Re: Including just cygwin1.dll in an archive

[Christopher Faylor <me at cgf dot cx>]

On Sun, Sep 11, 2005 at 09:31:02PM +0930, David Benn wrote:
>From the cygwin Licensing terms on the web, it appears to me that I
>cannot distribute an archive that looks like this:
>
>Archive:  scope_dist.zip
>  Length     Date   Time    Name
> --------    ----   ----    ----
>        0  09-10-05 23:43   scope_dist/
>   971080  09-10-05 23:43   scope_dist/cygwin1.dll
>        0  09-10-05 23:43   scope_dist/driver/
>   121158  09-10-05 23:43   scope_dist/driver/ascom.dll
>    22297  09-10-05 23:43   scope_dist/driver/skeleton.dll
>    22706  09-10-05 23:43   scope_dist/scope_client.dll
>    22814  09-10-05 23:43   scope_dist/tests.exe
> --------                   -------
>  1160055                   7 files
>
>for end users, irrespective of whether another archive containing full
>sources, Makefiles etc is separately released. 
>
>The point of contention here is the inclusion of cygwin1.dll. This is an
>*unmodified* cygwin1.dll.

If you distribute a binary then, under the GPL, you must make the source code
available for the binary using the same method.  It doesn't have to be available
in the same archive.

Look at the way the cygwin distribution does it.  The sources are distributed
separately.

If you are actually distributing the cygwin DLL, then you need to also distribute
the sources to the DLL as well.  Again, the source code can be in a different
package.

So, in the above, you'd presumably have to provide the sources for
ascom.dll, skeleton.dll, scope_client.dll, tests.exe, and cygwin1.dll.  The
easiest way to provide the sources to the cygwin DLL is just to use the
cygwin source archives as can be downloaded from the cygwin setup.exe program.

OTOH, we usually advise against people distributing the DLL since it will cause
problems if your archive is extracted into an existing cygwin installation.  It's
usually better to just point people to the cygwin web site and have them install
what is needed*.  In that scenario, you wouldn't have to provide the sources
for the cygwin DLL but you would need to provide sources for everyting else.

>Can someone please advise me or tell me where to find out?
>
>I'd be happy to replace the need for this dll with static linking,
>assuming that's even *possible* under cygwin. If it is, a pointer would
>be appreciated. 

Static linking wouldn't buy you anything.  You'd still need to provide
the source code.

The GPL FAQ is here:  http://www.gnu.org/licenses/gpl-faq.html .  You might
want to familiarize yourself with it.

cgf

*Yes, I understand that this may install more than what you want but you
still have to take the problem of existing cygwin configurations into
account no matter what you do.