{
   open(my $fh, '<:raw', $datfilename) or die $!;
   read_uint32($fh);
   while (!eof($fh)) {
      my $profile_id = read_uint32($fh);
      my @seqs;
      while (length( my $seq = read_pstring($fh) )) {
         push @seqs, $seq;
      }

      ...
   }
}