SandBoxありの場合

import Network

func getIPAddress() {
    var address: String = ""
    var ifaddr: UnsafeMutablePointer<ifaddrs>?
    guard getifaddrs(&ifaddr) == 0 else { return }
    var ptr = ifaddr
    while ptr != nil {
        defer { ptr = ptr?.pointee.ifa_next }
        let interface = ptr?.pointee
        let addrFamily = interface?.ifa_addr.pointee.sa_family
        if addrFamily == UInt8(AF_INET) || addrFamily == UInt8(AF_INET6) {
            if String(cString: (interface?.ifa_name)!) == "en0" {
                var hostname = [CChar](repeating: 0, count: Int(NI_MAXHOST))
                let res = getnameinfo(interface?.ifa_addr,
                                      socklen_t((interface?.ifa_addr.pointee.sa_len)!),
                                      &hostname,
                                      socklen_t(hostname.count),
                                      nil,
                                      socklen_t(0),
                                      NI_NUMERICHOST)
                if res == 0 {
                    let str = String(cString: hostname)
                    if isIPAddress(str) {
                        address = str
                    }
                }
            }
        }
    }
    freeifaddrs(ifaddr)
    Swift.print(address)
}

func isIPAddress(_ address: String) -> Bool {
    let pattern = "^[\\d.]+$"
    return address.range(of: pattern, options: .regularExpression,
                         range: nil, locale: .current) != nil
}

SandBoxなしでいい場合

import Foundation

var ip: String {
    let process = Process()
    process.launchPath = "/usr/sbin/ipconfig"
    process.arguments = ["getifaddr", "en0"]

    let pipe = Pipe()
    process.standardOutput = pipe
    process.standardError = pipe
    process.launch()

    let data = pipe.fileHandleForReading.readDataToEndOfFile()
    return String(data: data, encoding: .utf8) ?? "No connection"
}

Swift：macのIP Addressを取得する

SandBoxありの場合

SandBoxなしでいい場合

参照