Perl style:

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...
}
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Or template style:
(Whitespace added for readability.)
(The template system I use looks at the class for commands.)

<a class="if::Selector.link_prev
          sub::href::Selector.link_prev"
   href="{page_link_next}"
>&lt;&lt;Prev</a>

<span class="page_selector_cell">
   <span class="if::Selector.Page.is_current
                text::Selector.Page.page_num
                current-page"
   >{page num}</span>

   <a class="unless::Selector.Page.is_current
             sub::href::Selector.Page.link
             text::Selector.Page.page_num"
      href="{page_link}"
   >{page num}</a>
</span>

<a class="if::Selector.link_next
          sub::href::Selector.link_next"
   href="{page_link_next}"
>Next&gt;gt;</a>
[download]

given

Selector.link_prev  -> Link to prev page, if any.
Selector.link_next  -> Link to next page, if any.

page_selector_cell  -> Loops over all page nums, setting these:
  Selector.Page.is_current -> True if page_num is current page.
  Selector.Page.page_num   -> Loop variable.
  Selector.Page.link       -> Link to page page_num.
[download]