A Note about Printing

Printing the contents of files to the print stations in the classrooms from engineering servers such as goss or hex is notoriously unreliable. Output appears to vanish when crossing the gap between Engineering and the Computer Centre. Here's one solution to the problem, having logged into hex. The same solution works for goss, by just substituting "goss" for "hex" in the following:

This first procedure just sets a few conditions up and need only be typed once for all time.

rlogin sysa
(Type your PC/sysa password at this point)
echo "hex.eng.abdn.ac.uk" > .rhosts
chmod og=r .rhosts
logout
(brings you back to hex)

The above has created a file called .rhosts in your sysa home directory which gives your userID on hex permission to issue remote commands to sysa. As long as this file exists, your account on hex will be able to use the following commands (rcp and remsh).

You may want to be able to use the commands from both goss and hex, but you will find that repeating the above procedure from the other computer deletes the previous file. A slightly more involved procedure will allow you to access sysa remote commands from both hex and goss:

rlogin sysa
(Type your PC/sysa password at this point)
cat > .rhosts
hex.eng.abdn.ac.uk
goss.eng.abdn.ac.uk
"Ctrl+d" (press the Ctrl key and type "d" - this writes the .rhosts file to disk).
chmod og=r .rhosts
logout
(brings you back to hex)

Now, assuming that you have a file called tabulate.c, you can send this to the printer (via sysa) using the following commands:

rcp tabulate.c sysa:tabulate.c
remsh sysa /local/bin/aprint -Phold tabulate.c

The first command copies your file to your home directory on sysa. The second line issues the command
aprint -Phold tabulate.c remotely onto sysa. The file referred to here is the sysa copy of tabulate.c that you created with the first command.

You can create the effect of both of the above commands using the following:

remsh sysa /local/bin/aprint -Phold < tabulate.c

The < sign is very important here and redirects the contents of tabulate.c (the version on hex) into the remsh
command which is connected to the aprint command running on sysa. No named copy of your file is
ever actually created on sysa.

Rcp (remote copy) can be used in a number of ways. For example's sake (and not part of your exercise today)

rcp tabulate.c sysa:PCFILES/tab.c
(will copy tabulate.c from hex into your drive H: as you see it from a PC)

rcp sysa:PCFILES/graphs.m graphs.m
(will take a copy of graphs.m in your PC's drive H: into you current directory on hex. As you can see, rcp works in both directions: to as well as from hex)

etc..

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Author : Keith Halewood / Helge Nareid Current contact: Gorry Fairhurst G.Fairhurst@eng.abdn.ac.uk