func (h *DeviceHandle) GetStringDescriptorASCII(descIndex byte) (string, error) {
data := make([]byte, 1024)
start := (*C.uchar)(unsafe.Pointer(&data[0]))
r := C.libusb_get_string_descriptor_ascii(h.me(),
C.uint8_t(descIndex), start, C.int(len(data)))
return C.GoString((*C.char)(unsafe.Pointer(&data[0]))), toErr(r)
}
func getSerialNumber(dev *C.libusb_device, index C.uint8_t) string {
data := make([]byte, 1024)
var devHandle *C.libusb_device_handle
if errno := C.libusb_open(dev, &devHandle); errno != 0 {
return ""
}
defer Close(devHandle)
errno := C.libusb_get_string_descriptor_ascii(devHandle, index, (*C.uchar)(unsafe.Pointer(&data[0])), C.int(len(data)))
if errno <= 0 {
return ""
}
return C.GoString((*C.char)(unsafe.Pointer(&data[0])))
}
func (d *Device) GetStringDescriptor(desc_index int) (string, error) {
// allocate 200-byte array limited the length of string descriptor
goBuffer := make([]byte, 200)
// get string descriptor from libusb. if errno < 0 then there are any errors.
// if errno >= 0; it is a length of result string descriptor
errno := C.libusb_get_string_descriptor_ascii(
d.handle,
C.uint8_t(desc_index),
(*C.uchar)(unsafe.Pointer(&goBuffer[0])),
200)
// if any errors occur
if errno < 0 {
return "", fmt.Errorf("usb: getstr: %s", usbError(errno))
}
// convert slice of byte to string with limited length from errno
stringDescriptor := string(goBuffer[:errno])
return stringDescriptor, nil
}