Date: Wed, 23 Jul 2003 15:24:32 -0700
From: jw schultz <jw@pegasys.ws>
To: linux-kernel@vger.kernel.org
Subject: Re: kernel bug in socketpair()
Message-ID: <20030723222432.GC16188@pegasys.ws>
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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
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