WordPress: How do I get all the registered functions for ‘the_content’ filter

Simple function to print from the filter array?

function print_filters_for( $hook = '' ) {
    global $wp_filter;
    if( empty( $hook ) || !isset( $wp_filter[$hook] ) )
        return;

    print '<pre>';
    print_r( $wp_filter[$hook] );
    print '</pre>';
}

Call it where you need it.

print_filters_for( 'the_content' );