Lots of gaps to fill in, but this is the basic idea.

   my $first_file = pop @all4;
   my $master_list = get_all_mac_addresses_from_file($first_file);

   foreach my $filename (@all4) {
       my $this_list = get_all_mac_addresses_from_file($filename);
       foreach my $address (keys %$master_list) {
          if ( ! exists $this_list->{$address} ) {
              delete $master_list->{$address}
          }
        }
    }

    # now $master_list is a hashref whose keys are the
    # mac addresses in all the files, so output them
    # however you want.

sub get_all_mac_addresses_from_file {
   my ($file_name) = @_;

   # i dont know what format your files are
   # you need to write something to get the names 
   # out of the files, and return them as the keys 
   # of a hashref
   # The values dont matter.

   ...

   return \%the_list;
}
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