From: Eric Wong <normalperson@...>
Date: 2014-08-29T08:21:16+00:00
Subject: [ruby-core:64638] Re: [ruby-trunk - Feature #10181] [Open] New method File.openat()

Joel VanderWerf <joelvanderwerf@gmail.com> wrote:
> On 08/29/2014 12:55 AM, Eric Wong wrote:
> >Joel VanderWerf <joelvanderwerf@gmail.com> wrote:
> >>On 08/28/2014 02:53 PM, Eric Wong wrote:
> >>>I like this feature.
> >>>
> >>>If matz approves, I assume you also want to add other *at functions?
> >>>e.g. fstatat, renameat, unlinkat, mkdirat, etc.
> >>
> >>Hm, that suggests...
> >>
> >>Dir.at(...).open(...)
> >>Dir.at(...).fstat(...)
> >
> >How would that be implemented?
> 
> Couldn't Dir.at(...) return an object that wraps the fd of the dir?

Yes, but it would need to cache the _same_ object every time it's called
given that arg for a given thread.  Then it might not detect when that
thread might actually want a different FD/object, and the cache can fill
up or expire and we still end up with unpredictable behavior.