All right, great! Is it possible then to modify your script so it takes a direct link to the HTML, and not just a ZIP file?
Shouldn't be more than a couple of lines of code to check the extension of the URL/file, and if it is not ZIP, treat it as already unpacked archive? Thanks!
UPD: I see that the gutlrf.pl actually only gets and unzips the HTML, then I have to use the splitbook.pl to split it and feed it to the html2lrf. Sounds like everything is already there, no new changes required.