re = /Source:\s*\K.+\b/m
str = 'Art 1 This is article one. Source: The Guardian.
Art 2 This is article two. Source: New York Times.
Art 3 This is article three. Source: The Washington Post.
'
# 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