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Logging on and Doing Windows

This lesson provides a first introduction to our laboratory terminals, including how to log on and off, how to select and change your password, and how to manipulate windows with the window manager.

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We find that nearly all of our students are already familiar with Apple's or Microsoft's windows system. Our Unix classes use the SUN Software ``Java Desktop'' manager, which has a similar look and feel. So we assume this level of familiarity.

Class Accounts

If you didn't already have a Physics computer account before you enrolled in your class, you should have received a sheet of paper with your username and password. Students who registered late may have been missed. Please see the instructor if you don't have your account information.

Other Physics Computer Accounts

See instructions.

Terminals and Servers

The terminals in the lab are not really stand-alone computers. They are ``thin clients'', that is, they are graphical displays with a network connection to powerful servers that manage sessions for many users at the same time. You must first select a server to manage your session. Then you log in to the server.

Logging on to the terminals

You should see a bunch of server icons on the left of your screen. Click on the one appropriate to your class. For Physics 3730/6720 you should choose one of three: ``cygnus'', ``draco'', and ``orion''. Once you have selected the appopriate server, you should see a login banner. Enter your assigned login user name and password in the space provided. Unix is case-sensitive, so be sure to type upper and lower case exactly as given. If you are successful, you will get the window manager screen.

Changing Your Password

If this is the first time you have logged in, you must change your password. Do this in three steps explained in the next four paragraphs: (1) Choose a good password. (2) Open a terminal window. (3) Use the Unix passwd command to make the change.

Selecting Your Password

Your password is a string of letters, numbers, and/or special characters that you can remember easily but others would find it very difficult to guess. Unix distinguishes upper and lowercase letters. For the sake of security on this system, we urge you to choose your password wisely. Don't use names and words found in dictionaries. A combination of letters and numbers, upper and lowercase and/or special characters is good. Your password should contain at least six characters. For example, you could create a password from the first letters of a mnemonic phrase, such as ``Ga,mmd!CE'' for ``Go ahead, make my day! Clint Eastwood.''. (But don't use this one, now! Make up your own.)

Getting a terminal window

Right click on an empty space in your window and select ``Open in Terminal''. You should get a terminal window. You can have as many of them as you need in a session.

Typing in a Terminal Window

The terminal window is the basic interface for communicating with the shell. Any command or other information you type will not be interpreted until you hit <Enter>. Before that, you may hit <Backspace> to redo the previous character. To redo the entire command from the beginning, hold down the <Ctrl> key while typing u. (This operation is abbreviated C-u in these notes.)

Changing Your Password

After you have invented a new password, type passwd<Enter> (it i.e. the letters passwd followd by the Enter key) at the prompt in a terminal window to run the procedure that changes your password. You will first be asked for your old password, then your new choice, and you will be asked to repeat your new choice to verify that you didn't make a typing mistake. You may change your password as often as you want using this method. It takes about one hour for the change to take effect, so you may have to continue to use your old password for a while.