检测/监控嵌入式LINUX有没有插入USB设备，此代码主要是在应用程序启动后不能通过socket来获得消息的情况下使用。-Detection/monitoring of embedded LINUX there is no USB device, this code is primarily in the application starts, can not get the message through the socket to the case of use.

Linux简单字符设备驱动编写方法本示例代码实现了Linux下的一个简单字符设备驱动。由二个文件组成，驱动模块< dev_add.c> 和测试程序< test.c> 。-Linux character device driver writing simple methodThe sample code implements a simple under Linux character device drivers.Composed by two files, the driver