-C     Write multi-text-column output with entries sorted down the columns, according  to  the  collating
       sequence.  The  number  of  text  columns and the column separator characters are unspecified, but
       should be adapted to the nature of the output device.

-F     Do not follow symbolic links named as operands unless the -H or -L options are specified. Write  a
       slash  ( '/' ) immediately after each pathname that is a directory, an asterisk ( '*' ) after each
       that is executable, a vertical bar ( '|' ) after each that is a FIFO, and an at sign ( '@' ) after
       each that is a symbolic link. For other file types, other symbols may be written.

-H     If a symbolic link referencing a file of type directory is specified on the command line, ls shall
       evaluate the file information and file type to be those of the file referenced by  the  link,  and
       not  the  link  itself;  however,  ls  shall  write  the  name of the link itself and not the file
       referenced by the link.

-L     Evaluate the file information and file type for all symbolic links (whether named on  the  command
       line  or  encountered in a file hierarchy) to be those of the file referenced by the link, and not
       the link itself; however, ls shall write the name of the link itself and not the  file  referenced
       by the link. When -L is used with -l, write the contents of symbolic links in the long format (see
       the STDOUT section).

-R     Recursively list subdirectories encountered.

-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.

-c     Use time of last modification of the file status  information  (see  <sys/stat.h>  in  the  System
       Interfaces  volume  of  IEEE Std 1003.1-2001)  instead of last modification of the file itself for
       sorting ( -t) or writing ( -l).

-d     Do not follow symbolic links named as operands unless the -H or -L options are specified.  Do  not
       treat  directories  differently  than  other  types  of  files.  The  use  of  -d with -R produces
       unspecified results.

-f     Force each argument to be interpreted as a directory and list the name found in  each  slot.  This
       option  shall  turn  off -l, -t, -s, and -r, and shall turn on -a; the order is the order in which
       entries appear in the directory.

-g     The same as -l, except that the owner shall not be written.

-i     For each file, write the file's file serial number (see stat() in the System Interfaces volume  of
       IEEE Std 1003.1-2001).

-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.

-m     Stream output format; list files across the page, separated by commas.

-n     The  same  as  -l,  except  that the owner's UID and GID numbers shall be written, rather than the
       associated character strings.

-o     The same as -l, except that the group shall not be written.

-p     Write a slash ( '/' ) after each filename if that file is a directory.

-q     Force each instance of non-printable filename characters and <tab>s to be written as the question-
       mark  (  '?' ) character. Implementations may provide this option by default if the output is to a
       terminal device.

-r     Reverse the order of the sort to get reverse collating sequence or oldest first.

-s     Indicate the total number of file system blocks consumed by each file displayed. The block size is
       implementation-defined.

-t     Sort with the primary key being time modified (most recently modified first) and the secondary key
       being filename in the collating sequence.

-u     Use time of last access (see <sys/stat.h>) instead of last modification of the file for sorting  (
       -t) or writing ( -l).

-x     The  same  as -C, except that the multi-text-column output is produced with entries sorted across,
       rather than down, the columns.

-1     (The numeric digit one.) Force output to be one entry per line.