[uf-discuss] [citation] url field

[Alf Eaton]

Ross Singer wrote:
> Also, where do get that Jon Udell's Library Lookup 'is reliably
> extracting ISBNs from URLs'?  LibraryLookup finds ISBNs in /HTML/ and
> writes a URL to a library catalog based on it.

LibraryLookup does actually get the ISBN from the URL: it looks for
([\/-]|is[bs]n=)(\d{7,9}[\dX])

This means it only works on some URLs (Amazon, isbn.nu) and not others
(Barnes and Noble). The regexp could be adapated to cover more cases,
but it's debatable whether it could cover every URL that anyone might
use to identify any kind of work.

If you could fetch the resource identified by the URL/URI and it would
return metadata about itself, that would be another story...

alf.