From: Steffen Nurpmeso <steffen@sdaoden.eu>
To: Peter Pentchev <roam@ringlet.net>
Cc: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: Re: [TUHS] sockets (was Re: First appearance of named pipes)
Date: Sat, 28 Mar 2020 17:03:55 +0100 [thread overview]
Message-ID: <20200328160355.NCc9a%steffen@sdaoden.eu> (raw)
In-Reply-To: <20200328111428.GA1431416@straylight.m.ringlet.net>
Peter Pentchev wrote in
<20200328111428.GA1431416@straylight.m.ringlet.net>:
|On Sat, Mar 28, 2020 at 01:12:35PM +0200, Peter Pentchev wrote:
|> On Thu, Mar 26, 2020 at 01:38:17PM +1100, Dave Horsfall wrote:
|>> On Wed, 25 Mar 2020, Grant Taylor via TUHS wrote:
|>>
|>>> · netcat's STDOUT to grep's STDIN
|>>> · grep's STDOUT to netcat's STDIN
|>>
|>> Are you trying to set up a loop of processes or something? I'm \
|>> not sure if
|>> that is even possible, although you can't rule out creative uses \
|>> of dup2()
|>> etc...
|>
|> This can't really be done with netcat, but it's quite easy to do with
|> socat; here's an example with a trivial program that reads lines from
|> its standard input and writes a single line to its standard output:
|>
|> [roam@straylight ~]$ socat -v tcp4:nimbus.fccf.net:25 exec:./heysmtp.\
|> py
...
perl(1) has IPC::Open2 for that:
use IPC::Open2;
# We use `csop' for hashing
my $MAILX = 'LC_ALL=C s-nail -#:/';
sub hash_em{
die "hash_em: open: $^E"
unless my $pid = open2 *RFD, *WFD, $MAILX;
foreach my $e (@ENTS){
print WFD "csop hash32 $e->{name}\n";
my $h = <RFD>;
chomp $h;
$e->{hash} = $h
}
print WFD "x\n";
waitpid $pid, 0;
}
hash_em()
|...but, of course, this is still not what Derek was talking about
|earlier - there is no separation of the file descriptors connected to
|the socket: closing the stdout one would not result in a FIN being sent
|along the line.
Just wanted to add earlier in the thread that on some systems
shutdown(2) equals close(2). At least it was like that on Mac OS
X (by then) Snow Leopard.
--steffen
|
|Der Kragenbaer, The moon bear,
|der holt sich munter he cheerfully and one by one
|einen nach dem anderen runter wa.ks himself off
|(By Robert Gernhardt)
next prev parent reply other threads:[~2020-03-28 16:04 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-06 22:44 [TUHS] First appearance of named pipes Noel Chiappa
2020-03-07 12:17 ` Paul Ruizendaal
2020-03-07 13:29 ` Clem Cole
2020-03-07 16:39 ` Derek Fawcus
2020-03-08 2:36 ` Rob Pike
2020-03-08 2:47 ` Larry McVoy
2020-03-08 13:07 ` Ralph Corderoy
2020-03-08 13:25 ` arnold
2020-03-08 3:06 ` Dave Horsfall
2020-03-08 7:16 ` arnold
2020-03-08 15:13 ` [TUHS] sockets (was Re: First appearance of named pipes) Derek Fawcus
2020-03-09 23:22 ` Grant Taylor via TUHS
2020-03-09 23:44 ` Larry McVoy
2020-03-23 8:49 ` Peter Pentchev
2020-03-24 9:47 ` Derek Fawcus
2020-03-25 23:25 ` Grant Taylor via TUHS
2020-03-25 23:47 ` Richard Salz
2020-03-26 0:11 ` Grant Taylor via TUHS
2020-03-26 0:18 ` Richard Salz
2020-03-26 1:08 ` Grant Taylor via TUHS
2020-03-26 2:38 ` Dave Horsfall
2020-03-26 3:08 ` Rob Pike
2020-03-26 3:43 ` George Michaelson
2020-03-26 4:11 ` Grant Taylor via TUHS
2020-03-28 11:12 ` Peter Pentchev
2020-03-28 11:14 ` Peter Pentchev
2020-03-28 16:03 ` Steffen Nurpmeso [this message]
2020-03-26 1:20 ` Tony Finch
2020-03-27 10:51 ` Derek Fawcus
2020-03-09 23:22 ` [TUHS] First appearance of named pipes Grant Taylor via TUHS
2020-03-10 7:29 ` arnold
2020-03-11 2:47 ` Grant Taylor via TUHS
2020-03-11 7:02 ` arnold
2020-03-10 13:49 ` Chet Ramey
2020-03-10 20:26 ` Dave Horsfall
2020-03-10 20:37 ` Chet Ramey
2020-03-11 2:51 ` Grant Taylor via TUHS
2020-03-08 23:09 [TUHS] sockets (was Re: First appearance of named pipes) Norman Wilson
2020-03-09 17:09 ` Tony Finch
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