my $current_page_num = 2;
my $num_pages        = 6;

if ($current_page_num > 1) {
   ...display link to page $current_page_num-1...
}

for my $page_num (1 .. $num_pages) {
   if ($page_num == $current_page_num) {
      ...display page number...
   } else {
      ...display link to page $page_num...
   }
}

if ($current_page_num < $num_pages) {
   ...display link to page $current_page_num+1...
}