My helper for debugging wordpress filter the_content. put it in mu-plugins

debug-filters.php

<?php
/*
Plugin Name: Debug filters for WordPress
Version: 0.1
Author: Onni Hakala
Author URI: http://seravo.fi
*/

if (isset($_GET['debug']) && $_GET['debug']=='filters') {
  //remove_filter( 'the_content','capital_P_dangit');
  //remove_filter( 'the_content','do_shortcode');
  add_action('wp_head','koodimonni_debug_output_for_filters');
  function koodimonni_debug_output_for_filters() {
    global $wp_filter;
    ?>
    <pre>
      <?php var_dump($wp_filter['the_content']); ?>
    </pre>
    <?php
  }
  add_filter( 'the_content', 'koodimonni_debug_filter_content', 10);
  function koodimonni_debug_filter_content($value) {
    echo "<h1>The content value:</h1>";
    echo "<pre>";
    var_dump($value);
    echo "</pre>";
  }

  add_action('shutdown','koodimonni_output_debug_filter');
  function koodimonni_output_debug_filter() {
    // Pass the filter name here
    echo "<h1>The content</h1>";
    global $wp_filter;
    echo "<pre>";
    var_dump($wp_filter['the_content']);
    echo "</pre>";
  }
}