Calcuate the union, intersection, set difference and so forth of files considered as sets of lines

Usage: zet [OPTIONS] <COMMAND> <PATH...>

Commands:
  union      Prints lines appearing in ANY input file
  intersect  Prints lines appearing in EVERY input file
  diff       Prints lines appearing in the FIRST input file and no other
  single     Prints lines appearing exactly once; with --file, in exactly one file
  multiple   Prints lines appearing more than once; with --files, in more than one file
  help       Print this message

Options:
      --count-lines   Show the number of times each line occurs in the input
      --count-files   Show the number of files each line occurs in
  -c  --count         Like --count-lines, but if --files is present, like --count-files
      --file[s]       To count as multiple, a line must occur in more than one file. Affects the single and multiple commands, as well as the -c and --count options
      --color <WHEN>  [possible values: auto, always, never]
  -h, --help          Print this message
  -V, --version       Print version

Each line is output at most once, no matter how many times it occurs in the input. Lines are printed in the order they occur in the input.

Similar to:
  union      uniq
  intersect  comm -12
  diff       comm -23
  single     uniq -u
  multiple   uniq -d
