As it turned out in the discussion, OP needs the interface address on a Mac and not on an iOS device as I thought initially. The code referenced in the question checks for the
interface name “en0”, which is the WiFi interface on the iPhone. On a Mac it makes more
sense to check for any “up-and-running” interface instead.
Therefore I have rewritten the answer. It is now a Swift translation of the code in
Detect any connected network.
getifaddrs()
is defined in <ifaddrs.h>
, which is not included by default.
Therefore you have to create a bridging header and add
#include <ifaddrs.h>
The following function returns
an array with the names of all local “up-and-running” network interfaces.
func getIFAddresses() -> [String] {
var addresses = [String]()
// Get list of all interfaces on the local machine:
var ifaddr : UnsafeMutablePointer<ifaddrs> = nil
if getifaddrs(&ifaddr) == 0 {
// For each interface ...
var ptr = ifaddr
while ptr != nil {
defer { ptr = ptr.memory.ifa_next }
let flags = Int32(ptr.memory.ifa_flags)
let addr = ptr.memory.ifa_addr.memory
// Check for running IPv4, IPv6 interfaces. Skip the loopback interface.
if (flags & (IFF_UP|IFF_RUNNING|IFF_LOOPBACK)) == (IFF_UP|IFF_RUNNING) {
if addr.sa_family == UInt8(AF_INET) || addr.sa_family == UInt8(AF_INET6) {
// Convert interface address to a human readable string:
var hostname = [CChar](count: Int(NI_MAXHOST), repeatedValue: 0)
if (getnameinfo(ptr.memory.ifa_addr, socklen_t(addr.sa_len), &hostname, socklen_t(hostname.count),
nil, socklen_t(0), NI_NUMERICHOST) == 0) {
if let address = String.fromCString(hostname) {
addresses.append(address)
}
}
}
}
}
freeifaddrs(ifaddr)
}
return addresses
}
Update for Swift 3: In addition to adopting the code to the
many changes in Swift 3,
iterating over all interfaces can now use the new generalized
sequence()
function:
func getIFAddresses() -> [String] {
var addresses = [String]()
// Get list of all interfaces on the local machine:
var ifaddr : UnsafeMutablePointer<ifaddrs>?
guard getifaddrs(&ifaddr) == 0 else { return [] }
guard let firstAddr = ifaddr else { return [] }
// For each interface ...
for ptr in sequence(first: firstAddr, next: { $0.pointee.ifa_next }) {
let flags = Int32(ptr.pointee.ifa_flags)
let addr = ptr.pointee.ifa_addr.pointee
// Check for running IPv4, IPv6 interfaces. Skip the loopback interface.
if (flags & (IFF_UP|IFF_RUNNING|IFF_LOOPBACK)) == (IFF_UP|IFF_RUNNING) {
if addr.sa_family == UInt8(AF_INET) || addr.sa_family == UInt8(AF_INET6) {
// Convert interface address to a human readable string:
var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
if (getnameinfo(ptr.pointee.ifa_addr, socklen_t(addr.sa_len), &hostname, socklen_t(hostname.count),
nil, socklen_t(0), NI_NUMERICHOST) == 0) {
let address = String(cString: hostname)
addresses.append(address)
}
}
}
}
freeifaddrs(ifaddr)
return addresses
}