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Can anyone suggest me the method in objective c to get IP address of iPhone device when device is connected to WiFi.

Basically I wanted to know is there any other way apart from getifaddrs(&interfaces) to retrieve the IP address of the device when it is connected to WiFi?

David Ansermot
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rishu1992
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    What is the reason to find an alternate solution for that? Are you facing any shortcoming in the `getifaddrs(&interfaces)` method? If so, please include that in your question. – Gandalf Apr 17 '15 at 11:32
  • I'm facing this problem. http://stackoverflow.com/questions/29676138/ioscrash-in-64-bit-device – rishu1992 Apr 17 '15 at 11:39
  • that's weird. I have been using the same technique to get ip address of my 64 bit devices and it works perfectly. Have you tried it on some other 64 bit device? Perhaps something wrong with that specific device. – Gandalf Apr 17 '15 at 12:34
  • It works fine if i move the method to appdelegate class or any other class. This was crashing when I called the method from same class where i need ip address. Guessed that could be memory issue! – rishu1992 Apr 17 '15 at 13:15

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Getting information about network interfaces in Unix type systems like iOS or Mac OS X requires using some arcane C APIs. These APIs have varying amounts of visibility in and , and .

If you're exclusively targeting macOS with Objective-C, then is your best solution. However, if you require iOS compatibility then you'll have to drop down to lower level C API such as getifaddrs(...) or .

If you want a based solution even getifaddrs(...) comes with some bridging header requirements (making it unusable in a Framework).

Here is an example using CFHost and sockaddr_in struct that will work in Swift and on macOS and iOS (even in Frameworks). See Host.swift for a fully working example.

  1. Use CFHost to get the addressing info, this will be a CFArray of CFData objets.

    let sockaddrs = CFHostGetAddressing("apple.com", &resolved)?.takeRetainedValue()

  2. Get the first object

    let data = CFArrayGetValueAtIndex(sockaddrs, 0)

  3. Cast the bytes into a sockaddr struct

    var storage = sockaddr_storage()
data.getBytes(&storage, length: sizeof(sockaddr_storage))

  4. Then force the sockaddr struct into a sockaddr_in struct so we can use it

    let addr = withUnsafePointer(&storage) { UnsafePointer<sockaddr_in>($0).memory

  5. Use the inet_ntoa(...) function to turn addr.sin_addr (IP address) into a C-string. We can then use String(Cstring: encoding:) to get a nice String of the IP Address.

    let address = String(CString: inet_ntoa(addr.sin_addr), encoding: NSUTF8StringEncoding)

Here is a GitHub project called Hostess.swift that I created to solve these issues using the technique above.

Richard Stelling
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  • Can I ask you to please [How to offer personal open-source libraries?](https://meta.stackexchange.com/q/229085)? You've copied and pasted this to a lot of different places. – Martijn Pieters May 24 '16 at 19:53