while ( my $filename = readdir(DH) ) {
  next if $filename eq '.' or $filename eq '..';
  print $filename;
  if ( -f $filename ) {
    open my $FH, '<', $filename or die "open: $!\n";
    while ( my $line = <$FH> ) {
      print $line; 
    }
    close FH or die "close: $!\n";
  }    
}