Count entries for each directory in tree

Question

Say I have the following tree:

root:
d foo 
d bar

/foo:
d A
- tmp.txt

/bar:
d B
- tmp2.txt

/foo/A:
- tmp3.txt

/bar/B:

d = directory and - = file

I need to answer the following question: which directory (excluding the root) contains the least entries?

I have tried

  find . | grep -oE '/([a-zA-Z]+/)+'

to get the number of occurrences for each directory. The problem is this command exclude empty directories, in this case /bar/B is excluded.

Any guidance on how to solve this would be appreciated.

Answer 1

With GNU tools:

find . -printf '%h\0' -type d ! -name . -print0 |
  sort -z |
  uniq -zc |
  sort -zn |
  sed -z q |
  tr '\0' '\n'

If you can guarantee that file names won't contain newline characters, you can simplify it to:

find . -printf '%h\n' -type d ! -name . -print | sort | uniq -c | sort -n | head -n1

(the number reported is the number of files in the directory minus 1 (. is counted, but not ..)).

With zsh:

count() {
  set -- $REPLY/*(NDoN)
  REPLY=$#
}
print -r -- **/*(Do+count[1])

Answer 2

You could use something like this:

find . -type d -exec sh -c \
    'printf -- "%-20s: " {};
    find {} -maxdepth 1 -type f -printf "%i\n" | wc -l' \;

If you have this tree, (tree is a nice command btw.):

$ tree -a .
.
├── bar
│   ├── B
│   └── tmp2.txt
├── ff
├── .ff.swp
└── foo
    ├── A
    │   └── tmp3.txt
    ├── f2.txt
    ├── f3.txt
    └── tmp.txt

You get this:

.                   : 2
./foo               : 3
./foo/A             : 1
./bar               : 1
./bar/B             : 0

---

To list one of the lesser (more then one could have e.g. null files), one could do something like:

find . -type d -exec sh -c \
    'find "{}" -maxdepth 1 -type f -printf "%i\n" | \
    wc -l | xargs printf "%-2d";
    printf ": %s\n" "{}" ' \; | sort -k1,1 | head -n 1

if folders does not contain newline.

---

If -maxdepth is not available, an alternative could be:

find . -type d -exec sh -c \
    'printf -- "%-20s: " "{}";
    find "{}" ! -wholename "{}" -prune -type f -printf "%i\n" | wc -l' \;