Putting Your World Wide Web Pages on CNS

This section assumes basic familiarity with using UNIX, the operating system which runs on the NERSP computer. If you would like an introduction to UNIX systems at CNS, please refer to the CNS document D0107, CNS UNIX 101: An Introduction to NERSP (available on the Web via DOCWEB , or as a hard-copy booklet from CNS Information Services [112 Bryant SSRB, 352-392-2061]).

To set up space for your Web pages on NERSP;

First, log on to nersp.cns.ufl.edu.

Next, enter the command: cd

This ensures that you are in your "home directory."

In your home directory on NERSP, create a subdirectory named public_html by using the command, mkdir public_html

Move the documents that you want to make available to the World Wide Web into your public_html subdirectory.

You can do this by using the cp command to copy them from another NERSP directory, or you can use ftp to move them from your PC or other computer. As mentioned earlier, this document assumes some familiarity with the UNIX operating system. If you need assistance, refer to CNS document D0107, CNS UNIX 101: An Introduction to NERSP, or contact the UF Computing Help Desk (352-392-HELP, helpdesk@ufl.edu).

When you add new documents to your public_html subdirectory, be sure to give everyone access to them by using the command

chmod -R o+rX public_html

By convention, your home page document should be named index.html, and it would typically contain hypertext links to the other documents in your public_html subdirectory, and possibly links to other documents around the Web. Your home page (index.html) on NERSP can then be viewed by any World Wide Web user who opens the URL:

http://nersp.cns.ufl.edu/~userid

...where "~userid" is a tilde character followed by your CNS userid (with no spaces). For example, if your userid is sally, your home page on NERSP would have the URL

http://nersp.cns.ufl.edu/~sally

Web users can also view your other documents directly, bypassing your home page, by opening URLs like the following:

http://nersp.cns.ufl.edu/~userid/filename.type

...where "filename.type" matches any filename in your public_html subdirectory. For example, to view a plain text copy of sally's resume that is in a file named resume.txt, one would open the URL:

http://nersp.cns.ufl.edu/~sally/resume.txt

Remember, the documents MUST be in your public_html subdirectory in order to be accessible by other users. Conversely, files that are NOT in your public_html subdirectory remain private.

You might want to test your home page and other documents you create on NERSP before you move them to your public_html subdirectory. You can do this by using the lynx command as follows:

lynx filename.filetype

...where filename.filetype is the name of a file in the current directory. Lynx is a text-only browser, and so will not show you any images which you may have linked into your page.

The HTML markup language supports "form" tags which can be used to prompt the viewer for input. When someone views a document which includes a "form" and fills in one or more of the input fields, the data is transmitted back to the Web server where a specially-coded program associated with that HTML document processes the received data. The standardized interface between the Web server and these special programs is called the Common Gateway Interface, or CGI. Programs which process input from a Web browser are generally referred to as CGI programs.

CGI programs can be written in most languages available on CNS's NERSP UNIX system, including the Bourne-derived shells (bsh, ksh, bash), C-shell, Perl, and even C. For detailed information regarding using CGI programs on NERSP, see CNS document D0121, CGI Programs on NERSP.

Applets for the Web can be written in Java and stored on the NERSP system. The path to the Java compiler on NERSP is /usr/java130/bin/javac. Other relevent files may be found beginning in /usr/java130. Documentation about Java can be found at:

http://www.javasoft.com/.

NERSP also supports image maps, also known as clickable images. Image maps are a way to allow viewers of your Web document to link to other documents by clicking on different sections of a graphical image. The image might be a geographical map or a "tool bar" of icons. (Of course this only works if the viewer is using a graphical Web browser such as the Netscape browser or Internet Explorer by Microsoft.)

To use image maps in your Web documents on NERSP, you must:

Use one of the several tools available for Windows, MacOS, and X-windows. A list of such tools is located on the Web at Webreference.com . Your "map" file can be in the NCSA format or the CERN format. (We recommend creating new imagemaps in NCSA format).

The URLs within imagemap files can be partial (or "relative") URLs when refering to your own documents or CGI programs on NERSP, in which case the partial URLs must be of the form

/~username/file

or

/~username/cgi-bin/file (if you prefer to store your CGI programs in a separate "cgi-bin" directory)

Replace "username" with your username, file with the name of a document, or with the name of your own CGI program.

Transfer (in "text" or "ASCII" mode) the imagemap file you just created to your public_html directory on NERSP.

3. Write HTML which references the appropriate CNS-supplied CGI program which will use your imagemap file to convert coordinates to URLs.

You must use an HTML <A HREF=> tag to refer to the appropriate CGI "mapper" program: <A HREF="/cgi-bin/MAPPER/~username/filename.imagemap">

where "MAPPER" is either imagemap for NCSA-format imagemap files, or htimage for CERN-format imagemap files.

This HTML "anchor" construction should be followed by the URL for your image file. Your image file URL must include the ISMAP tag, to indicate to the browser/client that this is a "clickable" image. The </A> tag indicating the end of the "anchor" should follow the URL for your image.

For example, let's say user "alberta" has created an image named toolbar.gif and a corresponding NCSA-format imagemap file named toolbar.imagemap, both stored in her public_html directory on NERSP. She could then enable that toolbar in her index.html file by using the tags

<A HREF="/cgi-bin/imagemap/~alberta/toolbar.imagemap">

<IMG SRC="/~alberta/toolbar.gif" ISMAP></A>

Note the ISMAP attribute of the <IMG> tag: it tells browser programs that this is an image map.

For more information about image maps, see the NCSA image map tutorial at http://hoohoo.ncsa.uiuc.edu/docs-1.4/tutorials/imagemapping.html.

For Web pages stored on the NERSP, you can use a one-line command, issued at the NERSP command-prompt, to scan the Web-server logs. For more information about obtaining "hit" counts, please see CNS document D0130, Obtaining "Hit" Counts for Your CNS WWW Page.

NERSP's Web server provides a facility to allow you to restrict access to your Web pages; either via userid/password challenge, or IP address exclusion, or combinations of the two. This security facility is invoked automatically by the presence of a file named .htaccess in the directory to be secured. You must create this file and place it into the directory you wish to be password-protected. For detailed information and instructions on how to do this, see CNS document D0123, Controlling and Restricting Access to Web Pages on NERSP.