Re: [Qemu-devel] chardev's and fd's in monitors

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Oct 12, 2016 at 08:15:02PM +0100, Dr. David Alan Gilbert wrote:
> Hi,
>   I had a look at a couple of readline like libraries;
> editline and linenoise.  A difficulty with using them is that
> they both want fd's or FILE*'s; editline takes either but
> from a brief look I think it's expecting to extract the fd.
> That makes them tricky to integrate into qemu, where
> the chardev's hide a whole bunch of non-fd things; in particular
> tls, mux, ringbuffers etc.
> 
> If we could get away with just a FILE* then we could use fopencookie,
> but that's GNU only.
> 
> Is there any sane way of shepherding all chardev's into having an
> fd?

The entire chardev abstraction model exists precisely because we cannot
make all chardevs look like a single fd. Even those which are fd based
may have separate FDs for input and output.

IMHO the only viable approach would be to enhance linenoise/editline to
not assume use of fd* or FILE * abstractions.

Regards,
Daniel
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