Here's a way to have multiple config files for a single script. They're specified with a query such as myscript.pl?config1, myscript.pl?config2, etc.

$config=$ENV{QUERY_STRING};
unless(require $config){
  print "No Configuration File Specified!\n";
  exit;
}
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I learned that from Brent Michalski's excellent database tutorials that used to be at webreview.com