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From: rrr@u02.svl.cdc.com (Rich Ragan)
Newsgroups: comp.lang.perl
Subject: Problem opening pty/tty with perl
Keywords: pty tty perl37 perl40
Message-ID: <28619@shamash.cdc.com>
Date: 13 Nov 90 17:26:49 GMT
Sender: news@shamash.cdc.com
Reply-To: rrr@svl.cdc.com
Organization: Control Data Corporation, Silicon Valley Operations
Lines: 25

I have a Perl script that uses pty/tty to communicate with
another task. This all worked fine at patch level 28.
I upgraded to patch level 37 (and also tried 40 as well)
and found that the following (subsetted) part of the script
shows the problem:

open($pty,"+>/dev/ptyp1")|| die "cant open pty\n";
print "First open OK\n";
open($tty,"+</dev/ttyp1")|| die "cant open tty\n";
print "Second open OK\n";
close($pty); close($tty);

With PL28, this all works fine. Both open's complete.
With PL37 and PL40, the script always hangs on the
second open. The more general code is actually trying
all pty/tty pairs looking for a free one so the
problem should not be the hardwired pty/tty name.
Any ideas what might be going wrong?

By the way, PL40 fails on the last of the tests for
me as well (Mips RISC/OS based system).
Thanks.
--
Richard R. Ragan  rrr@svl.cdc.com  (408) 496-4340 
Control Data Corporation--Silicon Valley Operations