From: jnc@mercury.lcs.mit.edu (Noel Chiappa)
Subject: [TUHS] Excise process from a pipe
Date: Thu, 10 Jul 2014 11:10:21 -0400 (EDT) [thread overview]
Message-ID: <20140710151021.3ABE018C09F@mercury.lcs.mit.edu> (raw)
> From: Larry McVoy <lm at mcvoy.com>
> Every utility that you put in a pipeline would have to be reworked to
> pass file descriptors around
Unless the whole operation is supported in the OS directly:
if ((pipe1 = process1->stdout) == process2->stdin) &&
((pipe2 = process2->stdout) == process3->stdin) {
prepend_buffer_contents(pipe1, pipe2);
process1->stdout = process2->stdout;
kill_pipe(pipe1);
}
to be invoked from the chain's parent (e.g. shell).
(The code would probably want to do something with process2's stdin and
stdout, like close them; I wouldn't have the call kill process2 directly, that
could be left to the parent, except in the rare cases where it might have some
use for the spliced-out process.)
Noel
next reply other threads:[~2014-07-10 15:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-10 15:10 Noel Chiappa [this message]
2014-07-10 15:11 ` Larry McVoy
-- strict thread matches above, loose matches on Subject: below --
2014-07-18 15:33 Noel Chiappa
2014-07-17 15:42 Noel Chiappa
2014-07-16 21:31 Noel Chiappa
2014-07-14 15:12 Noel Chiappa
2014-07-14 14:13 Doug McIlroy
2014-07-10 16:12 Noel Chiappa
2014-07-10 16:06 Noel Chiappa
2014-07-10 16:04 ` Larry McVoy
2014-07-10 2:49 [TUHS] Subject:unpipeIt'seasy for a process to insert a new process intoapipelineeither upstream or down unpipe Doug McIlroy
2014-07-10 4:52 ` [TUHS] Excise process from a pipe Warren Toomey
2014-07-10 5:00 ` Dave Horsfall
2014-07-10 5:06 ` Christopher Vance
2014-07-10 8:43 ` Warren Toomey
2014-07-10 12:03 ` Doug McIlroy
2014-07-10 12:04 ` Doug McIlroy
2014-07-10 14:45 ` Larry McVoy
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