Path: utzoo!mnetor!uunet!husc6!linus!philabs!aecom!aecom2!schwell
From: schwell@aecom2.AECOM.YU.EDU (Dov Schwell)
Newsgroups: comp.unix.xenix
Subject: pseudo-tty driver
Message-ID: <424@aecom2.AECOM.YU.EDU>
Date: 8 Mar 88 00:47:09 GMT
Distribution: na
Organization: Yeshiva University, New York
Lines: 11

I need to place a shell around an application, sort of like the way bc
controls dc.  My problem is that the application checks to makke sure
that it's input is coming from a terminal.  When I try opening a pipe
(using the pipe() system call) or just try redirecting from the command
like, the program complains.  I need a way to create a device driver
from which I can filter input before sending it to the real device driver.
If I create a driver which does i/o through the real tty driver after
filtering the input, will this work?  What can I not do from a device driver
(e.g can I do file i/o, or open a pipe to another program)?  Any help would
be appreciated.
						Yosef Gold