Validate if a string in NSTextField is a valid IP address OR domain name

Question

I have an NSTextField where I am asking a user to input a string that is either in IPv4 format, or a domain name such as www.example.com. Currently, my code is:

@IBAction func verifyTarget(sender: NSTextFieldCell) {
    var txtTarget: NSTextFieldCell = sender

    var strRawTarget: String? = txtTarget.stringValue
    println("Input: " + strRawTarget!)
    var URLTarget: NSURL?

    URLTarget = NSURL.URLWithString(strRawTarget)
    if URLTarget {
        println("URL \(URLTarget) is valid!")
    }
    else {
        println("URL \(strRawTarget) is not valid!")
    }
}

Some example output:

Input: 
URL  is valid!
Input: adsfasdf
URL adsfasdf is valid!
Input: afe12389hfs. . afopadsf
URL afe12389hfs. . afopadsf is not valid!
Input: 192.292.111.3
URL 192.292.111.3 is valid!
Input: 0.a.0.a
URL 0.a.0.a is valid!
Input: %2
URL %2 is not valid!
Input: %20
URL %20 is valid!

Am I doing something wrong?

Answer 1

Check if IP address is IPv4 or IPv6 in Swift

func validateIpAddress(ipToValidate: String) -> Bool {

    var sin = sockaddr_in()
    var sin6 = sockaddr_in6()

    if ipToValidate.withCString({ cstring in inet_pton(AF_INET6, cstring, &sin6.sin6_addr) }) == 1 {
        // IPv6 peer.
        return true
    }
    else if ipToValidate.withCString({ cstring in inet_pton(AF_INET, cstring, &sin.sin_addr) }) == 1 {
        // IPv4 peer.
        return true
    }

    return false;
}

Answer 2

The new Network framework has failable initializers for struct IPv4Address and struct IPv6Address which handle the IP address portion very easily. Doing this in IPv6 with a regex is tough with all the shortening rules.

Unfortunately I can't address the domain name part.

Note that Network framework is recent, so it may force you to compile for recent OS versions.

    import Network
let tests = ["192.168.4.4","fkjhwojfw","192.168.4.4.4","2620:3","2620::33"]

for test in tests {
    if let _ = IPv4Address(test) {
        debugPrint("\(test) is valid ipv4 address")
    } else if let _ = IPv6Address(test) {
        debugPrint("\(test) is valid ipv6 address")
    } else {
        debugPrint("\(test) is not a valid IP address")
    }
}

output:
"192.168.4.4 is valid ipv4 address"
"fkjhwojfw is not a valid IP address"
"192.168.4.4.4 is not a valid IP address"
"2620:3 is not a valid IP address"
"2620::33 is valid ipv6 address"