How to parse .pdf files in Perl?

Question

How to parse .pdf files in Perl? Is perl is more efficient or should I use any other language?

Answer 1

When I want to extract text from a PDF, I feed it to pdftohtml (part of Poppler) using the -xml output option. This produces an XML file which I parse using XML::Twig (or any other XML parser you like except XML::Simple).

The XML format is fairly simple. You get a <page> element for each page in the PDF, which contains <fontspec> elements describing the fonts used and a <text> element for each line of text. The <text> elements may contain <b> and <i> tags for bold and italic text (which is why XML::Simple can't parse it properly).

You do need to use the top and left attributes of the <text> tags to get them in the right order, because they aren't necessarily emitted in top-to-bottom order. The coordinate system has 0,0 in the upper left corner of the page with down and right being positive. Dimensions are in PostScript points (72 points per inch).