mjhjmtu

I would like to remove all files from a directory /data which includes 8 other sub directories.

Is there a command which will recursively clear all subdirectories but not remove the actual folders?

The following would delete any non-directory files, like regular files, symbolic links, named pipes, sockets etc., in or under the /data directory:

find /data ! -type d -delete

For implementations of find that does not have the non-standard predicate -delete, use -exec rm -f + in its place:

find /data ! -type d -exec rm -f +

This would find all non-directory files in or under /data and would execute rm -f on as large batches of these as possible.

Use find command

find /data -type f -exec rm -rf ; 

will delete only files due to the type selection type f for files.

You can use the find command for this.

To create a test case to reproduce your description, let me do this:
1. cd /tmp
2. mkdir -p testing/a,b,c
3. cd testing/
4. touch a,b,c/1,2,3

To verify there are multiple directories each containing multiple files:

$ find -type f
./c/3
./c/2
./c/1
./b/3
./b/2
./b/1
./a/3
./a/2
./a/1

You can now use find again to delete whatever it finds:

find -type f -delete

If you now run find -type f again it will not return any results, because the files are gone, but you can see that the directories still exist:

$ ls
a b c

The find command is very powerful. You can discover more about it using man find.