Command to delete directories whose contents are less than a given size

directoryfind

I'm working in a directory ~/foo which has subdirectories

~/foo/alpha
~/foo/beta
~/foo/epsilon
~/foo/gamma

I would like to issue a command that checks the total size under each "level 1" subdirectory of ~/foo and deletes the directory along with its contents if the size is under a given amount.

So, say I'd like to delete the directories whose contents have less than 50K. Issuing $ du -sh */ returns

8.0K alpha/
114M beta/
20K  epsilon/
1.2G gamma/

I'd like my command to delete ~/alpha and ~/epsilon along with their contents. Is there such a command? I suspect this can be done with find somehow but I'm not quite sure how.

Best Answer

With GNU find and GNU coreutils, and assuming your directories don't have newlines in their names:

find ~/foo -mindepth 1 -maxdepth 1 -type d -exec du -ks {} + | awk '$1 <= 50' | cut -f 2-

This will list directories with total contents smaller than 50K. If you're happy with the results and you want to delete them, add | xargs -d \\n rm -rf to the end of the command line.

Sample data

And I had sample directories with files in them like this:

$ mkdir -p dirs/{1..5}
$ touch dirs/{1..5}/afile

Resulting in this:

$ tree dirs/
dirs/
|-- 1
|   `-- afile
|-- 2
|   `-- afile
|-- 3
|   `-- afile
|-- 4
|   `-- afile
`-- 5
    `-- afile

Example run

Now if we run this command against this tree:

$ find dirs/ -type f -print0 | fgrep -zFvf ./ignore.txt
dirs/5/afiledirs/4/afiledirs/3/afile

We can see that we're only getting back the files that are in directories not listed in ignore.txt.

So we can add a rm to the end to remove the non-excluded files.

$ find dirs/ -type f -print0 | fgrep -zFvf ./ignore.txt | xargs -0 rm -f

Checking we can see that it worked:

$ tree dirs/
dirs/
|-- 1
|   `-- afile
|-- 2
|   `-- afile
|-- 3
|-- 4
`-- 5

Problems to be worked out

One big problem with this approach is that the strings in the ignore.txt file might match other portions of the directory structure. So some care needs to be paid to making sure that the strings in this file are unique in the way that you expect.

Some blocking could be put around the strings so that they're anchored to the beginning or the end of the string to protect them.

Details

The above commands are doing the following:

finding all the files under the directory dirs
filtering out any files that are under a directory present in the igonre.txt file
passing the filter list via xargs to the rm -f command

Expected behavior of `find -depth` if execute permission denied for subdirectory

Probably the better approach is to handle such directories explicitly. I don't know whether these are standard features but at least with Gnu find this is possible:

find . \( -type d \( \! -executable -or \! -readable \) \) -prune -or -type d

of course, it is also possible to print a message if a directory is ignored:

find . \( -type d \( \! -executable -or \! -readable \) \) \
  -printf "Permission denied: %p\n" -prune -or -type d -print

Best Answer

Related Solutions

Bash – Delete all files in directories except those whose path are listed in a file

Sample data

Example run

Problems to be worked out

Details

Expected behavior of `find -depth` if execute permission denied for subdirectory

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