[Box Backup] GNU readline licence issue

Martin Ebourne boxbackup@fluffy.co.uk
Tue, 14 Dec 2004 12:36:05 +0000

Ben Summers <ben@fluffy.co.uk> wrote:
> On 14 Dec 2004, at 11:27, Martin Ebourne wrote:
>> From something mentioned on another list I've found that GNU readline is
>> licensed under the GPL, not the LGPL as you might have expected
> However, since the source distribution does not include readline and
> does not link to it, there may not be a problem. If you try and
> distribute a binary which links to it, there is a problem, but this is
> an issue for packagers and distributors, not for me.

I don't know the answer to that one. The implication from the readline
documentation was that it would affect programs distributed as source, but
I'm not sure if that really is the case.

I've looked into libedit a bit more. There seem to be two main versions: the
original does not have a readline compatible API, but then NetBSD have a
modified version so that it does support the readline API. The latter one
seems widespread amongst the BSDs, and it appears is even part of Gentoo,
Debian, and Mandrake linux. Mac OS X appears to have the original libedit.

If the compatible version of libedit is a complete drop in replacement for
readline (as is implied) then I think that pretty much answers the first
question; clearly there is no problem with source distribution because it
does not need to use readline, and will work perfectly well with libedit. It
might need changes to the configure script to look for (a compatible)
libedit rather than libreadline though. Maybe corresponding documentation
changes too.

As for binary packaging clearly that needs to either disable readline or link
against a compatible libedit. I'll look at making an RPM for libedit and
changing the box RPM to make use of that.