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

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.