Validation for URL/Domain using Regex? (Rails)

I am trying to create a validation that checks to make sure a domain/url is valid for example "test.com" def valid_domain_name? domain_name = domain.split(".") name = /(?:[A-Z0-9\-])+/.match(domain_name[0]).nil? tld = /(?:[A-Z]{2}|aero|ag|asia|at|be|biz|ca|cc|cn|com|de|edu|eu|fm|gov|gs|jobs|jp|in|info|me|mil|mobi|museum|ms|name|net|nu|nz|org|tc|tw|tv|uk|us|vg|ws)/.match(domain_name[1]).nil? if nam