static ssize_t send_json_cb(json_object *obj, uint64_t pos, char *buf, size_t max)
{
ssize_t len = stpncpy(buf, json_object_to_json_string(obj)+pos, max) - buf;
static ssize_t send_json_cb(json_object *obj, uint64_t pos, char *buf, size_t max)
{
ssize_t len = stpncpy(buf, json_object_to_json_string(obj)+pos, max) - buf;