Using the Unix Machine From Off Campus

You'll need an active, connected internet connection (dial-up, DSL, cable, etc.). You will also need an SSH client. This is a program that can perform a Secure SHell connection across the internet. (Another name for a terminal window — the $-prompt — is a shell window.) Although Windoze doesn't come with an SSH client, you can easily download one. My favorite is Putty (by Simon Tatham). To download this SSH client, just click to its download page and click on the putty.exe link. (If you want to put it on your USB key, you can get it at They specialize in making desktop applications run off of USB devices. *smile*)

Once you've saved the SSH client (I like the Desktop for its convenience), just double-click the icon to run it. Under the Session tab, you'll need to fill in the address/hostname for connecting to Harper's unix machine: The rest of the Session information should be fine for now.

Before you click to Open the connection, we can get a smoother experience by clicking to the Window tab/panel and making sure that the rows/columns are set to 24/80. Also within the Window pane we should choose that When [the] window is resized, Putty should Change the size of the font (instead of actually changing the size of the window).

And — just in case you might want to play around with unix a bit more later on — and especially if you might like to dabble in the graphics bits of Chapter 2 — let's go to the Connections tabset, open the SSH subtree, and click on the X11 panel. Now make sure the box Enable X11 forwarding is checked.

Although there are other things you can change, I'll just let you play around the the configuration tabs to find what works/what you like. For now click back to the Session tab and type 'ares' or 'harper unix' or something like that in the Saved sessions box. Click on Save (it's on the right side there) to save the settings you've just made under the name you just typed. (That way you won't have to make those settings/options changes each time you try to log on.)

Finally, we are ready to connect to Harper's unix machine. Click on the Open button (at the bottom of the Session panel). Putty will disappear for a second (...or several) and then pop up with two windows. The first is the terminal window you'll get to work in and the second smaller one (the one that's actually focused) is telling you that it has never connected to this machine before and asking for you to verify the security information. Make sure that the fingerprint information it displays is one of these three:

Fingerprints for Harper's ares *nix Server.
    ECDSA MD5:d2:b9:59:e1:9c:4d:87:4f:a3:58:c3:65:6f:31:b3:0e
    RSA  MD5:05:2c:b7:a7:d8:8e:e6:00:33:3d:66:91:f0:15:e5:60
    ED25519  MD5:d1:c8:a6:e8:dd:6d:3c:bf:d7:b8:03:8f:ea:9b:b7:64

If you get anything else, your connection may have been hi-jacked — immediately terminate the session! (This type of attack is known as a man-in-the-middle attack because someone sits between you and ares and catches both ends of the conversation but perhaps tweaks or at the very least steals information as it passes by. Very much like a wire-tap, really...)

If all is well, however, click Ok and the verification window disappears (and won't ever come back — Putty will remember the fingerprint information of ares and validate it automatically in future connection sessions). Now the terminal window is asking you to login. Use your login name and password just as if you were in lab using gnome-terminal or nedit. (Don't worry about sending this information across the internet, it — and everything you type and everything that is displayed in this window — is being encrypted and will not be plainly visible to hackers.)

Unlike with gnome-terminal in the lab, this terminal window is self-contained. It won't disappear and pop up with yet another window after you log in — it will simply display the login message and give you a $-prompt afterwards. The only drawback to this connection is that it is only the terminal window — you don't [necessarily] get access to the nedit program to edit nicely.

You can only use $ commands so you must use either vi or nano to edit your programs. Also don't try to print from home as there is no way to define your home printer to the unix machine.

Connecting From Another Campus Lab

Follow the instructions above for downloading Putty to the lab PC's Desktop and setting up the Session/connection. Your settings will be erased when you log out so you'll have to set it all back up each time.

Log in as normal. Again, you only have $ program access.

Other Remote Connection Potentials

If you are feeling adventurous, you could try to get the nedit to work through your Putty (or other SSH client) connection. We already did the beginnings of this sort of thing when we set up the X11 port forwarding checkbox above. To finish it off, you'll have to install and run an X11 client/server on your machine. One of the easiest to get is the X11 system that comes with CygWin. (Recall that CygWin is one of the free compiler options listed off of the main page.) luck with that...