Comment by wombatpm - Hacker Neue

wombatpm Dec 11, 2025 parent

Relevant XKCD

Https://xkcd.com/1168/

orthoxerox Dec 12, 2025

To quote bash.org (or qdb.us?), you have to talk to tar with a German accent:

    tar xzf file.tgz

where xzf stands for "extrakt ze feil"

marcosdumay Dec 12, 2025

It's `xaf`, because the modern world is way too complex for simple Germanic rules to solve it.

But GNU tar was never the issue. It's almost completely straight forward, the only problem it has is people confusing the tar file with the target directory. If you use some UNIX tar, you will understand why everybody hates it.

WJW Dec 12, 2025

Someone once tried this on me during Friday drinks and I successfully conquered the challenge with "tar --help". The challenger tried in vain to claim that this was not valid, but everyone present agreed that an exit code of zero meant that it was a valid solution.

tolciho Dec 12, 2025

  $ tar --help
  tar: unknown option -- -
  usage: tar {crtux}[014578beFfHhjLmNOoPpqsvwXZz]
             [blocking-factor | format | archive | replstr]
             [-C directory] [-I file] [file ...]
         tar {-crtux} [-014578eHhjLmNOoPpqvwXZz] [-b blocking-factor]
             [-C directory] [-F format] [-f archive] [-I file]
             [-s replstr] [file ...]
  $ echo $?
  1

pharrington Dec 12, 2025

That is not GNU tar's output. You might wanna make sure your installation is ok.

edit: maybe i missed the joke?

tolciho Dec 12, 2025

Some drunks in a gnu-shaped echo chamber concluded that the world is gnu-shaped. That's not much a joke, if there is one here. Such presently popular axioms as "unix means linux" or "the userland must be gnu" or "bash is installed" can be shown as poor foundations to reason from by using a unix system that violates all those assumptions. That the XCDD comic did not define what a unix system is is another concern; there are various definitions, some of which would exclude both linux and OpenBSD.

pharrington Dec 15, 2025

Out of curiosity, what OS are you using?

lloeki Dec 12, 2025

> maybe i missed the joke?

the bomb specifies only "unix" so you can't assume GNU (which, aha, is Not Unix)

necovek Dec 12, 2025

This works with GNU tar, but likely not with tar on other Unix systems.

"tar cf /tmp/a.tar $HOME" would, I guess, work on all POSIX systems.

chihuahua Dec 12, 2025

I seem to remember "tar xvf filename.tar" from the 1990s, I'll try that out. If I'm wrong, I'll be dead before I even notice anything. That's better than dying of cancer or Alzheimer's.

anyfoo Dec 12, 2025

I still do that at least once a week. Along with "tar xzpvf" or more complex invocations like:

    tar cvf - -C /foo/bar baz | zstd > foo.tar.zstd

tharkun__ Dec 12, 2025

    tar zxvf

Is burnt into my brain. One of my earliest Linux command line experience required untaring zipped tars.

So yeah that xkcd is "not funny" to me in that sense. Of course I couldn't tell you pretty much any other use without a man page.

necovek Dec 12, 2025

z requires it's compressed with gzip and is likely a GNU extension too (it was j for bzip2 iirc). It's also important to keep f the last because it is parametrized and a filename should follow.

So I'd always go with c (create) instead of x (extract), as the latter assumes an existing tar file (zx or xz even a gzipped tar file too; not sure if it's smart enough to autodetect compress-ed .Z files vs .gz either): with create, higher chances of survival in that xkcd.

thaumasiotes Dec 12, 2025

    tar xvzf file.name

is always a valid command, whether file.name exists or not. When the file doesn't exist, tar will exit with status '2', apparently, but that has no bearing on the validity of the command.

Compare these two logs:

    $ tar xvzf read.me
    tar (child): read.me: Cannot open: No such file or directory
    tar (child): Error is not recoverable: exiting now
    tar: Child returned status 2
    tar: Error is not recoverable: exiting now

    $ tar extract read.me
    tar: invalid option -- 'e'
    Try 'tar --help' or 'tar --usage' for more information.

Do you really not understand the difference between "you told me to do something, but I can't" and "you just spouted some meaningless gibberish"?

necovek Dec 12, 2025

The GGP set the benchmark at "returns exit code 0" (for "--help"), and even with XKCD, the term in use is "valid command" which can be interpreted either way.

The rest of your slight is unneccessary, but that's your choice to be nasty.

tharkun__ Dec 14, 2025

Like I said, I was operating on a lot of zipped tars. Not sure what you are replying about.

The other commenter already mentioned that the xkcd just said "valid", not return 0 (which to be fair is what the original non xkcd required so I guess fair on the mixup)

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