list contents of directory

-l     List  in  long  format,  giving  mode (see below), file system type (e.g., for devices, the # code
       letter that names it; see intro(3)), the instance or  subdevice  number,  owner,  group,  size  in
       bytes, and time of last modification for each file.

-t     Sort by time modified (latest first) instead of by name.

-r     Reverse the order of sort.