自学教程：C++ udev_enumerate_unref函数代码示例

int get_usbinfo(int bus, int dev, usbinfo_t *ui){  struct udev *udev;  struct udev_enumerate *enumerate;  struct udev_list_entry *devices, *dev_list_entry;  struct udev_device *udev_dev;  char bus_str[16], dev_str[16];  int found = 0;  memset(ui, 0, sizeof(usbinfo_t));  /* construct xenstore dev id */  if (dev > 0xFFF) {    xd_log(LOG_ERR, "bad device id %d", dev);    return -EINVAL;  }  ui->usb_virtid = bus << 12 | (dev & 0xFFF);  ui->usb_bus = bus;  ui->usb_device = dev;  /* udev scan */  udev = udev_new();  if (!udev) {    xd_log(LOG_ERR, "Can't create udev");    return -ENOMEM;  }  enumerate = udev_enumerate_new(udev);  if (!enumerate) {    xd_log(LOG_ERR, "Can't create enumeration");    return -ENOMEM;  }  snprintf(bus_str, sizeof(bus_str), "%d", bus);  snprintf(dev_str, sizeof(dev_str), "%d", dev);  udev_enumerate_add_match_subsystem(enumerate, "usb");  udev_enumerate_add_match_sysattr(enumerate, "busnum", bus_str);  udev_enumerate_add_match_sysattr(enumerate, "devnum", dev_str);  udev_enumerate_scan_devices(enumerate);  devices = udev_enumerate_get_list_entry(enumerate);  udev_list_entry_foreach(dev_list_entry, devices) {    const char *path;    path = udev_list_entry_get_name(dev_list_entry);    udev_dev = udev_device_new_from_syspath(udev, path);    sscanf(udev_device_get_sysattr_value(udev_dev, "idVendor"), "%x", &ui->usb_vendor);    sscanf(udev_device_get_sysattr_value(udev_dev, "idProduct"), "%x", &ui->usb_product);    udev_device_unref(udev_dev);    udev_enumerate_unref(enumerate);    udev_unref(udev);    return 0;  }  udev_enumerate_unref(enumerate);  udev_unref(udev);  return -ENOENT;}

/** * Search udev for usb device with specified idVendor and idProduct */const char* get_usb_device_syspath(const char* idVendor, const char* idProduct, char* buf) {    struct udev* udev;    struct udev_enumerate* en;    struct udev_list_entry* dev_list_entry;    udev = udev_new();    if (udev<0) {        return 0;    }    en = udev_enumerate_new(udev);    udev_enumerate_add_match_subsystem(en, "usb");    udev_enumerate_add_match_sysattr(en, "idVendor",idVendor);    udev_enumerate_add_match_sysattr(en, "idProduct",idProduct);    udev_enumerate_scan_devices(en);    dev_list_entry = udev_enumerate_get_list_entry(en);    if (dev_list_entry == 0 ) {        return 0;    }    sprintf(buf, udev_list_entry_get_name(dev_list_entry));    udev_enumerate_unref(en);    udev_unref(udev);    return buf;}

void joystick_linux::enumerate_joysticks(udev *p_udev) {	udev_enumerate *enumerate;	udev_list_entry *devices, *dev_list_entry;	udev_device *dev;	enumerate = udev_enumerate_new(p_udev);	udev_enumerate_add_match_subsystem(enumerate,"input");	udev_enumerate_add_match_property(enumerate, "ID_INPUT_JOYSTICK", "1");	udev_enumerate_scan_devices(enumerate);	devices = udev_enumerate_get_list_entry(enumerate);	udev_list_entry_foreach(dev_list_entry, devices) {		const char* path = udev_list_entry_get_name(dev_list_entry);		dev = udev_device_new_from_syspath(p_udev, path);		const char* devnode = udev_device_get_devnode(dev);		if (devnode) {			String devnode_str = devnode;			if (devnode_str.find(ignore_str) == -1) {				joy_mutex->lock();				open_joystick(devnode);				joy_mutex->unlock();			}		}		udev_device_unref(dev);	}	udev_enumerate_unref(enumerate);}

int scan_connected_devices(detector_state_t *state) {	struct udev_list_entry *cursor;	struct udev_enumerate *ue;	struct udev_device *ud;	const char *devnode = NULL;	if( !(ue = udev_enumerate_new(state->u)) )		return 1;	udev_enumerate_add_match_subsystem(ue, "tty");	udev_enumerate_add_match_property(ue, "ID_BUS", "usb");	udev_enumerate_scan_devices(ue);	cursor = udev_enumerate_get_list_entry(ue);	do {		ud = udev_device_new_from_syspath(			state->u, udev_list_entry_get_name(cursor));		if( (devnode = udev_device_get_devnode(ud)) )			spawn_server(state->exec_path, devnode);		udev_device_unref(ud);	} while( (cursor = udev_list_entry_get_next(cursor)) );	udev_enumerate_unref(ue);	return 0;}

intwgbm_get_default_fd_for_pattern(const char *pattern){    struct udev *ud;    struct udev_enumerate *en;    struct udev_list_entry *devices, *entry;    const char *path, *filename;    struct udev_device *device;    int fd;    ud = udev_new();    en = udev_enumerate_new(ud);    udev_enumerate_add_match_subsystem(en, "drm");    udev_enumerate_add_match_sysname(en, pattern);    udev_enumerate_scan_devices(en);    devices = udev_enumerate_get_list_entry(en);    udev_list_entry_foreach(entry, devices) {        path = udev_list_entry_get_name(entry);        device = udev_device_new_from_syspath(ud, path);        filename = udev_device_get_devnode(device);        fd = open(filename, O_RDWR | O_CLOEXEC);        udev_device_unref(device);        if (fd >= 0) {            udev_enumerate_unref(en);            udev_unref(ud);            return fd;        }    }

/* add or remove a ACL for a given uid from all matching devices */static void apply_acl_to_devices(uid_t uid, int add){	struct udev *udev;	struct udev_enumerate *enumerate;	struct udev_list_entry *list_entry;	/* iterate over all devices tagged with ACL_SET */	udev = udev_new();	enumerate = udev_enumerate_new(udev);	udev_enumerate_add_match_tag(enumerate, "udev-acl");	udev_enumerate_scan_devices(enumerate);	udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(enumerate)) {		struct udev_device *device;		const char *node;		device = udev_device_new_from_syspath(udev_enumerate_get_udev(enumerate),						      udev_list_entry_get_name(list_entry));		if (device == NULL)			continue;		node = udev_device_get_devnode(device);		if (node == NULL) {			udev_device_unref(device);			continue;		}		set_facl(node, uid, add);		udev_device_unref(device);	}	udev_enumerate_unref(enumerate);	udev_unref(udev);}

static intudev_input_add_devices(struct udev_input *input, struct udev *udev){	struct udev_enumerate *e;	struct udev_list_entry *entry;	struct udev_device *device;	const char *path, *sysname;	struct udev_seat *seat;	int devices_found = 0;	e = udev_enumerate_new(udev);	udev_enumerate_add_match_subsystem(e, "input");	udev_enumerate_scan_devices(e);	udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {		path = udev_list_entry_get_name(entry);		device = udev_device_new_from_syspath(udev, path);		sysname = udev_device_get_sysname(device);		if (strncmp("event", sysname, 5) != 0) {			udev_device_unref(device);			continue;		}		if (device_added(device, input) < 0) {			udev_device_unref(device);			udev_enumerate_unref(e);			return -1;		}		udev_device_unref(device);	}

void udevenum(){    struct udev_enumerate* enumerator = udev_enumerate_new(udev);    udev_enumerate_add_match_subsystem(enumerator, "usb");    udev_enumerate_add_match_sysattr(enumerator, "idVendor", V_CORSAIR_STR);    udev_enumerate_scan_devices(enumerator);    struct udev_list_entry* devices, *dev_list_entry;    devices = udev_enumerate_get_list_entry(enumerator);    udev_list_entry_foreach(dev_list_entry, devices){        const char* path = udev_list_entry_get_name(dev_list_entry);        struct udev_device* dev = udev_device_new_from_syspath(udev, path);        // If the device matches a recognized device ID, open it        const char* product = udev_device_get_sysattr_value(dev, "idProduct");        if(!strcmp(product, P_K70_STR)){            pthread_mutex_lock(&kblistmutex);            openusb(dev, 70);            pthread_mutex_unlock(&kblistmutex);            continue;        }        if(!strcmp(product, P_K95_STR)){            pthread_mutex_lock(&kblistmutex);            openusb(dev, 95);            pthread_mutex_unlock(&kblistmutex);            continue;        }        // Free the device if it wasn't used        udev_device_unref(dev);    }    udev_enumerate_unref(enumerator);}

voidUdevSubsystem::enumerate_udev_devices(){  assert(m_process_match_cb);  // Enumerate over all devices already connected to the computer  struct udev_enumerate* enumerate = udev_enumerate_new(m_udev);  assert(enumerate);  udev_enumerate_add_match_subsystem(enumerate, "usb");  // not available yet: udev_enumerate_add_match_is_initialized(enumerate);  udev_enumerate_scan_devices(enumerate);  struct udev_list_entry* devices;  struct udev_list_entry* dev_list_entry;  devices = udev_enumerate_get_list_entry(enumerate);  udev_list_entry_foreach(dev_list_entry, devices)  {    // name is path, value is NULL    const char* path = udev_list_entry_get_name(dev_list_entry);    struct udev_device* device = udev_device_new_from_syspath(m_udev, path);    // manually filter for devtype, as udev enumerate can't do it by itself    const char* devtype = udev_device_get_devtype(device);    if (devtype && strcmp(devtype, "usb_device") == 0)    {      m_process_match_cb(device);    }    udev_device_unref(device);  }  udev_enumerate_unref(enumerate);}

GamepadController::GamepadController()    : m_gamepadDevices(Nix::Gamepads::itemsLengthCap){    m_udev = udev_new();    m_gamepadsMonitor = udev_monitor_new_from_netlink(m_udev, "udev");    udev_monitor_enable_receiving(m_gamepadsMonitor);    udev_monitor_filter_add_match_subsystem_devtype(m_gamepadsMonitor, "input", 0);    GIOChannel *channel = g_io_channel_unix_new(udev_monitor_get_fd(m_gamepadsMonitor));    g_io_add_watch(channel, GIOCondition(G_IO_IN), static_cast<GIOFunc>(&GamepadController::onGamepadChange), this);    g_io_channel_unref(channel);    struct udev_enumerate* enumerate = udev_enumerate_new(m_udev);    udev_enumerate_add_match_subsystem(enumerate, "input");    udev_enumerate_add_match_property(enumerate, "ID_INPUT_JOYSTICK", "1");    udev_enumerate_scan_devices(enumerate);    struct udev_list_entry* cur;    struct udev_list_entry* devs = udev_enumerate_get_list_entry(enumerate);    udev_list_entry_foreach(cur, devs)    {        const char* devname = udev_list_entry_get_name(cur);        struct udev_device* device = udev_device_new_from_syspath(m_udev, devname);        if (isGamepadDevice(device))            registerDevice(udev_device_get_devnode(device));        udev_device_unref(device);    }    udev_enumerate_unref(enumerate);}

/* * Cleans up resources and set exception that will get thrown upon return to java layer. */jstring linux_listusb_clean_throw_exp(JNIEnv *env, int task, const char *expmsg,		struct jstrarray_list *list, struct udev_device *udev_device,		struct udev_enumerate *enumerator, struct udev *udev_ctx) {	(*env)->ExceptionClear(env);	free_jstrarraylist(list);	/* free memory first, so even if throwing JNI exception fails, this succeeds. */	if(task == 1) {		udev_device_unref(udev_device);		udev_enumerate_unref(enumerator);		udev_unref(udev_ctx);	}else {	}	jclass serialComExceptionClass = (*env)->FindClass(env, SCOMEXPCLASS);	if((serialComExceptionClass == NULL) || ((*env)->ExceptionOccurred(env) != NULL)) {		(*env)->ExceptionClear(env);		if(task == 1) {			LOGE(E_FINDCLASSSCOMEXPSTR, E_NEWSTRUTFSTR);		}else {			LOGE(E_FINDCLASSSCOMEXPSTR, expmsg);		}		return NULL;	}	if(task == 1) {		(*env)->ThrowNew(env, serialComExceptionClass, E_NEWSTRUTFSTR);	}else {		(*env)->ThrowNew(env, serialComExceptionClass, expmsg);	}	return NULL;}

QStringList QDeviceDiscovery::scanConnectedDevices(){    QStringList devices;    if (!m_udev)        return devices;    udev_enumerate *ue = udev_enumerate_new(m_udev);    udev_enumerate_add_match_subsystem(ue, "input");    udev_enumerate_add_match_subsystem(ue, "drm");    if (m_types & Device_Mouse)        udev_enumerate_add_match_property(ue, "ID_INPUT_MOUSE", "1");    if (m_types & Device_Touchpad)        udev_enumerate_add_match_property(ue, "ID_INPUT_TOUCHPAD", "1");    if (m_types & Device_Touchscreen)        udev_enumerate_add_match_property(ue, "ID_INPUT_TOUCHSCREEN", "1");    if (m_types & Device_Keyboard) {        udev_enumerate_add_match_property(ue, "ID_INPUT_KEYBOARD", "1");        udev_enumerate_add_match_property(ue, "ID_INPUT_KEY", "1");    }    if (m_types & Device_Tablet)        udev_enumerate_add_match_property(ue, "ID_INPUT_TABLET", "1");    if (udev_enumerate_scan_devices(ue) != 0) {#ifdef QT_QPA_DEVICE_DISCOVERY_DEBUG        qWarning() << "UDeviceHelper scan connected devices for enumeration failed";#endif        return devices;    }    udev_list_entry *entry;    udev_list_entry_foreach (entry, udev_enumerate_get_list_entry(ue)) {        const char *syspath = udev_list_entry_get_name(entry);        udev_device *udevice = udev_device_new_from_syspath(m_udev, syspath);        QString candidate = QString::fromUtf8(udev_device_get_devnode(udevice));        if ((m_types & Device_InputMask) && candidate.startsWith(QLatin1String(QT_EVDEV_DEVICE)))            devices << candidate;        if ((m_types & Device_VideoMask) && candidate.startsWith(QLatin1String(QT_DRM_DEVICE))) {            if (m_types & Device_DRM_PrimaryGPU) {                udev_device *pci = udev_device_get_parent_with_subsystem_devtype(udevice, "pci", 0);                if (pci) {                    if (qstrcmp(udev_device_get_sysattr_value(pci, "boot_vga"), "1") == 0)                        devices << candidate;                }            } else                devices << candidate;        }        udev_device_unref(udevice);    }    udev_enumerate_unref(ue);#ifdef QT_QPA_DEVICE_DISCOVERY_DEBUG    qWarning() << "UDeviceHelper found matching devices" << devices;#endif    return devices;}

rw_status_trw_udev_register_cb(rw_udev_handle_t *handle,                    void *userdata, rw_udev_cb_t cb){  struct udev_enumerate *enumerate = NULL;  struct udev_list_entry *devices, *dev_list_entry;  int ret = -1;  rw_status_t status = RW_STATUS_SUCCESS;  rw_pci_address_t pci_addr;  rw_pci_device_t *dev;  struct udev_device *udevice;    handle->cb = cb;  handle->userdata = userdata;    //walk throight he list and call the callback..  enumerate = udev_enumerate_new(handle->udev);  if (!enumerate){    goto free_and_ret;  }  udev_enumerate_add_match_subsystem(enumerate, "net");  udev_enumerate_scan_devices(enumerate);  devices = udev_enumerate_get_list_entry(enumerate);  udev_list_entry_foreach(dev_list_entry, devices) {    const char *path;    path = udev_list_entry_get_name(dev_list_entry);    ret = rw_sys_populate_pci_from_path(path, &pci_addr);    if (!ret){          }else{      udevice = udev_device_new_from_syspath(handle->udev, path);      dev = rw_udev_insert_device(handle, &pci_addr);      rw_udev_update_device(udevice, dev);      if (dev){        handle->cb(handle->userdata, dev, RW_UDEV_DEVICE_ADD);      }      udev_device_unref(udevice);    }  }    handle->mon = udev_monitor_new_from_netlink(handle->udev, "udev");  udev_monitor_filter_add_match_subsystem_devtype(handle->mon, "net", NULL);  udev_monitor_enable_receiving(handle->mon);  /* Get the file descriptor (fd) for the monitor.     This fd will get passed to select() */  handle->fd = udev_monitor_get_fd(handle->mon);  ret:  return status;  free_and_ret:  if (enumerate){    udev_enumerate_unref(enumerate);    enumerate = NULL;  }  status = RW_STATUS_FAILURE;  goto ret;}

static virInterfacePtrudevInterfaceLookupByMACString(virConnectPtr conn, const char *macstr){    struct udev_iface_driver *driverState = conn->interfacePrivateData;    struct udev *udev = udev_ref(driverState->udev);    struct udev_enumerate *enumerate = NULL;    struct udev_list_entry *dev_entry;    struct udev_device *dev;    const char *name;    virInterfacePtr ret = NULL;    enumerate = udevGetDevices(udev, VIR_UDEV_IFACE_ALL);    if (!enumerate) {        virReportError(VIR_ERR_INTERNAL_ERROR,                       _("failed to lookup interface with MAC address '%s'"),                       macstr);        goto err;    }    /* Match on MAC */    udev_enumerate_add_match_sysattr(enumerate, "address", macstr);    /* Do the scan to load up the enumeration */    udev_enumerate_scan_devices(enumerate);    /* Get a list we can walk */    dev_entry = udev_enumerate_get_list_entry(enumerate);    /* Check that we got something back */    if (!dev_entry) {        virReportError(VIR_ERR_NO_INTERFACE,                       _("couldn't find interface with MAC address '%s'"),                       macstr);        goto err;    }    /* Check that we didn't get multiple items back */    if (udev_list_entry_get_next(dev_entry)) {        virReportError(VIR_ERR_MULTIPLE_INTERFACES,                       _("the MAC address '%s' matches multiple interfaces"),                       macstr);        goto err;    }    dev = udev_device_new_from_syspath(udev, udev_list_entry_get_name(dev_entry));    name = udev_device_get_sysname(dev);    ret = virGetInterface(conn, name, macstr);    udev_device_unref(dev);err:    if (enumerate)        udev_enumerate_unref(enumerate);    udev_unref(udev);    return ret;}

udev_enumerate_ptr Root::mk_enumerate() const{    udev_enumerate_ptr res        (udev_enumerate_new(p.get())         , [](udev_enumerate *p) {            if (p) udev_enumerate_unref(p);        });    return res;}

  /*      This implementation uses udev to retrieve capture devices.     We support both udev and default v4l2 ways to retrieve      devices. Udev is not supported on all systems.   */  std::vector<V4L2_Device> v4l2_get_devices() {        std::vector<V4L2_Device> result;    struct udev* udev;    struct udev_enumerate* enumerate;    struct udev_list_entry* devices;    struct udev_list_entry* dev_list_entry;    struct udev_device* dev;     udev = udev_new();    if(!udev) {      printf("Error: Cannot udev_new()/n");      return result;    }     enumerate = udev_enumerate_new(udev);    udev_enumerate_add_match_subsystem(enumerate, "video4linux");    udev_enumerate_scan_devices(enumerate);    devices = udev_enumerate_get_list_entry(enumerate);    udev_list_entry_foreach(dev_list_entry, devices) {      /* Get the device by syspath. */      const char* syspath = udev_list_entry_get_name(dev_list_entry);      dev = udev_device_new_from_syspath(udev, syspath);      if(!dev) {        printf("Error: cannot get the device using the syspath: %s/n", syspath);        continue;      }      V4L2_Device v4l2_device;      v4l2_device.path = udev_device_get_devnode(dev);      if(v4l2_device.path.size() == 0) {        printf("Error: Cannot find devpath./n");        continue;      }      dev = udev_device_get_parent_with_subsystem_devtype(dev, "usb", "usb_device");      if(!dev) {        printf("Error:Cannot find related usb device./n");        continue;      }      v4l2_device.id_vendor = udev_device_get_sysattr_value(dev, "idVendor");      v4l2_device.id_product = udev_device_get_sysattr_value(dev, "idProduct");      result.push_back(v4l2_device);    }    udev_enumerate_unref(enumerate);    udev_unref(udev);        return result;  }

void input_init(char* mapfile) {  #ifdef HAVE_LIBCEC  init_cec();  #endif  udev = udev_new();  if (!udev) {    fprintf(stderr, "Can't create udev/n");    exit(1);  }  autoadd = (numDevices == 0);  if (autoadd) {    struct udev_enumerate *enumerate = udev_enumerate_new(udev);    udev_enumerate_add_match_subsystem(enumerate, "input");    udev_enumerate_scan_devices(enumerate);    struct udev_list_entry *devices = udev_enumerate_get_list_entry(enumerate);    struct udev_list_entry *dev_list_entry;    udev_list_entry_foreach(dev_list_entry, devices) {      const char *path = udev_list_entry_get_name(dev_list_entry);      struct udev_device *dev = udev_device_new_from_syspath(udev, path);      const char *devnode = udev_device_get_devnode(dev);      int id;      if (devnode != NULL && sscanf(devnode, "/dev/input/event%d", &id) == 1) {        input_create(devnode, mapfile);      }      udev_device_unref(dev);    }    udev_enumerate_unref(enumerate);  }  udev_mon = udev_monitor_new_from_netlink(udev, "udev");  udev_monitor_filter_add_match_subsystem_devtype(udev_mon, "input", NULL);  udev_monitor_enable_receiving(udev_mon);  udev_fdindex = numFds++;  sig_fdindex = numFds++;  if (fds == NULL)    fds = malloc(sizeof(struct pollfd)*numFds);  else    fds = realloc(fds, sizeof(struct pollfd)*numFds);  if (fds == NULL) {    fprintf(stderr, "Not enough memory/n");    exit(EXIT_FAILURE);  }  defaultMapfile = mapfile;  fds[udev_fdindex].fd = udev_monitor_get_fd(udev_mon);  fds[udev_fdindex].events = POLLIN;  main_thread_id = pthread_self();}

void GamepadInit(void) {	struct udev_list_entry* devices;	struct udev_list_entry* item;	struct udev_enumerate* enu;	int i;	/* initialize connection state */	for (i = 0; i != GAMEPAD_COUNT; ++i) {		STATE[i].flags = 0;		STATE[i].fd = STATE[i].effect = -1;	}	/* open the udev handle */	UDEV = udev_new();	if (UDEV == NULL) {		/* FIXME: flag error? */		return;	}		/* open monitoring device (safe to fail) */	MON = udev_monitor_new_from_netlink(UDEV, "udev");	/* FIXME: flag error if hot-plugging can't be supported? */	if (MON != NULL) {		udev_monitor_enable_receiving(MON);		udev_monitor_filter_add_match_subsystem_devtype(MON, "input", NULL);	}	/* enumerate joypad devices */	enu = udev_enumerate_new(UDEV);	udev_enumerate_add_match_subsystem(enu, "input");	udev_enumerate_scan_devices(enu);	devices = udev_enumerate_get_list_entry(enu);	udev_list_entry_foreach(item, devices) {		const char* name;		const char* sysPath;		const char* devPath;		struct udev_device* dev;		name = udev_list_entry_get_name(item);		dev = udev_device_new_from_syspath(UDEV, name);		sysPath = udev_device_get_syspath(dev);		devPath = udev_device_get_devnode(dev);		if (sysPath != NULL && devPath != NULL && strstr(sysPath, "/js") != 0) {			GamepadAddDevice(devPath);		}		udev_device_unref(dev);	}	/* cleanup */	udev_enumerate_unref(enu);}

/* * this function is not powerful because it reinitializes a new udev search each * time it would be nicer to call this only one time + one time at each hotplug * but it is already very fast, so, let's keep it simple and non intrusive */bool CLinuxInputDevices::IsUdevJoystick(const char *devpath){#if defined(HAVE_LIBUDEV)  struct udev *udev;  struct udev_enumerate *enumerate;  struct udev_list_entry *devices, *dev_list_entry;  struct udev_device *dev;  const char *path;  const char *devfoundpath;  udev = udev_new();  if (!udev)    return false; // can't create udev  enumerate = udev_enumerate_new(udev);  if (enumerate == NULL)  {    udev_unref(udev);    return false;  }  if (udev_enumerate_add_match_subsystem(enumerate, "input") == 0)  {    if (udev_enumerate_add_match_property(enumerate, "ID_INPUT_JOYSTICK", "1") == 0)    {      if (udev_enumerate_scan_devices(enumerate) >= 0)      {        devices = udev_enumerate_get_list_entry(enumerate);        udev_list_entry_foreach(dev_list_entry, devices)        {          path = udev_list_entry_get_name(dev_list_entry);          dev = udev_device_new_from_syspath(udev, path);          if (dev != NULL)          {            devfoundpath = udev_device_get_devnode(dev);            if (devfoundpath != NULL)            {              // found (finally !)              //printf("=> %s/n", devfoundpath);              if (strcmp(devfoundpath, devpath) == 0)              {                udev_device_unref(dev);                udev_enumerate_unref(enumerate);                udev_unref(udev);                return true;              }            }            udev_device_unref(dev);          }        }      }    }

int find_and_open_p6s() {    int result = -1;    char buf[300];    memset(buf, 0, sizeof(buf));    get_usb_device_syspath(ID_VENDOR_YEALINK,ID_PRODUCT_VOIPUSBPHONE, buf);    int len = strlen(buf);    if (len==0) {        return result;    }    printf("Found Skypemate P6S USB at %s /n", buf);    struct udev* udev;    struct udev_enumerate* enumerate;    struct udev_list_entry* dev_list_entry;    struct udev_device* dev;    udev = udev_new();    if (udev<0) {        perror("error creating udev object");        return result;    }    // enumerating all hidraw devices    enumerate = udev_enumerate_new(udev);    udev_enumerate_add_match_subsystem(enumerate, "hidraw");    udev_enumerate_scan_devices(enumerate);    dev_list_entry = udev_enumerate_get_list_entry(enumerate);    while ((dev_list_entry!=0) && (result==-1)) {        const char* syspath = udev_list_entry_get_name(dev_list_entry);        dev = udev_device_new_from_syspath(udev, syspath);        // get hidraw USB parent        struct udev_device* parent = udev_device_get_parent_with_subsystem_devtype(dev, "usb","usb_device");        if (parent != 0) {            const char* parent_syspath = udev_device_get_syspath(parent);            if ( strcmp(buf, parent_syspath) == 0) {                // found it                const char* devnode = udev_device_get_devnode(dev);                printf("Found corresponding hidraw device: %s /n", devnode);                result = open(devnode, O_RDONLY);            }        }        udev_device_unref(dev);        dev_list_entry = udev_list_entry_get_next(dev_list_entry);    }    udev_enumerate_unref(enumerate);    udev_unref(udev);    return result;}

//we have no seat filters, we account all input devices and all dce6 display//devicesvoid lwl_udev_input_cold_plug(void){  struct udev_enumerate *e;  e=udev_enumerate_new(lwl_udev);  if(!e){    PERRC("fatal:cold plug:unable to create enumeration/n");    exit(LWL_ERR);  }  int r=udev_enumerate_add_match_subsystem(e,"input");  if(r){    PERRC("fatal:cold plug:unable to select input subsystem for enumeration/n");    exit(LWL_ERR);  }  r=udev_enumerate_add_match_subsystem(e,"dce6_display");  if(r){    PERRC("fatal:cold plug:unable to select dce6_display subsystem for"                                                              " enumeration/n");    exit(LWL_ERR);  }  r=udev_enumerate_scan_devices(e);  if(r){    PERRC("fatal:cold plug:error while enumerating input devices/n");    exit(LWL_ERR);  }  struct udev_list_entry *first=udev_enumerate_get_list_entry(e);  struct udev_list_entry *item=0;  LOG_UDEV("cold plug:starting input devices enumeration.../n");  udev_list_entry_foreach(item,first){    struct udev_device *d=udev_device_new_from_syspath(lwl_udev,                                                udev_list_entry_get_name(item));    if(!d) continue;    void *subsys=(void*)udev_device_get_subsystem(d);    if(!strncmp(INPUT_STR,subsys,cs_n(INPUT_STR)))      input_device_add(d);    else if(!strncmp(DCE6_DISPLAY_STR,subsys,cs_n(DCE6_DISPLAY_STR))){      struct gbl *o=output_plugged(d);      if(o) registry_gbl_ref(o);    }    udev_device_unref(d);  }  LOG_UDEV("cold plug:end of input devices enumeration/n");  udev_enumerate_unref(e);}

static intudevNumOfInterfacesByStatus(virConnectPtr conn, virUdevStatus status,                            virInterfaceObjListFilter filter){    struct udev_iface_driver *driverState = conn->interfacePrivateData;    struct udev *udev = udev_ref(driverState->udev);    struct udev_enumerate *enumerate = NULL;    struct udev_list_entry *devices;    struct udev_list_entry *dev_entry;    int count = 0;    enumerate = udevGetDevices(udev, status);    if (!enumerate) {        virReportError(VIR_ERR_INTERNAL_ERROR,                       _("failed to get number of %s interfaces on host"),                       virUdevStatusString(status));        count = -1;        goto cleanup;    }    /* Do the scan to load up the enumeration */    udev_enumerate_scan_devices(enumerate);    /* Get a list we can walk */    devices = udev_enumerate_get_list_entry(enumerate);    /* For each item so we can count */    udev_list_entry_foreach(dev_entry, devices) {        struct udev_device *dev;        const char *path;        virInterfaceDefPtr def;        path = udev_list_entry_get_name(dev_entry);        dev = udev_device_new_from_syspath(udev, path);        def = udevGetMinimalDefForDevice(dev);        if (filter(conn, def))            count++;        udev_device_unref(dev);        virInterfaceDefFree(def);    } cleanup:    if (enumerate)        udev_enumerate_unref(enumerate);    udev_unref(udev);    return count;}

int show_sysfs(const char *seat, const char *prefix, unsigned n_columns) {        struct udev *udev;        struct udev_list_entry *first = NULL;        struct udev_enumerate *e;        int r;        if (n_columns <= 0)                n_columns = columns();        if (!prefix)                prefix = "";        if (isempty(seat))                seat = "seat0";        udev = udev_new();        if (!udev)                return -ENOMEM;        e = udev_enumerate_new(udev);        if (!e) {                r = -ENOMEM;                goto finish;        }        if (!streq(seat, "seat0"))                r = udev_enumerate_add_match_tag(e, seat);        else                r = udev_enumerate_add_match_tag(e, "seat");        if (r < 0)                goto finish;        r = udev_enumerate_scan_devices(e);        if (r < 0)                goto finish;        first = udev_enumerate_get_list_entry(e);        if (first)                show_sysfs_one(udev, seat, &first, "/", prefix, n_columns);finish:        if (e)                udev_enumerate_unref(e);        if (udev)                udev_unref(udev);        return r;}

static intget_usbinfo(int bus, int dev, usbinfo_t *ui){  struct udev_enumerate *enumerate;  struct udev_list_entry *devices, *dev_list_entry;  struct udev_device *udev_dev;  char bus_str[16], dev_str[16];  int vendor, product;  enumerate = udev_enumerate_new(udev_handle);  if (!enumerate) {    xd_log(LOG_ERR, "Can't create enumeration");    return -ENOMEM;  }  snprintf(bus_str, sizeof(bus_str), "%d", bus);  snprintf(dev_str, sizeof(dev_str), "%d", dev);  udev_enumerate_add_match_subsystem(enumerate, "usb");  udev_enumerate_add_match_sysattr(enumerate, "busnum", bus_str);  udev_enumerate_add_match_sysattr(enumerate, "devnum", dev_str);  udev_enumerate_scan_devices(enumerate);  devices = udev_enumerate_get_list_entry(enumerate);  udev_list_entry_foreach(dev_list_entry, devices) {    const char *path;    path = udev_list_entry_get_name(dev_list_entry);    udev_dev = udev_device_new_from_syspath(udev_handle, path);    sscanf(udev_device_get_sysattr_value(udev_dev, "idVendor"), "%x", &vendor);    sscanf(udev_device_get_sysattr_value(udev_dev, "idProduct"), "%x", &product);    udev_device_unref(udev_dev);    udev_enumerate_unref(enumerate);    return usbowls_build_usbinfo(bus, dev, vendor, product, ui);  }  udev_enumerate_unref(enumerate);  return -ENOENT;}

static int usb_dongle_probe(struct udev *udev, const char *subsystem){	struct udev_enumerate *udev_enumerate;	int ret;	mylog_trace("%s enumerate '%s'", __func__, subsystem == NULL ? "<all>" : subsystem);	udev_enumerate = udev_enumerate_new(udev);	if (udev_enumerate == NULL)		return -1;	udev_enumerate_add_match_subsystem(udev_enumerate, subsystem);	udev_enumerate_scan_devices(udev_enumerate);	ret = usb_dongle_probe_print_list(udev_enumerate);	udev_enumerate_unref(udev_enumerate);	return ret;}

int Storage::enumerate_mmcblk_devices(struct udev *udev){    struct udev_enumerate *udev_enumerate;    qDebug() << Q_FUNC_INFO << ": enumerate 'block' devices";    udev_enumerate = udev_enumerate_new(udev);    if (udev_enumerate == NULL)        return -1;    udev_enumerate_add_match_subsystem(udev_enumerate,"block");    udev_enumerate_scan_devices(udev_enumerate);    struct udev_list_entry *list_entry;    udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate))    {        struct udev_device *device;        device = udev_device_new_from_syspath(udev_enumerate_get_udev(udev_enumerate),                                      udev_list_entry_get_name(list_entry));        if (device != NULL) {            QString sysname("/dev/");            sysname += QString(udev_device_get_sysname(device));            if (sysname.contains(QRegExp("mmcblk[1-9]//d*"))  || sysname.contains(QRegExp("mmcblk[1-9]")))            {                QString path = udev_device_get_devpath(device);                QString parent = udev_device_get_devpath( udev_device_get_parent (device));                QString action = "add";                QString devtype = udev_device_get_devtype(device);                qDebug() << "Enumerate device " << path << ":" << action;                qDebug() << "    Got Device";                qDebug() << "    Node: " <<  udev_device_get_devnode(device);                qDebug() << "    Subsystem: "<< udev_device_get_subsystem(device);                qDebug() << "    Devtype: " << devtype;                qDebug() << "    Action: " << action;                qDebug() << "    Sysname: " << sysname;                qDebug() << "    sysnum: " << udev_device_get_sysnum (device);                qDebug() << "    parent: " << parent;                processRemovableUdevEvents(devtype, path, sysname, action);            }            udev_device_unref(device);        }    }    udev_enumerate_unref(udev_enumerate);    return 0;}

void Init(){  s_devnode_name_map.clear();  // During initialization we use udev to iterate over all /dev/input/event* devices.  // Note: the Linux kernel is currently limited to just 32 event devices. If this ever  //            changes, hopefully udev will take care of this.  udev* udev = udev_new();  _assert_msg_(PAD, udev != nullptr, "Couldn't initialize libudev.");  // List all input devices  udev_enumerate* enumerate = udev_enumerate_new(udev);  udev_enumerate_add_match_subsystem(enumerate, "input");  udev_enumerate_scan_devices(enumerate);  udev_list_entry* devices = udev_enumerate_get_list_entry(enumerate);  // Iterate over all input devices  udev_list_entry* dev_list_entry;  udev_list_entry_foreach(dev_list_entry, devices)  {    const char* path = udev_list_entry_get_name(dev_list_entry);    udev_device* dev = udev_device_new_from_syspath(udev, path);    const char* devnode = udev_device_get_devnode(dev);    // We only care about devices which we have read/write access to.    if (devnode && access(devnode, W_OK) == 0)    {      // Unfortunately udev gives us no way to filter out the non event device interfaces.      // So we open it and see if it works with evdev ioctls or not.      std::string name = GetName(devnode);      auto input = std::make_shared<evdevDevice>(devnode);      if (input->IsInteresting())      {        g_controller_interface.AddDevice(std::move(input));        s_devnode_name_map.insert(std::pair<std::string, std::string>(devnode, name));      }    }    udev_device_unref(dev);  }  udev_enumerate_unref(enumerate);  udev_unref(udev);  StartHotplugThread();}

cairo_drm_device_t *cairo_drm_device_default (void){    struct udev *udev;    struct udev_enumerate *e;    struct udev_list_entry *entry;    cairo_drm_device_t *dev;    /* optimistic atomic pointer read */    dev = _cairo_drm_default_device;    if (dev != NULL)	return dev;    udev = udev_new();    if (udev == NULL) {	_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);	return (cairo_drm_device_t *) &_nil_device;    }    e = udev_enumerate_new (udev);    udev_enumerate_add_match_subsystem (e, "drm");    udev_enumerate_scan_devices (e);    udev_list_entry_foreach (entry, udev_enumerate_get_list_entry (e)) {	struct udev_device *device;	device =	    udev_device_new_from_syspath (udev,		    udev_list_entry_get_name (entry));	dev = cairo_drm_device_get (device);	udev_device_unref (device);	if (dev != NULL) {	    if (dev->fd == -1) { /* try again, we may find a usable card */		cairo_drm_device_destroy (dev);		dev = NULL;	    } else		break;	}    }    udev_enumerate_unref (e);    udev_unref (udev);    cairo_drm_device_destroy (dev); /* owned by _cairo_drm_default_device */    return dev;}

bool QUdevService::isPropertyAvailable(const char *property, const char *value){    bool available = false;    struct udev_enumerate *enumerate = 0;    if (context) {        if ((enumerate = udev_enumerate_new(context))            && (0 == udev_enumerate_add_match_property(enumerate, property, value))            && (0 == udev_enumerate_scan_devices(enumerate))) {            available = (0 != udev_enumerate_get_list_entry(enumerate));        }    }    if (enumerate)        udev_enumerate_unref(enumerate);    return available;}

bool QUdevService::isSubsystemAvailable(const char *subsystem){    bool available = false;    struct udev_enumerate *enumerate = 0;    if (context) {        if ((enumerate = udev_enumerate_new(context))            && (0 == udev_enumerate_add_match_subsystem(enumerate, subsystem))            && (0 == udev_enumerate_scan_devices(enumerate))) {            available = (0 != udev_enumerate_get_list_entry(enumerate));        }    }    if (enumerate)        udev_enumerate_unref(enumerate);    return available;}