Re: My Network Configuration.

[Chris Albertson <chrisalbertson90278@yahoo.com>]

Some answers below but first another idea

The smartest system I saw for processing lots of image
files took advantage of the UNIX print queue.  Sending
am image file to the "priter" caused it to be put in a
common print queue several "printers" de-queued these
images and wrote the result to the next "printer".
You can use standard commands to add more "printers"
if the queue gets big.  The neat thing for Tom is that
even Windows PCs knowhow to send jobs to a UNIX print
queue using LP protocol.  

Any number of camera could feed a queue and any number
of data processing PCs could process that queue. and
all the computers have ways to track jobs waiting in
the queue, restart failed print jobs and so on.

It's not hard to set this up, you need an image
processing program that reads from STDIN and you put
that in /etc/printcap is an input filter

--- Thomas Droege <tdroege2@earthlink.net> wrote:

> I have a second network I use for internet access. 
> It has a Windows XP, a
> Windows 98, and a linux machine.  The connection
> goes DSL line, linksys
> router, network.  I try to run this in such a way
> that if someone gets at
> it I don't lose anything (except a mail archive)
> that I care about.  
> 
> 2nd question:  Is it safe to connect all the
> astronomy machines to the same
> network.

If you use the Linksys firewall/router and you have
not enabled "port forwarding" then it is very unlikely
anyone could get onto machines on your side of the
router.  Maybe someone could send you an e-mail that
contains some bad virus-like attachment but it would
be hard for even that to cause you trouble on a
machine other then the one Windows box that read the
mail and ran the attachment.  Just don't run
attachments.

Later if you did enable some ports on the router, say
for a public FTP server, you can do it safely. Ask for
advice first.  Most public servers (web and ftp) don't
get hacked  It can be _very_ secure it you could get a
second linksys router.  But don't worry to much with
all the ports closed you are pretty safe except for
those e-mail attachments can affect Windows PCs
> 
> 3rd question.  It would appear that the Windows 98
> machines often kill the
> network.  Sometimes the file transfer process just
> gets slower and
> slower...   Usually rebooting the Windows machines
> solves the problems. 
> But if a Windows machine dies while a linux machine
> is trying to access it,
> a Windows reboot may not solve the problem and I
> have to reboot the linux

You may not need to actually reboot the Linux PC.
rebooting works because it runs some start up script
that fixes your problem.    Likely you could run
something like

   /etc/init.d/XXX stop
   /etc/init.d/XXX start

Likely "XXX" = "network"

This one will be hard to figure out just from your
description but I'm sure a reboot is not required.
Just re-start some process.


> machine because of "stale file handle" or some such
> error.  This is a pain
>


> 
> 4th question.  Is there a simple "exit script if not
> root" shell command?  

Note that there is always an enviroment variable
called  "USER".  Try typing this
   echo $USER
it will print either "root", "tdroege" or whatever you
logged in as.  Now all you need is to compare $USER to
'root'  Something like if ($USER eq "root") exit
exact syntact depends on if you use tcsh or bash shell



=====
Chris Albertson
  Home:   310-376-1029  chrisalbertson90278@yahoo.com
  Cell:   310-990-7550
  Office: 310-336-5189  Christopher.J.Albertson@aero.org
  KG6OMK

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