I need to load perl modules on the fly from mod_perl. Here is my working solution.

In an apache conf file I have:

  <FilesMatch "\.pm">
    PerlSetVar           RootNamespace   CEMS::EXT
    PerlFixupHandler     CEMS::AutoLoader
  </FilesMatch>
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The code above tells apache to execute CEMS::AutoLoader::handler() whenever it sees a uri that looks like *.pm

Module CEMS::AutoLoader looks like this

package CEMS::AutoLoader;

use Apache::Constants qw(:common);
use strict;

sub handler {
  my $r = shift;
  return DECLINED unless $r->is_main; 

  #get package name
  my $module = join ('::',$r->dir_config('RootNamespace'),
    split (/\//, substr($r->uri(),1,-3) ) );

  #see if package really exists and set content handler
  if (eval "require ".$module) {
    $r->push_handlers(PerlHandler => $module);
    $r->handler('perl-script');
    return OK;
  } 

  #require threw an exception so package does not exist
  return DECLINED if ($@);
}

1;
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The above code is working, but there has to be a better way to do this. Calling require on every request just to see if a package exists probably isn't efficient. Most likely the package will already be loaded.

Does someone know of a better way to see if a package is already loaded?

Edit kudra, 2001-08-30 Added p breaks; code->single spaced