This type of thing is possible in PL/SQL:

Code:
BEGIN
	FOR r IN (
		SELECT cns.table_name, cns.constraint_name
		     , cns.search_condition
		FROM   user_constraints cns
		     , user_cons_columns col
		WHERE  cns.constraint_type = 'C'
		AND    col.owner = cns.owner
		AND    col.table_name = cns.table_name
		AND    col.constraint_name = cns.constraint_name
	)
	LOOP
		DBMS_OUTPUT.PUT_LINE
		( 'ALTER TABLE ' || r.table_name ||
		 ' ADD CONSTRAINT ' || r.constraint_name ||
		 ' CHECK (' || r.search_condition || ');');
	END LOOP;
END;
However DBMS_METADATA might be a better approach.