Basics of World Wide Web publishing on pangea

Last revision July 20, 2004

Table of Contents: Basics of WWW publishing Setup your home page General style considerations for web pages Options for creating pages in HTML Graphics considerations Controlling access to web directories on pangea Using include files and templates on pangea Uniform Resource Locator (URL) syntax

You can publish your own information on the Web, using the pangea Web server or the campus Web server. All you need to do is to organize your content into "pages", wrap it up in the HTML markup language, and create appropriate links both among your pages and from your pages to other sites and indexes. For example, your pages can be linked into the department pages within the School.

The Web can serve multiple types of media: text, graphic images, movies or animations, and sounds. To begin simply, you can restrict yourself to simple text and graphics images. Text must be converted, or at least wrapped within, a document using the HTML language. Graphics can be stored in several formats, but the most universal are the GIF format (best for line drawings) and JPEG format (best for photographs), which are usually displayed directly within the page by the Web browser.

Pangea runs the full-featured Apache Web server. This is the most popular web server software. Like most installations, for security reasons pangea runs the web server from a special account that has very limited privileges. One result is that the web server can only see and serve files stored on pangea that have world read access and are linked into directories with world read and execute access.

On pangea, the Unix directory /WWW is the "home directory" of the web server and the "base" from which all standard URLs (web addresses) are expanded. For example, if there were a file named file.html stored in the /WWW directory, so that its full pathname as viewed by Unix commands was /WWW/file.html, then it would be served by the web server with the address

http://pangea.stanford.edu/file.html

The /WWW directory sits on its own disk partition and is used to store department and group pages, each in its own subdirectory. You must ask the pangea webmaster to make a subdirectory for your group, and to set up the correct permissions to allow specified members of your group to add or modify files therein. Be sure to follow the group write protocol if multiple members of your group will be sharing responsibility for maintaining the group web pages, or you have problems uploading files.

If your group web pages are buried several levels deep in the directory structure on pangea, you can request a virtual hostname from the pangea webmaster that lets people access your pages with a simple URL. (Virtual hostnames are also available for campus system web pages For example, the virtual hostname

http://hartley.stanford.edu/

actually loads the web page

http://pangea.stanford.edu/facilities/hartley/

Individual users of pangea can also share web pages from their personal home directories. Like many other sites, the web server on pangea has been configured to associate the special URL http://pangea.stanford.edu/~username/ with the subdirectory WWW within the Unix home directory of the pangea account username. The tilde character (~) before the username in the URL is the flag that tells the web server to look for a personal web directory rather than one of the group directories in its own home /WWW.

There are no general restrictions on content or usage of your personal web pages, other than general University computing rules that prohibit for-profit use and monopolizing system resources. Do not store general pages for your department or group in your personal web space, however. When you leave Stanford and your pangea account is closed, your personal web pages will be removed.

Apache has features that allow users to control access to their web pages. You can restrict viewing of your personal or group web pages to specific computers or domains (for example, only computers on the Stanford campus). You can also limit access to specific users who must supply a password to see the pages.

The Apache server on pangea has been configured to support server-side includes. This feature allows you to extract HTML code that you use in multiple pages, for example, a fancy header, and put it into a single file that is included in the other pages automatically. As a result, it is easy to maintain this common section; whenever you change the "include file", the change is automatically picked up by all the pages that use this include file. On pangea, we use this feature to allow departments and groups to have a common page layout and header that is defined in a simple template file.

Web pages can contain forms to collect information, which can then be processed by a program (called a CGI script). For security reasons, scripts must be installed by the pangea webmaster in a special system directory. If you create one in a group or personal web directory space, the web server will ignore it.

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