The first two lines declare a hash and fill the hash with the elements of @_ as keys with each pointing to undef. The third line of the sub does a bitwise-or on $^H with the return of the default strict import unless "no_strict" was in @_. The first two lines are just a quick way of telling whether or not "no_strict" was present in the import list.

In other words you control what operation gets performed from the import list. For more information I offer the following reading material: perldsc, use, Exporter, perlvar and perlmod.

Hope this helps.

antirice    
The first rule of Perl club is - use Perl
The ith rule of Perl club is - follow rule i - 1 for i > 1