Different permalinks for users who are not logged in

I’m currently showing my blog posts on a single page (via a shortcode), and I only show the excerpts to each posts. I then want only logged in users to be able to read the entire blog post, but can’t seem to figure it out.

This is my shortcode function in functions.php:

function custom_query_shortcode($atts) {

   // EXAMPLE USAGE:
   // [loop_shortcode the_query="showposts=100&post_type=page&post_parent=453"]

   // Defaults
   extract(shortcode_atts(array(
      "the_query" => ''
   ), $atts));

   // de-funkify query
   $the_query = preg_replace('~&#x0*([0-9a-f]+);~ei', 'chr(hexdec("\\1"))', $the_query);
   $the_query = preg_replace('~&#0*([0-9]+);~e', 'chr(\\1)', $the_query);

   // query is made
   query_posts($the_query);

   // Reset and setup variables
   $output = '';
   $temp_title = '';
   $temp_link = '';
   $temp_ex = '';
   $temp_content = '';
   $temp_thumb = '';
   $temp_id = '';

   // the loop
   if (have_posts()) : while (have_posts()) : the_post();
      $temp_id = $post->ID;
      $temp_title = get_the_title($post->ID);
      $temp_link = get_permalink($post->ID);
      $temp_content = get_the_content($post->ID);
      $temp_ex = get_the_excerpt();
        if ( has_post_thumbnail() ) {
        $temp_thumb = get_the_post_thumbnail($post->ID);
        } else {
        $temp_thumb = "" ;
        }

      // output all findings -
     $output .= "<div class='post-$temp_id' id='post-$temp_id'>
                <h2 class='entry-title'>
                    <a title='$temp_title' rel='bookmark' href='$temp_link'>$temp_title</a>
                </h2><!--BEGIN .entry-content-->
                <div class='entry-content'>
                    <div class='theExrp'>
                    <p>
                        <a href='$temp_link'>
                            $temp_thumb
                        </a>
                    </p>
                    <p>
                            $temp_ex
                    </p>
                    </div>
                </div><!--END .hentry-->
            </div>";
    endwhile; else:
      $output .= "Not found.";
   endif;
   wp_reset_query();
   return $output;
}
add_shortcode("loop_shortcode", "custom_query_shortcode");

How can I alter this code to show excerpt to public users, but only logged in users can access the single posts? Non-logged in users should get redirected to the login page.