From: jw schultz <jw@pegasys.ws>
To: linux-kernel@vger.kernel.org
Subject: Re: kernel bug in socketpair()
Date: Wed, 23 Jul 2003 15:24:32 -0700 [thread overview]
Message-ID: <20030723222432.GC16188@pegasys.ws> (raw)
In-Reply-To: <200307231929.PAA77754@raptor.research.att.com>
On Wed, Jul 23, 2003 at 03:29:03PM -0400, Glenn Fowler wrote:
>
> On Wed, 23 Jul 2003 12:14:36 -0700 David S. Miller wrote:
> > I missed the reason why you can't use pipes and bash
> > is able to, what is it?
>
> we have some applications, ksh included, with semantics that require
> stdin be read at most one line at a time; an inefficient implementation
> of this does 1 byte read()s until newline is read; an efficient
> implementation does a peek read (without advancing the read/seek offset),
> determines how many chars to read up to and including the newline,
> and then read()s that much
>
> linux has ioctl(I_PEEK) for stream devices and recv() for sockets,
> and neither of these work on pipes; if there is a linux alternative
> for pipes then we'd be glad to use it
>
> we switched from pipe() to socketpair() to take advantage of the linux
> recv() peek read
Perhaps you'd rather code a patch adding peek functionality
for pipes.
--
________________________________________________________________
J.W. Schultz Pegasystems Technologies
email address: jw@pegasys.ws
Remember Cernan and Schmitt
next prev parent reply other threads:[~2003-07-23 22:10 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-07-23 14:28 Re: kernel bug in socketpair() David Korn
2003-07-23 14:46 ` David S. Miller
2003-07-23 16:56 ` Glenn Fowler
2003-07-23 17:00 ` David S. Miller
2003-07-23 17:24 ` Glenn Fowler
2003-07-23 17:31 ` David S. Miller
2003-07-23 18:14 ` Glenn Fowler
2003-07-23 18:23 ` David S. Miller
2003-07-23 18:54 ` Glenn Fowler
2003-07-23 19:04 ` David S. Miller
2003-07-23 19:11 ` Glenn Fowler
2003-07-23 19:14 ` David S. Miller
2003-07-23 19:29 ` Glenn Fowler
2003-07-23 19:56 ` David S. Miller
2003-07-23 22:24 ` jw schultz [this message]
2003-07-23 19:08 ` Alan Cox
2003-07-23 19:41 ` Andreas Jellinghaus
2003-07-23 17:50 ` Alan Cox
2003-07-23 23:27 ` Bill Rugolsky Jr.
-- strict thread matches above, loose matches on Subject: below --
2003-07-23 13:32 David Korn
2003-07-23 14:04 ` David S. Miller
2003-07-23 14:20 ` Alan Cox
2003-07-23 15:36 ` David S. Miller
2003-07-23 16:13 ` Alan Cox
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