use strict;
use Bio::Seq;

my $dna = 'accatgagctgtacgtagcatctgagcgcgcatgactgtgactgacgtaggcagca';
my $seq = Bio::Seq->new( -seq => $dna);
my $end =  $seq->length -10;

my @windows;
for(my $i= 1; $i < $end; $i+=2) #increase by one codon each time.
  {
    push @windows, $seq->subseq($i, $i+9);
  }
print join "\n", @windows;