$ ls --help
Usage: ls [OPTION]... [FILE]...
List information about the FILEs (the current directory by default).
Sort entries alphabetically if none of -cftuSUX nor --sort.
 
Mandatory arguments to long options are mandatory for short options too.
  -a, --all                  do not hide entries starting with .
  -A, --almost-all           do not list implied . and ..
      --author               print the author of each file
  -b, --escape               print octal escapes for nongraphic characters
      --block-size=SIZE      use SIZE-byte blocks
  -B, --ignore-backups       do not list implied entries ending with ~
  -c                         with -lt: sort by, and show, ctime (time of last
                               modification of file status information)
                               with -l: show ctime and sort by name
                               otherwise: sort by ctime
  -C                         list entries by columns
      --color[=WHEN]         control whether color is used to distinguish file
                               types.  WHEN may be `never', `always', or `auto'
  -d, --directory            list directory entries instead of contents
  -D, --dired                generate output designed for Emacs' dired mode
  -f                         do not sort, enable -aU, disable -lst
  -F, --classify             append indicator (one of */=@|) to entries
      --format=WORD          across -x, commas -m, horizontal -x, long -l,
                               single-column -1, verbose -l, vertical -C
      --full-time            like -l --time-style=full-iso
  -g                         like -l, but do not list owner
  -G, --no-group             inhibit display of group information
  -h, --human-readable  print sizes in human readable format (e.g., 1K 234M 2G)
      --si                   likewise, but use powers of 1000 not 1024
  -H, --dereference-command-line  follow symbolic links on the command line
      --indicator-style=WORD append indicator with style WORD to entry names:
                               none (default), classify (-F), file-type (-p)
  -i, --inode                print index number of each file
  -I, --ignore=PATTERN       do not list implied entries matching shell PATTERN
  -k                         like --block-size=1K
  -l                         use a long listing format
  -L, --dereference          when showing file information for a symbolic
                               link, show information for the file the link
                               references rather than for the link itself
  -m                         fill width with a comma separated list of entries
  -n, --numeric-uid-gid      like -l, but list numeric UIDs and GIDs
  -N, --literal              print raw entry names (don't treat e.g. control
                               characters specially)
  -o                         like -l, but do not list group information
  -p, --file-type            append indicator (one of /=@|) to entries
  -q, --hide-control-chars   print ? instead of non graphic characters
      --show-control-chars   show non graphic characters as-is (default
                             unless program is `ls' and output is a terminal)
  -Q, --quote-name           enclose entry names in double quotes
      --quoting-style=WORD   use quoting style WORD for entry names:
                               literal, locale, shell, shell-always, c, escape
  -r, --reverse              reverse order while sorting
  -R, --recursive            list subdirectories recursively
  -s, --size                 print size of each file, in blocks
  -S                         sort by file size
      --sort=WORD            extension -X, none -U, size -S, time -t,
                               version -v
                             status -c, time -t, atime -u, access -u, use -u
      --time=WORD            show time as WORD instead of modification time:
                               atime, access, use, ctime or status; use
                               specified time as sort key if --sort=time
      --time-style=STYLE     show times using style STYLE:
                               full-iso, long-iso, iso, locale, +FORMAT
                             FORMAT is interpreted like `date'; if FORMAT is
                             FORMAT1<newline>FORMAT2, FORMAT1 applies to
                             non-recent files and FORMAT2 to recent files;
                             if STYLE is prefixed with `posix-', STYLE
                             takes effect only outside the POSIX locale
  -t                         sort by modification time
  -T, --tabsize=COLS         assume tab stops at each COLS instead of 8
  -u                         with -lt: sort by, and show, access time
                               with -l: show access time and sort by name
                               otherwise: sort by access time
  -U                         do not sort; list entries in directory order
  -v                         sort by version
  -w, --width=COLS           assume screen width instead of current value
  -x                         list entries by lines instead of by columns
  -X                         sort alphabetically by entry extension
  -1                         list one file per line
      --help     display this help and exit
      --version  output version information and exit
 
SIZE may be (or may be an integer optionally followed by) one of following:
kB 1000, K 1024, MB 1,000,000, M 1,048,576, and so on for G, T, P, E, Z, Y.
 
By default, color is not used to distinguish types of files.  That is
equivalent to using --color=none.  Using the --color option without the
optional WHEN argument is equivalent to using --color=always.  With
--color=auto, color codes are output only if standard output is connected
to a terminal (tty).
 
Report bugs to <bug-fileutils@gnu.org>.