CGI
: Common Gateway Interface
The Common
Gateway Interface (CGI) is a standard for interfacing external
applications with information servers, such as HTTP or Web servers.
A plain HTML document that the Web daemon retrieves is static,
which means it exists in a constant state: a text file that doesn't
change. A CGI program, on the other hand, is executed in real-time,
so that it can output dynamic information. CGI can be used to
interact with your website visitors,everything from a simple email
contact form to online booking systems. There are thousands of
CGI and Perl scripts available for download on the internet, which
saves you the trouble of having to write your own script.
Since a CGI
program is executable, it is basically the equivalent of letting
the world run a program on the server, which isn't the safest
thing to do. Therefore, there are some security precautions that
need to be implemented when it comes to using CGI programs. Probably
the one that will affect the typical Web user the most is the
fact that CGI programs need to reside in a special directory,
so that the Web server knows to execute the program rather than
just display it to the browser. In your hosting account there
is a directory called /cgi-bin. This is the special directory
mentioned above where all of your CGI programs will reside.
CGI scripts
are usually written in a scripting language called Perl.
Perl is a stable, cross platform programming language. It
is used for mission critical projects in the public and
private sectors and is widely used to program web applications
of all needs.
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