re = /example.com\/(?!fr|FR)/m
str = 'example.com/fr/products/lighting
example.com/fr/products/kitchen
example.com/FR/products
example.com/de/products/lighting
example.com/it
example.com/en/products/outdoor-furniture'
# 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