groff(1) — Linux manual page

Name | Synopsis | Description | Options | Using groff | Environment | Examples | Notes | Bugs | Installation Directories | Availability | Authors | See also | COLOPHON

groff(1)                 General Commands Manual                groff(1)

Name         top

       groff - front-end for the GNU roff document formatting system

Synopsis         top

       groff [-abcegijklpstzCEGNRSUVXZ] [-d cs] [-D arg] [-f fam]
             [-F dir] [-I dir] [-K arg] [-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 ...]
       groff --version [option ...]

Description         top

       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 ⟨⟩.  The groff
       system has all features of the classical roff, but adds many

       The groff program allows control of the whole groff system by
       command-line options.  This is a great simplification in
       comparison to the classical case (which uses pipes only).

Options         top

       --help displays a usage message and exits.

       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 -k.

       -e     Preprocess with eqn.

       -g     Preprocess with grn.

       -G     Preprocess with grap.  Implies -p.

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

       -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 spooler program.

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

       -p     Preprocess with pic.

       -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     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
              following troff requests: .open, .opena, .pso, .sy, and
              .pi.  For security reasons, safer mode is enabled by

       -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

                     lbp    Canon CAPSL printers (LBP-4 and LBP-8 series
                            laser printers; postprocessor is grolbp).

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

                     ps     PostScript output (postprocessor is grops).

                     pdf    Portable Document Format (PDF) output
                            (postprocessor 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
              ‘postprocessor’ (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
              option -S.

              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
              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

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

       -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; see groff_out(5).

   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.  Please consult the grotty(1) man
              page for more details.

       -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; see also

       -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.

Using groff         top

       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.

   Paper size
       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
       convenient interface.

       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 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 classical roff(7) can be avoided.

       The grog(1) program can be used for guessing the correct groff
       command line to format a file.

       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,

              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
       understand.  It is always run first before any other

       Besides these, there are some internal preprocessors that are
       automatically run with some devices.  These aren't visible to the

   Macro packages
       Macro packages can be included in a roff document by using 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.

       Available macro packages include:

       an     is the man page formatter originating in Version 7 Unix
              (1979); see groff_man(7).  It can be specified on the
              command line as -man or -m man.

       doc    is the man page formatter originating in 4.3BSD-Reno
              (1990); see groff_mdoc(7).  It can be specified on the
              command line as -mdoc or -m mdoc.

       andoc  is a wrapper that automatically recognizes whether a
              document uses man or mdoc format and branches to the
              corresponding macro package.  It can be specified on the
              command line as -mandoc or -m mandoc.

       e      is the BSD general-purpose document formatter; see
              groff_me(7).  It can be specified on the command line as
              -me or -m me.

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

       om     (invariably called “mom”) is a modern package written by
              Peter Schaffter specifically for groff.  Consult the mom
              home page ⟨⟩ for extensive
              documentation.  She—for mom takes the female pronoun—can
              be specified on the command line as -mom or -m 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 or -m ms.

       www    is a supplemental package providing HTML-like macros for
              inclusion in arbitrary groff documents; see groff_www(7).

       Details on the naming of macro files and their placement can be
       found in groff_tmac(5); this page also documents some other,
       minor auxiliary macro packages not mentioned here.

   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).

       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

       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

       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)

       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.

       groff 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 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

              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 are available.

              Add information to troff font description files for use
              with groff.

              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.

              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 historically distributed with the X Window

              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.

              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 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 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), 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.

              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

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 | tbl | troff -me -Tutf8 | grotty

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

              groff -p -t -me -T utf8

       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

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

              Directory containing groff's executable commands.

              List of common words for indxbib(1).

              Directory for data files.

              Default index for lkbib(1) and refer(1).

              Documentation directory.

              Example directory.

              Font directory.

              HTML documentation directory.

              Legacy font directory.

              Local font directory.

              Local macro package (tmac file) directory.

              Macro package (tmac file) directory.

              Font directory for compatibility with old versions of
              groff; see grops(1).

              PDF documentation directory.

              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:

              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/1.23.0/font.
       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.

Availability         top

       Information on how to get groff and related information is
       available at the groff page of the GNU website 

       Three groff mailing lists are available:

              bug tracker activity (read-only) ⟨⟩;

              general discussion ⟨⟩; and

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

       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 ⟨⟩, can be found at the grap website 
       ⟨⟩.  This is
       the only grap supported by groff.

Authors         top

       groff was written by James Clark ⟨⟩.  This document
       was rewritten, enhanced, and put under the GNU FDL license in
       2002 by Bernd Warken ⟨⟩.

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:

              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:

       Formatter program:

       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:

       “groff guess” utility:

COLOPHON         top

       This page is part of the groff (GNU troff) project.  Information
       about the project can be found at 
       ⟨⟩.  If you have a bug report
       for this manual page, see ⟨⟩.
       This page was obtained from the project's upstream Git repository
       ⟨⟩ on 2021-04-01.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-03-29.)  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 1.23.0.rc1.259-531129-dir1t3yMarch 2021                     groff(1)

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