func wifi_info() -> String? {
    let connection = xpc_connection_create_mach_service("com.apple.nehelper", nil, 2)
    xpc_connection_set_event_handler(connection, { _ in })
    xpc_connection_resume(connection)
    let xdict = xpc_dictionary_create(nil, nil, 0)
    xpc_dictionary_set_uint64(xdict, "delegate-class-id", 10)
    xpc_dictionary_set_uint64(xdict, "sdk-version", 1) // may be omitted entirely
    xpc_dictionary_set_string(xdict, "interface-name", "en0")
    let reply = xpc_connection_send_message_with_reply_sync(connection, xdict)
    if let result = xpc_dictionary_get_value(reply, "result-data") {
        let ssid = String(cString: xpc_dictionary_get_string(result, "SSID"))
        let bssid = String(cString: xpc_dictionary_get_string(result, "BSSID"))
        return "SSID: \(ssid)\nBSSID: \(bssid)"
    } else {
        return nil
    }
}