Re: license relaxation request

[Eric Blake]

On 10/17/2011 05:58 PM, Bruno Haible wrote:
> Hi Eric,
>
> > Can we relax the license of the following modules from LGPLv3+ down to
> > LGPLv2+, so that libvirt can use them, and on the grounds that they are
> > shipped as part of LGPLv2+ glibc?
> >
> > grantpt
> > unlockpt
> > pt_chown
> > ptsname
> > ttyname_r
>
> This is fine with me. ttyname_r is written by me, not from glibc, and I'm
> not sure the code in glibc would help if someone would want to reimplement it.
> But fine with me.
>
> > I'm also planning on adding a posix_openpt module.
>
> This is not needed. As you can see from the code in lib/openpt.c,
> posix_openpt() is one part of openpty(). Since we have an openpty() that
> works on all Unix platforms, and openpty() comes from the glibc API,
> why should anyone want to use posix_openpt()?

Libvirt is currently using open("/dev/ptmx", flags), which is great on 
Linux but not portable.  posix_openpt() is the portable alternative to 
this, which works when you want to do things with just the master side 
without opening the slave side; and while openpty() is available and 
relatively portable, it is not POSIX, and the gnulib version is 
currently LGPLv3+.  Besides, openpty needs -lpty on some platforms, 
while posix_openpt() should not.

On the other hand, you have a point - there's not much to do with the 
master side unless you also plan on opening the slave side, at which 
point openpty() abstracts away a lot of the pieces in building up the pair.

--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org