bug#44273: "total used in directory 19 available 5.2 GiB"

[Drew Adams]

> > FWIW, looking for something else I came across this
> > emacs-develpost from 2016, which also talks about
> > "files N/M", i.e., showing the number of files that
> > are currently listed and the total number of files
> > (including hidden/omitted):
> 
> And maybe also show the number of marked/flagged files,
> updated on every marking/unmarking.

IMO, that's better done in the mode line, which is what
Dired+ does.

The "total" line we're talking about, for each subdir
listing, shows the # of visible files for that subdir
listing and the total # of files in the top-level dir
of the buffer.

The mode line shows Dired/date or Dired/name, and the
# of marks (*) and # of flags (D).  And it shows the
ordinal # of the file or dir on the current line (point),
with the current sorting, as well as the total number of
files/dirs for that subdir listing.