re = /href=["']https?:\/\/(?<hostname>[^\/]+)[^>]+>(?:https?:\/\/)?\k'hostname'/i
str = '<A HREF="http://phishers.org/we_want_your_money.htm">http://someLegitimateSite.com/somewhere </A>
<a href="https://example.com/subfolder">example.com</a>
<a href="http://somebadsite.com">https://somegoodsite.com</a>
'
# 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