OK, you want to parse PDFs with PHP and just put out the content.
In PHP itself there is no such function. You either have to search google if somebody ever programmed such a function or you have to use a programm on OS-Level and call this Program with system() or exec(). On Sourceforge there is an Experimental Program called pdftohtml: http://sourceforge.net/projects/pdftohtml/
You would have to compile this on your Computer, then running it from PHP and forward the created Ressources to the user.