grog

GROG(1)                     General Commands Manual                    GROG(1)

NAME
       grog - guess options for a following groff command

SYNOPSIS
       grog [-C] [-T device] [--run] [--warnings] [--ligatures] [groff-option
            ...] [--] [filespec ...]

       grog -h
       grog --help

       grog -v
       grog --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.  A suitable device is now always written as -Tdevice including
       the groff default as -T ps.

       The  corresponding  groff command is usually displayed in standard out-
       put.  With the option --run, the generated line is output into standard
       error  and  the  generated groff command is run on the standard output.
       groffer(1) relies on a perfectly running groff(1).

OPTIONS
       The option -v or --version prints information on  the  version  number.
       Also  -h or --help prints usage information.  Both of these options au-
       tomatically end the grog program.  Other options are  thenignored,  and
       no  groff  command  line is generated.  The following 3 options are the
       only grog options,

       -C     this option means enabling the groff compatibility  mode,  which
              is also transfered to the generated groff command line.

       --ligatures
              this  option forces to include the arguments -P-y -PU within the
              generated groff command line.

       --run  with this option, the command line is output at  standard  error
              and then run on the computer.

       --warnings
              with  this option, some more warnings are output to standard er-
              ror.

       All other specified short options (words starting with one minus  char-
       acter  -)  are  interpreted as groff options or option clusters with or
       without argument.  No space is allowed between options and their  argu-
       ment.   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, -g, -G, -j, -p, -R, -s, -t (preprocessors); and -man, -mdoc,
       -mdoc-old, -me, -mm, -mom, and -ms (macro packages).

       The guessed groff command including those options and the  found  file-
       spec 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 op-
       tions.

       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  pack-
       age.  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.

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 -p -t -e -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 of the former example 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 with-
       out any interface to grog.  These are the option cluster -ksS  consist-
       ing of -k, -s, and -S; and the option -T with argument dvi.  The output
       is
              groff -k -s -S -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.

AUTHORS
       grog was originally written by James Clark.  The current Perl implemen-
       tation was written by Bernd Warken <groff-bernd.warken-72@web.de>  with
       contributions  from Ralph Corderoy, and is maintained by Werner Lemberg
       <wl@gnu.org>.

SEE ALSO
       groff(1), groffer(1)

groff 1.22.4                     21 March 2020                         GROG(1)