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From: les@chinet.chi.il.us (Leslie Mikesell)
Newsgroups: comp.unix.questions
Subject: Re: cu & sb/rb
Message-ID: <1991Mar27.155607.28799@chinet.chi.il.us>
Date: 27 Mar 91 15:56:07 GMT
Article-I.D.: chinet.1991Mar27.155607.28799
References: <50867@apple.Apple.COM>
Distribution: na
Organization: Chinet - Chicago Public Access UNIX
Lines: 23

In article <50867@apple.Apple.COM> erekose@apple.com (Erik Scheelke) writes:

>I have a cu connection to another machine.  I want to use sb and rb (Y-Modem)
>to send a file back and forth between machines.  How can I do this?

Basically, you can't.  Cu forks into two processes, one of which reads
from the remote tty line and writes to your terminal.  When you do
a ~! or ~$ escape, the process reading from your terminal stops but
the other one continues to read from the remote line.  This means that
any other program that tries to read from the remote line is going to
lose data.  If you happen to have source for cu, there is supposed to
be an #ifdef'ed option to enable the ~+ command to stop the reading
process while running the specified process connected to the remote
line (exactly what you need for a file transfer protocol).  As far as
I know, this option is not enabled in any released versions of cu.

If you have kermit set up for dial-out on your machine you can do
shell escapes to run other programs without any interference.
However, you have to choose the outbound device for kermit and remember
it for explicit i/o redirection in the other command.

Les Mikesell
  les@chinet.chi.il.us