Mandatory arguments to long options are mandatory for short options too.

1. a, –all do not ignore entries starting with .
2. A, –almost-all do not list implied . and ..
   1. -author with -l, print the author of each file
3. b, –escape print C-style escapes for nongraphic characters
   1. -block-size=SIZE with -l, scale sizes by SIZE when printing them;

                           e.g., '--block-size=M'; see SIZE format below

-B, –ignore-backups do not list implied entries ending with ~

1. 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, newest first

-C list entries by columns

1. -color[=WHEN] colorize the output; WHEN can be 'always' (default

                           if omitted), 'auto', or 'never'; more info below

-d, –directory list directories themselves, not their contents

1. D, –dired generate output designed for Emacs' dired mode
2. f do not sort, enable -aU, disable -ls –color
3. F, –classify append indicator (one of /⇒@|) to entries –file-type likewise, except do not append ''
   1. -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