Provided by: groff-base_1.21-7_amd64 bug

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

       ·      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.

       ·      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.

       ·      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.

       ·      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.

       ·      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.