请问如何获得“esp_netif_t *esp_netif”？

我想生成一个带有 mac 地址的服务器主机名。

什么时候必须调用函数“void set_unique_hostname()”？

代码：全选
void init_my_server()  
{      
    ESP_ERROR_CHECK(nvs_flash_init());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
   
    // Register event handlers to start server when Wi-Fi is connected,
    // and stop server when disconnection happens.     
    ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &connect_handler, NULL));
    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_DISCONNECTED, &disconnect_handler, NULL));
   
    // This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
    // Read "Establishing Wi-Fi or Ethernet Connection" section in
    // examples/protocols/README.md for more information about this function.
    //
    ESP_ERROR_CHECK(example_connect());   // replace this function with "own implementation".
}


void set_unique_hostname()
{
/*
typedef enum {
    ESP_MAC_WIFI_STA,
    ESP_MAC_WIFI_SOFTAP,
    ESP_MAC_BT,
    ESP_MAC_ETH,
} esp_mac_type_t;
*/

    uint8_t get_mac[6];

    esp_err_t ret = esp_read_mac( get_mac, ESP_MAC_WIFI_STA );
   
    if( ret != ESP_OK )
    {        
        printf( "\nError Reading Mac Address: %s\n", esp_err_to_name(ret) );
        return;
    }


    char new_hostname[50];

    sprintf( new_hostname, "www.%02X:%02X:%02X.domain.local", get_mac[3], get_mac[4], get_mac[5] );  // I believe that in production i would not need to use this function. i need to read the mac address, generate the hostname string, and write it once to flash memory. Maybe a script ?????

    char old_hostname[50];

    esp_netif_get_hostname(      , old_hostname );    // How to get "esp_netif_t *esp_netif"  ???
                                                                                  // old_hostname must be pointer to pointer argument ???        


    if ( strncmp( new_hostname, old_hostname, strlen(old_hostname) ) == 0 )
    {
        return;
    }   

    esp_netif_set_hostname(     , new_hostname );    // How to get "esp_netif_t *esp_netif"  ???
}