Rails 3: Validate IP String

Question

In Rails 3, is there a built in method for seeing if a string is a valid IP address?

If not, what is the easiest way to validate?

Answer 1

You can also just call standard's library IPAddr.new that will parse subnets, IPV6 and other cool things: (IPAddr) and return nil if the format was wrong.

Just do:

valid = !(IPAddr.new('192.168.2.0/24') rescue nil).nil?  
#=> true

valid = !(IPAddr.new('192.168.2.256') rescue nil).nil?  
#=> false

Answer 2

Just wanted to add that instead of writing your own pattern you can use the build in one Resolv::IPv4::Regex

require 'resolv'

validates :gateway, :presence => true, :uniqueness => true,
  :format => { :with => Resolv::IPv4::Regex }

Answer 3

You can use Resolv::IPv4::Regex as Jack mentioned below if you don't need to accept subnets.

If you need to accept it, activemodel-ipaddr_validator gem may help you. (disclaimer: I'm the author of the gem)

validates :your_attr, ipaddr: true

Answer 4

You can also use Regexy::Web::IPv4 which can match ip addresses with port numbers too.

Answer 5

i dont know about RoR a lot, but if you dont find any built in method for validation of IP Address.

Try on this regular expression :

"^([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(\.([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}$"

to validate the IP Address.

I recently used it in one module so had it on desktop.

Answer 6

You should use a Regular Expression

Here is one that does what you want:

/^([1-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(\.
([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}$/.match("#{@systemIP}")