MIT

Web Guide is no longer being maintained and the information on this page may be out of date. For assistance with managing course materials, please visit MIT's Stellar course management system.

Academic Web Page Creation Guide


Publishing Your Pages > Using an Athena Course Locker

Using an Athena Course Locker for Your Web Site

A Web site whose URL begins with http://web.mit.edu/ is a collection of files stored on Athena and delivered through MIT's central Web servers. This document is a basic guide to maintaining a Web site in an Athena course locker. The information given applies whether you are working directly on an Athena workstation or working on Athena by remote login.

For a comprehensive introduction to using Athena, read Working on Athena. For specific information on managing Athena course lockers, read the Course Locker Maintenance Guide, and for instructions on how to create HTML files and other content for the Web, see the Building Your Pages section of Web Guide.

Use the Course Locker Request Form if you do not yet have a course locker, or to request modifications to ownership or quota of existing course lockers.

On this page:

Locating Your Site: URLs, Athena, and AFS

The general naming scheme for a course URL is:

    http://web.mit.edu/subject-number/www/
This corresponds to the full AFS path of your Athena course locker:
    /afs/athena.mit.edu/course/course-number/subject-number/www/
A shorter path, known as the /mit path, may be used:
    /mit/subject-number/www/
Continue reading for further details, including an explanation of the short path, and examples of the correspondence between URLs and Athena lockers.

Athena Course Lockers

An Athena locker is simply disk space housed on an AFS file server. Among the types of Athena lockers are: A course locker may contain Web files (typically, in a directory named "www") as well as other course materials (for example, data or program files). The following is a diagram of a sample course locker hierarchy:

tree structure of sample course locker

URLs and Athena Directory Paths

In the following examples, 29.123 is used as a hypothetical MIT course number. The 29.123 Web site would have the URL:
    http://web.mit.edu/29.123/www/
This corresponds to the www directory of the 29.123 course locker, where the Web files are actually stored. The full Athena path of the www directory (i.e., its actual location in the AFS filesystem hierarchy) is:
    /afs/athena.mit.edu/course/29/29.123/www/
You would need to use this path in certain maintenance tasks, such as file transfers. In other cases, when working directly on Athena you can use the short path, as follows:
  1. Attach the course locker; for example:
        athena% attach 29.123
    
  2. You can now use the short path during that Athena session when you need to specify the location of the www directory; for example:
        /mit/29.123/www/
    

In the examples that follow, the short /mit path is shown for convenience, except when the full path is necessary.

Viewing Your Site With a Browser

A convention of the Web is that the starting point for a site is a file named index.html. This file is known as the index or top-level page. If it exists, it is displayed by default when a URL of the following format is typed in the browser's Location: or Go to: line. For example:

    http://web.mit.edu/29.123/www/

Another convention of the Web and most recent browsers is that you do not need to include the prefix http:// when typing a URL in the Location: line. For example:

    web.mit.edu/29.123/www/

Either way, the file displayed by default is:

    /mit/29.123/www/index.html

This is equivalent to entering the following, but without the extra typing:

    http://web.mit.edu/29.123/www/index.html

Should the URL's directory not contain a file index.html, the browser displays a listing of the contents of the corresponding directory instead. For example, if the directory /mit/29.123/www/ contains a file named test.html, and two directories named exams and images, the browser would display a list similar to the following:

    Index of /29.123/www/

    Name              Last modified           Size     Description
    ------------------------------------------------------------------
    Parent directory
    test.html          23-May-99 06:04           4K     29.123 Home Page
    exams/             01-Jun-99 12:22            -
    images/            23-May-99 06:00            -

The correspondence between the URL and the Athena path holds for individual files and subdirectories as well. For example, the following URLs relate to their corresponding files, respectively:

URL:

    http://web.mit.edu/29.123/www/syllabus.html
    http://web.mit.edu/29.123/www/exams/

File:

    /mit/29.123/www/syllabus.html
    /mit/29.123/www/exams/index.html

Restricted Access for Web Sites on Athena

It is now possible to restrict access to your Web pages to particular individuals or groups with MIT personal certificates, or to the entire MIT community. For details on the current methods for access restriction and other options, see Restricting Access to Your Web Pages.

Alternate URLs for Web Sites on Athena

You can reach sites on web.mit.edu through shortcut URLs. For example, the shortcut equivalent to the full URL given in the examples above is:
    mit.edu/29.123/www/

Course Web sites may also be accessed through the SIPB Web server, with the URL format:

    http://www.mit.edu/~lockername/
    http://www.mit.edu/~29.123/

Shortcuts and alternate URLs may be useful for your maintenance and testing purposes, but you should not burden your students with multiple URL formats for reaching the same Web site.

URLs to course lockers may be set up without the /www/ directory indication; for example http://web.mit.edu/acs/ instead of http://web.mit.edu/acs/www/. You can also designate a directory name other than www; for example, http://web.mit.edu/29.123/Web. For details, see the section on Changing ACLs.

Getting to Your Site for Maintenance

You can access the Athena course locker that hosts your Web site in one of two ways:

Getting to Your Course Locker on Athena

For certain maintenance tasks (such as managing directories and quota), you will need to access your course locker directly on Athena. The first step is to log into Athena, either on an Athena workstation or by connecting remotely from your own system.

Remote Athena Login

  1. Use a telnet or SSH (Secure Shell) program to connect. For more information, see Secure Remote Login to Athena).
  2. For the connection address or hostname, use athena.dialup.mit.edu.
    (If you need to do a only few short tasks you can use express.dialup.mit.edu. This connects you to a machine with a smaller load, but it also limits you to 15 minutes of connect time when there are more than 10 users logged simultaneously.)

Changing Directories

When you first log into Athena, you will be in your home directory (your personal space). At any time in your Athena session, you can check where you are in Athena with the command pwd (present working directory).

For example, when J. Q. Prof first logs in:

    athena% pwd
    /afs/athena.mit.edu/user/j/q/jqprof
To change to your course Web directory, use the command cd (change directory), with the following format:
    athena% cd path
For example, change to the www directory for 29.123, then type the command pwd:
    athena% cd /mit/29.123/www
    athena% pwd
    /afs/athena.mit.edu/course/29/29.123/www
Note: The pwd command always shows the full path of a directory, regardless of whether or not you used the short /mit path in your commands.

Managing files and directories on Athena

Controlling Access

Summary of Differences Between Athena and Standard Unix

The underlying operating system of Athena is Unix. Lockers are stored in Athena's centralized AFS file system, which handles permissions differently from other Unix file systems. Information on AFS permissions, Athena directory paths, and some useful shortcuts is summarized below.

Further Information