path of the top-level directory relative to the current
directory (typically a sequence of "../", or an empty string).
+--git-dir::
+ Show `$GIT_DIR` if defined else show the path to the .git directory.
+
+--short, short=number::
+ Instead of outputting the full SHA1 values of object names try to
+ abbriviate them to a shorter unique name. When no length is specified
+ 7 is used. The minimum length is 4.
+
--since=datestring, --after=datestring::
Parses the date string, and outputs corresponding
--max-age= parameter for git-rev-list command.