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From: Axel Belinfante <Axel.Belinfante@cs.utwente.nl>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: Re: [9fans] trying to understand how fork/pipe a filtering program
Date: Thu, 31 Aug 2006 22:45:54 +0200	[thread overview]
Message-ID: <200608312045.k7VKjsw01324@demeter.cs.utwente.nl> (raw)
In-Reply-To: Your message of "Thu, 31 Aug 2006 21:24:58 +0100." <43797a19394ce8f10a30710c76d1d46b@vitanuova.com>

> oops skim reading again!
> i'd thought i'd read "using two pipes unidirectionally *doesn't* make it work."
> so why can't you just use two pipes unidirectionally? you can't do anything
> else in this example, because by using the same pipe for input and output,
> the command itself keeps its own input open, and therefore never receives EOF.

seems it took me a while to realize that.


the funny thing is that, somehow, using the same pipe
for input and output does work (at least for me)
if in the parent I have an fprint or a sleep between
the writing+closing part and the reading part,
as in the message with which I started this thread.
that said, I'm much happier with the 'two unidirectional pipes' solution.

Axel.


  reply	other threads:[~2006-08-31 20:45 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-08-30 22:46 Axel Belinfante
2006-08-30 23:05 ` geoff
2006-08-31 16:26 ` "Nils O. Selåsdal"
2006-08-31 19:55   ` Axel Belinfante
2006-08-31 20:15     ` rog
2006-08-31 20:24       ` Axel Belinfante
2006-08-31 20:24     ` rog
2006-08-31 20:45       ` Axel Belinfante [this message]
2006-09-01  3:43     ` geoff
2006-09-01 10:57       ` rog
2006-09-01 14:35 ` rog
2006-09-01 15:33   ` Skip Tavakkolian
2006-09-01 15:59     ` rog
2006-09-01 18:42       ` Skip Tavakkolian
2006-09-03 19:09   ` Axel Belinfante
2006-09-04 14:52     ` Gorka guardiola
2006-09-04 20:50       ` Gorka guardiola
2006-09-04 19:26     ` Skip Tavakkolian
2006-09-04 20:25       ` Francisco J Ballesteros

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