list directory contents

-a     Write out all directory entries, including those whose names begin with a period ( '.' ).  Entries
       beginning  with  a  period shall not be written out unless explicitly referenced, the -a option is
       supplied, or an implementation-defined condition shall cause them to be written.

-l     (The  letter  ell.) Do not follow symbolic links named as operands unless the -H or -L options are
       specified. Write out in long format (see the STDOUT section). When -l (ell) is specified, -1 (one)
       shall be assumed.