re = /\((?:[^\)\[\]]+|(?:[^\[\]\)]*\[[^\[\]\)]*\][^\[\]\)]*))*\)(?![^\[]*\])/
str = '(hello world) [oh (hello) there, (how) are you?] (hey!!) [(Uh, can you hear me?)] (Yep, [fine]) [be sure (to be)( coming (tonight) for the (party)] [(fasfj])'
# Print the match result
str.scan(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