How to exclude different levels of subdirectories with cp?

Question

This is a follow-up question to my original post: find & cp command doesn't copy 1st level directory

I have a directory structure like this:

test folders
├── 1
│   ├── 1-1
│   ├── 1-2
│   └── 1-3
├── 2
│   ├── 2-1
│   ├── 2-2
│   └── 2-3
├── 3
│   ├── 3-1
│   ├── 3-2
│   └── 3-3
└── 4
    ├── 4-1
    ├── 4-2
    └── 4-3
16 directories, 0 files

and I am struggling with copying ONLY the 1st level folders -- 1,2,3,4 excluding all subfolders using find & cp commands

├── 1
├── 2
├── 3
└── 4

Working directory is /home/username/Downloads/test folders.

My failed attempt is in the linked question. There we've established the fact that cp doesn't see find's commands with -maxdepth.

Is there another command with find and cp that allows -maxdepth to make it easier to copy files? Is there even a -maxdepth equivalent for cp, if find's commands can't be linked with cp?

[edit]: In addition, I want to only copy the 1st level directories, such as 1, 2, 3 and 4. I do not want to copy files. Sorry for the confusion

Answer 1

If you only want to copy the directories and no files or sub-directories, it' easy:

terdon@oregano test folders $ tree
.
├── 1
│   ├── 1-1
│   ├── 1-2
│   ├── 1-3
│   ├── file-1
│   └── file-2
├── 2
│   ├── 2-1
│   ├── 2-2
│   ├── 2-3
│   ├── file-1
│   └── file-2
├── 3
│   ├── 3-1
│   ├── 3-2
│   ├── 3-3
│   ├── file-1
│   └── file-2
└── 4
    ├── 4-1
    ├── 4-2
    ├── 4-3
    ├── file-1
    └── file-2
17 directories, 8 files

Using the above example, you can re-create the top level directories with:

terdon@oregano test folders $ find . -maxdepth 1 -type d -exec mkdir ../results/{} \;
mkdir: cannot create directory ‘../results/.’: File exists
$ tree ../results/
../results/
├── 1
├── 2
├── 3
└── 4
5 directories, 0 files

You can safely ignore the error message. That is just because it also finds ., the current directory, and tries to create ../results/., that current directory, which already exists.

If you also want to copy the top-level files, you can do it in two steps:

terdon@oregano test folders $ find . -maxdepth 1 -type d -exec mkdir ../results/{} \;
mkdir: cannot create directory ‘../results/.’: File exists
$ find . -maxdepth 2 -type f -exec cp {} ../results/{} \;

Which produces:

$ tree ../results/
../results/
├── 1
│   ├── file-1
│   └── file-2
├── 2
│   ├── file-1
│   └── file-2
├── 3
│   ├── file-1
│   └── file-2
└── 4
    ├── file-1
    └── file-2

You can also do it in a single pass with:

$ find . -maxdepth 1 -type d -exec sh -c 'mkdir ../results/$1 && cp {}/* ../results/$1' sh {} \;
mkdir: cannot create directory ‘../results/.’: File exists
cp: -r not specified; omitting directory './3/3-1'
cp: -r not specified; omitting directory './3/3-2'
cp: -r not specified; omitting directory './3/3-3'
cp: -r not specified; omitting directory './1/1-1'
cp: -r not specified; omitting directory './1/1-2'
cp: -r not specified; omitting directory './1/1-3'
cp: -r not specified; omitting directory './4/4-1'
cp: -r not specified; omitting directory './4/4-2'
cp: -r not specified; omitting directory './4/4-3'
cp: -r not specified; omitting directory './2/2-1'
cp: -r not specified; omitting directory './2/2-2'
cp: -r not specified; omitting directory './2/2-3'

Since we are using cp without -r, only files will be copied. You'll get those warnings, but again, you can safely ignore them. You can also silence them by redirecting to /dev/null:

find . -maxdepth 1 -type d -exec sh -c 'mkdir ../results/$1 && cp {}/* ../results/$1' sh {} \; 2>/dev/null