What is Copyleft?

[Ian Lance Taylor]

"Rod Dixon, J.D., LL.M." <rod at cyberspaces.org> writes:

> I don't understand your last sentence, and it sounds as if you might be
> making an important distinction. I am confused by your reference to linked
> to static version and "unlinked objects." How could both be occurring with
> the same library?

The paragraph in question:

> > So, since glibc is available as a dynamic library, most uses of glibc
> > do not conflict with the LGPL.  The only way to conflict would be link
> > against the static version of glibc and distribute the resulting
> > binary without distributing the unlinked objects.

glibc is distributed as both a dynamic library (libc.so) and a static
library (libc.a).

The LGPL says that if you distributed a binary linked with a static
library, you must also distribute, in addition, the unlinked objects.
That way, if the library is updated, the recipient will be able to
relink against the new version of the library, producing a new binary.

You are correct that one would not normally have both a binary linked
to a static library, and unlinked objects.  The LGPL, however, says
that you must provide both.

Does that make more sense?  I've been working with linker internals
for so long that I'm no longer sure what is general knowledge and what
is weird stuff that only a few people know.

Ian