Re: [PATCH] ls: issue error message on removed directory

[Colin Watson]

On Wed, Feb 12, 2020 at 10:54:43AM +0000, Pádraig Brady wrote:
> Sorry I sent the following to the list only.
> Please cc address@hidden on any responses...
> 
> On 11/02/2020 10:45, Colin Watson wrote:
> > If the current directory has been removed, then "ls" confusingly
> > produced no output and no error message, indistinguishable from the case
> > of running on an empty directory.  It makes more sense to report ENOENT
> > in this case.
> 
> I don't think this is a general solution as the opendir() spec states:
> https://pubs.opengroup.org/onlinepubs/9699919799/functions/opendir.html
> "The directory entries for dot and dot-dot are optional".
> I've also seen reference to FUSE file systems that don't provide those 
> entries.

Ah.  Fair point; that is unfortunate.

I do think this is a confusing problem and worth trying to solve,
though.  The only other idea I have is, if there are no entries in the
directory, to fstat the directory fd and see if st_nlink == 0; if so,
issue a warning message, perhaps more like "directory may have been
removed" than "no such file or directory".  There are probably still
FUSE-like situations where that goes wrong, but IIRC naïve FUSE
implementations tend to set st_nlink to 1 rather than 0.

Might something like that be acceptable?

-- 
Colin Watson                                       [address@hidden]