Finding empty directories

Question

I need to find empty directories for a given list of directories. Some directories have directories inside it.

If inside directories are also empty I can say main directory is empty otherwise it's not empty.

How can I test this?

For example:

A>A1(file1),A2 this is not empty beacuse of file1
B>B1(no file) this is empty
C>C1,C2 this is empty

Solution 1

Check whether find <dir> -type f outputs anything. Here's an example:

for dir in A B C; do
    [ -z "`find $dir -type f`" ] && echo "$dir is empty"
done

Solution 2

It depends a little on what you want to do with the empty directories. I use the command below when I wish to delete all empty directories within a tree, say test directory.

find test -depth -empty -delete

One thing to notice about the command above is that it will also remove empty files, so use the -type d option to avoid that.

find test -depth -type d -empty -delete

Drop -delete to see the files and directories matched.

If your definition of an empty directory tree is that it contains no files then you be able to stick something together based on whether find test -type f returns anything.

find is a great utility, and RTFM early and often to really understand how much it can do :-)

Solution 3

You can use the following command:

find . -type d -empty

Solution 4

find directory -mindepth 1 -type d -empty -delete

This is the version that I found most interesting. If executed from inside directory, it will delete all empty directories below (a directory is considered empty if it only contains empty directories).

The mindepth option prevents the directory itself from being deleted if it happens to be empty.

Solution 5

find . -type d -empty

finds and lists empty directories and sub-directories in the current tree. E.g. resulting list of empty dirs and subdirs:

./2047
./2032
./2049
./2063
./NRCP26LUCcct1/2039
./NRCP26LUCcct1/2054
./NRCP26LUCcct1/2075
./NRCP26LUCcct1/2070

No operation is made on the directories. They are simply listed. This works for me.

View more solutions

Comments

[Michal aka Miki]

I think Martin's answer is the most appropriate here. The current accepted answer is only an incomplete pseudocode.

[Joseph Holsten]

Related: Checking from shell script if a directory contains files

[Alex S]

-empty only works if the current directory is completely empty, not if the subtree contains no files.

[Alex S]

No, it will not output subdirectories. That's what the -type f is for.

[mosg]

@soField Tested find . -type d -empty with FreeBSD & CentOS. Works fine. What your OS?

[Admin]

the op asks for test/test2 to be returned also

[YasirA]

Howerver if there are empty files, your solution won't yield the message.

[soField]

hp-ux so there is no empty parameter

[mosg]

@soField So, you see, that it's better (for all of us) to post this data at the top of your question...

[Ukko]

Yasir: I would think that a directory containing an empty file wound not be empty itself. Would that not be the correct result?

[devdavid]

Indeed. But I figured he could read the find man page to go further. A script that adjusts depths based on results would work just fine.

[xslash]

find doesn't have -empty on solaris either, but it does have -depth to enforce depth-first traversal so that empty subdirectories can be deleted before the parent directory is checked for emptiness.

[SO Stinks]

-delete implies -depth (at least for GNU findutils 4.4.2)

[P. Dmitry]

You can follow this up with rmdir --ignore-fail-on-non-empty -p directory to get rid of the parents as well.

[Alex S]

@akostadinov: If I create the directories and files as indicated by the OP — mkdir A B C A/A1 A/A2 B/B1 C/C1 C/C2; touch A/A1/file1 — and run the code in my answer, it reports that B and C are empty, as required by the OP. So you will need to be a little more specific than, "it wont work".

[akostadinov]

@MarceloCantos, I said everything needed to reproduce. Having your script work with some example data, does not prove it correct in all corner cases... or course I'm not telling this could be a problem for the OP's use case.

[Alex S]

In the example, B1, C1, and C2 are empty directories for $dir values B and C, and it clearly works for them. I'm not saying you're wrong — there possibly is a bug in my code — but it most certainly isn't clear from your comments what the problem is. Perhaps you could supply an example that fails.

[Alex S]

@akostadinov: I just noticed that I didn't address the above response to you, so here's a ping.

[akostadinov]

@MarceloCantos, looks like I misread the question. It's very ugly lacking punctuation... sorry for confusion. I think your answer is nice.

[Andreas]

This was the most useful version for mye use, thanks

[SO Stinks]

@Pete Peterson My command seems to remove directories that only contain other empty directories (which is what OP also seems to want). I note that your command will usually leave the user in a directory with a missing i-node even if they accomplish what they want, which may be confusing to them. Maybe I'm missing the point.

[Raffi]

did not know about -empty, so convenient!

[anthony]

However on machine that are not the latest and greatest linux. (EG Solaris), then you have no fancy find features like -empty or -delete.

[Martin]

@antofthy been a while since I touched Solaris, but you used to have a choice between Sun's own version and the GNU version of various utilities. GNU tools was prefixed with g so perhaps gfind might work

[anthony]

Something I have done at times, for general clean up. Also done things like rmdir */*/* */* * Though that does not handle 'dot-files' but then in manual situations (cleaning data files) you generally don't expect 'dot-files'. The recursive methods, however are for more automated general clean up, especially in very large directory structures.

[anthony]

In one case was more complicated as I needed to remove empty directories where 'empty' included directories that could contain a single 'readme' file. Anything else in the directory and it wasn't 'empty'. In that example the directory structure involved tens of thousands of sub-directories.

[Olie]

On MacOS-X, for almost empty directories, run find test -name ".DS_Store" -delete first, then the -empty delete command. Also note, like to pushd to the parent directory, so that find test becomes find ., but the rest of the commands are the same.

[Michal aka Miki]

@Martin Can you please add the definition of -depth here i.e. Cause find to perform a depth-first traversal, i.e., directories are visited in post-order and all entries in a directory will acted on before the directory itself. I think it is relevant here.

[OmarOthman]

If you are a Bash noob like me, check what -z means here.

[Znik]

hp-ux curreltny is completly exotic system, usually based on intel itanium cpu. try find GNU tools with its find command.

[hpavc]

You can mix actions as well, such as adding and -ls or -print "find . -depth -type d -empty -ls -delete"

[kittygirl]

@LéoLéopoldHertz준영,what's the difference between add -depth or not in this question?

[Ethan Hohensee]

rmdir -vp helped me immensely since I needed to not just delete all empty dirs under a root, but check for empty dirs and parent dirs after deleting a file. In my situation empty dirs are fine as long as they are not in the tree i'm currently removing a file from. Thanks!

[myol]

Be careful in what order you use -delete and -type d with -o unless you want to loose a few hours googling ext4magic and loose a few gigs of data still to be backed up.