DNS IP Address Lookup from Host name in Swift

dnsLookup.swift

import UIKit

// You many want to run this in the background
func getIPs(dnsName: String) -> String? {
    let host = CFHostCreateWithName(nil, dnsName as CFString).takeRetainedValue()
    CFHostStartInfoResolution(host, .addresses, nil)
    var success: DarwinBoolean = false
    if let addresses = CFHostGetAddressing(host, &success)?.takeUnretainedValue() as NSArray? {
        for case let theAddress as NSData in addresses {
            var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
            if getnameinfo(theAddress.bytes.assumingMemoryBound(to: sockaddr.self), socklen_t(theAddress.length),
                           &hostname, socklen_t(hostname.count), nil, 0, NI_NUMERICHOST) == 0 {
                let numAddress = String(cString: hostname)
                return numAddress
            }
        }
    }
    
    return nil
}

print(getIPs(dnsName: "HostName"))

Nice.
However, this is actually only returning one ip address, even if there's multiple.

You could return an array of addresses populated from the numAddress in line 14 or rename the function to getIP depending on your use-case.