CGI _ What is it? and How Do I Use it?

Part of the course for HTML 2 is using cgi.  While it is not covered extensively there are usually some questions that hopefully this will help answer for those who attempt to use their own cgi bin if provided by their host.

There are a number of different methods Web developers can use to enhance the content of Web pages over and above what simple HTML provides. Most of these methods involve writing little programs or routines using a scripting language or another.

CGI is utilized by placing an appropriate HTML tag in your HTML code. The script is called for by the server and executes the script file that is specified in the tag.  

Create a sub-directory (folder) in your root Web directory called cgi-bin by using your ftp program. Many isp's already have the folder there.  Your scripts will not run unless your server allows cgi and not all do.

Once you have set up your cgi-bin and downloaded the script you want to use you must follow these steps:

1.  Modify the script for your server.  Mainly it will be things like your domain, your sendmail, and your e-mail address that will have to be modified in the script itself.  Most downloaded scripts give directions on what you will have to modify.  You will have to contact your hosting service to find the path to "sendmail" for use in your scripts, if it is required.  Most hosts have faqs and directions for the use of cgi and the different paths that will need to be set.  

2. Transfer the script's files (the script file itself and any necessary data files) to your cgi-bin and set the permissions.  Permissions are done through CHMOD  which sets permissions on your file as to who can read it, write to it and execute the file. These permissions are necessary so your Website visitors can have your scripts execute so they can access them. There is a great tutorial  found here from WSFTP http://faq.solutionscripts.com/misc/chmod_ws_ftp.html

3. Add the script's HTML tag to the page where you want to use the script.

Some of the most common uses of these scripts are for web page counters and contact forms.  You can download many free scripts from the internet.  Here is a link to The CGI Resource pages where you can found countless scripts and site where you can host your cgi script if you do not have that capability on your own server.  

There you have it - happy scripting :)