tie %hash, 'MyHashClass', @files;
  my @data = $hash{$key};                # convienent!

##</code><code>##

package MyHashClass;
use strict;
use Carp;
use Tie::Hash;

@MyHashClass::ISA = qw/ Tie::StdHash /;

sub FETCH {
  my ($self, $key) = @_;
  my @ret = ();

  foreach my $filename ( @files ) {
    open( F, $filename ) or croak "$!";
    while( <F> ) {
      if ( matches ) { push @ret, $_; }
    }
    close F;
  }

  return @ret;
}
1;