Ah, I see. And I have to disappoint you, I use XML::Twig for XML processing in Perl and my own tools for XSLT stuff. I would not grep for it, instead there must be more XML-ish way of doing things. After all it's just a Node of a specific type, i.e. NodeType 'processing-instruction'. So I imagine parsing the file and retrieving the information should do the trick, i.e. walk the DOM tree. Suddenly the grepping doesn't sound so bad anymore;) Another option is to use SAX, I see a processingInstructionSAXFunc in the libxml2 API. However there is another Perl module that might come in handy: XML::LibXML::PI can't you do a getData?

Mind you, in "my" environment it's as simple as one method call: getAssociatedStylesheet()!