NAME | SYNOPSIS | DESCRIPTION | OPTIONS | USING GROFF | ENVIRONMENT | EXAMPLES | BUGS | POSITIONS FROM INSTALLATION | AVAILABILITY | SEE ALSO | COPYING (LICENSE) | AUTHORS | COLOPHON

GROFF(1)                   General Commands Manual                  GROFF(1)

NAME         top

       groff - front-end for the groff 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 | --help
       groff -v | --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 ⟨http://www.gnu.org⟩.  The groff system has all fea‐
       tures of the classical roff, but adds many extensions.

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

OPTIONS         top

       The command line is parsed according to the usual GNU convention.
       The whitespace between a command line option and its argument is
       optional.  Options can be grouped behind a single ‘-’ (minus
       character).  A filename of - (minus character) denotes the standard
       input.

       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.

       -h
       --help Print a help message.

       -I dir This option may be used to specify a directory to search for
              files (both those on the command line and those named in .psbb
              and .so requests, and \X'ps: import' and \X'ps: file'
              escapes).  The current directory is always searched first.
              This option may be specified more than once; the directories
              are searched in the order specified.  No directory search is
              performed for files specified using an absolute path.  This
              option implies the -s option.

       -j     Preprocess with chem.  Implies -p.

       -k     Preprocess with preconv.  This is run before any other
              preprocessor.  Please refer to preconv's manual page for its
              behaviour if no -K (or -D) option is specified.

       -K arg Set input encoding used by preconv to arg.  Implies -k.

       -l     Send the output to a spooler program for printing.  The
              command that should be used for this is specified by the print
              command in the device description file, see groff_font(5).  If
              this command is not present, the output is piped into the
              lpr(1) program by default.  See options -L and -X.

       -L arg Pass arg to the spooler program.  Several arguments should be
              passed with a separate -L option each.  Note that groff does
              not prepend ‘-’ (a minus sign) to arg before passing it to the
              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 -option
       -P -option -P arg
              Pass -option or -option arg to the postprocessor.  The option
              must be specified with the necessary preceding minus sign(s)
              ‘-’ or ‘--’ because groff does not prepend any dashes before
              passing it to the postprocessor.  For example, to pass a title
              to the gxditview postprocessor, the shell command

                     groff -X -P -title -P 'groff it' foo

              is equivalent to

                     groff -X -Z foo | gxditview -title 'groff it' -

       -R     Preprocess with refer.  No mechanism is provided for passing
              arguments to refer because most refer options have equivalent
              language elements that can be specified within the document.
              See refer(1) for more details.

       -s     Preprocess with soelim.

       -S     Safer mode.  Pass the -S option to pic and disable the follow‐
              ing troff requests: .open, .opena, .pso, .sy, and .pi.  For
              security reasons, safer mode is enabled by default.

       -t     Preprocess with tbl.

       -T dev Set output device to dev.  For this device, troff generates
              the intermediate output; see groff_out(5).  Then groff calls a
              postprocessor to convert troff's intermediate output to its
              final format.  Real devices in groff are

                     dvi    TeX DVI format (postprocessor is grodvi).

                     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).

                     lj4    HP LaserJet4 compatible (or other PCL5 compati‐
                            ble) printers (postprocessor is grolj4).

                     ps     PostScript output (postprocessor is grops).

                     pdf    Portable Document Format (PDF) output (postpro‐
                            cessor is gropdf).

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

                     ascii  7bit ASCII.

                     cp1047 Latin-1 character set for EBCDIC hosts.

                     latin1 ISO 8859-1.

                     utf8   Unicode character set in UTF-8 encoding.  This
                            mode has the most useful fonts for TTY mode, so
                            it is the best mode for TTY output.

              The following arguments select gxditview as the ‘postproces‐
              sor’ (it is rather a viewing program):

                     X75    75dpi resolution, 10pt document base font.

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

                     X100   100dpi resolution, 10pt document base font.

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

              The default device is ps.

       -U     Unsafe mode.  Reverts to the (old) unsafe behaviour; see
              option -S.

       -v
       --version
              Output version information of groff and of all programs that
              are run by it; that is, the given command line is parsed in
              the usual way, passing -v to all subprograms.

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

       -X     Use gxditview instead of using the usual postprocessor to
              (pre)view a document.  The printing spooler behavior as out‐
              lined with options -l and -L is carried over to gxditview(1)
              by determining an argument for the -printCommand option of
              gxditview(1).  This sets the default Print action and the cor‐
              responding menu entry to that value.  -X only produces good
              results with -Tps, -TX75, -TX75-12, -TX100, and -TX100-12.
              The default resolution for previewing -Tps output is 75dpi;
              this can be changed by passing the -resolution option to
              gxditview, for example

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

       -z     Suppress output generated by troff.  Only error messages are
              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     ASCII approximation of output.

       -b     Backtrace on error or warning.

       -c     Disable color output.  Please consult the grotty(1) man page
              for more details.

       -C     Enable compatibility mode.

       -d cs
       -d name=s
              Define string.

       -E     Disable troff error messages.

       -f fam Set default font family.

       -F dir Set path for font DESC files.

       -i     Process standard input after the specified input files.

       -m name
              Include macro file name.tmac (or tmac.name); see also
              groff_tmac(5).

       -M dir Path for macro files.

       -n num Number the first page num.

       -o list
              Output only pages in list.

       -r cn
       -r name=n
              Set number register.

       -w name
              Enable warning name.  See troff(1) for names.

       -W name
              disable warning name.  See troff(1) for names.

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 ...

   Front-ends
       The groff program is a wrapper around the troff(1) program.  It
       allows to specify the preprocessors by command line options and auto‐
       matically runs the postprocessor that is appropriate for the selected
       device.  Doing so, the sometimes tedious piping mechanism of classi‐
       cal roff(7) can be avoided.

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

       The groffer(1) program is an allround-viewer for groff files and man
       pages.

   Preprocessors
       The groff preprocessors are reimplementations of the classical pre‐
       processors with moderate extensions.  The standard preprocessors dis‐
       tributed with the groff package are

       eqn(1) for mathematical formulae,

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

       pic(1) for drawing diagrams,

       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 under‐
       stand.  It is always run first before any other preprocessor.

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

   Macro Packages
       Macro packages can be included by option -m.  The groff system imple‐
       ments and extends all classical macro packages in a compatible way
       and adds some packages of its own.  Actually, the following macro
       packages come with groff:

       man    The traditional man page format; see groff_man(7).  It can be
              specified on the command line as -man or -m man.

       mandoc The general package for man pages; it automatically recognizes
              whether the documents uses the man or the mdoc format and
              branches to the corresponding macro package.  It can be speci‐
              fied on the command line as -mandoc or -m mandoc.

       mdoc   The BSD-style man page format; see groff_mdoc(7).  It can be
              specified on the command line as -mdoc or -m mdoc.

       me     The classical me document format; see groff_me(7).  It can be
              specified on the command line as -me or -m me.

       mm     The classical mm document format; see groff_mm(7).  It can be
              specified on the command line as -mm or -m mm.

       ms     The classical ms document format; see groff_ms(7).  It can be
              specified on the command line as -ms or -m ms.

       www    HTML-like macros for inclusion in arbitrary groff documents;
              see groff_www(7).

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

   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).

       The groff language as a whole is described in the (still incomplete)
       groff info file; a short (but complete) reference 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 clas‐
       sical nroff.  It tries to automatically select the proper output
       encoding, according to the current locale.

       The formatter program generates intermediate output; see
       groff_out(7).

   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 fol‐
       lows.

       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-ori‐
              ented terminals or line-printers.

       Today, most printing or drawing hardware is handled by the operating
       system, by device drivers, or by software interfaces, usually accept‐
       ing PostScript.  Consequently, there isn't an urgent need for more
       hardware device postprocessors.

       The groff software devices for conversion into other document file
       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.

       groffer(1)
              General viewer program for groff files and man pages.

       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 distributed with X window.

       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 search for the devname
              directory in addition to the default ones.  See troff(1) and
              groff_font(5) for more details.

       GROFF_TMAC_PATH
              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.

       GROFF_TMPDIR
              The directory in which temporary files are created.  If this
              is not set but the environment variable TMPDIR instead,
              temporary files are created in the directory $TMPDIR.  On MS-
              DOS and Windows 32 platforms, the environment variables TMP
              and TEMP (in that order) are searched also, after GROFF_TMPDIR
              and TMPDIR.  Otherwise, temporary files are created in /tmp.
              The refer(1), groffer(1), grohtml(1), and grops(1) commands
              use temporary files.

       GROFF_TYPESETTER
              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.

EXAMPLES         top

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

       To process a roff file using the preprocessors tbl and pic and the me
       macro set, classical troff had to be called by

              pic foo.me | tbl | troff -me -Tlatin1 | grotty

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

              groff -p -t -me -T latin1 foo.me

       An even easier way to call this is to use grog(1) to guess the pre‐
       processor and macro options and execute the generated command (by
       using backquotes to specify shell command substitution)

              `grog -Tlatin1 foo.me`

       The simplest way is to view the contents in an automated way by call‐
       ing

              groffer foo.me

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.

       Report bugs to the groff mailing list ⟨bug-groff@gnu.org⟩.  Include a
       complete, self-contained example that allows the bug to be repro‐
       duced, and say which version of groff you are using.

POSITIONS FROM INSTALLATION         top

       There are some directories in which groff installs all of its data
       files.  Due to different installation habits on different operating
       systems, their locations are not absolutely fixed, but their function
       is clearly defined and coincides on all systems.

   Collection of Installation Directories
       This section describes the position of all files of the groff package
       after the installation — got from Makefile.comm at the top of the
       groff source package.

       /usr/dict/papers/Ind
              index directory and index name

       /usr/lib/font
              legacy font directory

       /usr/local/bin
              directory for binary programs

       /usr/local/lib/groff/site-tmac
              system tmac directory

       /usr/local/share/doc/groff-1.22.3
              documentation directory

       /usr/local/share/doc/groff-1.22.3/examples
              directory for examples

       /usr/local/share/doc/groff-1.22.3/html
              documentation directory for html files

       /usr/local/share/doc/groff-1.22.3/pdf
              documentation directory for pdf files

       /usr/local/share/groff/1.22.3
              data subdirectory

       /usr/local/share/groff/1.22.3/eign
              file for common words

       /usr/local/share/groff/1.22.3/font
              directory for fonts

       /usr/local/share/groff/1.22.3/oldfont
              directory for old fonts

       /usr/local/share/groff/1.22.3/tmac
              tmac directory

       /usr/local/share/groff/1.22.3/tmac/mm
              mm tmac directory

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

       /usr/local/share/groff/site-tmac
              local tmac directory

   groff Macro Directory
       This contains all information related to macro packages.  Note that
       more than a single directory is searched for those files as
       documented in groff_tmac(5).  For the groff installation
       corresponding to this document, it is located at
       /usr/local/share/groff/1.22.3/tmac.  The following files contained in
       the groff macro directory have a special meaning:

       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/1.22.3/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 GNU website ⟨http://www.gnu.org/software/groff⟩.

       Three groff mailing lists are available:

              for reporting bugs ⟨bug-groff@gnu.org⟩.

              for general discussion of groff, ⟨groff@gnu.org⟩.

              the groff commit list ⟨groff-commit@ffii.org⟩, a read-only
              list showing logs of commitments to the groff repository.

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

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

SEE ALSO         top

       The groff info file contains all information on the groff system
       within a single document, providing many examples and background
       information.  See info(1) on how to read it.

       Due to its complex structure, the groff system has many man pages.
       They can be read with man(1) or groffer(1).

       But there are special sections of man-pages.  groff has man-pages in
       sections 1, 5,and 7.  When there are several man-pages with the same
       name in the same man section, the one with the lowest section is
       should as first.  The other man-pages can be shown anyway by adding
       the section number as argument before the man-page name.  Reading the
       man-page about the groff language is done by one of
              man 7 groff
              groffer 7 groff

       Introduction, history and further readings:
              roff(7).

       Viewer for groff files:
              groffer(1), gxditview(1), xditview(1x).

       Wrapper programs for formatters:
              groff(1), grog(1).

       Roff preprocessors:
              eqn(1), grn(1), pic(1), chem(1), preconv(1), refer(1),
              soelim(1), tbl(1), grap(1).

       Roff language with the groff extensions:
              groff(7), groff_char(7), groff_diff(7), groff_font(5).

       Roff formatter programs:
              nroff(1), troff(1), ditroff(7).

       The intermediate output language:
              groff_out(7).

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

       Groff macro packages and macro-specific utilities:
              groff_tmac(5), groff_man(7), groff_mdoc(7), groff_me(7),
              groff_mm(7), groff_mmse(7), groff_mom(7), groff_ms(7),
              groff_www(7), groff_trace(7), mmroff(7).

       The following utilities are available:
              addftinfo(1), afmtodit(1), eqn2graph(1), gdiffmk(1),
              grap2graph(1), groffer(1), gxditview(1), hpftodit(1),
              indxbib(1), lkbib(1), lookbib(1), pdfroff(1), pfbtops(1),
              pic2graph(1), tfmtodit(1), xtotroff(1).

COPYING (LICENSE)         top

       Copyright © 1989-2014 Free Software Foundation, Inc.

       Rewritten in 2002 by Bernd Warken <groff-bernd.warken-72@web.de>

       This document is part of groff, a free GNU software project.

       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.3 or
       any later version published by the Free Software Foundation; with the
       Invariant Sections being the macro definition or .co and .au, with no
       Front-Cover Texts, and with no Back-Cover Texts.

       A copy of the Free Documentation License is included as a file called
       FDL in the main directory of the groff source package.

       It is also available in the internet at the GNU copyleft site 
       ⟨http://www.gnu.org/copyleft/fdl.html⟩.

AUTHORS         top

       This document is based on the original groff man page written by
       James Clark ⟨jjc@jclark.com⟩.  It was rewritten, enhanced, and put
       under the FDL license by Bernd Warken <groff-bernd.warken-72@web.de>.
       It is maintained by Werner Lemberg ⟨wl@gnu.org⟩.

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 tarball groff-1.22.3.tar.gz fetched from
       ⟨ftp://ftp.gnu.org/gnu/groff/⟩ on 2016-08-07.  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 Version 1.22.3           4 November 2014                      GROFF(1)