Question

I’m trying to read metadata attached to arbitrary PDFs: title, author, subject, and keywords.

Is there a PHP library, preferably open-source, that can read PDF metadata? If so, or if there isn’t, how would one use the library (or lack thereof) to extract the metadata?

To be clear, I’m not interested in creating or modifying PDFs or their metadata, and I don’t care about the PDF bodies. I’ve looked at a number of libraries, including FPDF (which everyone seems to recommend), but it appears only to be for PDF creation, not metadata extraction.

Answer 1

The Zend framework includes Zend_Pdf, which makes this really easy:

$pdf = Zend_Pdf::load($pdfPath);

echo $pdf->properties['Title'] . "\n";
echo $pdf->properties['Author'] . "\n";

Limitations: Works only on files without encryption smaller then 16MB.