Re: Question regarding utility exit status

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Mon, 25 Dec 2017 15:04:44 +0800 (+08)
    From:        Paul Goyette <paul%whooppee.com@localhost>
    Message-ID:  <Pine.NEB.4.64.1712251454140.25688%speedy.whooppee.com@localhost>

  | Does POSIX take any particular view on this?

For both the file and ls (and most other commands - though stat(1)
is not POSIX) (one from each of your qroups) it says...

EXIT STATUS

    The following exit values shall be returned:

     0
        Successful completion.
    >0
        An error occurred.

So I guess it depends what you consider to be "successful completion"...
What does it mean for ls to be successful (all the args can be listed
is reasonable) or for file (perhaps if we can extract a description from
amongst the files named?)

  | (And does POSIX take different views for different utilities?)

There are some that are different for one reason or another
but most are as above.

Also remember that POSIX documents the common (or perhaps sometimes
one particular) systems do, it did not set out to decide what the
systems should be like, and document that (which is how it ended up
with abominations like cd -L - which fortunately we do not support).

kre