re = /^((?![!?$]*[^!?$]))?(?:[^!]\2?+(?=(!*)(\\\3?+.(?!\3)))){4}(?(1)|Ha! No one will ever get this one...)|(?!(?1))\Q\1?!($!?)?\E\1?!($!?)?(?<!.{12})\Q(?=(?1))\E(?=(?1))!\?$/
str = ''
# Print the match result
str.match(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html