This page is here to help you understand the many ways of accessing the
johnny computer for Math 210.
Huh?
Put it this way--the johnny computer is a store, and we are a customer.
Now, there are many ways of getting in touch with the store: we can call
them, we can fax then, we can read their catalog, we can mail them, or we
can even drive to their store and walk in ourselves. With each way we can
do different things. For instance, we can request information from all
the manners, but we can get the item the quickest if we drive and pick it
up ourselves.
The same can be said with johnny. We need to get and put information onto
the computer, but some ways of doing it are better than others. We can
telnet to the computer (similar to a phone conversation), we can ftp to
the computer (similar to using the post office or UPS), and we can even
use VNC to connect to the store (similar to
being one with the store). We can't actually be in physical contact with
the computer because it's locked up in some room in DRL. So we access it
over the internet using either telnet or ftp.
Okay. First, what's telnet?
Telnet, to put it mildly, lets the user access the basics of the computer.
With telnet, you access the computer and can read what is printed on its
screen at the same time. Think of it as having your monitor and keyboard
linked directly into the system. When you type ELM into telnet, you are
typing ELM into johnny. When you press , johnny runs the program
and sends you the result. With telnet, especially with johnny, you can
access your files and edit them. This is very handy for a quick edit of
your html pages and perl scripts.
Okay, so then what's ftp?
When we ftp to johnny, we are accessing the computer in a different way.
This time, we can't see what the screen is saying, nor can we type
directly to the computer. Instead, ftp (file transfer protocol) allows us
to directly add and delete files to our account. If I had some graphics
that I wanted to add to my webpage, I would ftp them to my account. I
couldn't telnet them, because telnet doesn't allow file transfer, just
like how the telephone doesn't allow you to send packages and UPS doesn't
allow you to talk directly to the sender.
I'm still in left field on this one
Email me and I'll see how I can
help.