Re: gnu tar 1.19 requires open() with O_DIRECTORY?

[John E. Malmberg]

Bruno Haible wrote:
> John E. Malmberg wrote:

> > The open() would have to open or dup a file descriptor to the /dev/null 
> > device to reserve a unique file descriptor, and then something needs to 
> > map that file descriptor back to the pointer to the *DIR structure.
>
> Do you need a pointer to the DIR structure, or only memorize the filename
> of the directory? In the latter case, you can reuse most of the code from
> gnulib/lib/fchdir.c.

Then the filename would have to be attached to the file descriptor 
obtained by opening the null device.

> Btw, does VMS have the dirfd function (as a function or as a macro)?
> It should return the file descriptor to a directory that is "held inside"
> a DIR structure.

There is no dirfd() function on VMS, and replacement function in 
lib/dirfd is returning a -1.

The DIR structure on VMS is opaque to user code.  It is unlikely that it 
contains a file descriptor, as the VMS native I/O does not use file 
descriptors.

Regards,
-John
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