[Info-vax] Request description of UFS for VMS person

[Bill Gunshannon]

In article <gsl18u$bja$6 at naig.caltech.edu>,
	glen herrmannsfeldt <gah at ugcs.caltech.edu> writes:
> Bill Gunshannon <billg999 at cs.uofs.edu> wrote:
> (snip on od or cat on unix directories)
>  
>> Current version of dd won't do it either.  Of course, you could grab the
>> source to cat and write your own version that ignores it being a directory.
>> Or just copy the stripped down version fromt he K&R C book.  :-)
> 
> I believe the failure is at the system call level, propagated
> back through errno and perror.  Likely the programs don't know
> or care that it is a directory, but just that the open fails.

Seems unlikely.  Always could "cat" a directory in the past because,
after all, it, too, is just a stream of bytes.  :-)  For the hell of
it, tonite, I will take a look at the source for the current version
of cat.  I think I will find a test for directories and a deliberate
fail if it is.

> 
>>> but it's
>>>    worth looking to see if this directory is on a UFS, NFS, or some
>>>    other volume because it might be the file system forcing the error.
>  
>> I didn't look at the source, but I assume it is the utility.  Another case
>> of protecting people from themselves a tthe expense of the people who really
>> need the capability. (Have you ever seen what "cating" binary data to a
>> terminal can do?  :-)
> 
> In the case of NFS, reading directories doesn't make much sense.

As much sense as reading other directories with cat or od.  :-)

> The server might have a completely differnet file system, even
> one that doesn't allow directories to be read, or even where 
> directories are not files.  To make this more applicable, 
> consider an NFS mount off a VMS server.  What would you expect
> NFS to supply on the read attempt?

Don't know, but it would be fun to find out.  :-)

bill

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>