CGI Scripts

CGI Caveats

CGI Caveats | Language Choice | CGI and Forms

There are at least a couple of aspects of creating CGI programs that place instruction in this topic outside the scope of this Tutorial.

They Are More Complicated than HTML

First of all, CGI programs must be written in some language other than HTML. Consequently, if you want to create programs that are custom designed to meet your particular needs, you may have to learn another more complicated computer language. Teaching such a language is beyond the scope of this introductory Tutorial.

They Require Security Privileges

Second, since such programs allow a user to execute programs on the server, they introduce potentially serious security risks. Consequently, most computer systems require that all gateway scripts reside in special places in the computer's filesystem, places to which access is limited. This provides some control over what sort of gateway scripts may placed on the machine and, in turn, on what sort of ways the server may be manipulated.

On Unix machines, gateway scripts often must be placed in a directory called cgi-bin, which is within the directory that houses the Web server software itself. Because this is done for security reasons, ordinary users often will not have access (or at least not direct access) to this area. So even those who can write gateway scripts may not be able to place the scripts where they can be executed if their Web pages are served from a computer on which they do not have administrative privileges. Check with your system administrator for the policy on the server that you use.