Parsing PDFs is not at all trivial. Search this forum for the discussions on parsing PDFs to get an idea of why. In a nutshell PDFs are really a layout standard rather than a text document standard, which is why it is possible to do things like this:
that LaTeX package displays text (e.g. email address) in the correct order, but the characters are stored in the PDF in a random order. Think about that for a minute. And now try think how a PDF parser should be able to "know" the correct character order that you see on the page: any naive file parser will only read random text.
Summary: parsing PDFs is not trivial, and not fast.
The best solution is to avoid using PDFs to store text data, and use a more suitable format (TXT, XML, ODF, etc).
