re = /<a.*?href='(.*?)'.*?<\/a>/
str = '<h1 class=\'blablabla\'><a class=\'Title\' href=\'https://www.url.com\' rel=\'rel\'>blablabla</a></h1>
'
# 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