Conditional SSI

While many of you are familiar with SSI (Server Side Includes) and its tremendous usefulness as a server feature, did you know that the technology supports conditions? Imagine being able to give your SSI code logic, so it executes different commands, depending on variables such as browser type, time of day, referring URL, and whatever else can be accessed and compared in Perl. Something like that would be nothing less than revolutionary, and fortunately, possible! Just to review, SSI are “codes” you place on your page that the server picks up and executes. The most common use of SSI is to include a file on the page: [an error occurred while processing this directive] The above command will cause the file “afile.htm” to be inserted and displayed, as if it were manually added to the page.

More: continued here