WordPress Plugin: List Comment Filters

list-comment-filters.php

<?php
/*
Plugin Name: List Comment Filters
Description: List all comment filters on wp_footer
Version:     1.1
Author:      Thomas Scholz
Author URI:  http://toscho.de
License:     GPL v2
*/

add_action( 'wp_footer', 'list_comment_filters' );

function list_comment_filters()
{
	global $wp_filter;

	$comment_filters = array ();
	$h1  = '<h1>Current Comment Filters</h1>';
	$out = '';
	$toc = '<ul>';

	foreach ( $wp_filter as $key => $val )
	{
		if ( FALSE !== strpos( $key, 'comment' ) )
		{
			$comment_filters[$key][] = var_export( $val, TRUE );
		}
	}

	foreach ( $comment_filters as $name => $arr_vals )
	{
		$out .= "<h2 id=$name>$name</h2><pre>" . implode( "\n\n", $arr_vals ) . '</pre>';
		$toc .= "<li><a href='#$name'>$name</a></li>";
	}

	print "$h1$toc</ul>$out";
}