function exec_php($matches){

eval('ob_start();'.$matches[1].'$inline_execute_output = ob_get_contents();ob_end_clean();');

return $inline_execute_output;

}

function inline_php($content){

$content = preg_replace_callback('/[exec]((.|n)*?)[/exec]/', 'exec_php', $content);

$content = preg_replace('/[exec off]((.|n)*?)[/exec]/', '$1', $content);

return $content;

}

add_filter('the_content', 'inline_php', 0);