Carplay 参考代码：
int UdevIsCarplay(int nVid, int nPid)//int UsbModeSwitch(pUdevStatus pStatus)
{
    ;
    if (nVid != APPLE_IDVENDOR){
        ;
    }
    r = libusb_init(NULL);
    ) {
        pError("failed to initialise libusb\n");
        ;
    }
    struct libusb_device_handle *devh = NULL;
    devh = libusb_open_device_with_vid_pid(NULL, nVid, nPid);
    if (NULL == devh) {
        pError("Could not find/open device(%s)\n", strerror(errno));
        r = ;goto end;
    }
    //libusb_device *dev = libusb_get_device(devh);
    ];// if tmp is {0x01, 0x00, 0x00, 0x00} support carplay;else close carplay.
    memset(tmp, , );
    r = libusb_control_transfer(devh, , , tmp, , );//Page 715
    //r = libusb_control_transfer(devh, 0x40, 0x51, 0x01, 0, NULL, 0, 0);//Page 716 UsbModeSwitch
    ) {
        pError("UdevIsCarplay --- get support capabilities error !!! r = %d(%s)\n", r, strerror(errno));
        r = ;
    }
    ) {
        pError("short write (%d)\n", r);
        r = ;
    }
    else {
        //int nTmp = tmp[0] + (int)(tmp[1]<<8) + (int)(tmp[2]<<16) + (int)(tmp[3]<<24);
        pInfo(],tmp[],tmp[],tmp[]);
        ])
            r = ;
    }
    libusb_close(devh);
end:
  libusb_exit(NULL);
  return r ;
}

邹工：
    参考代码如下：
void* UdevEventMonitorThread(void* pParam)
{
    int fd;
    struct udev_device *dev;
    struct udev_monitor *mon;

    pUdevContainer pUdevCon = (pUdevContainer)pParam;
    mon = udev_monitor_new_from_netlink(pUdevCon->m_pUdev, "udev");//"kernel"或"udev"。基于"kernel"的事件通知要早于"udev"，但相关的设备结点未必创建完成
    if (mon == NULL)
    {
        pError("udev_monitor_new_from_netlink FAILED \n");
        return;
    }
    )
    {
        pError("UdevAddFilter FAILED \n");
        return;
    }
    )
    {
        pError("udev_monitor_enable_receiving FAILED \n");
        return;
    }

    UdevStatus status[];//status[0] is OTG atatus; status[1] is HOST atatus; //pUdevStatus status = calloc(2, sizeof(UdevStatus));
    memset(status,  ,  * sizeof(UdevStatus));
    status[].m_eUdevStatus = status[].m_eUdevStatus = UDEVOTHER;

    /* Get the file descriptor (fd) for the monitor.This fd will get passed to select() */
    fd = udev_monitor_get_fd(mon);

    );

    struct epoll_event ev;
    ev.events = EPOLLIN;
    ev.data.fd = fd;
    epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);

    ];

    pInfo("UdevEventMonitorThread --- start ok !!!!!!!!!!! \n");

    /* This section will run continuously, calling usleep() at the end of each pass. This is to demonstrate how to use a udev_monitor in a non-blocking way. */
    )
    {
        ;
        //pError("epoll_wait event start!\n");
        , -);//-1 is block,>=0 is noblock;
        //pWarn("epoll_wait event ok ret = %d!\n",ret);
        ; i < ret; i++)
        {
            /* Make the call to receive the device. select() ensured that this will not block. */
            dev = udev_monitor_receive_device(mon);
            if (dev)
            {
                const char* szAction = udev_device_get_action(dev);
                const char* szDevNode = udev_device_get_devnode(dev);
                const char* szSysPath = udev_device_get_syspath(dev);

                int nStatus = SetUdevStatus(pUdevCon, szAction);//pStatus,
                if(UDEVOTHER == nStatus)
                {
                    //pDebug("nStatus = 0(OTHER);
                    goto end;
                }
                //pDebug("nActionStatus = %d\n",nStatus);
                int nPort = UdevPortJudge(pUdevCon, szSysPath, nStatus);
                if(OTHERPORT == nPort)
                {
                    //pDebug("nPort = OTHERPORT(%d)\n", nPort);
                    goto end;
                }
                pUdevStatus pStatus = &status[nPort-];//status+(nPort-1)*sizeof(UdevStatus);
                //pDebug("   status[%d]=(%d),pStatus->m_eUdevStatus(%d),pStatus->m_nChecked(%d)~~~~~~~~~~~~~~\n", nPort-1, nStatus,pStatus->m_eUdevStatus,pStatus->m_nChecked);
                if(nStatus == UDEVCHANGE)
                {
                    pStatus->m_eUdevStatus = nStatus;
                    print_all_properties(pUdevCon, pStatus, dev, "prop");
                    goto end;
                    //pDebug("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
                }
                else if(nStatus == UDEVREMOVE)
                {
                    if(UDEVREMOVE != pStatus->m_eUdevStatus)//插入USB上电可能没有检测到设备，导致拔出状态错误
                    {
                        ResetStatus(pStatus);
                        if(NULL != szDevNode)
                            pUdevCon->m_pUdevEvent->UdevStatusProc(pUdevCon->m_eUdevPort, pStatus->m_eUdevStatus, USBNODEV, szDevNode);
                        else
                            pUdevCon->m_pUdevEvent->UdevStatusProc(pUdevCon->m_eUdevPort, pStatus->m_eUdevStatus, USBNODEV, "USBNODEV");
                        pUdevCon->m_eUdevPort = OTHERPORT;
                    }
                    goto end;
                }
                //ADD event
                pStatus->m_eUdevStatus = nStatus;

                )//nStatus == ADD
                {
                    print_all_attributes(pStatus, dev, "attr");
                    )
                    {
                        pInfo("[DM-SMING] %d\n", __LINE__);
                        if(pStatus->m_eUdevType == USBHUB)
                            pUdevCon->m_pUdevEvent->UdevStatusProc(nPort, nStatus, USBHUB, "USBHUB");
                        else if(pStatus->m_eUdevType == USBOTHER)
                            pUdevCon->m_pUdevEvent->UdevStatusProc(nPort, nStatus, USBOTHER, "USBOTHER");
                    }
                    )
                    {
                        pInfo("[DM-SMING] %d\n", __LINE__);
                        int nCheck = UdevCheckContinue(pStatus, szDevNode);
                        )
                        {
                            pInfo("[DM-SMING] %d\n", __LINE__);
                            if(pStatus->m_eUdevType == USBHID)
                                pUdevCon->m_pUdevEvent->UdevStatusProc(nPort, nStatus, USBHID, "USBHID");
                            else
                                pUdevCon->m_pUdevEvent->UdevStatusProc(nPort, nStatus, pStatus->m_eUdevType, szDevNode);
                        }
                    }
                }
            end:
                udev_device_unref(dev);
            }
            else
            {
                pDebug("No Device from receive_device().\n");// An error occured.
            }
        }
        //else
        //    usleep(100*1000);
        //fflush(stdout);
    }
    return;
}

static void print_all_properties(pUdevContainer pUdevCon, pUdevStatus pStatus, struct udev_device *device, const char *key)
{
    struct udev_list_entry *properties;
    udev_list_entry_foreach(properties, udev_device_get_properties_list_entry(device))
    {
        const char *szName = udev_list_entry_get_name(properties);
        const char *szValue = udev_list_entry_get_value(properties);

        if(NULL != szValue)
            pDebug("  [%s]{%s}==\"%s\"\n", key, szName, szValue);
        )
        {
            )
            {
                                //通过回调给上层USBNORESPOND消息，设备节点为”USBNORESPOND“
                pUdevCon->m_pUdevEvent->UdevStatusProc(pUdevCon->m_eUdevPort, pStatus->m_eUdevStatus, USBNORESPOND, "USBNORESPOND");
                return;
            }
        }
    }
}