includes and filenames

Hi. This is my setup. I have a PHP file that pulls in two includes - content and footer. content is done with readfile() since no processing done (in most cases). footer in done with include() - or will be once i find an answer to my question. currently the footer is exactly the same for each page. i want to add a dynamic link that uses the filename of the includer file. in effect i want a function that will find the filename of the includer file and past it into a link. something like this would appear in the include file. $path = filename [this is a function or functions that find the filename of the file accessing the include file, footer.txt] text text text <A href="http://validator.w3.org/check?uri=.$path>text</a> I want to tack the value of $path onto the end of the first part of the HREF. How can I do this? travis