bug#36729: 27.0.50; Unclear total in directory listing

[Drew Adams <drew.adams@oracle.com>]

> >> The first line of a directory listing reads
> >>
> >>   total used in directory 71752 available 65.2 GiB
> >>
> >> where it is a mystery what the first number represents. Often it is 512-byte
> >> blocks, which is confusing and not very useful, and cannot easily be
> >> compared with the 'available' number (which is crystal clear).
> >
> > Feel free to suggest a clarification in the doc string of 'dired'.
> 
> An alternative is to do for "total used" what was done for "available".
> On systems that use `ls' (at least the GNU version), users can do that
> by setting the environment variable BLOCK_SIZE, but since the change to
> the display of "available" was unconditional (if I'm not mistaken), we
> could do the same for the display of "total used", e.g. as in the below
> patch.  (But since this won't work on systems that don't use GNU `ls',
> either another solution just for them or a different general one would
> be needed.)

FWIW, my `ls-lisp+.el' code gives this:

 files 38/38 space used 2563 available 103423152

and mouse-over (`help-echo') on the `files 38/38' says:

 Files shown / total files in directory

and mouse-over on the `space used ...' part says:

 Kbytes used in directory, Kbytes available on disk

and `RET' or `mouse-2' anywhere on that line pops up
`*Help* with info like this (` help-fns+.el' is also
needed, for function `describe-file'):

 g:/usr/foo/bar
 --------------

 File Type:                  Directory
 Permissions:                drwxrwxrwx
 Time of last access:        Mon Apr 22 04:48:30 2019 (Pacific Daylight Time)
 Time of last modification:  Mon Apr 22 04:48:30 2019 (Pacific Daylight Time)
 Time of last status change: Wed Jul 25 08:00:46 2018 (Pacific Daylight Time)
 Number of links:            1
 User ID (UID):              68752
 Group ID (GID):             312
 Inode:                      281474976872649
 Device number:              315267003

Maybe some such aids could be added to vanilla Dired.