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Date: Thu, 17 May 2001 19:00:31 -0400
From: Christopher Faylor <cgf AT redhat DOT com>
To: Cygwin Mailing List <Cygwin AT cygwin DOT com>
Subject: Re: O_NOCTTY flag sticky under Cygwin
Message-ID: <20010517190031.A3836@redhat.com>
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References: <002b01c0d7c4$815a1420$21c9ca95 AT mow DOT siemens DOT ru>
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In-Reply-To: <002b01c0d7c4$815a1420$21c9ca95@mow.siemens.ru>; from Andrej.Borsenkow@mow.siemens.ru on Tue, May 08, 2001 at 05:40:54PM +0400

On Tue, May 08, 2001 at 05:40:54PM +0400, Andrej Borsenkow wrote:
>It appears, that O_NOCTTY is sticky. I.e. if a tty was opened with this flag,
>it will never become a controlling tty. The following pseudo code:
>
>fd = open("/dev/pts/1", O_RDWR|O_NOCTTY);
>close(0);
>close(1);
>close(2);
>dup2(fd,0);
>
>does not make /dev/pts/1 controlling tty under Cygwin. It does it on most
>major Unix flavours (Solaris, Linux, BSD, AIX, HP-UX).
>
>If I understand SUS V2 correctly, this flag applies only to open() call
>itself:
>
>O_NOCTTY
>If set and path identifies a terminal device, open() will not cause the
>terminal device to become the controlling terminal for the process.

Hmm.  I made an obvious fix for this to Cygwin and Corinna reported that
this broke ssh.  Apparently something in ssh is relying on this
functionality.

I'll have to investigate more under linux.

cgf

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