Using ls in Linux to show directories only - linux

Question

I'm getting myself familiar with Linux (Debian 9). However I managed to get myself confused with the ls command manual. I made up the following trivial setting for testing:
meouser:~/triv_dir$ ls -laR
.:
total 24
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 .
drwxr-xr-x 19 meouser meouser 4096 Mar 27 15:41 ..
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 a
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:42 b
-rw-r--r-- 1 meouser meouser 6 Mar 27 15:44 c
-rw-r--r-- 1 meouser meouser 6 Mar 27 15:44 d
./a:
total 24
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 .
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 ..
-rw-r--r-- 1 meouser meouser 4 Mar 27 15:50 aa
-rw-r--r-- 1 meouser meouser 4 Mar 27 15:50 ab
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 a_sub_1
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 a_sub_2
./a/a_sub_1:
total 12
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 .
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 ..
-rw-r--r-- 1 meouser meouser 4 Mar 27 15:55 aaa
./a/a_sub_2:
total 8
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 .
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 ..
./b:
total 16
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:42 .
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 ..
-rw-r--r-- 1 meouser meouser 4 Mar 27 15:50 ba
-rw-r--r-- 1 meouser meouser 4 Mar 27 15:50 bb
I would like to see all the directory names and their subdirectories, but not the filenames. That is, I want something like ls --insert-options-here so that the output is this subset from above:
.:
total 24
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 .
drwxr-xr-x 19 meouser meouser 4096 Mar 27 15:41 ..
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 a
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:42 b
./a:
total 24
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:55 .
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 ..
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 a_sub_1
drwxr-xr-x 2 meouser meouser 4096 Mar 27 15:55 a_sub_2
According to ls manual that should be achieved by ls -ldR.
meouser:~/triv_dir$ man ls
-a, --all
do not ignore entries starting with .
-d, --directory
list directories themselves, not their contents
-l use a long listing format
-R, --recursive
list subdirectories recursively
But this is what happens instead: only the '.' is shown.
meouser:~/triv_dir$ ls -ldR
drwxr-xr-x 4 meouser meouser 4096 Mar 27 15:42 .
What am I missing from the manual?
I noticed from https://stackoverflow.com/a/29277454/11199684 that this can be achieved by
find . -maxdepth 2 -type d -print
which is impressive but it gives less information than the ls output above. Besides, I might not know beforehand the correct maxdepth? And above all, for future needs I'm actually interested in teaching myself from the manuals. Advice are appreciated.

Answer 1

The -d option apply to [FILE] given as input, in your case, as none are given, you fall back to the default one : the current directory. The recursivity doesn't apply as no directory are returned.
To get the same output as ls with the find command, you can combine them :
find . -type d -exec ls -ld {} \;

Answer 2

in some way you could use the grep tool to filter the results:
ll -A | grep ^d
if you want to use it programatically, in a bash script you can have only the dir names (but find might be better for that):
ll -A | grep / | awk '{print $9}'