# grog(1) - man - phpMan [GROG(1)](https://www.chedong.com/phpMan.php/man/GROG/1/markdown) General Commands Manual [GROG(1)](https://www.chedong.com/phpMan.php/man/GROG/1/markdown) ## 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)](https://www.chedong.com/phpMan.php/man/groff/1/markdown) options are needed to perform the input with the **groff** program. A suitable device is now always written as **-T**_device_ including the groff default as **-T** **ps**. The corresponding **groff** command is usually displayed in standard output. 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)](https://www.chedong.com/phpMan.php/man/groffer/1/markdown) relies on a perfectly running [**groff**(1)](https://www.chedong.com/phpMan.php/man/groff/1/markdown). ## OPTIONS The option **-v** or **--version** prints information on the version number. Also **-h** or **--help** prints usage information. Both of these options automatically 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 the generated **groff** command line. ### --ligatures this option forces to include the arguments **-P-y** **-PU** within the generated **groff** com‐ mand 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 error. 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 **-m**_arg_ 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 _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 **-m**_arg_ options. The **groff** program has trouble when the wrong **-m**_arg_ 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 **-m**_arg_ 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 **-m**_arg_ 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 **-m**_arg_ 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)](https://www.chedong.com/phpMan.php/man/groffer/1/markdown) 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 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 -k -s -S -Tdvi grnexmpl.g so no additional option was added by **grog**. As no option **-m**_arg_ was found by **grog** this file does not use a macro package. ## AUTHORS **grog** was originally written by James Clark. The current Perl implementation was written by Bernd Warken ⟨⟩ with contributions from Ralph Corderoy, and is maintained by Werner Lemberg ⟨⟩. ## SEE ALSO [**groff**(1)](https://www.chedong.com/phpMan.php/man/groff/1/markdown), [**groffer**(1)](https://www.chedong.com/phpMan.php/man/groffer/1/markdown) groff 1.22.4 23 March 2022 [GROG(1)](https://www.chedong.com/phpMan.php/man/GROG/1/markdown)