re = /(?<!(;|^))(?!"(;|$))"/m
str = '1;200;345;"Apotheker "Blue tongue"";"Apeldoorn";12;"ABCD12"
2;232;312;"Café "Blue Oyster";"Rotterdam";33;"DCBA21"
"aul";1;200;"aap"noot";"cafe "\'t hoekje"";piet'
# 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