of a username:
            http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap03.html#tag_03_426
            http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap03.html#tag_03_276

            Falls back to 'current working directory' as we assume 'home is where the remote user ends up'
        ú