Function get_report

lib/hidapi/mac/hid.c:1140–1177

}

static int get_report(hid_device *dev, IOHIDReportType type, unsigned char *data, size_t length)
{
	unsigned char *report = data;
	CFIndex report_length = length;
	IOReturn res = kIOReturnSuccess;
	const unsigned char report_id = data[0];

	register_device_error(dev, NULL);

	if (report_id == 0x0) {
		/* Not using numbered Reports.
		   Don't send the report number. */
		report = data+1;
		report_length = length-1;
	}

	/* Avoid crash if the device has been unplugged. */
	if (dev->disconnected) {
		register_device_error(dev, "Device is disconnected");
		return -1;
	}

	res = IOHIDDeviceGetReport(dev->device_handle,
	                           type,
	                           report_id,
	                           report, &report_length);

	if (res != kIOReturnSuccess) {
		register_device_error_format(dev, "IOHIDDeviceGetReport failed: (0x%08X) %s", res, mach_error_string(res));
		return -1;
	}

	if (report_id == 0x0) { /* 0 report number still present at the beginning */
		report_length++;
	}

	return (int) report_length;
}

int HID_API_EXPORT hid_write(hid_device *dev, const unsigned char *data, size_t length)
{