Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
select any dictionary - this will apply to sys owned tables and views.
For 12c it does NOT include SYS.USER$ (and others), you will need to grant select on that directly, but there is usually no need to do that and is not recommended.
for procedures, pacakges, functions and triggers I assume you mean you want to view the source.
with select any dictionary you can read dba_source for all of those
if you are trying to read the code by behind wrapped objects, you can't. There is no privilege that allows that, not even SYS has that authority.