$window_start = 5;
$window_size = 5;
$text_body = "Please ignore all this text, this is the text wanted, please none of this text";

if ($window_start > 0) {
        $text_body =~ /\S+/g foreach 1..$window_start;
        $start_index = pos($text_body); 
}  else {
        $start_index = 0;
}

$text_body =~ /\S+/g foreach 1..$window_size; 

$end_index = pos($text_body); 

$windowed_text = substr($text_body, $start_index, ($end_index - $start_index));

print $windowed_text;

#prints " this is the text wanted,"