#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

my ($fasta_in, $fasta_out) = qw{
    pm_1205271_bio_fasta_extract_dummy_in.fasta
    pm_1205271_bio_fasta_extract_dummy_out.fasta
};

my $re = qr[(.{10}GG)\z];

{
    open my $in_fh, '<', $fasta_in;
    open my $out_fh, '>', $fasta_out;

    local $/ = "\n>";

    while (<$in_fh>) {
        chomp;
        substr $_, 0, 1, '' if $. == 1;
        my ($head, $seq) = split /\n/;
        next unless $seq =~ $re;
        next if index($seq, $1) < length($seq) - length($1);
        print $out_fh ">$head\n$seq\n";
    }
}