Test the ls command. Duplicated Option types are not tested e.g. -a and -d are the same Option type.

The following is the man output for 'ls'. See http://www.rt.com/man/ls.1.html.

  LS(1) FSF LS(1)

  NAME ls - list directory contents

  SYNOPSIS ls [OPTION]... [FILE]...

  DESCRIPTION List information about the FILEs (the current directory by default). Sort entries alphabetically if none of -cftuSUX nor --sort.

  -a, --all do not hide entries starting with .

  -A, --almost-all do not list implied . and ..

  -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 sort by change time; with -l: show 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, sin- gle-column -1, verbose -l, vertical -C

  --full-time list both full date and full time -g (ignored)

  -G, --no-group inhibit display of group information

  -h, --human-readable print sizes in human readable format (e.g., 1K 234M 2G)

  -H, --si likewise, but use powers of 1000 not 1024

  --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, --kilobytes like --block-size=1024 -l use a long listing format

  -L, --dereference list entries pointed to by symbolic links -m fill width with a comma separated list of entries

  -n, --numeric-uid-gid list numeric UIDs and GIDs instead of names

  -N, --literal print raw entry names (don't treat e.g. control characters specially) -o use long listing format without group info

  -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)

  -Q, --quote-name enclose entry names in double quotes

  --quoting-style=WORD use quoting style WORD for entry names: literal, 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 -t sort by modification time

  -T, --tabsize=COLS assume tab stops at each COLS instead of 8 -u sort by last access time; with -l: show atime -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

  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 con- nected to a terminal (tty).