19

I can probably write a shell script to find files only, then pass the list to tar, but I am wondering whether there already is a built-in feature in tar that allows doing just that, in a single command line?

For example, I found the --no-recursion switch, but when I do:

tar --no-recursion -cvf mydir.tar mydir

It only archives the names of the entries in the directory (including subdirectories!), but it doesn't archive any files.

I also tried:

 tar --no-recursion -cvf mydir.tar mydir/*

But while it archives files only, it also archives the names of the subdirectories.

Is there a way to tell tar files only, no directories?

10
  • 5
    Just to clarify: do you want to create an archive with "flat" structure (i.e. all files mixed up in one directory)? Commented Nov 18, 2011 at 14:47
  • 1
    You could create a new directory and find mydir -type f |xargs cp -t tempdir and then tar tempdir.
    – Kevin
    Commented Nov 18, 2011 at 15:05
  • @rozcietrzewiacz Yes, flat, but only from that directory, not from subdirectories.
    – ateiob
    Commented Nov 18, 2011 at 15:17
  • 1
    OK, I think I see what you're trying to do. How about find mydir -depth 1 -type f | xargs tar cf mydir.tar
    – Kevin
    Commented Nov 18, 2011 at 15:30
  • 3
    Ah, spaces. Use find's -exec instead: find mydir -maxdepth 1 -type f -exec tar cvf mydir.tar {} +. The + puts all the files on the same command line like xargs.
    – Kevin
    Commented Nov 18, 2011 at 15:49

8 Answers 8

17

When you want to use find with tar, the best way is to use cpio instead of tar. cpio can write tar archives and is designed to take the list of files to archive from stdin.

find mydir -maxdepth 1 -type f -print0 | cpio -o -H ustar -0 > mydir.tar

Using find and cpio is a more unix-y approach in that you let find do the file selection with all the power that it has, and let cpio do the archiving. It is worth learning this simple use of cpio, as you find it easy to solve problems you bang your ahead against when trying tar.

4
  • Brilliant! I've used cpio in the distant past, but never knew of the ustar option. Commented Feb 23, 2016 at 18:07
  • 2
    This worked much better for me than the accepted answer. Commented Sep 22, 2016 at 16:47
  • 1
    just a nit. the -maxdepth 1 should come before the -type f or you'll get a warning from some finds
    – kdubs
    Commented Dec 23, 2019 at 18:24
  • Thanks @kdubs. I've updated the answer to put -maxdepth before -type.
    – camh
    Commented Dec 28, 2019 at 3:20
13

As camh points out, the previous command had a small problem in that given too many file names, it would execute more than once, with later invocations silently wiping out the previous runs. Since we're not compressing too, we can append instead of overwrite:

find mydir -maxdepth 1 -type f -print0 | xargs -0 tar Avf mydir.tar
find mydir -maxdepth 1 -type f -exec tar Avf mydir.tar {} +

Iocnarz's answer of using tar's --null and -T options works as well. If you have cpio installed, camh's answer using it is also fine. And if you have zsh and don't mind using it for a command, Gilles's answer using a zsh glob (*(.)) seems the most straightforward.


The key was the -maxdepth option. Final answer, dealing with spaces appropriately:

find mydir -maxdepth 1 -type f -print0 | xargs -0 tar cvf mydir.tar

This should also work:

find mydir -maxdepth 1 -type f -exec tar cvf mydir.tar {} +
4
  • 4
    Both of these can result in multiple invocations of tar. Both xargs and find with the + variant has a maximum number of arguments that can be passed to tar. This will result in the second invocation of tar overwriting the output of the first.
    – camh
    Commented Apr 6, 2012 at 22:30
  • 2
    Expanding on the xargs limit, xargs default to a maximum 128KiB command line. If the file list is larger, you get a second (or more) invocation of the command (tar), leading to silent data loss. You can use -x to force xargs to fail instead of losing data, and while better than a silent data loss bug, it's still not ideal. This sort bug is so dangerous because everything seems OK at first, but as the file list grows over time, you start triggering it and may not notice until you try to restore your backup. Then it's too late.
    – camh
    Commented Apr 6, 2012 at 22:49
  • @camh You're right, thanks for pointing that out; I've updated to reflect that.
    – Kevin
    Commented Apr 7, 2012 at 3:22
  • 1
    The "final answer" is not correct, if you use "tar c" without -T you might get partial results.
    – eckes
    Commented May 31, 2013 at 17:27
4

You may even use find ... -print0 and tar ... --null directly without using xargs at all.

find . -maxdepth 1 -type f -print0 | tar cvf mydir.tar --null -T -

In the given example, the --no-recursion option to tar is not necessary because only paths of files (and not directories) will be passed from find to tar.

Using the --no-recursion option to tar in the following example, however, prevents tar from double archiving directories. find will do the directory tree recursion instead of tar then.

# compare
find . -print0 | tar cf mydir.tar --null -T -
tar -tf mydir.tar | nl

find . -print0 | tar cf mydir.tar --null --no-recursion -T -
tar -tf mydir.tar | nl
3

As the introductory paragraph in man tar says (last sentence),

The use of a directory name always implies that the subdirectories below should be included in the archive.

Which I understand as a "no" answer to your question.

2
  • Good catch, except that tar now includes numerous exclusion meachisms (e.g. --no-recursion, --exclude-tag, etc.). I am looking into --exclude-tag which looks promising but seems to be the exact opposite of what I am looking for.
    – ateiob
    Commented Nov 18, 2011 at 15:21
  • I tried this and I saw characters being removed from long pathnames. Using tar with -T and --null as camh proposed avoided this problem. Commented May 26, 2015 at 19:45
3

I'm not sure I understand your requirements. If you want to store the regular files in mydir but not its subdirectories, the easiest way is to use zsh, where matching regular files only is the simple matter of using the . glob qualifier:

tar cf mydir.tar mydir/*(.)
1
star -c -C startdir -find . ! -type d > out.tar

Omit -C startdir and replace . with startdir if it should appear in the archive.

This is the most efficient method based on the features of libfind. Libfind also offers primaries -chown -chgrp -chmod that modify struct stat in place and allow to archive different metadata. This also works in list and extract mode and avoids the need to extract the whole archive in many cases.

7
  • Can you use -find in -copy mode. The man page synopsis suggests you can but I've not been able to make it work (while trying to answer How to copy modified files while preserving folder structure) (with schily-2016-02-10) Commented Feb 23, 2016 at 17:58
  • I did not test this for a longer time. It may be that there currently is a bug. The man page says that the last argument would be the extraction directory, but when I try this, I get: "Path arguments not yet supported in extract mode". Is this what you get when you try?
    – schily
    Commented Feb 23, 2016 at 18:39
  • yes. The man page also says you can only have find arguments after -find but if I put the destination directory before -find I also get an error Commented Feb 23, 2016 at 20:06
  • There is code to switch off the find code in the extract process and the error message is from an incorrect check that expects -c but should also permit -copy. In -copy mode, the find parser should not include the last argument.
    – schily
    Commented Feb 23, 2016 at 22:35
  • 1
    A final solution now has been published in the schily tools at sourceforge.net/projects/schilytools/files/schily-2016-03-11.tar.bz2 this also fixes a problem from a missing setlocale() in star and this enables -C directrory for star -find.
    – schily
    Commented Mar 11, 2016 at 10:53
0

I might have found a solution.

find mydir -type f -printf '%P\0'|tar czvf mydir.tar.gz -C mydir --null -T -

This might be costly a little, but anyway it will work, because this doesn't depend on xargs.

-1

dir=your_dir ; cd $dir ; tar -cvf file.tar `find . -maxdepth 1 -type f -print`

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