From: Gary Wright <gwtmp01@...>
Date: 2007-03-20T07:16:57+09:00
Subject: Re: Passing File Descriptors?


On Mar 19, 2007, at 12:43 PM, Worky Workerson wrote:

> Is there a ruby way to pass file descriptors to separate processes?
> I'm thinking of interfacing with a C program, which uses the
> SCM_RIGHTS cmsg over a unix-domain socket ... is this idiom
> implemented in Ruby?  How would I marshall an IO object into (and out
> of) the integer file descriptor, or does this "just work"?

In case folks were looking for a use case.

A client makes a request to a server which opens the file
and sends the opened file descriptor back to the client.
Presumably the server process has special permissions to allow it
access to the files that the client doesn't have.  The server
can also implement any additional security controls.

The client gets to read and write a file without having had
permission to open the file directly.

This only works via Unix Domain sockets and so it only
works between processes on the same machine.  It won't work
across a network.

Gary Wright