Xref: utzoo comp.sources.wanted:2705 comp.sys.ibm.pc:9542
Path: utzoo!mnetor!uunet!husc6!bu-cs!madd
From: madd@bu-cs.BU.EDU (Jim Frost)
Newsgroups: comp.sources.wanted,comp.sys.ibm.pc
Subject: Re: Need LOGIN Shell for MS-DOS
Message-ID: <17405@bu-cs.BU.EDU>
Date: 14 Dec 87 02:38:55 GMT
References: <145@tsdiag.UUCP> <17389@bu-cs.BU.EDU> <7216@sunybcs.UUCP>
Reply-To: madd@bu-it.UUCP (Jim Frost)
Organization: Boston University Distributed Systems Group
Lines: 52
Keywords: MSDOS

In article <7216@sunybcs.UUCP> ugfailau@joey.UUCP (Fai Lau) writes:
>In article <17389@bu-cs.BU.EDU> madd@bu-it.bu.edu (Jim Frost) writes:
[method of doing a login... see referenced articles]
>
>	Why don't you do this? Issue a "rename" at the end of
>the *default* autoexec.bat to change its name, and issue
>another "rename" to change the name of another bat file to 
>autoexec.bat, which is to be brought in for another command
>shell.

[stuff on restoring the original autoexec.bat and related topics
deleted]

>Of course, this doesn't solve the problem of
>having two shells in the system. If there is a way
>to "substitute the current shell with a new shell....,
>but then the login program in the first shell may
>have to be lost. I only have experience in UNIX multitasking
>in PC, so I can't say much about MS-DOS multi-
>user environment.

Ok, one thing at a time.  This is a dandy idea but it has several
flaws.  Our system is multitasking.  What would happen if two users
logged on at once?  It wouldn't even have to be too close, either,
given the amount of time it'll take command.com to get through an
autoexec.bat file of any complexity.  (BTW, we don't have UNIX
multitasking.  We have one PC running 5 processors.  Basically a
bus-oriented LAN with diskless workstations.)  This wouldn't matter if
you have a single-user system, but there are other problems.

Also, issuing a command.com /p (permanent) to allow a shell to become
permanent and to allow the shell to switch to interactive mode makes
life real difficult when you're trying to log out.  The only easy way
to do it is to reboot, often a painfully slow process.

Another flaw is that we wanted to keep things simple.  Each user
has his/her own directory.  We wanted their autoexec.bat file THERE so
that they could always see it and modify it to boot.  Essentially
their home directory was "root" so far as they were concerned.  All we
have to do with our system is make sure they know that that last line
in the autoexec.bat file (command.com) is SUPPOSED to be there.

You might note that my system of doing things makes it easy to run
programs as you log out, too, since anything after the line that calls
command.com will be run when command.com exits.  Basically .login and
.logout in a single file....

>Fai  Lau

jim frost
madd@bu-it.bu.edu
"I wasn't wrong.  Just inaccurate."