Re: CreateFile/mailslot

From:

"Igor Tandetnik" <itandetnik@mvps.org>

Newsgroups:

microsoft.public.vc.language

Date:

Mon, 3 Aug 2009 22:08:43 -0400

Message-ID:

<#VxfGiKFKHA.1540@TK2MSFTNGP02.phx.gbl>

Vincent Fatica wrote:

(VC9/XPSP3) What's going on here? There are no mail slots, certainly
not one with the name below. Yet CreateFile() succeeds. This is a
simplified (and tested) version; originally I inadvertently created
the slot name with wsprintf() and a quoted host name ("\".\"").

HANDLE hSlot = CreateFile(L"\\\\\".\"\\mailslot\\my_slot",
GENERIC_WRITE, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);
wprintf(L"hSlot = %X\r\n", hSlot);

I see the likes of:

hSlot = E88

Why does CreateFile() succeed and what do I have a handle to? Note
that a subsequent WriteFile() returns after about 5 seconds.

If I had to guess, I'd imagine CreateFile opened a handle to a mailslot
on a remote host named "." (including quotes), and WriteFile actually
tried to access said host.
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925