re = /(?<=>)([0-9]{8}.+)(?=<)/m
str = '<option value="20150110.1932.mtsat_2.visir.bckgr.NW_Pacific_Overview.DAYNGT.jpg">20150110.1932.mtsat_2.visir.bckgr.NW_Pacific_Overview.DAYNGT.jpg</option>
<option value="20150110.1901.mtsat_2.visir.bckgr.NW_Pacific_Overview.NGT.jpg">20150110.1901.mtsat_2.visir.bckgr.NW_Pacific_Overview.NGT.jpg</option>'
# 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