How to recursively list subdirectories in Bash without using “find” or “ls” commands?

Question

I know you can use the find command for this simple job, but I got an assignment not to use find or ls and do the job. How can I do th

Answer 1

Try using

tree -d

Answer 2

The du command will list subdirectories recursively.

I'm not sure if empty directories get a mention, though

Answer 3

Based on this answer; use shell options for the desired globbing behaviour:

• enable ** with globstar (Bash 4.0 or newer)
• include hidden directories with dotglob
• expand to the empty string instead of **/*/ if there is no match with nullglob

and then use printf with the %q formatting directive to quote directory names with special characters in them:

shopt -s globstar dotglob nullglob
printf '%q\n' **/*/

so if you have directories like has space or even containing a newline, you'd get output like

$ printf '%q\n' **/*/
$'has\nnewline/'
has\ space/

with one directory per line.

Answer 4

Technically, neither find nor ls are used by find2perl|perl or File::Find directly.

$ find2perl -type d | perl
$ perl -MFile::Find -e'find(sub{-d&&print"$File::Find::name\n"},".")'