From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <dd669f2c79418e4b94833a3db9b18616@quanstro.net>
From: erik quanstrom <quanstro@quanstro.net>
Date: Mon, 20 Jul 2009 22:15:58 -0400
To: 9fans@9fans.net
In-Reply-To: <dd6fe68a0907201904oc1a29f2r29b01c955fcde3a2@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Subject: Re: [9fans] i/o on a hangup channel asymmetry
Topicbox-Message-UUID: 296a97ce-ead5-11e9-9d60-3106f5b1d025

On Mon Jul 20 22:05:50 EDT 2009, rsc@swtch.com wrote:
> The programs that know about the signal are
> not the programs that need to be worried about.
> I'm much more worried about making sure that
> commands like
>
> grep pattern /n/dump/slow/slow/sys/log/mail | sed 5q
>
> stop as early as possible.  The note is nice
> precisely because it doesn't involve editing the
> source for every command.

if the grep has very few matches, it could process
for quite a long time before needing to write at all.
is this really effective in saving cpu?

also, the only case that is a problem is
when the return status of writes is not checked.
(or am i missing something?)  and the problem
will resurface on a pipe accessed through the
mount driver.

- erik