GROG(1)                    OpenBSD Reference Manual                    GROG(1)



NAME
       grog - guess options for groff command

SYNOPSIS
       grog [-C] [groff-option ...] [--] [filespec ...]
       grog -h | --help
       grog -v | --version

DESCRIPTION
       grog reads the input (file names or standard input) and guesses which
       of the groff(1) options are needed to perform the input with the groff
       program.  The corresponding groff command is output.

OPTIONS
       The only grog options recognized are -C (which is also passed on) to
       enable compatibility mode; -v and --version print information on the
       version number; and -h and --help print usage information.  -v,
       --version, -h, and --help stop the program directly without printing a
       groff command to standard output.

       All other specified short options (words starting with one minus
       character -) are interpreted as groff options or option clusters with
       or without argument.  No space is allowed between options and their
       argument.  Except from the -marg options, all options will be passed
       on, i.e. they are included unchanged in the command for the output
       without effecting the work of grog.

       A filespec argument can either be the name of an existing file or a
       single minus - to mean standard input.  If no filespec is specified
       standard input is read automatically.

DETAILS
       grog reads all filespec parameters as a whole.  It tries to guess which
       of the following groff options are required for running the input under
       groff: -e, -man, -me, -mm, -mom, -ms, -mdoc, -mdoc-old, -p, -R, -g, -G,
       -s, and -t.  The guessed groff command including those options and the
       found filespec parameters is put on the standard output.

       It is possible to specify arbitrary groff options on the command line.
       These are passed on the output without change, except for the -marg
       options.

       The groff program has trouble when the wrong -marg option or several of
       these options are specified.  In these cases, grog will print an error
       message and exit with an error code.  It is better to specify no -marg
       option.  Because such an option is only accepted and passed when grog
       does not find any of these options or the same option is found.

       If several different -marg options are found by grog an error message
       is produced and the program is terminated with an error code.  But the
       output is written with the wrong options nevertheless.

       Remember that it is not necessary to determine a macro package.  A roff
       file can also be written in the groff language without any macro
       package.  grog will produce an output without an -marg option.

       As groff also works with pure text files without any roff requests,
       grog cannot be used to identify a file to be a roff file.

       The groffer(1) program heavily depends on a working grog.

       The grog source contains two files written in different programming
       languages: grog.pl is the Perl version, while grog.sh is a shell script
       using BR awk (1).  During the run of make(1), it is determined whether
       the system contains a suitable version of perl(1).  If so, grog.pl is
       transformed into grog; otherwise grog.sh is used instead.

EXAMPLES
       o      Calling

                     grog meintro.me

              results in

                     groff -me meintro.me

              So grog recognized that the file meintro.me is written with the
              -me macro package.

       o      On the other hand,

                     grog pic.ms

              outputs

                     groff -pte -ms pic.ms

              Besides determining the macro package -ms, grog recognized that
              the file pic.ms additionally needs -pte, the combination of -p
              for pic, -t for tbl, and -e for eqn.

       o      If both files are combined by the command

                     grog meintro.me pic.ms

              an error message is sent to standard error because groff cannot
              work with two different macro packages:

                     grog: error: there are several macro packages: -me -ms

              Additionally the corresponding output with the wrong options is
              printed to standard output:

                     groff -pte -me -ms meintro.me pic.ms

              But the program is terminated with an error code.

       o      The call of

                     grog -ksS -Tdvi grnexmpl.g

              contains several groff options that are just passed on the
              output without any interface to grog.  These are the option
              cluster -ksS consisting of -k, -s, and -S; and the option -T
              with argument dvi.  The output is

                     groff -ksS -Tdvi grnexmpl.g

              so no additional option was added by grog.  As no option -marg
              was found by grog this file does not use a macro package.

       o      grog can also handle files using the chem language.  The example

                     grog chAh_brackets.chem

              outputs

                     chem chAh_brackets.chem | groff -pe

              So chem is run first and groff is appended.  The option -p for
              pic is implied automatically by chem.  Additionally, the file
              uses eqn with -e.

SEE ALSO
       groff(1), troff(1), tbl(1), pic(1), eqn(1), refer(1), grn(1), grap(1),
       soelim(1), groff_me(7), groff_ms(7), groff_mm(7), groff_mom(7),
       groff_man(7), groffer(1)

COPYING
       Copyright (C) 1989-2000, 2001, 2002, 2003, 2006, 2007, 2009, 2010 Free
       Software Foundation, Inc.  Written by James Clark.  Maintained by
       Werner Lemberg <wl@gnu.org>.  Rewritten and put under GPL by Bernd
       Warken.

       This file is part of grog, which is part of groff, a free software
       project.  You can redistribute it and/or modify it under the terms of
       the GNU General Public License (GPL) as published by the Free Software
       Foundation, either version 2, or (at your option) any later version.

       You should have received a copy of the GNU General Public License along
       with groff, see the files COPYING and LICENSE in the top directory of
       the groff source package.  Or read the man page gpl(1).  You can also
       write to the Free Software Foundation, 51 Franklin St - Fifth Floor,
       Boston, MA 02110-1301, USA.



Groff Version 1.21             31 December 2010                        GROG(1)
