From: Daniel Berger <djberg96@...>
Date: 2008-05-21T04:24:51+09:00
Subject: Re: Arbitrary IO object



On May 20, 12:36 pm, Gary Wright <gwtm...@mac.com> wrote:
> On May 20, 2008, at 1:34 PM, Daniel Berger wrote:
>
>
>
> > info = Process.create(
> >    input  = IO.new(x, 'w+')  # Want next available fd
> >    output = IO.new(y, 'w+') # Want next available fd
> >    error  = IO.new(z, 'w+')  # Want next available fd
>
> >    :app_name       => command,
> >    :creation_flags => Process::DETACHED_PROCESS,
> >    :startup_info   => {
> >       :stdin  => input,
> >       :stdout => output,
> >       :stderr => error
> >    }
> > )
>
> IO.new is for associating a Ruby IO object with
> an already open OS file descriptor.   So you've got
> to acquire the file descriptor through some non-Ruby
> mechanism in order to be useful via IO.new.  You can
> use IO#fileno to discover the underlying OS file
> descriptor from a Ruby object but if you've already
> got a Ruby IO object you don't need to use IO.new.
>
> At the C/POSIX level I don't think there is really
> any concept of specifying the 'next available fd'.
> You just call open/create/pipe/dup and use the integer
> file descriptors that are returned.  The OS figures
> out which integer descriptors are available.

Yep, looks like I should just use IO.pipe.

Thanks,

Dan