From owner-freebsd-current  Tue Apr 17 11:18:19 2001
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Date: Tue, 17 Apr 2001 14:17:38 -0400 (EDT)
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
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To: "John W. De Boskey" <jwd@bsdwins.com>
Cc: Current List <freebsd-current@FreeBSD.ORG>
Subject: Re: FIO* doc added to tty.4 (review)
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<<On Tue, 17 Apr 2001 03:38:05 -0400, "John W. De Boskey" <jwd@bsdwins.com> said:

> ie: FIONREAD will succeed from a backgrounded process, but the
>     data read itself with hang (tty driver).

You are describing a general property of the terminal subsystem, which
any process dealing with terminals needs to be aware of.

(AFAIK, ioctl(tty, FIONREAD, &n) should set n to zero if the process
is in the background; if it does not that's probably a bug.)

The new POSIX revision group discussed this briefly in the
mailing-list, but the group did not want to innovate in this area.

-GAWollman


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