WordPress pagination without plugins

global $wp_query; 

$total_pages = $wp_query->max_num_pages; 

if ($total_pages > 1){ 

$current_page = max(1, get_query_var('paged')); 

echo '<div class="page_nav">'; 

echo paginate_links(array( 

'base' => get_pagenum_link(1) . '%_%', 

'format' => 'page/%#%', 

'current' => $current_page, 

'total' => $total_pages, 

'prev_text' => 'Prev', 

'next_text' => 'Next' 

)); 

echo '</div>'; 

}