[ECOS] How to find out if socket closed?

[Grant Edwards]

On Tue, Jul 15, 2003 at 03:16:02PM -0600, Gary Thomas wrote:

> > > If I submitted a patch (to the old stack) adding an ioctl that
> > > returned the SS_CANTRECVMORE flag, what are the chances of it
> > > being accepted?
> > 
> > Here's a patch that adds an option for getsockopt() to retrieve
> > the state of the SS_CANTRCVMORE flag.  The current
> > implimentation of getsockopt(SO_ERROR) seemed to be the closest
> > thing I could find to what I was adding, so that's where it went.
> 
> A better question is "how is this solved elsewhere?"  E.g. how
> can one tell what's happening with a socket on Linux?

AFAICT, there are two options for detecting that in Linux:

 1) you get sent a SIGHUP.
 
 2) you can use poll() and ask for POLLHUP events on the file
    descriptor.

> It would be nice to have a solution which matches other systems.
> If it turns out that this is a special case, then your patch seems
> OK, but I'd also like to see it for the new stack as well.

I don't yet have a working build with the new stack, but it's
on my list of things to do.

-- 
Grant Edwards
grante@visi.com

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