re = /.*scan=(\d+)$/
str = 'mzspec=20161213_NGHF_DBJ_SA_Exp3A_HeLa_1ug_7min_15000_02.raw: controllerType=0 controllerNumber=1 scan=2'
# Print the match result
str.match(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