PROBE-FILE

[greek@DEC-HUDSON]

Rob's proposal makes sense.  A few comments:

1.  Yup, use a keyword, namely :DIRECTION.

2.  If we believe in :DIRECTION for PROBE-FILE, then we have to admit
    that :DIRECTION :PROBE makes no sense for OPEN, because probing
    is orthogonal to direction.  I suggest we either add :PROBE T
    as another keyword to OPEN, or, better yet, remove the feature
    from OPEN.

3.  PROBE-FILE needs to tell me more.  I want to know if I can't get
    at the file because:
      a)  the file spec is bad.
      b)  the device doesn't exist.
      c)  the directory doesn't exist.
      d)  I don't have sufficient access privilege.
      e)  etc., etc.

The basic need addressed by Rob is a real one:  Is this file spec good,
can I get to the file, and what can I do to it (read, write, etc).

- Paul