[arch-general] Howto properly set LD_LIBRARY_PATH to /opt/trinity/lib from PKGBUILD (postbuild)

Guys, After building trinity-kdelibs, I need to create an entry and set LD_LIBRARY_PATH to /opt/trinity/lib. I manually created: '/etc/ld.so.conf.d/trinity.conf' containing "/opt/trinity/lib" and then ran ldconfig. That worked. What I need to know is how to properly do this from the kdelibs PKBUILD. I can do it by creating the file in $pkgdir, but is there a standard way to do it? Also, what about calling ldconfig after install? Is there a standard (post-install) snippet to add? Thanks. -- David C. Rankin, J.D., P.E.