finding foreign keys

Can anyone suggest a more elegant way of finding foreign keys than
parsing the tgargs value returned by this query? I'd really rather do
pure SQL, sans string parsing, if possible.

------------------------------------------------------------------------
-- Find tables and foreign keys

CREATE VIEW foreignkeysa AS
SELECT t.oid as toid,
c1.relname AS relid,
c2.relname AS constrrelid,
t.tgargs AS tgargs

FROM pg_trigger AS t,
pg_class AS c1,
pg_class AS c2

WHERE t.tgrelid=c1.oid AND
t.tgconstrrelid=c2.oid AND
t.tgfoid=1644;
------------------------------------------------------------------------

-Ron-