From owner-freebsd-hackers Wed Feb 5 17:31:23 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id RAA03060 for hackers-outgoing; Wed, 5 Feb 1997 17:31:23 -0800 (PST) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id RAA03051 for ; Wed, 5 Feb 1997 17:31:12 -0800 (PST) Received: (from msmith@localhost) by genesis.atrad.adelaide.edu.au (8.8.2/8.7.3) id MAA28813; Thu, 6 Feb 1997 12:01:08 +1030 (CST) From: Michael Smith Message-Id: <199702060131.MAA28813@genesis.atrad.adelaide.edu.au> Subject: Re: fcntl, F_SETFL, O_NONBLOCK & /dev/null In-Reply-To: <199702060050.LAA03861@freebsd1.cimlogic.com.au> from John Birrell at "Feb 6, 97 11:50:16 am" To: jb@cimlogic.com.au (John Birrell) Date: Thu, 6 Feb 1997 12:01:07 +1030 (CST) Cc: hackers@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL28 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk John Birrell stands accused of saying: > > I can open /dev/null with O_NONBLOCK. If I open /dev/null without > O_NONBLOCK and then try to fcntl F_SETFL to change the file descriptor > to non-blocking, I get ENODEV returned. Can someone tell me why? Probably because the ioctl handler for /dev/null doesn't understand F_SETFL. I can't find the sucker, so I can't actually give you an authorative answer 8( > John Birrell CIMlogic Pty Ltd -- ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[ ]] Genesis Software genesis@gsoft.com.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control. (ph) +61-8-8267-3493 [[ ]] Unix hardware collector. "Where are your PEZ?" The Tick [[