X-Recipient: archive-cygwin AT delorie DOT com
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 948F33857C5A
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1692092806;
	bh=iP2XkXiBA06yQVrgSuYzqouYZ9ai/7jmWqZAu/yAnGQ=;
	h=Date:To:Cc:Subject:In-Reply-To:References:List-Id:
	 List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe:
	 From:Reply-To:From;
	b=Tp/V3liAk0nfyAFltUlvqOdBrjFWWmpj2EQFL73JpJvmCl8y92GMQRZ96Qk7HHrzr
	 280OVQtPEzMt5huuIriKGLjLKN7QsadN7EtsaK1XI7GOnzkWwxCTVwRn05FrFsdy2e
	 m3JFszveHaHohEHkyA8FUx25KhiwK25mVzpJ1FoY=
X-Original-To: cygwin AT cygwin DOT com
Delivered-To: cygwin AT cygwin DOT com
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1CFF13858404
Date: Tue, 15 Aug 2023 18:45:57 +0900
To: cygwin AT cygwin DOT com
Cc: =?ISO-2022-JP?B?GyRCJS0lYyVtJSYhISVeITwlLxsoQg==?= <github AT callow DOT im>
Subject: Re: Pipes truncating data in cygwin from main and cygwin-3_4-branch
Message-Id: <20230815184557.12de355232f32a95b7a70990@nifty.ne.jp>
In-Reply-To: <FCF9C3F3-7ED6-406A-8420-05379E4C5875@callow.im>
References: <13B0370E-B61A-44B9-A885-5FF1B8F4AC5F AT callow DOT im>
 <20230815093042 DOT 4c5fd1034837098aaff45e10 AT nifty DOT ne DOT jp>
 <CCC360AD-21B1-40E4-8B6B-FCFAF5612939 AT callow DOT im>
 <20230815154219 DOT f03a40176f281f598ab0ffc4 AT nifty DOT ne DOT jp>
 <FCF9C3F3-7ED6-406A-8420-05379E4C5875 AT callow DOT im>
X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.30; i686-pc-mingw32)
Mime-Version: 1.0
X-Spam-Status: No, score=-4.3 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 NICE_REPLY_A, RCVD_IN_DNSWL_NONE, SPF_HELO_PASS, SPF_PASS,
 TXREP autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
 server2.sourceware.org
X-BeenThere: cygwin AT cygwin DOT com
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe: <https://cygwin.com/mailman/options/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From: Takashi Yano via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>
Content-Type: text/plain; charset="iso-2022-jp"
Content-Transfer-Encoding: 7bit
Errors-To: cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>

On Tue, 15 Aug 2023 18:09:50 +0900
キャロウ　マーク wrote:
> > On Aug 15, 2023, at 15:42, Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp> wrote:
> > 
> >> 
> >>> 
> >>> New pipe implementation since cygwin 3.4.x provides the pipes
> >>> more similar to pipe in command prompt for non-cygwin apps.
> >> 
> >> What are the differences between these pipes? What changed?
> > 
> > Many changes. But, the change which triggers this behaviour
> > is setting FILE_SYNCHRONOUS_IO_NONALERT create option.
> > 
> > With this option, seekg() of Microsoft library gets success
> > for pipes, despite it should not I suppose.
> 
> On what create is this option specified?

Pipe itself. We use NtCreateNamedPipeFile() to create a pipe.
https://learn.microsoft.com/en-us/windows/win32/devnotes/nt-create-named-pipe-file

-- 
Takashi Yano <takashi DOT yano AT nifty DOT ne DOT jp>

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple