debug_filters()

debug_filters.php

<?php

/**
 * @param string $tag The hook name
 */
function debug_filters( $tag = false ) {
	global $wp_filter;

	if ( $tag ) {
		$hook[ $tag ] = $wp_filter[ $tag ];

		if ( !is_array( $hook[ $tag ] ) ) {
			trigger_error("Nothing found for '$tag' hook", E_USER_NOTICE);
			return;
		}
	}
	else {
		$hook = $wp_filter;
		ksort( $hook );
	}

	echo '<pre>';
	foreach ( $hook as $tag => $priority ) {
		echo "<br />&gt;&gt;&gt;&gt;&gt;\t<strong>$tag</strong><br />";
		ksort( $priority );
		foreach ( $priority as $priority => $function ) {
			echo $priority;
			foreach( $function as $name => $properties )
				echo "\t$name<br>\n";
		}
	}
	echo '</pre>';
}