Display HEAD pointer
$ cat .git/HEAD ref: refs/heads/foo1
Display HEAD pointer (detached head case)
$ cat .git/HEAD 1fd2aa6a8ff7205c91fde3d9557c6d67eeaf4eb1
$ cat .git/HEAD ref: refs/heads/foo1
$ cat .git/HEAD 1fd2aa6a8ff7205c91fde3d9557c6d67eeaf4eb1