Getting Started on Athena Tutorial (AC-03)

Table of Contents || Revision history || Copyright information

How to Use This Tutorial

This document is designed to provide a hands-on introduction to Athena, MIT's academic computing environment, for new MIT students or other new users of Athena. This tutorial supplements the introductions provided in the Athena minicourses (offered during Orientation, IAP and during the semester) and in the Athena documentation.

With this tutorial, you can sit down at any Athena workstation and learn basic tasks. This document does not assume that you have any background with computers. It is useful if you have used computers before; it compares some Athena commands and concepts with Macintosh and DOS commands and concepts.

Note that this tutorial is only an introduction. None of the concepts or commands are covered thoroughly. When you have finished this tutorial, please refer to the other Athena documentation for further, more in-depth information. (It is especially important that all new users familiarize themselves with the Athena Rules of Use, which are listed in detail in Welcome to Athena.)

Using this tutorial

To learn about Athena using this tutorial--indeed, to use Athena at all--you need an Athena account. All MIT students (and most members of the MIT community) are eligible to get an Athena account. If you do not already have an account, directions for registering for an Athena account and choosing your username and password are in the pamphlet How to Register for an Athena Account, available in the Athena Consultants and User Accounts office (N42 1st Floor). The day after you register, you can use your account.

Once you have an account, find a workstation in any Athena cluster, and work your way through this tutorial.

The chapters of this tutorial are organized into specific tasks, so you can do as much or as little in one sitting as you like. The chapters build on each other, so you should work in order, although that's not necessary for all the chapters.

Conventions used in this tutorial

Using the mouse

The mouse next to your keyboard is used to control the mouse pointer on your screen. The mouse pointer is usually shaped like an arrow, a letter "I," or a letter "X," depending on what program is running. As you move the mouse pointer around your screen, it changes shape as it enters different windows.

Use the mouse to select which window you want to work in, and to perform other actions. The following terms are used to describe mouse techniques:

Point: You point to an object on the screen by moving the mouse pointer until the tip of the arrow is over that object.
Click: You click by pointing to an object, then pressing and releasing a mouse button once. (Directions will specify left, middle, or right button.) Don't move the mouse while you click.
Press: You press by pointing to an object, then pushing down steadily on a mouse button. Don't move the mouse while you press.
Drag: You drag the mouse by pointing to an object, then pressing the mouse button and moving the mouse without releasing the button.
Double-click: You double-click by pointing to an object, then quickly clicking the mouse button twice. Don't move the mouse while you double-click.

Chapter organization

Each chapter begins with an overview of the material covered in that chapter.
After the overview, there is usually a section called For more information. This section lists documents you can read for more in-depth information on the subject, as well as Athena minicourses you can take. (The chapter Getting Further Help explains how to find these documents and how to get a minicourse schedule.)
There are also several Review sections throughout this tutorial. For shorter chapters, there is a single Review at the end. Longer chapters have Reviews after each main topic.

Styles and symbols in this tutorial

The following styles and symbols help you use this tutorial.

Lists and other paragraphs:

Bulleted lists, like this one, provide information but not procedural steps.
Numbered lists (1, 2, ...) indicate a procedure with two or more sequential steps.
When you are told to perform an action (such as typing a command name), the expected results are indicated like this:
Result: The expected results of the action appear in an indented environment.
A dialog between you and the computer (text you type and the text the system displays) is set in a typewriter font. In the following example, athena% is the system prompt (which you don't type), and ls is the command you type:
```
athena% ls
```
Athena commands are case-sensitive. The ls command must be lowercase, and the "Public" directory is different from the "public" directory.
Notes appear in an emphasized indented environment. These notes might compare Athena commands and concepts to MS-DOS or Macintosh commands and concepts, or they might contain other important or nice-to-know information.

Logging In and Logging Out

This chapter assumes you have already registered for an Athena account, as described in How to Register for an Athena Account, and that your account has been created.

Logging in is the process of identifying yourself to the Athena network and starting to work. Logging out disconnects you from the workstation when you end your session. To log in, you need a username and password.

You can log into the Athena system via a modem and a personal computer, but this tutorial only covers working at workstations in Athena clusters.

For more information

Documentation:

Athena Minicourses:

Intro to Athena

Logging in

Find a workstation

Go to any Athena cluster. The door combination is available on the Welcome New Students flyer and the Athena Clusters Pocket Reference.
There are large clusters in the Student Center, in bldg 12, and on the 3rd floor of bldg 37. For a full list of clusters, see Athena Clusters Pocket Reference, available at the Copy Tech Center.
Find an unoccupied workstation displaying, "Welcome to Athena."
If the display also says "Press any key to start...", press any of the keys on the workstation's keyboard (or click any of the mouse buttons).
Result: The "login window" appears:

Figure 2-1: The Athena login window

Enter your username and password
Type your username in the first box, and press Return.
Result: The cursor moves to the Password box.
Type your password in the second box, and press Return.
The screen does not display your password as you type it.

Result: After a pause, this screen is displayed:

Figure 2-2: The initial screen
If a window, not the console window, appears on your screen with a message from the system, move the mouse cursor into that window and click any mouse button to make it disappear once you have read it.

Logging out

Logging out tells Athena that you have completed your session. Always log out when you are finished so the next person to use the workstation cannot access your personal workspace and files. Here are two common methods of logging out:

type logout at any athena% prompt and press Return
click on the Logout button (located at the bottom right corner of the screen), then click on "Yes, logout" when the logout window appears

Figure 2-3: The logout window

Review

Logging in is the process of identifying yourself to the Athena system and starting to work. To log in, enter your username and password on the login screen.
Logging out disconnects you from the workstation. Make sure any programs you started during your session have finished. To log out, use the logout command or click on the Logout button.

Working with Files

All information on Athena is stored in files that are organized into directories. Papers, programs, and mail messages are all stored in files. You can organize your own files into subdirectories, and you can explore Athena by browsing through public directories. This chapter covers several tasks that are common on most UNIX systems, including Athena:

For more information

Documentation:

Working on Athena (AC-11)

Athena Minicourses:

Working on Athena

Looking at your files

Listing files

Move the mouse pointer into the window labeled "xterm" at the top on the left side of your screen.
Unlike the Macintosh, the window border changes color when the mouse pointer enters the window.
Type the ls (list) command and press Return:
```
athena% ls
```
The ls command is like the dir command in MS-DOS.

Result: A list like the following appears:

Figure 3-1: List of files
Displaying a file
Type the more command and a filename to view a file, and press Return:
```
athena% more welcome
```
Press Return at the end of each command you type at the athena% prompt.

Result: The screen clears and the contents of the file appear:

Figure 3-2: Contents of the file "welcome"
Not all files are readable. For example, if you try to use more on an executable program instead of a text file, it will display nonsense.
The more command works like more < in MS-DOS.

Review

Windows are active when the mouse pointer is inside the window.
The ls command lists the currently available files.
The more command displays the contents of text files.

About your home directory

Your home directory

"Directories" on Athena work like "folders" on a Macintosh computer or MS-DOS directories.

When you log into Athena, the system puts you in your home directory, which is the area of Athena where your files are stored. Before you start moving between directories, you need to know where "home" is. The pathname for this directory looks like this (substituting your username for jarandom):

/afs/athena.mit.edu/user/j/a/jarandom

The / character separates directories and subdirectories in pathnames, like the \ character does in MS-DOS.

In shorthand, your home directory also looks like this:

/mit/jarandom

(These concepts are explained more fully in the document Working on Athena.) Finally, in Athena commands, you can use the ~ (tilde) character to refer to your home directory.

The "~" character is at the upper left corner of your keyboard. (On SUN workstations, it's at the upper right.

Default subdirectories

New Athena accounts come with several subdirectories already created for you.

The Public subdirectory is set so that anyone can read any file that is stored there.
The Private subdirectory is set so that only you can see and read the files stored there.

Since Public is a subdirectory of your home directory, you can refer to it as any of the following:

/mit/jarandom/Public
~/Public
/afs/athena.mit.edu/user/j/a/jarandom/Public

Likewise, you can refer to other subdirectories in the same ways (including ~/Private).

Getting to your home directory

To change to your home directory, no matter where you are, type:

athena% cd

Making a copy of a file with a new name

To put a copy of the file "welcome" named "intro", use the cp command:

The cp command is analagous to the copy command in MS-DOS.

athena% cp welcome intro
athena% ls

Result: A new file "intro" exists, which is an exact copy of the file "welcome":

Figure 3-3: Making a copy of the file "welcome" named "intro"

Making a copy of a file in another directory

To make a copy of file "welcome" in the subdirectory "Public", type:
```
athena% cp welcome ~/Public
athena% ls ~/Public
```
The "~/" indicates that "Public" is a subdirectory of your home directory.
The ls command can also list files in other directories.

Result: A copy of the file "welcome" now exists in your "Public" directory as well as your home directory:

Figure 3-4: Making a copy of "welcome" in your "Public" subdirectory

Review

The copy (cp) command duplicates files.
You can make a copy of a file with a different name in the same directory, or create a copy of a file with a different name or the same name in a new directory.

Renaming and moving files

To change the name of a file, use the mv command:
```
athena% mv intro practice
athena% ls
```
Result: The file "intro" is renamed to "practice". The file is no longer accessible under the name "intro".

Figure 3-5: Renaming the file "intro" to "practice"

You can also use the mv command to move a file to a subdirectory. Type:
```
athena% mv practice ~/Public
athena% ls ~/Public
```
Result: The file "practice" moves to your "Public" directory and no longer exists in your home directory.

Figure 3-6: Moving the file "practice" to the "Public" subdirectory

Review

The move (mv) command is similar to the copy (cp) command, except that instead of copying the contents of the first file into a file with a new name, it gives the old file a new name.
Use mv to rename a file or move it to a new directory.

Navigating directories

To change to another directory, use the cd command:
```
athena% cd ~/Public
athena% ls
```
Result: The files listed are the files you moved and copied to your Public directory in the Moving files section above.
To find out what directory you're currently working in, use the pwd command (print working directory). Type:
The pwd command is equivalent to the cd command in MS-DOS.
```
athena% pwd
```
Result: The directory displayed should match:
```
/afs/athena.mit.edu/user/j/a/jarandom/Public
```
Figure 3-7: Changing directories
To change to the directory immediately above the current directory, type:
```
athena% cd ..
athena% pwd
```
The space is necessary between "cd" and "..", unlike MS-DOS.

Result: Your current working directory is now your home directory, where you started.

Making and removing directories
1. To create a subdirectory in your current directory, use the mkdir command:
```
athena% cd
athena% mkdir MyDir
athena% ls
```
  Result: A new directory, "MyDir", is created in your home directory.
2. To remove an empty subdirectory from your current directory, use the rmdir command:
  Caution: Unlike files, directories are not recoverable with the undelete command.
  If the subdirectory is not empty, rmdir does not remove it. You need to delete the files in it first.
```
athena% rmdir MyDir
athena% ls
```
  Result: MyDir no longer exists.
  
  Figure 3-8: Creating and removing the MyDir directory
  Review
  - You can change your current working directory with the change directory (cd) command.
  - You can make and remove your own directories with mkdir and rmdir.
  Several abbreviations are used for directories:
  - Two dots (..) indicate the parent directory, or the directory which contains the current directory.
  - A single dot (.) indicates the current directory. This abbreviation is most useful in move (mv) and copy (cp) commands.
  - A tilde (~) represents your home, or default, directory.
  Deleting and recovering files
  1. To delete a file, use the delete command:
```
athena% delete welcome
athena% ls
```
    Result: The file "welcome" is marked for eventual removal and is no longer shown.
  2. To recover a recently deleted file, use the undelete command:
    Caution: Files erased more than three days are not recoverable; they are automatically purged. Use delete with care!
```
athena% undelete welcome
athena% ls
```
    Result: The file "welcome" has been restored:
    
    Figure 3-9: Deleting and recovering the "welcome" file
    Review
    - You can erase files with the delete command when you no longer need them.
    - It is often possible to restore a deleted file with the undelete command.
    Working with Windows
    
    The X Window System is a set of programs that runs behind the scenes on your Athena workstation and lets you divide your workstation's screen into one or more overlapping windows. The Working with Files chapter used an xterm window to list and manipulate files. This chapter has you:
    - Start a new program (xclock) that uses a separate X window
    - Move the window
    - Re-size the window (two methods)
    - Iconify the window
    These tasks are the same with every window, no matter what application is running in it.
    For more information
    
    Documentation:
    - Working on Athena (AC-11)
    Athena Minicourses:
    - Working on Athena
    Starting xclock
    1. At the athena% prompt, type:
```
athena% xclock &
[1] 14540
athena%
```
      When you use "&" after a command, the program runs in the background so you can type other commands (i.e., the athena% prompt returns right away instead of waiting for the command to finish).
      
      Result: A job number (here, [1]) and process ID number (here, 14540) appear. The mouse pointer changes to a rectangular window outline.
    2. Move the mouse pointer to position the rectangle.
    3. Click the left mouse button.
      Result: A new window appears with a clock in it.
      
      Figure 4-1: Screen with a new xclock window
      Alternate method: You can also start xclock from Dash: Dash >> Screen Accessories >> Analog Clock
    Moving the window
    1. Move the mouse pointer to the top of the new window, over the title "xclock".
      Result: The mouse pointer changes to an arrow.
    2. Drag the mouse pointer with the left mouse button.
      Result: The mouse pointer changes to a four-headed arrow, and the outline of the window moves with your mouse pointer.
    3. Release the mouse button when the outline is in a new position.
      Result: The xclock window moves to the new position.
    Re-sizing the window by the edges
    1. Move the mouse pointer to any edge of the window.
      Result: The mouse pointer changes to an arrow pointing to the edge.
    2. Drag the mouse with the left mouse button.
      Result: The outline of the edge of the window follows the mouse pointer.
    3. Release the mouse button when the outline is the desired size.
      Result: The window adjusts itself to the new outline.
    Re-sizing the window by the corners
    1. Move the mouse pointer near a corner of the window.
      Result: The mouse pointer changes to an arrow pointing into the corner.
    2. Drag the mouse with the left mouse button.
    3. Release the mouse button when the outline is in a new position.
      
      Figure 4-2: Re-sizing the xclock window by the corners
    Iconifying windows
    
    To iconify a window means to replace it with a small symbol that represents that window (an icon). The icon remembers the size and location of the window, so when you restore the iconified window, it appears in its old location. Iconifying helps reduce screen clutter when you have several windows open.
    "Iconifying" is also called "minimizing"; "iconify" is the most popular term among Athena users.
    1. To iconify the window, click the left mouse button in the box with a small dot inside it at the top right of the xclock window.
      Result: The xclock window disappears and an xclock icon window appears in the lower left corner of your screen.
      
      Figure 4-3: Xclock and Xclock icon
    2. Double-click on the icon to de-iconify the window.
      Result: The xclock window appears with the same size and position as before you iconified.
    Review
    - Programs started with an ampersand (&) from the xterm window can run simultaneously with other programs in other windows.
    - Use the mouse to position the upper left corner of a new window.
    - Move a window to a new location by dragging the title bar.
    - Resize windows by dragging the edges or corners.
    - Use the mouse to iconify and de-iconify the window.
    Working with a Text Editor
    
    Emacs is the most commonly used text editor on Athena. This section has you:
    For more information
    
    Documentation:
    - Emacs on Athena (AC-41)
    - GNU Emacs Users Manual (available for reference in the Consulting Office, Building N42 1st Floor)
    - on-line manual pages, type man emacs at the athena% prompt
    - help within Emacs
    Athena Minicourses:
    - Basic Word Processing and E-mail
    - Serious Emacs (for experienced Emacs users)
    Starting Emacs and creating an Emacs file
    
    You start Emacs in the same way you start most Athena applications--by issuing a command at your athena% prompt:
    1. Move the mouse pointer into any xterm window.
    2. Type the emacs command at the athena% prompt:
```
athena% emacs &
[1] 14376
athena%
```
      Result: The job message appears, as described in the Windows chapter, and the athena% prompt returns. The mouse pointer changes to a large rectangle.
      
      Alternate method: You can also start Emacs from Dash: Text/Graphics >> Text >> Emacs
    3. Move the rectangle to the position on the screen where you want the Emacs window to appear, and click the left mouse button.
      Result: An Emacs window appears, displaying copyright text:
      
      Figure 5-1: The Emacs window
      Type text to create the Emacs file:
    4. Move the mouse pointer into the Emacs window.
    5. Type the following text, and press Return at the end of each line:
      You can edit text and fix mistakes using:
      
      the arrow keys, located toward the lower right of the keyboard
      the Backspace or Delete key located above the Return key
```
This is a sample Emacs document. Emacs is the default standard text
editor on Athena Workstations. It is most commonly used for typing papers and
letters, taking notes, creating e-mail messages, and editing text files.
```
      Result: The copyright text disappears when you start typing.
    Naming and saving your work
    1. Press Ctrl-x Ctrl-w.
      Ctrl-x Ctrl-w is an example of a control key sequence. To type Ctrl-x, press and hold the Ctrl key and press x. (Like holding Shift to type a capital X.) Ctrl-x is often abbreviated C-x.
      
      Result: The following prompt appears at the bottom of the Emacs window:
```
Write file: ~/
```
    2. To name your file, type sample and press Return:
```
Write file: ~/sample
```
      Result: You now have a new file in your home directory (~) called sample.
      
      Figure 5-2: Saving a file
      Editing your text
    3. Move the mouse pointer to the end of the text.
    4. Click the left mouse button.
      Result: The Emacs cursor moves to the end of the text.
    5. Type the rest of the text:
```
Emacs is only one application on the Athena network. Other applications,
such as EZ, LaTeX, and FrameMaker provide more formatting and publishing power
than Emacs. There are applications for dealing with numbers, and other
applications for locating information across the globe on the Internet.
```
      Saving your text
      
      To keep the changes you have made in the Emacs window, you need to "save" the working copy into your permanent file.
      You do not need to specify the file name again. Emacs uses the file name you previously specified.
    6. To save your current version (replacing the old version), press C-x C-s.
      Result: Emacs responds at the bottom of its window that it wrote the file:
```
Wrote /afs/athena.mit.edu/user/j/r/jruser/sample
```
      It is a good habit to save your work often using C-x C-s. That way, in case of a power failure or computer crash, you still have a recent copy of your work.
      C-x C-w (write file) is equivalent to "Save As..." in many word processing programs. C-x C-s (save file) is equivalent to "Save."
      
      Exiting Emacs
      
      When you are finished editing, save the final version and quit Emacs.
    7. Press C-x C-c
      Result: If you have not made any changes to your text since the last time you saved it, the Emacs window disappears. If you have made changes to the file since your last save, Emacs does not exit immediately, but instead asks if you want to save changes before exiting. Look at the bottom of the window for this message if the Emacs window doesn't disappear.
```
Save File /afs/athena.mit.edu/user/j/r/jruser/sample? (y or n) 
```
    8. To save the file and exit Emacs, type y.
    Review
    - Access Emacs just like any other X application, by typing the command name at the athena% prompt or using Dash.
    - Once Emacs is started, enter text from the keyboard and edit using the arrow keys and the Delete key.
    - To move the Emacs cursor, move the mouse pointer and click the left button.
    - Issue special commands by holding Ctrl and pressing a character.
    - C-x C-s saves your file; C-x C-c exits Emacs.
    Communicating with Others using Electronic Mail
    
    Electronic mail ("e-mail") is a way for users to send messages to each other. E-mail messages are just like memos, letters, or other documents, but you transmit them using Athena rather than on pieces of paper or diskettes. This chapter covers:
    - sending e-mail messages
    - receiving e-mail messages
    There are several different e-mail programs available on Athena. Your choice will depend largely on your preferences; in general, the different programs allow you to do the same tasks. The document Electronic Mail on Athena covers more detail, and also covers some of the different programs.
    For more information
    
    Documentation:
    - Electronic Mail on Athena (AC-31)
    - on-line manual pages, type man comp, man inc, etc., at the athena% prompt
    Athena Minicourses:
    - Basic Word Processing and E-mail
    Sending e-mail
    1. Use the comp command to compose a message to send. To start Emacs with a blank message header:
```
athena% comp
```
      Result: The first time you use comp, it asks to create your Mail directory:
```
Your MH-directory "/afs/athena.mit.edu/user/j/a/jarandom/Mail" doesn't exist;
Create it?
```
    2. Type y.
      Result: The mail subdirectory is created in your home directory, and the mouse pointer changes to a rectangle.
    3. Move the rectangle to the position on the screen where you want the comp/Emacs window to appear, and click the left mouse button.
      Result: An Emacs window appears, displaying the blank message header:
      
      Figure 6-1: The Emacs window for composing an e-mail message.
    4. Use the arrow keys to move the cursor to the end of the first line, after the To: colon, and type your username.
      To send e-mail to most MIT users, use their usernames. To send to someone at another site, you'll need a longer address.
    5. Use the arrow keys to move the cursor to the end of the Subject: line, and type the subject of the message, "test."
      Result: The Emacs window contains this text:
```
To: jarandom
Cc:
Subject: test
--------
```
    6. Use the arrow keys to move the cursor below the dotted line, and type a message to yourself, pressing Return at the end of each line:
```
E-mail makes it easy to communicate with people all over the globe!
```
    7. Press C-x C-c to exit Emacs when you are finished.
      Result: Emacs asks if you want to save the file:
```
Save file /mit/jarandom/Mail/draft? (y or n):
```
    8. Type y to save the file and quit Emacs.
      Result: The Emacs window disappears and the xterm window gives a What now? prompt.
    9. Type s to send the message.
      Result: The message gets sent from your workstation to the "post office machine" of the user to whom it is addressed (in this case, yourself). The next section shows you how to pick up your e-mail from the post office.
    Receiving e-mail
    
    Incorporating (picking up) new mail
    - To incorporate, or "pick up" your mail, type:
```
athena% inc
```
    Result: Your messages are picked up from the post office machine and filed in your inbox subdirectory. A "scan listing" of all the new messages appears, showing a message number, the date, the sender, and the beginning of the text.
```
1+ 05/01 jarandom@mit.edu   test<<E-mail makes it
2  05/01 jarandom@mit.edu   another test<<I think
```
    Reading your mail
    1. After you have incorporated your mail, use the show command to read it:
```
athena% show
```
      Result: The number of the current message appears, then the text of the current message appears.
    2. If the message is longer than a screenful, press the Spacebar to scroll forward one screenful, b to go back one screenful, or q to quit.
    3. To show a specific message, use show with the message number:
```
athena% show 2
```
    Review
    - The comp command opens an Emacs window so you can specify an address, compose an e-mail message, and send it.
    - The inc command gets your e-mail from the post office machine.
    - The show command displays an e-mail message.
    Communicating with Others in Real Time
    
    Zephyr is a way for users to send instantaneous messages to each other. When someone sends you a Zephyr message, it appears on your screen in its own window, known as a windowgram. Zephyr is the way to find someone or send a quick message to a person or group of people among the several hundred workstations scattered across campus. This chapter covers:
    For more information
    
    Documentation:
    - Zephyr on Athena (AC-34)
    - on-line manual pages, type man zlocate, man zwrite, etc., at the athena% prompt
    Athena Minicourses:
    - Intro to Athena
    Finding out who's logged in
    
    Finding a specific user
    
    Zephyr lets you locate other users if they are logged in and using Zephyr at the same time as you.
    - To find the machine a specific user is logged into, and what time they logged in, use the zlocate command. Try it with your own username:
```
athena% zlocate jarandom
w20-575-3.MIT.EDU      :0.0 Mon Aug 5 13:52:21  1996
```
    Finding several users
    1. Using Emacs, create a file called "~/.anyone" in your home directory:
```
athena% emacs ~/.anyone &
```
    2. Type in a list of usernames of people you want to find. Type Return after each username, to put each on a separate line. For example:
```
jarandom
bjuser
patdoe
newfrosh
```
    3. Save the file and exit Emacs:
```
C-x C-s
C-x C-c
```
    4. Type the znol (Zephyr notify on login) command at the athena% prompt:
      Result: Znol tries to "zlocate" each username in your "~/.anyone" file. If the user is logged in and running Zephyr, their information is displayed. If they are not logged in, nothing is reported:
```
 
athena% znol
jarandom: w20-575-3.MIT.EDU         :0.0 Mon Aug 5 13:52:21  1996
bjuser: m37-318-3.MIT.EDU           :0.0 Mon Aug 5 15:49:21  1996
```
    Sending messages
    1. The zwrite command sends a message from you to another user, as long as you are both logged in. To zwrite to yourself (as a test), type:
```
athena% zwrite jarandom 
```
      Result: Zwrite responds with:
```
Type your message now. End with control-D or a dot on a line by itself.
```
    2. Type a message, pressing Return at the end of each line:
```
Zephyr makes it easy to communicate with friends all over campus!
```
    3. When you're finished, type C-d or "." on a line by itself to send the message.
      Type C-c to cancel the message.
```
.
jarandom: Message sent
athena%
```
      Result: A windowgram appears on the screen of the recipient. In this example, the windowgram appears on your screen:
      
      Figure 7-1: A Zephyr windowgram
    Receiving messages
    - When a windowgram appears on your screen, move the mouse cursor into the windowgram and click any mouse button to make it disappear. You cannot retrieve it, so don't click until you have read it.
    Exploring the Internet via the World Wide Web
    
    The World Wide Web is the vast collection of files and services accessible over the Internet via browsers such as Netscape and lynx. Web documents can include formatting, graphics, and links to other documents when read by browsers specifically designed for the Web. This chapter covers:
    For more information
    
    Documentation:
    - on-line manual pages, type man netscape at the athena% prompt
    Athena Minicourses:
    - Information Resources
    - HTML -- Making a WWW Home Page
    Starting Netscape
    - Add the infoagents locker so you can find the Netscape program. Type the following commands at the athena% prompt:
```
athena% add infoagents
athena% netscape &
```
      Alternate method: You can also start Netscape from Dash: Communication >> WorldWideWeb >> Netscape >> Netscape - MIT Home Page
      
      Result: A Netscape window appears, displaying the MIT home page (note that the graphics on the MIT home page change frequently):
      
      Figure 8-1: The Netscape window with the MIT home page
    Selecting links
    
    Notice that some of the text on the MIT home page is underlined and highlighted (e.g., colored on a color monitor). These pieces of text are hypertext links.
    - Click the left mouse button on "Academics" in the column of the MIT Home Page to go to the Academics Web page.
      Result: The Academics web page is displayed in the Netscape window:
      
      Figure 8-2: The Netscape window with the Academics page displayed
    Navigational tips
    - You can move back and forth between pages you have seen by clicking on the "Back" and "Forward" buttons at the top of the Netscape window.
    - You can use the scroll bar on the right side of the window to see the rest of the page. Press the left mouse button on the arrows to scroll.
    Opening specific pages (URLs)
    
    Besides clicking on a hypertext link, you can also get to a specific Web page if you know its address. Web addresses are known as Uniform Resource Locators, URLs for short.
    1. Click the left mouse button on the "File" menu at the top left hand side of the Netscape window and choose the option open.
      Result: An "Open Location:" window appears.
      
      Figure 8-3: The Open URL dialog box
    2. To visit the Beginner's Guide to Athena page, move the mouse cursor into the text box (not just into the dialog box) and type the URL (URL's are case sensative and have no spaces, so type carefully):
```
http://web.mit.edu/olh/Frosh/
```
    3. Click on the "Open In Communicator" button or press Return.
      Result: The Beginner's Guide to Athena page appears.
      
      Figure 8-4: The Netscape window with The Beginner's Guide to Athena
      To choose the links from this page, you can click on the buttons in the image, or on the text links farther down the page.
    Obtaining Digital Certificates
    In order to use many of MIT's web based applications, you first need to obtain digital certificates. Digital certificates allow the applications to know who you are and communicate personal information to you securely. These applications allow you to register for classes, view your Bursars account, obtain educational discounts when purchasing computer equipment through NECX and more. If this is not the first time you are obtaining certificates, you may be shown less dialog boxes because you have already set your preferences.
    1. To obtain digital certificates, open the following URL as you did to go to the Beginners Guide.
```
http://web.mit.edu/is/help/cert/
```
      Result: Table of Contents Appears
    2. The first thing you want to do is obtain an MIT Site Certificate. Click on the highlighted words "Get MIT Certificate Authority site certificate" in the section labeled Get Certificates Now.
      Result: A Dialog Box Appears
    3. This dialog box informs you that you are starting the process of obtaining a site certificate. Click on the Next> button to continue.
      Result: Another Dialog Box Appears
    4. This dialog box informs you of the purpose of a site certificate, which is to make sure the infromation you receive is from a reliable source. Click on the Next> button to continue.
      Result: Another Dialog Box Appears
    5. You are now shown the name of the certificate and given the option of accepting it or declining it. To accept the certificate, click on the Next> button.
      Result: Another Dialog Box Appears
    6. You are now given several options as to how this certificate will be used. For the purpose of the MIT certificate, you want to be sure to click on the first button Accept this Certificate Authority for Certifying Network Sites then click on the Next> button.
      Result: Another Dialog Box Appears
    7. You are now given the option of being warned whenever a site that is certified by this certificate is contacted. If you wish to recieve warning messages when this certificate is used, make sure the button is depressed as shown then click on the Next> button.
      Result: Another Dialog Box Appears
    8. Now you are asked to give the certificate a nickname. Choose something that you will recognize in the future such as MIT Site Certificate then click on the Finish button.
      Result: The dialog box goes away.
    9. You have successfully downloaded the MIT site certificate and the instruction page is still open in your web browser. The next step is to obtain a personal certificate. This certificate allows web applications to know who you are and give you personalized information. Click on the highlighted words "Get MIT Personal Certificate" in the section labeled Get Certificates Now.
      Result: A dialog box appears
    10. This dialog box lets you know that you are about to enter a secure site. This means that the information sent to you and received by you was encrypted during transit. Click on the OK button to continue.
      Result: A new document appears in your web browser
    11. Enter your Kerberos name (your username), password and MIT ID number in the spaces provided and click on the Do It! button.
      Result: A new document appears in your web browser
    12. Choose the key size and certificate lifetime. The larger the key size, the more secure the transfer of private information. The maximum lifetime for a certificate is 365 days; you can choose to make your certificate valid for a shorter time period. Click on the Do It button to continue.
      Result: A dialog box appears
    13. This dialog box informs you that Netscape will create a private key for your certificate and that it might take a little while. Click on OK to generate the private key.
      Result: A new screen appears in your web browser.
    14. Congratulations, you have MIT personal and site certificates! You can now access the web-based applications avaliable at MIT.
    Launching Applications with the Athena Menu Bar
    
    Using Dash
    
    The Dash menu bar at the top of the Athena workstation screen contains much useful information on using Athena.
    - Some of the items, marked with a question mark in the menu, are merely informational--click on the "?" to display information.
    - Other items do things when you click on them. For instance, click on "New xterm window" under the "Special" menu to get a new xterm window. These items also offer information if you click on the "?" next to them.
    - Still other items, followed by an arrow, are submenus. Click on the arrow to display more items.
    Dash is especially useful for new Athena users who want to access a wide variety of programs. When Athena documentation refers to a Dash item, the menus and submenus are separated by >>. For example, to display a map of the Athena clusters from Dash, follow these menus: Help >> Help on Athena >> Athena Cluster Map.
    
    Getting Further Help
    
    This chapter describes some of the groups within Information Systems that provide special services specifically for the Athena user community:
    - The Athena Training group runs free minicourses throughout the year on such essential Athena topics as Intro to Athena and Basic Word Processing and E-mail.
    - The Athena Documentation staff creates, maintains, and distributes publications and online documents to help the user community make the best use of the Athena system.
    - Athena Consultants can answer general questions about Athena and help with problems running supported software on Athena.
    Attending minicourses
    
    The Athena training group offers free minicourses on essential Athena topics. Each minicourse is about an hour long and consists of a short lecture with examples covering interesting and useful features of Athena. The classes are free and require no pre-registration.
    To get a minicourse schedule:
    - Pick up a yellow Minicourse Index & Schedule (distributed all over campus at the beginning of the term)
    - View the minicourse schedule and list of available courses online via the Web:
```
 http://web.mit.edu/minidev/www/
```
    - View the minicourse schedule online via Dash:
```
Help >> Help on Athena >> Athena Minicourses 
```
    Getting Athena documentation
    
    All of the Athena-generated end-user documents, are available at the Copy Tech Center, at no cost, in 11-004.
    Looking at Athena documentation online
    
    Most documentation about Athena is available right at your workstation via the Athena On-Line Help (OLH) documentation collection. To access OLH, type the following at the athena% prompt:
```
athena% help
```
    Alternate method: You can also access OLH from Dash: Help >> Help on Athena >> On Line Help
    
    The help command displays the Athena OLH home page in an appropriate WWW browser. If you already have a Netscape window open, you don't need to type help, you can go directly to URL:
```
http://web.mit.edu/olh/
```
    Looking at Athena manual pages online
    
    The UNIX operating system comes with an extensive (but often highly technical) online documentation system. You access this system with the man command.
    If you know the name of a command but do not know exactly how it works, you can see an online UNIX Programmer's Manual reference page for that command by using the man (manual) command at your athena% prompt. For example, to get the manual page about the man command itself, you would type:
```
athena% man man
```
    This displays the first screenful of online information about the command. (To go on to the next page, press the Spacebar; if the display is not over but you want to quit, enter q or Ctrl-c.)
    Each manual page gives a description of the command and lists all the options available with it. The online manual pages are written as reference documents for people who already know UNIX, so many of the man pages can seem overly technical. Nevertheless, some man pages are quite readable, and most provide thorough information.
    Using the online consultants
    
    You can usually reach an Athena User Consultant 24 hours a day, somewhere on campus, right from your workstation.
    - Drop by the Consulting Office, Building N42 1st Floor
    - Call the Athena Consulting Hotline, 253-4435
    - Ask your question online, by typing olc at the athena% prompt to connect to the On-Line Consultant (OLC) program. The OLC program will guide you through the process.
    Please give as much detail as possible when asking a question. The more information you give, the more help the Consultant can give you. You can type help whenever you see the olc> prompt to get a list of OLC commands.