Quoting Simon Hobson (linux@???):

> However, without a lot of work, doesn't the ability to link mean
> pulling in some sort of interface file and "building in" that file to
> your code ?

Much depends on the particulars of a specific case, but in general the
code elements used for that purpose would tend to be adjudicated to be
'functional elements', which are not eligible for copyright coverage, as
opposed ot 'expressive elements', which are.

I don't have UK caselaw linked from my knowledgebase page posted
upthread, but do have links to the leading USA cases, which you might
find of interest. (Jurisprudence on this matter of course differs
between countries, but tends to be generally similar on account of
treaties.)

> And I suppose that then brings up ... to what extent does reading the
> interface description and then typing it out (rather than just "cp"ing
> the file) constitute copying ?

See above about the distinction between expressive and functional
elements. That distinction is one of the main ways the law enforces the
'idea/expression dichotomy': The overarching rule is that useful ideas
should be eligible for patent coverage if at all, but not copyright, and
creative expressions should be eligible for copyright coverage if at
all, and not patents.

-- 
Cheers,                       "I know there is a joke to be made with the word
Rick Moen                      asymptote, but I just can't seem to reach it."
rick@???                                           -- @j_c_fitz
McQ! (4x80)