Now it's time to move any existing CGI scripts from the /somewhere/cgi-bin directory to /home/stas/modperl. Once moved, they should run much faster when requested from the newly configured base URL (/perl/). For example, a CGI script called test.pl that was previously accessed as /cgi-bin/test.pl can now be accessed as /perl/test.pl under mod_perl and the Apache::Registry module.

Some of the scripts might not work immediately and may require some minor tweaking or even a partial rewrite to work properly with mod_perl. We will talk in depth about these issues in Chapter 6. Most scripts that have been written with care and developed with warnings enabled and the strict pragma[15] will probably work without any modifications at all.

[15]Warnings and strict abort your script if you have written sloppy code, so that you won't be surprised by unknown, hidden bugs. Using them is generally considered a good thing in Perl and is very important in mod_perl.

A quick solution that avoids most rewriting or editing of existing scripts that do not run properly under Apache::Registry is to run them under Apache::PerlRun. This can be achieved by simply replacing Apache::Registry with Apache::PerlRun in httpd.conf. Put the following configuration directives instead in httpd.conf and restart the server:

Alias /perl/ /home/stas/modperl/
PerlModule Apache::PerlRun
<Location /perl/>
    SetHandler perl-script
    PerlHandler Apache::PerlRun
    Options ExecCGI
    PerlSendHeader On
    Allow from all
</Location>

Almost every script should now run without problems; the few exceptions will almost certainly be due to the few minor limitations that mod_perl or its handlers have, but these are all solvable and covered in Chapter 6.

As we saw in Chapter 1, Apache::PerlRun is usually useful while transitioning scripts to run properly under Apache::Registry. However, we don't recommend using Apache::PerlRun in the long term; although it is significantly faster than mod_cgi, it's still not as fast as Apache::Registry and mod_perl handlers.