Given the above, it is possible that SWI-Prolog packages and
extensions rely on the GPL, LGPL or other licenses. The predicates below
allow for registering license requirements for Prolog files and foreign
modules. The predicate license/0
reports which components from the currently configured system are
distributed under non-permissive open source licenses and therefore may
need to be replaced to suit your requirements.
- license
- Evaluate the license conditions of all loaded components. If the system
contains one or more components that are licenced under GPL-like
restrictions the system indicates this program may only be distributed
under the
GPL license as well as which components prohibit
the use of other license conditions. Likewise for for LGPL components.
- license(+LicenseId,
+Component)
- Register the fact that Component is distributed under a
license identified by LicenseId. Known license identifiers
can be listed using known_licenses/0.
A new license can be registered as a known language using a declaration
like below. The second argument defines the
category if the license, which is one of
gpl,
lgpl, permissive or proprietary.
:- multifile license:license/3.
license:license(mylicense, permissive,
[ comment('My personal license'),
url('http://www.mine.org/license.html')
]).
:- license(mylicense).
- license(+LicenseId)
- Intended as a directive in Prolog source files. It takes the current
filename and calls license/2.
- void PL_license(const
char *LicenseId, const char *Component)
- Intended for the install() procedure of foreign libraries. This call can
be made before PL_initialise().
- known_licenses
- List all licenses known to the system. This does not imply the
system contains code covered by the listed licenses. See license/2.