> Still, using directory-files-and-attributes etc. would be more
> portable than doing it with 'find' and 'du'.

That's what I do, actually.  I've provided two "listing" functions (customizable):

- disk-usage--directory-size-with-emacs: use `directory-files-and-attributes'
  recursively everywhere.  This is portable but very slow.

- disk-usage--directory-size-with-du: This uses `directory-files-and-attributes'
  on the root folder to get the size of its direct subfiles, then `du -sb' on
  the remaining subfolders.  This is much faster.

Makes sense?

-- 
Pierre Neidhardt
https://ambrevar.xyz/