Server-Side Includes with mod_perl (Perl in a Nutshell, 2nd Edition)

11.5. Server-Side Includes with mod_perl

Server-side includes (SSIs) are tags embedded directly into an HTML file that perform special functions. They are most commonly used for running CGI scripts and displaying the result; most web page counters are performed using SSIs.

If you use mod_perl with mod_include (another Apache server module), you can embed Perl subroutines into SSI directives. For example:

<!--#perl sub="sub {print ++Count}" -->

The Apache::Include module lets you include entire Apache::Registry scripts:

<!--#perl sub="Apache::Include" arg="/perl-bin/counter.pl"-->

You could have used standard SSIs to include a CGI script for the same purpose, but this way is faster. To use mod_include with mod_perl, you need to configure mod_perl to do so at compile time.