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Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!elroy!gryphon!sarima
From: sarima@gryphon.COM (Stan Friesen)
Newsgroups: comp.unix.questions,comp.unix.wizards
Subject: Pty's and cpio
Message-ID: <12715@gryphon.COM>
Date: 28 Feb 89 22:10:44 GMT
Reply-To: sarima@gryphon.COM (Stan Friesen)
Distribution: usa
Organization: Trailing Edge Technology, Redondo Beach, CA
Lines: 28


	Hello again. Tanks to all of you who responded to my question
about pseudo-ttys.  It was quite helpful.  I will try to find some time to
assemble a summary of the responses to post, since I got several requests
for that.

	Now, on to my real current problem.  I am trying to attach cpio
as a background/slave process while retaining the ability to process
multiple tapes.  The problem: the moment it tries to *read* the response
from the master program telling it that the tape has been switched, it dumps
core!  At first I assumed that this was because it opened /dev/tty to read
the response.  That is why I wanted pseudo-ttys, so I could make the slave
end of one the control terminal for the cpio.  Well, all my test programs
worked perfectly, the pseudo-ttys were opened and attached as control terminal,
my test master properly did I/O on them and the slave's open() of /dev/tty
went to the pseudo-tty as I wished.  So I assumed everything was peachy and
installed the whole mess in my actual application.  Result: no change in the
behavior of cpio, it still dumps core on the read of /dev/tty!!  I have
verified, from another terminal, that the control terminal for the cpio is
in fact the slave end to the pseudo-tty, so I *assume* it must be proeprly
attached.

	Could anyone help me? Why is the cpio dieing?? What can I do to
get it to properly read the response from the master?
-- 
Sarima Cardolandion			sarima@gryphon.CTS.COM
aka Stanley Friesen			rutgers!marque!gryphon!sarima
					Sherman Oaks, CA