PHP recursively delete empty parent directories

Question

Problem Background

I have a multimedia web applications where users can save and delete files. The saved files are used for various application wide functionalities.

When files are saved, they are put deep inside directory tree (usually 6 to 9 folders deep). The files are put at such deep level to make sure that they are easily distinguishable by admin/superuser looking at file structure and to match with existing manual system.

For Example,
"UploadedAssets" is the root directory and can contain following folder structure :
\ith\sp\cookery\ckpe\interactives\timestep\blahblah\item1\image01.png
\ith\sp\cookery\ckpe\interactives\timestep\blah_only\item1\image02.png
\ith\sp\cookery\ckpe\interactives\timestep\blah_only\item2\image03.png
\ith\sp\cookery\abcd\interactives\timestep\blahblah\item1\image66.png

1. The first 5 names are user selectable (from dynamic dropdown menus) form approx 20-25 options each.
2. The last 3 depends on whatever user inputs (e.g. category , title, etc.). This is received from user using text input fields. These can be 1 or up to 4 directories.
3. The last directory "item1" can have one or more files but no sub directories
4. Each directory EXCEPT the last one (item1) can have other sub directories
5. When I remove/delete a file, obviously program knows the full path of the file location.

Because of number of possible directory name options, even in the testing phase, the root "UploadedAssets" directory has exploded and there are plenty of empty unused directories and dead branches.

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My question is

Once the user deletes one/more files from a directory (e.g. image01.png from item1),

1. How can I traverse up the tree from deleted file (going only to straight parents) and delete the parent node if its empty.
2. While deleting if one of the directoy has other children/files then not to delete that directory and finish the process.
3. While deleting stop at pre-defined root directory OR
4. Stop after going UP n directory levels

E.g. in the above given example directory structure,
if user deletes image01.png then it should delete item1 and blahblah directories
if user deletes image02.png then it should delete only its parent item1 directory
if user deletes image66.png then it should delete all parent directories including abcd

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My Attempts / research

I know how to remove single directory using php's rmdir. But couldn't think on how can I use it recursively to solve my problem.

I have tried to get my head around following stuff, but I don't know if any of those can fit my problem PHP: Unlink All Files Within A Directory, and then Deleting That Directory

Delete files then directory

http://php.net/manual/en/function.glob.php

https://stackoverflow.com/a/4490706/2337895

Answer 1

Because this has some overhead, I'm going to suggest that you only do this from PHP if absolutely needed. You can use the Linux find command for this:

find /path/to/dir -empty -type d -delete

I would put that in a cron job. If you like you can use the php system command to do this though:

system('find /path/to/dir -empty -type d -delete', $retval);

Using this you would simply delete the file and then let this run only every day or so to go through and take care of any empty directories. This may seem more hackish than making it all in PHP but it'll run much faster. It is less portable but that shouldn't matter too much for most sites. Save this as rdel.bat (I walways make sure you have the [Show hidden file extensions][2] explorer folder option turned on but if you don't then use the drop-down in your text editors Save As... dialog to ensure it has the proper extension).

UPDATE:

To do the same thing in Windows use a batch file with just this one line:

for /f "delims=" %%d in ('dir /s /b /ad ^| sort /r') do rd "%%d"

Test this by changing to a directory and running your new file. It should remove any empty directories below the current.

To schedule this just add an entry to your task scheduler. That is a little different depending on which version of Windows you use. Be sure to set the working directory correctly (this is how the batch file knows where to start).

The problem with this is that in Windows a lot of junk files get created in empty directories (ie Thumbs.db). You can handle that by adding code to your batch file to remove any of those files too:

del /s /q Thumbs.db

Add this above the other line and repeat for anything else which may be unneeded.