From: David Rompel (rompel@target.uucp)
Date: Tue Apr 20 1993 - 21:34:15 CDT

To everyone who replied thank you!!

As promised I am distributing a summary of what I recieved.

My answer was to use modempool. It seems to be good, was a simple port
( even to sysVr3.2 ) and does what I need. Still haven't got into
setting it up for others but it has been tested and will be installed.

Another reply was of interest. "expect" looks like a neat way to do
interactive shell programming. I will have to find time to play with it.

Below some of the messages in abridged format which I received.

>I am in need of a program that I can hang off a serial port instead
>of getty which will allow me to secure a modem by requiring a caller
>to identify himself login with a password then choose one of say three
>locations to be called back at. The program must then be able to
>call the user back and provide them the standard getty login prompt.
>Would someone please point me in the right dirrection to find it or
>something I can use a starting point as I am willing to hack something
>together but really don't have the time to do it from scratch.

Kurt Hockenbury REPLIED:
Well I haven't tried it yet, but have a look at modempool, just posted to
comp.unix.sources last week.

Submitted-By: (Lars Berntzon)
Posting-Number: Volume 26, Issue 104
Archive-Name: modempool/part01

Modempool is a program that handles a pool of modems. When a user calls a
modempool controlled modem he/she is requested a name, password and,
sometimes, a phone number. If everything is ok, modempool will dialup the
user and start a login prompt. Modempool has the following features:

    - Your site only have to have one external phone line and still have many
      modems on local lines.

    - Users do only have to known one number, this makes it easier for both
      the system administrator and the user who does't have to try many numbers
      to find a free line.

    - A user can have a list of valid phone numbers or asterisk for
      any number.

    - If compiled with the RLOGIN-switch callback will login a user
      on a specified machine.

    - Extensive logging of users loging in and of problems with the
      modem and lines.

Also try asking an archie server "whatis call" "whatis dial".

From: "Anna Pluzhnikov" <>

callback.tar.Z can be found on archie


    Location: /pub/utils/callback
           FILE -r--r--r-- 13926 Jan 17 1990 callback.tar.Z


From: (Steven Grimm)

Contact QualTrak Corp. at (408) 730-2674. Their TermServ program does
what you're looking for.

From: "Joseph C. Lawrence" <>

You might want to try 'expect' it will allow you to do all sorts of things.
(although, I'm not sure how secure it is). Installation is *very* easy.
Once you got expect up and
running (along with tcl), you should post to comp.languages.tcl to
see if anyone has already has an expect script written to do what you want.

>From archie:

Host (
Last updated 06:13 13 Apr 1993

    Location: /languages/tcl
      DIRECTORY rwxr-xr-x 512 Mar 17 23:08 expect

>From the man pages:

     Expect is a program that "talks" to other interactive pro-
     grams according to a script. Following the script, Expect
     knows what can be expected from a program and what the
     correct response should be. An interpreted language pro-
     vides branching and high-level control structures to direct
     the dialogue. In addition, the user can take control and
     interact directly when desired, afterward returning control
     to the script.

     Expectk is a mixture of Expect and Tk. It behaves just like
     Expect and Tk's wish. Expect can also be used directly See

     The name "Expect" comes from the idea of send/expect
     sequences popularized by uucp, kermit and other modem con-
     trol programs. However unlike uucp, Expect is generalized
     so that it can be run as a user-level command with any pro-
     gram and task in mind. (Expect can actually talk to several
     programs at the same time.)

     For example, here are some things Expect can do:

          + Cause your computer to dial you back, so that you
              can login without paying for the call.

          + Start a game (e.g., rogue) and if the optimal con-
              figuration doesn't appear, restart it (again and
              again) until it does, then hand over control to

          + Run fsck, and in response to its questions, answer
              "yes", "no" or give control back to you, based on
              predetermined criteria.

          + Connect to another network or BBS (e.g., MCI Mail,
              CompuServe) and automatically retrieve your mail so
              that it appears as if it was originally sent to
              your local system.

          + Carry environment variables, current directory, or
              any kind of information across rlogin, telnet, tip,
              su, chgrp, etc.

     There are a variety of reasons why the shell cannot perform
     these tasks. (Try, you'll see.) All are possible with


     In general, Expect is useful for running any program which
     requires interaction between the program and the user. All
     that is necessary is that the interaction can be character-
     ized programmatically. Expect can also give the user back
     control (without halting the program being controlled) if
     desired. Similarly, the user can return control to the
     script at any time.

From: Jim Prescott <>

Note that callback is only secure if the host->user call goes out on
a phone line configured outgoing-only at the phone company. Calling
someone back on the same line they called you is trivial to defeat (the
key point is that the host cannot tell the difference between picking
up the phone to dial and picking up the phone to answer).

From: (Gary Martin)

We market such a program for SunOS that does this and much more. It is
called CoSECURE. Please call Steve Martinez at 408.748.2194 to discuss
business details.

Gary Martin
CoSystems, Inc.

From: gecko!!eric@uunet.UU.NET (Eric Peterson)

        If you're on a System V style system, look at the "ct" program -
        it does what you need.

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