Re: [perl #82802] [PATCH] fileno should return undef when PerlIOreturns -1

On Wed, Jan 26, 2011 at 8:23 AM, Leon Timmermans <fawaka@gmail.com> wrote:

> On Wed, Jan 26, 2011 at 11:21 AM, Bo Lindbergh <blgl@stacken.kth.se>
> wrote:
> > s/fixes/breaks/;
> >
> > A return value of -1 from a fileno method is not an error indicator;
> > it means that there's no operating system file descriptor
> > at the bottom of the layer stack (e.g. PerlIO::Scalar).
> >
> > The current behaviour of pp_fileno is correct since defined(fileno(FOO))
> > is the canonical way of testing whether a filehandle is open.
>
> The documentation of fileno explicitly disagrees: «Filehandles
> connected to memory objects via new features of "open" may return
> undefined even though they are open.» It has been in there for 10
> years (b76cc8ba).
>
> There is a way to check if a filehandle is open, it just hasn't ever
> been documented and it is rather obscure (welcome to PerlIO): that's a
> good reason to abstract it in openhandle. Overloading fileno with this
> never was a good idea IMO.
>
> Leon
>

So is the obscure method for checking if a filehandle is open now
documented?

Steve

• [perl #82802] [PATCH] fileno should return undef when PerlIO returns -1 by Leon Timmermans
• Re: [perl #82802] [PATCH] fileno should return undef when PerlIO returns -1 by Bo Lindbergh
• Re: [perl #82802] [PATCH] fileno should return undef when PerlIOreturns -1 by Leon Timmermans
• Re: [perl #82802] [PATCH] fileno should return undef when PerlIOreturns -1 by Steve Peters
• Re: [perl #82802] [PATCH] fileno should return undef when PerlIOreturns -1 by Leon Timmermans