DECLARE
        l_cursor        integer default dbms_sql.open_cursor;
        l_cursor2       integer default dbms_sql.open_cursor;
        l_long_val      varchar2(2000);
        junk            integer;
BEGIN
        dbms_sql.parse(l_cursor,
                'select ''alter rollback segment ''||segment_name||'' shrink''
                from dba_rollback_segs where segment_name != ''SYSTEM''
                and status = ''ONLINE''',
                dbms_sql.native);
        dbms_sql.define_column(l_cursor, 1, l_long_val, 2000);
        junk := dbms_sql.execute(l_cursor);
        while dbms_sql.fetch_rows(l_cursor) > 0 loop
                dbms_sql.column_value(l_cursor, 1, l_long_val);
                dbms_sql.parse(l_cursor2, l_long_val, dbms_sql.native);
                junk := dbms_sql.execute(l_cursor2);
--              dbms_sql.close_cursor(l_cursor2);
        end loop;
        dbms_sql.close_cursor(l_cursor);
END;
/