf(1)).

              For the following TTY output devices (where postprocessor
              is grotty(1)), -T selects the output encoding:

                     ascii  ISO 646 1991:IRV, also known as US-ASCII.

                     cp1047 IBM code page 1047, an EBCDIC arrangement of
                            ISO Latin-1.

                     latin1 ISO Latin-1 (ISO 8859-1).

                     utf8   ISO 10646 (“Unicode”) character set in UTF-8
                            encoding.  This encoding has the largest
                            character repertoire, so it is the best
                            choice for terminal output.

              The following arguments select gxditview as the
              postprocessor.

                     X75    75dpi resolution, 10pt document base font.

                     X75-12 75dpi resolution, 12pt document base font.

                     X100   100dpi resolution, 10pt document base font.

                     X100-12
                            100dpi resolution, 12pt document base font.

              The default device is ps.

       -U     Unsafe mode; see -S.

       -v
       --version
              Write version information of groff and of 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
              all subprograms.

       -V     Output the pipeline that would be run by groff (as a
              wrapper program) to the standard output stream, but do not
              execute it.  If given more than once, the commands are
              both written to the standard error stream and run.

       -X     Use gxditview(1) 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 by determining an argument for its -printCommand
              option.  This sets the default Print action and the
              corresponding menu entry to that value.  -X produces good
              results only with -Tps, -TX75, -TX75-12, -TX100, and
              -TX100-12.  The default resolution for previewing -Tps
              output is 75dpi, but this can be changed by passing the
              -resolution option to gxditview.

                     groff -X -P-resolution -P100 -man foo.1

       -z     Suppress output generated by troff.  Only error messages
              are printed.

       -Z     Disable postprocessing.  troff output will appear on the
              standard output stream (unless suppressed with -z); see
              groff_out(5) for a description of this format.

   Transparent options
       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     Generate a plain text approximation of the typeset output.

       -b     Backtrace on error or warning.

       -c     Disable color output (to any device) and use legacy output
              format for terminal devices; see grotty(1).

       -C     Enable compatibility mode.

       -d cs
       -d name=s
              Define string.

       -E     Inhibit troff error messages; implies -Ww.

       -f fam Set default font family.

       -F dir Set path for device DESC files.

       -I dir Search dir for files (those on the command line, those
              named in .psbb and .so requests, and those named in
              certain device commands issued with the \X escape).

       -i     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 category name.  See troff(1) or the groff
              Texinfo manual for a list of names.

       -W name
              Disable warning category name.  See troff(1) or the groff
              Texinfo manual for a list of names.

Usage         top

       The architecture of the GNU roff system follows that of other
       device-independent roff implementations, comprising
       preprocessors, macro packages, output drivers (or
       “postprocessors”), a suite of utilities, and the formatter troff
       at its heart.  See roff(7) 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 summarizes the constituent parts of the GNU
       roff system.  It complements roff(7) 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!” document.

       $ 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 syntax 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
       \# We can see that the division rounded toward zero.
       \# 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].
       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 size
       In groff, 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 combination of page offset and
       line length provides the information necessary to derive it.  The
       papersize macro package, automatically loaded by troffrc at
       start-up, 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 driver, the size of the output medium can be set
       in its DESC file.  Most output devices also recognize a command-
       line option -p to override the default dimensions and an option
       -l to use landscape orientation.  See groff_font(5) 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 output devices; 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

   Front ends
       The groff program is a wrapper around the troff(1) program.  It
       allows one 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 traditional roff(7) systems can be avoided.

       The grog(1) program can be used to infer an appropriate groff
       command line to format a document.

   Preprocessors
       The groff preprocessors are reimplementations of the classical
       preprocessors with moderate extensions.  The standard
       preprocessors distributed with the groff package are

       eqn(1) for mathematical formulae,

       grn(1) for including gremlin(1) pictures,

       pic(1) for drawing diagrams,

       chem(1)
              for chemical structure diagrams,

       refer(1)
              for bibliographic references,

       soelim(1)
              for including macro files from standard locations,

       and

       tbl(1) for tables.

       A new preprocessor not available in classical troff is preconv(1)
       which converts various input encodings to something groff can
       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
       Macro packages can be loaded prior to a roff input document by
       using the option -m.  The groff system implements most well-known
       macro packages for AT&T troff in a compatible way, extends them,
       and adds some packages of its own.  Several of them have one- or
       two-letter names due to the intense sense of naming economy
       practiced in early Unix culture.  This laconic approach led to
       many of the packages being identified in general usage with the
       nroff and troff option 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 fundamental tasks, and defining their own lexicon of macros
       for document composition; each of these stands alone and a given
       document can use at most one.  GNU roff provides the following
       such packages.

       an     is used to compose man pages in the format originating in
              Version 7 Unix (1979); see groff_man(7).  It can be
              specified on the command line as -man-old; the package
              name “an” is used to force the loading of andoc instead
              (see below).

       doc    is used to compose man pages in the format originating in
              4.3BSD-Reno (1990); see groff_mdoc(7).  It can be
              specified on the command line as -mdoc.

       andoc  is a wrapper package specific to groff 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 or -man; groff redirects -man
              users through this wrapper because users typically are not
              aware of which macro package was used to compose a given
              man page.

       e      is the Berkeley general-purpose document formatter,
              developed as an alternative to AT&T's s; see groff_me(7).
              It can be specified on the command line as -me.

       m      is the second-generation AT&T general-purpose document
              formatter, a successor to s; see groff_mm(7).  It can be
              specified on the command line as -mm.

       om     (invariably called “mom”) is a modern package written by
              Peter Schaffter specifically for groff.  Consult the mom
              home page ⟨https://www.schaffter.ca/mom/⟩ 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 ms document
              formatter; see groff_ms(7).  It can be specified on the
              command line as -ms.

       Others are supplemental, and 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 described, along with details of macro
       file naming and placement, in groff_tmac(5).

   Programming language
       General concepts common to all roff programming languages are
       described in roff(7).

       The groff extensions to the classical troff language are
       documented in groff_diff(7).

       An overview of language features, including all supported escapes
       and requests, can be found in groff(7).

   Formatters
       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 as possible.

       There is a shell script nroff(1) that emulates the behavior of
       classical nroff.  It tries to automatically select the proper
       output encoding, according to the current locale.

       The formatter program generates a device-independent, but not
       device-agnostic, intermediate output format, documented in
       groff_out(5).

   Devices
       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
       follows.

       ascii  Text output using the ascii(7) character set.

       cp1047 Text output using the EBCDIC code page IBM cp1047 (e.g.,
              OS/390 Unix).

       dvi    TeX DVI format.

       html   HTML output.

       latin1 Text output using the ISO Latin-1 (ISO 8859-1) character
              set; see iso_8859_1(7).

       lbp    Output for Canon CAPSL printers (LBP-4 and LBP-8 series
              laser printers).

       lj4    HP LaserJet4-compatible (or other PCL5-compatible)
              printers.

       ps     PostScript output; suitable for printers and previewers
              like gv(1).

       pdf    PDF files; suitable for viewing with tools such as
              evince(1) and okular(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.

   Postprocessors
       groff provides 3 hardware postprocessors:

       grolbp(1)
              for some Canon printers,

       grolj4(1)
              for printers compatible to the HP LaserJet 4 and PCL5,

       grotty(1)
              for text output using various encodings, e.g., on text-
              oriented terminals or line printers.

       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 postprocessors.

       The groff software devices for conversion into other document
       file formats are

       grodvi(1)
              for the DVI format,

       grohtml(1)
              for HTML and XHTML formats,

       grops(1)
              for PostScript.

       gropdf(1)
              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.

   Utilities
       The following utility programs around groff are available.

       addftinfo(1)
              Add information to troff font description files for use
              with groff.

       afmtodit(1)
              Create font description files for PostScript device.

       eqn2graph(1)
              Convert an eqn image into a cropped image.

       gdiffmk(1)
              Mark differences between groff, nroff, or troff files.

       grap2graph(1)
              Convert a grap diagram into a cropped bitmap image.

       gxditview(1)
              The groff X viewer, the GNU version of xditview.

       hpftodit(1)
              Create font description files for lj4 device.

       indxbib(1)
              Make inverted index for bibliographic databases.

       lkbib(1)
              Search bibliographic databases.

       lookbib(1)
              Interactively search bibliographic databases.

       pdfroff(1)
              Create PDF documents using groff.

       pfbtops(1)
              Translate a PostScript font in .pfb format to ASCII.

       pic2graph(1)
              Convert a pic diagram into a cropped image.

       tfmtodit(1)
              Create font description files for TeX DVI device.

       xditview(1x)
              roff viewer historically distributed with the X Window
              System.

       xtotroff(1)
              Convert X font metrics into GNU troff font metrics.

Environment         top

       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.

       GROFF_BIN_PATH
              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.

       GROFF_COMMAND_PREFIX
              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.

       GROFF_ENCODING
              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.

       GROFF_FONT_PATH
              A list of directories in which to seek the selected output
              device's directory of device and font description files.
              See troff(1) and groff_font(5).

       GROFF_TMAC_PATH
              A list of directories in which to seek macro files.  See
              troff(1) and groff_tmac(5).

       GROFF_TMPDIR
              The directory in which temporary files are created.  If
              not set, but the environment variable TMPDIR is set,
              temporary files are created there instead.  On MS-DOS and
              Windows platforms, 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 refer(1), grohtml(1), and grops(1) commands use
              temporary files.

       GROFF_TYPESETTER
              Preset the default device.  If not set, ps device is used
              as default.  The -T option overrides GROFF_TYPESETTER.

       SOURCE_DATE_EPOCH
              A timestamp (expressed as seconds since the Unix epoch) to
              use as the creation timestamp in place of the current
              time.  The time is converted to human-readable form using
              ctime(3) 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 (or
              value of SOURCE_DATE_EPOCH) to human-readable form; see
              tzset(3).

Examples         top

       The following example illustrates the power of the groff program
       as a wrapper around troff.

       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 accustomed, one would type (or script) a pipeline.

              pic foo.me | tbl | troff -me -Tutf8 | grotty

       Using groff, this pipe can be shortened to the equivalent command

              groff -p -t -me -T utf8 foo.me

       An even easier way to do this is to use grog(1) to guess the
       preprocessor and macro options and execute the result by using
       the command substitution feature of the shell.

              $(grog -Tutf8 foo.me)

Notes         top

       When paging output for the “ascii”, “cp1047”, “latin1”, and
       “utf8” devices, programs like more(1) and less(1) may require
       command-line options to correctly handle some output sequences;
       see grotty(1).

Bugs         top

       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.

Installation directories         top

       groff installs files in varying locations depending on its
       compile-time configuration.  On this installation, the following
       locations are used.

       Application defaults directory for
              gxditview(1).

       /usr/local/bin
              Directory containing groff's executable commands.

       /usr/local/share/groff/1.23.0/eign
              List of common words for indxbib(1).

       /usr/local/share/groff/1.23.0
              Directory for data files.

       /usr/dict/papers/Ind
              Default index for lkbib(1) and refer(1).

       /usr/local/share/doc/groff-1.23.0
              Documentation directory.

       /usr/local/share/doc/groff-1.23.0/examples
              Example directory.

       /usr/local/share/groff/1.23.0/font
              Font directory.

       /usr/local/share/doc/groff-1.23.0/html
              HTML documentation directory.

       /usr/lib/font
              Legacy font directory.

       /usr/local/share/groff/site-font
              Local font directory.

       /usr/local/share/groff/site-tmac
              Local macro package (tmac file) directory.

       /usr/local/share/groff/1.23.0/tmac
              Macro package (tmac file) directory.

       /usr/local/share/groff/1.23.0/oldfont
              Font directory for compatibility with old versions of
              groff; see grops(1).

       /usr/local/share/doc/groff-1.23.0/pdf
              PDF documentation directory.

       /usr/local/lib/groff/site-tmac
              System macro package (tmac file) 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/1.23.0/tmac.  The following files contained in the
       groff macro directory have a special meaning:

       troffrc
              Initialization file for troff.  This is interpreted by
              troff before reading the macro sets and any input.

       troffrc-end
              Final startup file for troff.  It is parsed after all
              macro sets have been read.

       name.tmac
       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 groff installation corresponding to this
       document, it is located at /usr/local/share/groff/1.23.0/font.
       The following files contained in the groff font directory have a
       special meaning:

       devname/DESC
              Device description file for device name, see
              groff_font(5).

       devname/F
              Font file for font F of device name.

Availability         top

       Information on how to get groff and related information is
       available at the groff page of the GNU website 
       ⟨http://www.gnu.org/software/groff⟩.

       Three groff mailing lists are available:

              bug tracker activity (read-only) ⟨bug-groff@gnu.org⟩;

              general discussion ⟨groff@gnu.org⟩; and

              commit activity (read-only) ⟨groff-commit@gnu.org⟩, which
              reports changes to groff's source code repository by its
              developers.

       Details on repository access and much more can be found in the
       file README at the top directory of the groff source package.

       A free implementation of the grap preprocessor, written by Ted
       Faber ⟨faber@lunabase.org⟩, can be found at the grap website 
       ⟨http://www.lunabase.org/~faber/Vault/software/grap/⟩.  This is
       the only grap supported by groff.

Authors         top

       groff was written by James Clark ⟨jjc@jclark.com⟩.  This document
       was rewritten, enhanced, and put under the GNU FDL license in
       2002 by Bernd Warken ⟨groff-bernd.warken-72@web.de⟩.

See also         top

       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:
              roff(7), ditroff(7)

       Viewer for groff (and AT&T device-independent) troff documents:
              gxditview(1)

       Preprocessors:
              chem(1), eqn(1), neqn(1), glilypond(1), grn(1),
              preconv(1), gperl(1), pic(1), gpinyin(1), refer(1),
              soelim(1), tbl(1)

       Macro packages and macro-specific utilities:
              groff_hdtbl(7), groff_man(7), groff_man_style(7),
              groff_mdoc(7), groff_me(7), groff_mm(7), groff_mmse(7),
              mmroff(1), groff_mom(7), pdfmom(1), groff_ms(7),
              groff_rfc1345(7), groff_trace(7), groff_www(7)

       Bibliographic and index tools:
              indxbib(1), lkbib(1), lookbib(1)

       Language, conventions, and GNU extensions:
              groff(7), groff_char(7), groff_diff(7),
              groff_filenames(5), groff_font(5), groff_tmac(5)

       Intermediate output language:
              groff_out(5)

       Formatter program:
              troff(1)

       Formatter wrappers:
              nroff(1), pdfroff(1)

       Postprocessors for output devices:
              grodvi(1), grohtml(1), grolbp(1), grolj4(1), lj4_font(5),
              gropdf(1), grops(1), grotty(1)

       Font support utilities:
              addftinfo(1), afmtodit(1), hpftodit(1), pfbtops(1),
              tfmtodit(1), xtotroff(1)

       Graphics conversion utilities:
              eqn2graph(1), grap2graph(1), pic2graph(1)

       Difference-marking utility:
              gdiffmk(1)

       “groff guess” utility:
              grog(1)

COLOPHON         top

       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 project's upstream Git repository
       ⟨https://git.savannah.gnu.org/git/groff.git⟩ on 2021-06-20.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-06-17.)  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
       man-pages@man7.org

groff 1.23.0.rc1.654-4e1db-dirt1y8 June 2021                      groff(1)

Pages that refer to this page: addftinfo(1)afmtodit(1)chem(1)eqn(1)eqn2graph(1)gdiffmk(1)glilypond(1)gperl(1)gpinyin(1)grap2graph(1)grn(1)grodvi(1)groffer(1)grog(1)grohtml(1)grolbp(1)grolj4(1)gropdf(1)grops(1)grotty(1)hpftodit(1)man(1)mmroff(1)nroff(1)pdfmom(1)pdfroff(1)pfbtops(1)pic2graph(1)preconv(1)refer(1)roff2dvi(1)roff2html(1)roff2pdf(1)roff2ps(1)roff2text(1)roff2x(1)soelim(1)tbl(1)tfmtodit(1)troff(1)zsoelim(1)groff_font(5)groff_out(5)groff_tmac(5)lj4_font(5)ditroff(7)groff(7)groff_char(7)groff_diff(7)groff_hdtbl(7)groff_me(7)groff_mm(7)groff_mmse(7)groff_mom(7)groff_ms(7)groff_rfc1345(7)groff_trace(7)groff_www(7)man(7)roff(7)suffixes(7)