int environment_add(environment_t *env, const char *format, ...) {
if(env->n >= env->size) {
int environment_add(environment_t *env, const char *format, ...) {
if(env->n >= env->size) {
environment_add(env, "DEVICE=%s", device);
if(iface)
environment_add(env, "INTERFACE=%s", iface);
environment_add(env, "DEVICE=%s", device);
if(iface)
environment_add(env, "INTERFACE=%s", iface);