Count the number of directories in a list of directories

Question

I have a large number of directories, and I want to count with bash commands the number of directories in each of these directories. I am having a hard time piping ls and wc to achieve what I want.

E.g., if I have the following folder structure (where the leaf folders might contain further subfolders):

.
├── folder1
│   └── subfoldera
├── folder2
│   ├── subfoldera
│   └── subfolderb
├── folder3
│   ├── subfoldera
│   ├── subfolderb
│   └── subfolderc
└── folder4
    ├── subfoldera
    ├── subfolderb
    └── subfolderc

Then I wish to have the counts

1
2
3
3

and so on.

Answer 1

With bash and arrays:

dirs=(*/)                      # get all directories with globbing
                               # in current directory

for d in "${dirs[@]}"; do
  sub=("$d"*/)                 # get all subdirs in $d
  echo "${#sub[@]}"            # print number of array elements/subdirs
done

Output:

1
2
3
3

As one line:

dirs=(*/); for d in "${dirs[@]}"; do sub=("$d"*/); echo "${#sub[@]}"; done

Answer 2

If the names of the dirs do not contain '\n' this should work:

parallel 'ls -d {}/*/ | wc -l' ::: */

If you want to include the dir in the output:

parallel --tag 'ls -d {}/*/ | wc -l' ::: */