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Message-ID:	<3A87DABB.F72D55C0@etr-usa.com>
Date:	Mon, 12 Feb 2001 05:44:43 -0700
From:	Warren Young <warren AT etr-usa DOT com>
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To:	Cygwin-L <cygwin AT cygwin DOT com>
Subject:	Re: DuplicateHandle() failing under MS Telnet Server
References:	<20010212174335 DOT A5323 AT systematik DOT co DOT nz>

Dan Plimak wrote:
> 
> This patently won't work under MS Telnet server as from what I can tell (I
> _may_ be wrong), they are using a kludge where they make a handle from a
> socket fd, which is distinct from a regular Windows resource/file handle and
> hence things that may be done with a handle fail.

This is a "feature" of Microsoft stacks.  You can use DuplicateHandle()
with Winsock 1.1 to do odd things that normally require the new
WSADuplicateSocket() and other new Winsock 2/Win32 functionality.  For a
fuller explanation, there's an article in my FAQ about this, called
"Passing Sockets Between Processes".

This feature could be used to implement dup() or maybe dup2() on Winsock
1.1 systems, but that's basically only Windows 95, so it's of fairly
little value these days.  (Win98+ and NT 4+ have Winsock 2 installed by
default.)
-- 
= Warren Young, maintainer of the Winsock Programmer's FAQ at:
=     http://www.cyberport.com/~tangent/programming/winsock/
= 
= ICBM Address: 36.8274040 N, 108.0204086 W, alt. 1714m

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