re = /^(.*?)(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?(?:;(.+?))?$/mix
str = '1.jpg;2.jpg;3.jpg;4.jpg;5.jpg;6.jpg;7.jpg;8.jpg;9.jpg;10.jpg;11.jpg;12.jpg;13.jpg;14.jpg;15.jpg;16.jpg;17.jpg;18.jpg;19.jpg;20.jpg'
# 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