--show-toplevel::
Show the absolute path of the top-level directory.
+--show-superproject-working-tree
+ Show the absolute path of the root of the superproject's
+ working tree (if exists) that uses the current repository as
+ its submodule. Outputs nothing if the current repository is
+ not used as a submodule by any project.
+
--shared-index-path::
Show the path to the shared index file in split index mode, or
empty if not in split-index mode.