--git-dir::
Show `$GIT_DIR` if defined else show the path to the .git directory.
+--is-inside-git-dir::
+ Return "true" if we are in the git directory, otherwise "false".
+ Some commands require to be run in a working directory.
+
--short, --short=number::
Instead of outputting the full SHA1 values of object names try to
abbreviate them to a shorter unique name. When no length is specified