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### 3.5 GNU `tar` documentation

Being careful, the first thing is really checking that you are using GNU `tar`, indeed. The `--version` option causes `tar` to print information about its name, version, origin and legal status, all on standard output, and then exit successfully. For example, ‘`tar --version`’ might print:

    tar (GNU tar) 1.27.1
    Copyright (C) 2013 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.

    Written by John Gilmore and Jay Fenlason.

The first occurrence of ‘`tar`’ in the result above is the program name in the package (for example, `rmt` is another program), while the second occurrence of ‘`tar`’ is the name of the package itself, containing possibly many programs. The package is currently named ‘`tar`’, after the name of the main program it contains6.

Another thing you might want to do is checking the spelling or meaning of some particular `tar` option, without resorting to this manual, for once you have carefully read it. GNU `tar` has a short help feature, triggerable through the `--help` option. By using this option, `tar` will print a usage message listing all available options on standard output, then exit successfully, without doing anything else and ignoring all other options. Even if this is only a brief summary, it may be several screens long. So, if you are not using some kind of scrollable window, you might prefer to use something like:

    $ tar --help | less

presuming, here, that you like using `less` for a pager. Other popular pagers are `more` and `pg`. If you know about some keyword which interests you and do not want to read all the `--help` output, another common idiom is doing:

    tar --help | grep keyword

for getting only the pertinent lines. Notice, however, that some `tar` options have long description lines and the above command will list only the first of them.

The exact look of the option summary displayed by `tar --help` is configurable. See Configuring Help Summary, for a detailed description.

If you only wish to check the spelling of an option, running `tar --usage` may be a better choice. This will display a terse list of `tar` options without accompanying explanations.

The short help output is quite succinct, and you might have to get back to the full documentation for precise points. If you are reading this paragraph, you already have the `tar` manual in some form. This manual is available in a variety of forms from http://www.gnu.org/software/tar/manual. It may be printed out of the GNU `tar` distribution, provided you have TeX already installed somewhere, and a laser printer around. Just configure the distribution, execute the command ‘`make dvi`’, then print `doc/tar.dvi` the usual way (contact your local guru to know how). If GNU `tar` has been conveniently installed at your place, this manual is also available in interactive, hypertextual form as an Info file. Just call ‘`info tar`’ or, if you do not have the `info` program handy, use the Info reader provided within GNU Emacs, calling ‘`tar`’ from the main Info menu.

There is currently no `man` page for GNU `tar`. If you observe such a `man` page on the system you are running, either it does not belong to GNU `tar`, or it has not been produced by GNU. Some package maintainers convert `tar --help` output to a man page, using `help2man`. In any case, please bear in mind that the authoritative source of information about GNU `tar` is this Texinfo documentation.

#### Footnotes

### (6)

There are plans to merge the `cpio` and `tar` packages into a single one which would be called `paxutils`. So, who knows if, one of this days, the `--version` would not output ‘`tar (GNU paxutils) 3.2`’.

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