Maybe this is obvious, but the config variable lives in the IkiWiki module, and one probably 
wants to call defaultconfig for most applications. 
<pre>
%IkiWiki::config=IkiWiki::defaultconfig();
IkiWiki::Setup::load($config_file);
print  join(",",keys %IkiWiki::config);
</pre>

[[DavidBremner]]