The lab itself consists of a number of tasks which will help familiarize you with the computers we will be using in this course. Actually, we will be using two types of computers in this course: Linux and SGI workstations. Both are Unix systems that have XWindows-based user interfaces.
Although we assume in the following that you have never logged into either type of computer, both computer systems have reasonably intuitive user interfaces. Therefore, rather than explaining how to do each task in gory detail, we will simply give you the tasks together with some optional explanations you can refer to if you find the tasks obscure or otherwise difficult. However, we encourage you to try to figure out how to do the tasks on your own. When that doesn't work, don't be shy: ask!
One important remark: In our introductory course, MC27, we encourage students to take advantage of the easy-to-learn user interfaces on the Linux and/or SGI workstations. Our tack in this course is quite different: your work will primarily be done through a Unix shell (also called a terminal), which is a program that allows you to issue system commands; and through emacs, which is a programming and editing environment especially well suited for our needs. In fact, we even encourage you to call up Netscape through the shell, although you are welcome to use any of the many GUI ways of calling it up, should you prefer.
There is a printer in the small room adjoining the classroom/lab. Its name is mcs-lab, so if you need to select a printer to print to, that is the one you should use when in the third-floor Olin computer labs.
Each Gustavus student has been given a computer account; this handout assumes that you already have read your account letter and changed your password. If not, and you need help with this, let one of us know. It does not matter which workstation you log into; you will have access to all your files on all computers, since they are stored on a central file server.
The following instructions assume some familiarity with such terms as single-click, double-click, and drag, which refer to the use of the mouse (the small doohickey next to the keyboard). If you don't understand something or if the instructions seem impenetrable, don't worry. These are examples of things better shown than described in words. Ask your lab instructor or one of the tutors to explain it to you. Also, feel free to talk with your fellow students. Computers are unfortunately fraught with many arcane terms, and defining them all would unduly clutter these handouts. Fortunately, if you are not shy about asking someone when you have a question, you should get the hang of it fairly quickly.
Check-offs are worth one point each, and will be indicated in bold face in the labs.
We do not include instructions for these task because we figure that most of you already know how to do this. Furthermore, you can't even be reading this unless you are using a web browser such as Netscape, so these are basic boot-up tasks. We will briefly describe how to do this in the first class, and will help anyone who needs help during the first lab. You should also be sure you can do this on both platforms (Linux and SGI), since you shouldn't be limited to one or the other.
Our personal homepages are located at
http://www.gac.edu/~karl http://www.gac.edu/~wolfeThe course home page is located at
http://www.gac.edu/~mc38You may wish to bookmark these ask well.
The SGIs create a special directory which keep track of how your desktops are set up between sessions. In other words, when you log on to the same SGI the next time, it will look pretty much like how you left it.
In order that your desktop looks the same on other SGIs, you may need to tell a new SGI to share its desktop with one that you have previously used. All you have to do is the first time you log in to a new SGI that you haven't used before, respond to the panel that pops up upon login by saying that you want to ``share'' the same desktop. (Ask for help with this the first time you login on a different SGI if you need it; for now it isn't an issue.)
The Unix computers on campus (among which are the Linux and SGI workstations) share a tree-structured file system. This means that the files on the computers are located in directories, which may themselves include files and subdirectories, which may contain files and other subdirectories, ....
When your account was created, you were given a home directory in which you can store and create files and subdirectories. This home directory resides on a file server maintained by the Department of Information Technology (which is located on the first floor of Olin Hall). Since your home directory (as well as other user accounts) are automatically loaded onto the Linux and SGI computers, it really doesn't matter which specific computer you use. Whichever computer you use, you will have access to the files you created in your previous sessions.
For this course, we recommend you learn how to navigate the directory structure using a a shell or terminal window, which is less system dependent and graphically based than other methods. Click on the hyper-link below to go to the page that is appropriate for your system.
Following are some tasks which will help you learn how to view and manipulate the directory structure using a Unix shell on and SGI or Linux workstation.
A shell (also known as terminal) is a program that allows you to issue commands to the computer's operating system. Unfortunately, these commands are often somewhat arcane and difficult to remember. Fortunately, there aren't many commands that you need to remember.
The easiest way to launch a shell is through the main menu for the SGI or Linux workstation. On an SGI, choose ``Desktop'' on the Desk1 menu, and then select the ``Unix Shell'' item on the sub-menu. On a Linux workstation, get the main menu by holding down the left mouse button while on an open area of the screen, and then select the ``Xterm'' item on that menu.
In either case (SGI or Linux), the shell window will pop up, and you will be presented with a command line prompt from which you can issue commands. How it looks will vary from person to person, but will probably end with the % character.
As described before, each computer user at Gustavus has a home directory that is stored on the central file server. When you start up a shell, the present work directory is your home directory. To see what that is, type pwd. (You must press the ``Enter'' key to actually issue the command.) Do so. Your home directory should end with your username.
You can view the present work directory by entering the command ls. This will list all files and directories in the present work directory.
To get a more informative listing, type ls -l. This gives more information about the files and directories.
To add a directory called mc38 into your home directory, type mkdir mc38. Do so, and then type ls -l to see the newly created sub-directory.
pwd to show that you are there and a directory
listing to show that it is currently empty.You can move to mc38 by typing cd mc38 (think of cd as Change Directory). Do so.
Typing cd .. will cause you to move up one directory
in the file system; typing cd will take you to your home
directory.
On the SGIs, the logout option is again in the Desk 1 menu's Desktop sub-menu. Be sure to respond to the ``Do you want to log out now?'' confirmation panel by clicking the ``Yes'' button. On the Linux workstations, move the mouse cursor to an open area of the screen and hold down the left mouse button; the last menu-cell presents a sub-menu that allows you to quit.
One problem you will encounter is how to make yourself aware of all of the applications available to you. This is a rather daunting task, and one which we will not directly address in this course. Instead, we suggest that you make use of the main source of useful computer arcana and trivia we have found, namely your fellow computer users. We are always learning new things from our students. So don't be shy!