How to list sub directories of a directory?

Question

I need to list the sub directories of a certain path. The separation should be with spaces and not new lines.

I also do not want the absolute path to the sub directories, just their names.

# correct
dir1 dir2 dir3
incorrect: separation with new lines
dir1
dir2
dir3
incorrect: absolute paths
/home/x/y/dir1 /home/x/y/dir2 /home/x/y/dir3

I've seen a lot of other posts like this SO post, but they do not accomplish my request.

I've tried ls -d ~/y but it lists absolute paths and separates with new lines. I guess I could use sed to remove the irrelevant part of the path, and then remove all the new lines. But I couldn't get it to work, and it seems like there should be a better solution

Answer 1

Assuming that you are using GNU tools, you could use GNU basename to get the names of all subdirectories in a particular directory. You could then use paste to format this as a space-delimited list.

basename -a /some/path/*/ | paste -d ' ' -s -

The above command uses the fact that GNU basename has an -a option to return the filename portion of multiple pathnames given as operands on its command line.

We use a file-globbing pattern ending in / to generate the pathnames for GNU basename. Only directories can match such a pattern.

In the end, the paste creates the space-separated list from the newline-separated list produced by GNU basename.

Note that it would be difficult to parse the generated list of filenames if any of the original names of directories contain space characters.

Note that if the directory contains symbolic links, this method will try to follow those symbolic links.

---

Restricting us from using any external tools, we could use an array in the bash shell to store and manipulate the directory paths.

shopt -s nullglob
topdir=/some/path
dirpaths=( "$topdir"/*/ )
dirpaths=( "${dirpaths[@]#$topdir/}" )
dirpaths=( "${dirpaths[@]%/}" )
printf '%s\n' "${dirpaths[*]}"

The above shell code expands the same globbing pattern as we used in the first part of this answer but stores the resulting directory paths in the array dirpaths. It then deletes the known prefix $topdir/ from each element of the array and the trailing / before printing the array as a single string of space-delimited names. The delimiter used between the names on the last line will be the first character from $IFS, which by default is a space.

---

Using find, you could look for subdirectories in the particular top directory you're interested in while making sure not to return the top directory itself. You would also stop find from progressing into the subdirectories.

topdir=/some/path
find "${topdir%/}/." ! -name . -prune -type d -exec basename {} \; | paste -d ' ' -s -

The above command avoids the search starting point using a negated -name test, and it prunes the search tree with -prune so that find does not recurse down into any subdirectories. We call basename for each found directory which outputs the filename of the directories onto separate lines. As the last step, we're piping the result from find through paste to format the output into a space-separated list on a single line.

With GNU find, you could write this as

find /some/path -mindepth 1 -maxdepth 1 -type d -printf '%f\n' | paste -d ' ' -s -

Using find like this will list directories with hidden names, and you will not see any symbolically linked directories.

---

In the zsh shell, you would be able to use a more advanced shell globbing pattern to pick out the filenames of only directories and print them in one go.

print -r -- /some/path/*(/:t)

This command uses a glob qualifier, /:t, consisting of two parts, affecting the preceding globbing pattern /some/path/*. The / makes the pattern only match directories (not symbolically linked ones; for that use -/), while :t extracts the "tail" of each generated pathname, i.e., the filename component.

The print -r command prints its arguments with spaces as delimiters while avoiding expanding escape sequences like \n or \t in the data. Using -- to delimit the operands from the options (also works with - like in the ksh shell) makes sure directory names resulting from the glob expansion are not taken as options even if they start with -.

You could use this from within the bash shell to generate your list.

zsh -c 'print -r -- /some/path/*(/:t)'

Answer 2

Since you already know the directory from which you are listing the subdirectories, you can use the following ...

find /home/x/y -maxdepth 1 -type d -printf '%P '

Answer 3

Here is my suggestion using a for loop:

$ echo "$(for node in $(ls ~/); do if test -d "${node}"; then printf "${node} "; fi; done)"
Desktop Documents Downloads Music Pictures Public Templates Videos

Alternate using find:

$ echo "$(for node in $(find ~/ -mindepth 1 -maxdepth 1 -type d); do printf "$(basename ${node}) "; done)"
.mozilla Videos Pictures Music Documents Public Templates Downloads .gnupg .config .local .cache Desktop

Edit: In regards to they's comment, you would need to change the IFS variable for directories with spaces:

$ IFS_orig=${IFS}
$ IFS=$'\n'
$ echo "$(for node in $(ls ~/); do if test -d "${node}"; then printf "'${node}' "; fi; done)"
'Desktop' 'Documents' 'Downloads' 'Music' 'My Test' 'Pictures' 'Public' 'Templates' 'Videos'
$ IFS=${IFS_orig}

Edit: The simplest option seems to be to use ls -d *:

$ ls -d *
 Desktop   Documents   Downloads   Music  'My Test'   Pictures   Public   Templates   Videos

Also, forgot that in the for loops, should test using absolute or relative path:

$ echo "$(for node in $(ls "${HOME}"); do if test -d "${HOME}/${node}"; then printf "'${node}' "; fi; done)"
'Desktop' 'Documents' 'Downloads' 'Music' 'My Test' 'Pictures' 'Public' 'Templates' 'Videos'

Answer 4

The final command I got to is: ls -d ~/y/*/ | awk -F/ '{print$5}' | sed 's/ /\\ /' | tr '\n' ' '

Origin was from a user who has now deleted their post, but they didn't account for not using ls on the current directory, so I adjusted for that. I also added the sed pipe so it adds backslashes for directory names' which have spaces in them.

It is pretty hardcoded with print$5 so it'll only work with directories right in the ~ directory.