Re: epoll vs stdin/stdout

[H. Peter Anvin]

Followup to:  <beckj5$e2a$[e-mail]>
By author:    "Miquel van Smoorenburg" <[e-mail]>
In newsgroup: linux.dev.kernel
>
> In article <[e-mail]>,
> Jamie Lokier  <[e-mail]> wrote:
> >Unfortunately I cannot think of a way for a process to know, in
> >general, whether two fds that it is passed correspond to the same file
> >*.  Well, apart from trying epoll on it and seeing what happens :/
> 
> fstat() and compare st_dev and st_ino
> 

That doesn't show if they share the same file *.  Two fd's can be open
to the same file or other object without sharing the same file *.

Seriously, this is not something userspace should have to worry
about.  The interface should handle it, otherwise it's broken.

	-hpa
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