Obfuscated printing of "wat"

history_of_shortening.rb

# ruby -e '$.-=~$.;$_=-~$.<<-~-~-~$.;$:<<$_|=$_<<$.;$_|=$_>>$.;$:.<<(-~$.<<$.);$>.<<$/[$....$.]<<$_+$:[-$.]+-~$.+$.<<$:[~$.]+$.<<$_+$:[-$.]<<$/'
# ruby -e '$.-=~$.;$_=-~$.<<-~-~-~$.;$:<<$_|=$_<<$.;$_|=$_>>$.;$:<<(-~$.<<$.);$>.<<$/[$....$.]<<$_+$:[-$.]+-~$.+$.<<$:[~$.]+$.<<$_+$:[-$.]<<$/'
# ruby -e '$.-=~$.;$_=-~$.<<-~-~-~$.;$:<<$_|=$_<<$.;$_|=$_>>$.;$:<<-~$.*-~$.;$>.<<$/[$....$.]<<$_+$:[-$.]+-~$.+$.<<$:[~$.]+$.<<$_+$:[-$.]<<$/'
# ruby -e '$.-=~$.;$;=-~$.<<-~-~$.;$;|=$;<<$.;$:<<$;--$;;$;|=$;--$;;$:<<-~$.-~$.;$>.<<$/[$....$.]<<-~$;--$:[-$.]-~$.<<-~$:[~$.]<<-~$;-~-~$.<<$/'
# ruby -e '$.-=~$.;$;=-~$.<<-~-~$.;$;|=$;<<$.;$>.<<$/[$....$.]<<-~[$;|$;--$;][~-$.]-~$.-~$.-~$.<<-~$;--$;<<-~[$;|$;--$;][~-$.]-~-~$.<<$/'
# ruby -e '$;=$.-=~-~$.;$.<<=$.;$;=--~-$.<<-~-~$;;$>.<<$/[$.-$....$.-$.]<<$;--~-$.<<-~$;-$.-$.<<-~-~-~-~$;<<$/'

require 'stringio'
$stdout = StringIO.new
eval(code=DATA.read.strip)
$stdout.string # => "wat\n"

code.chars.length + "ruby -e''".length # => 108
code.chars.uniq                        # => ["$", ";", "=", ".", "-", "~", "<", ">", "/", "[", "]"]
          .length                      # => 11

__END__
$;=$.-=~-~$.;$.<<=$.;$;=--~-$.<<-~-~$;;$>.<<$/[$.-$....$.-$.]<<$;--~-$.<<-~$;-$.-$.<<-~-~-~-~$;<<$/

other-forms.sh

# Tweeted as https://twitter.com/josh_cheek/status/765261304231628800
ruby -e '$.-=~$.;$_=-~$.<<-~-~-~$.;$:<<$_|=$_<<$.;$_|=$_>>$.;$:<<(-~$.<<$.);$><<(""<<$_+$:[-$.]+-~$.+$.<<$:[~$.]+$.<<$_+$:[-$.]<<$/)'

# Since improved to this
# * removed these chars: |_():+"
# * added 4 periods in a row
# * confusing semicolons
# * If there was a way to get an empty string, I could also get rid of the brackets
ruby -e '$;=$.-=~-~$.;$.<<=$.;$;=--~-$.<<-~-~$;;$>.<<$/[$.-$....$.-$.]<<$;--~-$.<<-~$;-$.-$.<<-~-~-~-~$;<<$/'

wat.rb

$\=$/[$....$.]
$.-=~$.
$_=-~$.<<-~-~-~$.
$:<<$_|=$_<<$.
$_|=$_>>$.
$:<<-~$.*-~$.
$>.<<$\<<$_+$:[-$.]-~$.+$.<<$:[~$.]+$.<<$_+$:[-$.]<<$/

# >> wat