/**
  *
  */
 function system_load(&$system_load)
 {
     if ($this->status != sCCC_PICTURE) {
         return ccERR_STATUS;
     }
     $pack = new cc_packet();
     $pack->setVer(CC_PROTO_VER);
     $pack->setCmd(cmdCC_SYSTEM_LOAD);
     $pack->setSize(0);
     if ($pack->packTo($this->s) === FALSE) {
         return ccERR_NET_ERROR;
     }
     if ($pack->unpackFrom($this->s) === FALSE) {
         return ccERR_NET_ERROR;
     }
     if ($pack->getSize() != 1) {
         return ccERR_UNKNOWN;
     }
     switch ($pack->getCmd()) {
         case cmdCC_SYSTEM_LOAD:
             $arr = unpack('Csysload', $pack->getData());
             $system_load = $arr['sysload'];
             return ccERR_OK;
         default:
             // unknown error
             return ccERR_UNKNOWN;
     }
 }