CGI

• CGI Stands for ``Common Gateway Interface''. If you've ever seen forms, counters, or e-mail access on the Web, then it's done through CGI. When you click on a form, the information is sent to a CGI script somewhere in the Web. That script processes the information in some meaningful way and then usually returns some message in HTML to your browser to confirm what you did. Unfortunately, we will not be able to make our own CGI scripts to work with our server because these scripts have to be put into a directory that accessable only through root or superuser access.
• Here are a few things that CGI allows us to do :

  forms

  - If you look at http://www.rpi.edu/phserver.html you will see a ``form''. This one allows you to type in someone's name and the CGI script behind it find information on the person. The HTML book talks about forms in more detail if you're interested, but since we can't really implements any of it at the moment, I'm going to skip it.

  mailto

  - You've probably seen buttons or text that you click on that allow you to send mail to a certain person. This is just another form. The scripts behind these forms are public and anyone can use them. I've seen quite a few mailto URLs, but this is the one that I have found to be the most reliable : <A HREF="mailto:escobj@rpi.edu">Click Here to Send Mail</a>. You can add that to your page and just change my e-mail address to yours and it should work.

  counters

  - These count the number of times your page has been accessed. The CS department has one that keeps track of only the hits that come from other users, it works on my account, hopefully it will work for RCS accounts - give it a try if you wish. Here it is:
  

  Total Hits : <img src="http://www.cs.rpi.edu/cgi-bin/
                            count?type=web1&length=3" align=middle><br>

  All you have to do is copy the above code into your index.html file. This is pretty generic, there are other counters with digits of different colors and types (i.e. bananas). To check out some of these, see my friend John's page at: http://www.cs.rpi.edu/~puninj/