Perform an action in every sub-directory using Bash

Question

I am working on a script that needs to perform an action in every sub-directory of a specific folder.

What is the most efficient way to write that?

Answer 1

This will create a subshell (which means that variable values will be lost when the while loop exits):

find . -type d | while read -r dir
do
    something
done

This won't:

while read -r dir
do
    something
done < <(find . -type d)

Either one will work if there are spaces in directory names.