[lug] LGPL question

[Ed Hill]

On Tue, 2003-03-04 at 15:52, Michael J. Hammel wrote:
> Something that I can never remember the rules to:
> 
> Can you link a static library that is LGPL to a non-free program without
> the license "infecting" the non-free program?  Does the library have to
> be shared in order for the program to be linked to a LGPL library (I
> know doing this with a shared library works fine - that's why libc can
> be used with proprietary apps)?  If it must be a shared library, can you
> dlopen() an LGPL static library from within a non-free program without
> the LGPL affecting that program?


Hi Michael,

Good question!

I'd love to see this discussed in greater detail since I'm still a bit
fuzzy on the LGPL (versus GPL) license terms.  According to the text at:

  http://www.gnu.org/licenses/lgpl.html

Section 6 says that you "may also combine or link a 'work that uses the
Library'" provided that you meet one of five (a--e) different options. 
To paraphrase, those five options are:

  a) statically link the LGPL'ed library with your code and then 
     provide enough of your source code so that one may both re-
     compile and then re-link with the LGPL'ed library in order 
     to produce a new executable

  b) "Use a suitable shared library mechanism for linking"

  c--e) essentially, make the source code available


So, as I read it, dynamic linking is fine and static linking is possible
if you provide enough of your source code (some sort of wrapper?) so
that a user can re-compile and re-link.

Or am I missing something?

Ed


-- 
Edward H. Hill III, PhD 
Post-Doctoral Researcher   |  Email:  ed at eh3.com,  ehill at mines.edu
Division of ESE            |  URLs:   http://www.eh3.com
Colorado School of Mines   |    http://cesep.mines.edu/people/hill.htm
Golden, CO  80401          |  Phones:  303-384-2094, 303-273-3483
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL: <http://lists.lug.boulder.co.us/pipermail/lug/attachments/20030304/f0053798/attachment.pgp>