ISO a tool that combines many HTML files into one
I'm finishing up a documentation project which produced about three dozen HTML files. Now the client says he wants the content delivered in a single PDF.
I'd like to do this by creating a file that says in effect, "include this HTML file, then this one, then this one,..." A tool will read this file, assemble all of HTML files into one big HTML file, and resolve all of the cross-links (links from one HTML file to another) into internal links (links from one part of the combined HTML to another). Then I can convert the combined HTML file to a PDF.
My object is not so much to create the PDF file more efficiently, as to avoid having to update two parallel versions of the content once I've done so. If I had this tool I could regenerate the PDF in a couple of steps whenever an HTML file changes.
Does such a tool exist?