Lab 1: Windows, Unix and all that

By the end of this lab, you will be able to:

• Find your way around Windows 2000 and its file system
• Log onto a remote Unix computer and navigate its file system
• Send and receive email with Pine
• Transfer files across a network

Here's what follows. Each part contains some explanations and may ask you to collect information to be submitted.

Part 1: Introduction
Part 2: Using Windows
Part 3: Exploring the file system
Part 4: Using Unix
Part 5: Email with Pine
Part 6: Transferring files
Part 7: Submitting your work

What exactly is Windows?

Windows is an operating system, which is a program that manages the resources of a computer for you. It lets you run programs like browsers and word processors and Napster (or what's left of it); it lets you store and retrieve information on disks; it lets you use peripheral devices like printers and CD-ROMs and speakers; and it lets you communicate with other machines via a network.

"Windows" is a family of operating systems from Microsoft. Microsoft cranks out a new version every year or two; Windows 2000 is barely a year old, and Windows XP comes out in a few weeks. Unix, Linux, MacOS and PalmOS are also operating systems, not from Microsoft, that all perform the same basic functions, though with myriad differences in style, philosophy, and details.

One of the main functions of an operating system is to provide an environment in which you can run programs. Most operating systems allow you to run several programs at once, switching your attention from one to another at will. Some like Unix are text-based and mostly controlled by typing on the keyboard. Others (Windows, MacOS, PalmOS) are graphical and are most often controlled with a mouse or pen.

Logging on

To begin using Windows you must log on, which lets the computer know that you are a valid user and gives you access to your own information. Windows 2000 keeps track of its users and can remember specific preferences for each of them. This is particularly important in the computing clusters, where the machines are shared among lots of random different people. In that case, the operating system has to make sure that you can access your own information, but no one else's. Some aspects of this will be investigated in this lab.

Follow these instructions to log in to Windows. If you're using Windows 95/98/ME, you probably won't have to log in, since you are the sole user.

1. Hold down the Ctrl and Alt keys and then press Delete.
2. If this brings up a window called Windows Security, click the button labeled "Logoff..." and after a few seconds repeat step 1.
3. You should see a Window labeled "Log on to Windows". Enter your user name or "net id" and password and click OK. (Your user name is the part of your email address that goes before "@princeton.edu".) Your password will be the last 8 digits of your social security number, unless you've changed it already.
4. If this is the first time you are logging into Windows, it will request you to change your password. We encourage you to change it IMMEDIATELY, since social security numbers are not nearly as private as they should be. It might be a good idea to change it to your UNIX password.

There's good advice on how to choose a password on the web; for example, check out CIT, IIT, and MIT, three pages out of thousands.

After a few moments, you should see the Windows desktop with a bar across the bottom of the screen and several icons scattered across the left. Congratulations! You've successfully logged on. Remember these steps, because you will need to log on again at the beginning of every lab.

Using the Desktop

Now it's time to explore Windows. If you've used Windows before, this will be familiar. If not, just use the mouse to click on buttons, icons and anything else that looks interesting until you feel confident with the way things work. Keep the following things in mind as you experiment:

• Icons - Windows and other graphical operating systems use icons as shortcuts to run programs. Sometimes these shortcuts represent the programs themselves, and sometimes they represent files or documents used by those programs. Either way, double-clicking on the icon should start the associated program.
  Double-Click on the "Cluster Computer" icon. (On other Windows systems, it is usually called "My Computer" instead.)
  
  
  

  This should bring up a window with several different icons representing disk drives and other resources on your computer. Generally the icon labeled C: is the local disk (that is, the disk physically in the machine you are using), A: is the floppy drive, D: or E: is the CD-ROM. There may also be some "network drives", which are connections to disks on other computers.

  Double-click any of these icons. You should see another window (or a fresh view in the current window) listing files on that drive. This is one way to see all the files that are on your computer.
  
  

• Individual Windows - Now you probably have several windows cluttering up your screen. Each Windows window has a colored stripe across the top and a thin frame around the edges. The stripe is called the titlebar and is used to minimize, maximize, restore and destroy the window. It also shows the title of the program (or folder) and sometimes information about what that program is working on.
  
  Maximizing a window will cause it to take up the entire screen, blocking out all other windows. When a window is maximized, the maximize button will be replaced by a Restore button. Clicking that will cause the window to return to normal size. Minimizing the window will cause it to go away temporarily, leaving only a button on the Taskbar (see below). To restore a minimized window, simply click on its button on the Taskbar. Minimizing a program does not stop it, it simply frees up space on your screen.
  
  You can also change the size of a window by selecting its rim or corners with the mouse and dragging (holding down the left button and moving the mouse) them to the desired size. You can move the entire window by clicking on an empty part of the titlebar and dragging it to where you want.
  
  Finally, when you are finished with a window or program, you can stop it by clicking on the "X" button in the top right corner. You can also usually stop it by clicking on the "File" menu beneath the titlebar and choosing "Exit".
  
  
• Taskbar - This long bar at the bottom of your screen is the main tool for managing windows in Windows.
  
  

  On the far left is the Start Button (explained below). Next, there should be a long button for each currently open program or folder. One of these buttons may look depressed (or at least a little unhappy), indicating which window is currently selected. Some of these buttons will correspond to windows you can see on your screen. Others represent minimized programs and only expand to a visible window when you click on them. As you proceed in this lab and open more and more programs, each should appear on the taskbar. You can switch among them at any time by clicking the appropriate program on the taskbar.

  At the far right of the task bar, there are a few small icons and a clock in an area known as the "tray". These icons represent programs which are running in the background (without using a window), such as volume control and an anti-virus program. Try clicking with the right and left mouse buttons on some of these to see what happens.
  
  

• Start Button - The Start Button is used to start programs, find files, change settings or shut down the computer. Try clicking on the Start Button now. A menu should pop up with 7 or more different options. Some of these have arrows at the right, indicating that they lead to other menus instead of windows. For example, when you select Settings, you will see three more options which you can then select. An instruction to select "Settings | Taskbar" would mean to select Settings and then Taskbar. The following options should be available on your Start Menu:
  
  
  Programs - This is where you can find programs such as Netscape and Word.
  
  Documents - This is a list of recently used data files. Selecting one of these will start the program that is associated with that file. For instance, if you select a file that ends in ".html", Windows will start a web browser (like Netscape) to view it.
  
  Settings - This is where Windows stores information about everything from which printers are connected to which color scheme you prefer. Try not to change these settings unless you know what you're doing.
  
  Find - With this option, you can search for a file by name, even if you don't know where it is stored on the computer.
  
  Help - When you're really stuck, there's always Windows help, though you're often better off asking someone else who knows what's going on.
  
  Run - With this option, you can start programs by typing in their location on the computer. For example, typing in "c:\windows\notepad.exe" will start a program called Notepad which is in the "windows" folder on the C drive. In fact, you can usually get by just typing "notepad" in the Run dialog box; Windows fills in the rest for you.
  
  Shut Down - Selecting this will give you the option to restart the computer, shut down the computer, or log off of Windows. You should end every lab by selecting Shut Down and then, in the window that appears, choosing "Log off your-name".
  
  
  

Editing and Saving with Notepad

One of the tasks you do most often on the computer is word processing. There are numerous ways to do this, as we will see in this lab. You are perhaps most used to using Microsoft Word to process documents. An alternative is Notepad which is a text editor of more limited capabilities (but also easier to use).

Notepad cannot do as many things as a word processor like Word or WordPerfect but it is much simpler, loads much more quickly and is very useful for small notes and documents (just like a small paper notepad). It also saves information in a format that can be easily used by other programs. For the rest of this lab, you will use Notepad to record your work as you go along, and then copy it into an email at the end.

Open Notepad by choosing "Programs | Accessories | Notepad" from the Start Menu, or by typing "notepad" into the Run dialog box. A window should appear with a blinking cursor. Click on the various menus (File, Edit, Search and Help) to see what options are available. Experiment with typing text and editing it with the mouse and with items from the Edit menu; be sure you're comfortable with the Cut, Copy and Paste features, since they get used in a lot of different situations.

Do this to begin collecting data for submission:

• Type a line with your name and email address.
• Type a second line with what operating system you are using for this lab.
• Select "Save" from the "File" Menu.

The top half of this window tells you where on the computer you are saving your file. At the very top, you should see the name of the currently open folder. This may be "Desktop", "C:\" or just about anything else. The contents of the folder should be listed in the box below. Double-clicking on a folder in that box will open it. Double-clicking on a file will overwrite that file with yours.

Remember, however, that if you have a file format selected (below the file name) then you may not see all of the files in a particular folder. For instance, if you've selected the file format "Text Documents (*.txt)", then inside each folder, you will only see other folders and files whose names end with ".txt". This can be useful in a folder containing dozens of files, but may be confusing at times. By clicking on the white text box next to "Save as Type" and selecting "All files", you can force it to make all files visible, regardless of their extensions.

At the top right are several buttons. The first will move you up one directory/folder to the parent folder. Click this button until you are in the Desktop folder. The second button creates a new folder inside the current folder. The other buttons toggle the display -- try pressing each to see what happens.

Now follow these instructions to save your file:

• If you are not in the Desktop folder, move to it by either pressing the up-directory button several times or clicking on the current folder name and choosing "Desktop" from the list.
• Make sure that "Save as Type" is set to "Text documents (*.txt)".
• Type the name lab1.txt next to "File Name", in lower case!
• Press "Save" to save your file lab1.txt to the Desktop.

Because the Desktop is a special folder meant to represent a real desktop, all of the files you save to it will show up on the Windows Desktop as icons. If you move your other windows out of the way or minimize them, you should see an icon for your new file.

Leave Notepad running. You will be adding content to this file for the rest of the lab. Each time you add something, save the file; this protects you (mostly) in case something goes awry, and is always a good idea.

Part 3: Exploring the File System

A file system is how the operating system organizes all the data that is stored on the computer, in a form that is convenient for users to save information, organize it, and retrieve it as needed. The same organizing structures that are useful for the information on a hard disk are also useful for removable media like floppy disks and CD-ROMs, and even for information physically stored on other computers and accessed through a network, so all of these are packaged as file systems as well.

Information in a file system is organized hierarchically: at the top level is a set of folders (often equivalently called directories) and files. A folder contains the names of files and folders that are being grouped together for some purpose. A file holds specific information, such as a Word document, a spreadsheet, a mail message, a picture, an MP3 song, or a program like Word itself.

On Windows, the usual organization creates a file system on the computer's hard drive, in a folder called (for ancient historical reasons) "C:". For even more ancient reasons, the floppy drive is called "A:". If there is a second hard drive, it is usually D:, and if there is a CD-ROM drive, it takes the next letter, and is thus either D: or E:.

Other "drives", like network connections, have even more arbitrary letter names; at Princeton, student files can be stored in a big file system on a central CIT machine and your part of that file system is accessible from a PC or Mac as the "H:" (for "home") drive.

There are a variety of way to explore the contents of these file systems. The simplest, though not the most flexible, is to double-click on "Cluster Computer" or "My Computer", then double-click on one of the icons therein. That will uncover more icons for files and folders. Each double-click on a folder expands its contents.

A double-click on a file, however, typically executes a program that is associated with the presumed type of information that the file contains, as indicated by the suffix of the name. For instance, filenames ending in .doc are assumed to be Word files, and clicking on such a file will cause Word to be started up with that file. Filenames ending in .txt are usually associated with Notepad, so another way to start Notepad is to click on a file like lab1.txt. You should be cautious about this mechanism if you don't know what you're doing, however, especially for files of type .exe, which are "executable" files -- programs -- unless you know exactly what will happen.

Using Windows Explorer

Both the My Computer icon, and the Save (and Save As... or Open) Dialog box allow you to look through folders and find files. If you want to move files around, however, or find a program and start it, then Windows Explorer (not to be confused with Internet Explorer, which is a web browser) is much more convenient.

Use the Start Menu to find and start Windows Explorer; it will usually be under Programs or Accessories. (You can also type "explorer" in the Run dialog box.)

Explorer gives a split-screen view of the file system. To the left is the entire folder hierarchy. When you click on a folder, its contents will be displayed on the right. Notice that some folders have +'s or -'s next to them. This means that the folder has subfolders. If it is a plus, then Explorer is hiding the subfolders. If it is a minus, then you should see the expanded list of subfolders. By clicking on the + or -, you can toggle between the condensed + view to the expanded - view.

Find the file lab1.txt by clicking "Desktop".

The various programs for displaying directories normally give an almost worthless visual display of icons. There's quite a bit more useful information that you can see from Explorer, by selecting View, then Details. You can also sort the items in order by date or size or type, either by selecting View, then Arrange Icons, or by clicking on the corresponding column heading.

In spite of its name, Explorer is most useful when you already know approximately where you're going in the file system. If you know even part of the name of a folder or file, however, you can often find it most easily with a different program. Select Start, then Find, then "For Files or Folders...".

You are now going to use Find Files and Explorer to find some interesting files (and some boring ones too, but that's life). Do the following operations.

• The "desktop" is really a folder in the file system somewhere. Find out the real name of the directory that holds your file lab1.txt. Enter the result in lab1.txt on a single line.
• As mentioned above, executable programs are stored in files whose names end in .exe. Find all such files on the C: drive by searching for filenames that contain the letters "exe".
• How many are there? (Hint: There are a lot). Add a line to lab1.txt.
• Some of these files do not have names that end with .exe. Add the name of one such file to lab1.txt.
• What's the largest executable program? Add a line to lab1.txt with the name and size
• What's the oldest exectuable program? Add a line to lab1.txt with the name and date
• What is the name of the PowerPoint executable?
• Which is bigger: Word or Excel? Give the size of each.
• Cookies are a mechanism for leaving little bits of information on your computer for subsequent retrieval, often for advertising purposes. Find out where cookies are stored on your machine. Add a line to lab1.txt with at least one directory and file name that seems to be cookie-related; no need for more than one. (Cookies are just text files, so you can look at them with Notepad.)
• What virus-prevention software are you running on your machine? Add a line to lab1.txt. (If you're not, you should be -- if nothing else, we take a dim view of people who inadvertently send us viruses -- and the consequences can be a lot more severe than disapproval.)

Add each of these as a line to lab1.txt. Save each time, so in case something bad happens, you still have the info.

	tucson.Princeton.EDU% 

If the prompt never appears, or if you keep getting a message such as "login incorrect" after several tries, ask a TA for assistance.

Basic Unix Commands

Unix has a different flavor from Windows. Rather than running a program by clicking on an icon with a mouse, you type the name of the program in a window. Keyboard commands like "ls" and "cd" run programs to help you navigate Unix and can be typed in whenever you see a command prompt such as

	flagstaff.Princeton.EDU% 

Try the following commands:

• ls - Lists the contents of the directory you are in; you can get more information with the command ls -l. The ls command is the keyboard equivalent of Explorer.
  
  
• mkdir - Makes a new directory. Type mkdir cos109 now and then hit Enter. (If you're taking COS 111, type mkdir cos111 instead.) Now if you try the ls command again, you should see your new directory show up. Again, this is rather like File / New Folder in Explorer.
  
  
• cd - Change directory. Type cd cos109 (or cd cos111). This will move you to the directory you just created. To get back to your home directory, type cd by itself. You can also type cd .. to move up one level in the file system, and you can type pwd to print the name of the directory you are working in.
  
  
• who - Tells you who else is logged into the same computer as you are. You will notice that there are lots of other users. One major difference between Unix and Windows is that Unix supports multiple users running on the same computer at the same time.
  
  

Why use Unix instead of Windows? It largely depends on what task you are trying to do. Windows has an enormous collection of useful programs, many of which have no Unix equivalent, and Windows comes installed on all PC's. Unix is a good environment for writing programs, however, expecially programs that are meant to work on more than one kind of computer, so it is often preferred by programmers. Meanwhile, don't worry if Unix seems strange at first. You won't need to use it very often, though it is helpful to know how to move around.

If you are interested in learning a bit more about UNIX, check out this UNIX primer.

Note: When logged into UNIX, you may have to use the "DEL" key instead of "Backspace" to delete a character.

Exercises:

• Add a line to lab1.txt telling us whether you used SSH or telnet to log in.
• Do ls -l on your home Unix directory, copy first few lines of result into lab1.txt by Copy and Paste.
• Type the command who | wc. (That character is the vertical bar, not the letter i or ell.) This will tell you exactly how many users are logged into the Unix system (in the first of the three numbers it prints). Add a line to lab1.txt with the answer.
• Look at your Unix directory using Explorer and the H: drive.

Part 5: Email with Pine

Using Pine to read email

Every student has an email address username@phoenix.princeton.edu, where username is the name you used to log into Windows and Unix. You can read mail sent to that address (as well as username@princeton.edu) and send mail to others across the world, using any of several mail programs. Normally, you will use Netscape to read mail; Microsoft's Outlook Express is another popular option.

This section will guide you through using the Pine mail program. Pine, like other Unix programs, is text-based instead of mouse-based. Although it will probably not be your first choice for most email use, Pine has some advantages. It works from any SSH or telnet window; you don't need a browser. It is also not vulnerable to PC viruses, since it runs on Unix and it does not run other programs automatically.

To begin, type pine after the prompt, and push Enter. (This is in an SSH window, remember.) Follow the instructions it gives you for setting up Pine on your account.

If you opened Pine correctly, you should now see a menu with options to compose messages, view messages in current folder and view a list of folders. You can adjust the size of the Pine window as you like.

In the top right corner, you should see the name of the currently open folder and how many messages it holds. At first, this should be INBOX, which lets you check all of your new mail. Later, you can make your own folders to organize old messages from different senders.

Because we are still in Unix, you will need to use arrow keys and keyboard commands to navigate Pine. Do not try to use the mouse.

Using the arrow keys, select "Folder Index" and press Enter (or just press "I") to see an index of current email messages.

Even if you have never used email before, there should be at least one message in your INBOX. Using the arrow keys, select the message you would like to read and hit Enter to read it. Notice that many of the available commands are listed at the bottom of the screen. We've explained a few below:

M - Returns you to the main menu
I - Returns you to the message index
S - Saves the message in the specified folder and deletes it from your inbox. (Note: You can create a new folder by saving a message to one that doesn't exist.)
D - Deletes a message without saving it
C - Composes a new message to anyone
R - Composes a reply to the sender of the currently selected message
N - Moves to the next message
P - Moves to the previous message

There are many other useful options, but you can probably discover them on your own with questions and experimentation.

Sending mail with pine

Now you will send a message to yourself with pine. The process is pretty self-explanatory, but we'll help you through it this first time. In these instructions, you do not need to use upper-case letters when holding the Ctrl key.

1. Press C to compose a new message
   
2. Next to "To:" type in your email address and then hit Enter.
3. Press Enter twice to scroll past "Cc:" and "Attchmnt".
4. Next to "Subject:" type in a phrase describing the subject of your message and then press Enter again.
5. Underneath "Message Text", type in your message.
6. When you are finished, hold down Ctrl and press X (this is called Ctrl-X).
7. Confirm that you want to send the message by pressing Y.

While you were composing, you may have noticed that the commands at the bottom of the screen looked like this:

The caret (^) is how Pine reminds you to use the Ctrl key. Thus, ^X is equivalent to Ctrl-X. All of these commands use Ctrl because you need letters like "x" and "c" for your message text.

Leave your SSH window open. Pine will soon notice that new mail has arrived (though it won't be a big surprise, since it's the mail you just sent yourself). There is usually a beep to announce incoming mail.

• When new mail arrives, add a line to lab1.txt that tells how Pine reported that fact.

Once the new mail has been observed, you can delete it, leave Pine by typing "q", and log out of Unix by typing "logout".

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Part 6: Transferring files

There are a variety of ways to copy files from one place in a file system to another, or from one file system to another. In Windows, the clearest and most uniform way is to select the file of interest by a single mouse click in a program like Explorer (so it is highlighted), select Copy from the Edit menu or by right-clicking on the filename, then select the folder where you want the copy to appear (so the folder name is highlighted), then select Paste from the Edit menu or by right-clicking.

There are shortcut mouse actions for Copy (control-C) and for Paste (control-V), and those are well worth learning. In some situations you can "drag and drop" the file to make a copy, which is very graphical and intuitive. But we generally recommend against drag and drop, since in some contexts, it means "copy" and in others it means "move", and these are i>not the same operation: "move" means to remove the file from the place it was and put it into a new place, leaving you with a single instance, while "copy" leaves you with two instances.

Make a copy of the file lab1.txt that you are building up on the deskop in your Unix directory as seen through the H: drive:

• Right click on lab1.txt on the desktop, select Copy.
• In Explorer, highlight your cos109 or cos111 directory.
• Select Paste to make the copy.
• After the file is copied (it should take no time at all) verify that it seems to be correct: the file exists in both places, has the same size and sensible modification times.

Somewhat irritatingly, Explorer does not always update the display of a folder when a change is made. To be sure you have a consistent and up to date display you may need to use View / Refresh.

Verifying the transfer

Here is a chance for you to use your newfound Unix skill to see if the file was copied correctly.

• In your SSH window, go to your cos109 or cos111 directory.
• Type ls -l to see that the file is there and about the right size. Is it about the same size as on desktop? Add a line to lab1.txt with the size reported by Unix and the size reported by Windows Explorer.
• Type "cd" to bring you back to your home directory
• Move to your cos109/111 directory by typing "cd cos109" (or "cd cos111)
• Check the contents of that directory by typing "ls"

You should see the file you just uploaded in this directory if you uploaded it correctly. If you are having problems, ask a TA for assistance.

Congratulations! You've finished this lab. Now go on to learn how to submit your work and shut down Windows.

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Part 7: Submitting your work

Submitting your work

VERY IMPORTANT: When you submit labs, or when you send us mail for any other reason, please be sure that you are logged in as yourself, not using a friend's account. If you are using someone else's account, the mail comes from them, and we don't know who sent it!

At the end of most labs, you will be asked to send your results to the appropriate one of cs109@princeton.edu or cs111@princeton.edu by email. Be sure to include everything we asked for. If you have comments or suggestions, we'd be happy to get those as well.

Mail us the text of the file lab1.txt that you have been laboriously creating.

• In Notepad, use the mouse to highlight the text and choose "Copy" from the "Edit" menu.
• Using either pine or Netscape, start a new mail message and paste that text into the message body.
• Send the mail to cs109@princeton.edu or cs111@princeton.edu.

The content of your mail message should be essentially the same as what's in the file in your cos109 or cos111 directory.

Remember these things as you send your message:

• If you're using Netscape Mail, be sure that your identity is set correctly (as explained previously)
• If you're using pine, you may be experiencing mouse difficulties. Although you can highlight and copy text from your SSH window, you cannot use the mouse to select where you would like to paste it. Once you've begun your new message, use the arrow keys to move to the message body and then select paste from the Edit menu.
• The subject of your message should say "LAB 1 - Your Name".
• Make any additional comments or observations at the top of the message and then sign it with your name.

Send a copy of the mail to yourself; it's a good check on whether you really sent the right stuff.

Transferring saved work

In most of these labs, you will save files to the Desktop or elsewhere on the hard drive of a lab computer. Because these computers are public and not meant for private storage, however, you cannot rely on this to save your work. Not only will it be impossible to use the same computer every week, but other students and support staff will erase your files to free up space.

For these reasons, if there are files you have to save from week to week, you must transfer them to your Unix account. Be sure that you've done this properly. Once you know your work is saved on the Unix system, you can remove the files from the public cluster machine; there's no need to remove them from your personal machine if you don't want to.

Logging off of Windows

If you've completed the lab, sent your email to cs109@princeton.edu or cs111@princeton.edu, and transferred your work to your Unix account, then you are finished and ready to log off of Windows.

• Select "Shut Down..." from the Start Menu. Choose "Log Off your-name" and click "OK"