WP function to create shortcode that display posts base on attribute

wp-query-shortcode.php

<?php

function jay_query_shortcode($atts) {
 
   // Example usage of this shortcode:
   // [loop the_query="showposts=100&post_type=page&post_parent=453"]
   
   // Defaults
   extract(shortcode_atts(array(
      "the_query" => ''
   ), $atts));
 
   // the 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 = '';
   
   // the loop
   if (have_posts()) : while (have_posts()) : the_post();
   
      $temp_title = get_the_title($post->ID);
      $temp_link = get_permalink($post->ID);
     
      // output all findings - CUSTOMIZE TO YOUR LIKING
      $output .= "<li><a href='$temp_link'>$temp_title</a></li>";
         
   endwhile; else:
   
      $output .= "nothing found.";
     
   endif;
   
   wp_reset_query();
   return $output;
   
}
add_shortcode("jay_loop", "jay_query_shortcode");