How To Break The GPL

[Mark Wells]

On Sat, 4 Mar 2000, David Johnson wrote:

> Ah, but the question is whether everything is a derivitive or not. If they
> are, then it is only because of provisions within the Linux and Glibc licenses
> that allow many of them to exist in their current form. In other words, if
> there were no Linux exception and the Glibc were under the GPL, then would
> Linus and Richard be able to sue SuSE for Yast? I would strongly argue that,
> regardless of license, Yast is not derived from either Linux nor Glibc.

But it _links_ to glibc, and it probably links to the kernel also.[0]  If
linking is derivation, every Linux program is derived from glibc.

> On Sat, 04 Mar 2000, Mark Wells wrote:
> > Unfortunately, while taking a principle to extremes is useful in logic,it's
> > somewhat less effective in law.  The courts frequently overrule logic in favor
> > of what seems right to them.
> 
> Of course, a judge could rule that black is white and fish are birds, and then
> get appointed to a higher seat for his daring judicial activism :-) It's much
> better to attempt an application of logic than to continually second guess what
> a court will do.

I'm not sure I agree.  The whole purpose of a license is to impose certain
legal conditions for certain uses of a copyrighted piece of code.
Therefore, the only interpretation that really matters is the court's.

> > I'm not just talking about the run-time vs. compile-time linking
> > question that's important for Java and Perl.  What about a shell script?  You
> > might call 'grep' an application, but if I use it to perform some task in a
> > Shell script it's acting more like a library.  (And my shell script itself
> > might be a library from the perspective of other applications that pipe data
> > through it.)
> 
> 99 out of a hundred, the usage of a shell script is just that, usage. Even if I
> call it from within another script, it's still just a normal use by the end
> user. That's because (nearly) everything I can do in a shell script I can do
> manually at the command prompt. 

And everything I can do in a C program I can also do manually in a
debugger.

But the use of a shell script from another script wasn't really my point.
I was talking about the use of an application (in this case, grep) from
within another program--that is, the use of an application as a _library_.
If linking is derivation (for the purposes of the GPL), every shell script
is derived from every program that it calls.  So if I use the GNU version
of grep on my machine, and I use a shell script that calls grep, I'm
linking to a GPL'd library.


[0] In any case, glibc itself links to the kernel, right?  So if the Linux
kernel were under the standard GPL with no exceptions, glibc would have to
be also, as would every Linux program that links to glibc (i.e. all of
them).