说明：  功能：arm系列开发板，linux系统下的截屏程序，直接对FBdev设备进行读写，保存为bmp格式的图片。对arm开发板的嵌入式用户很有用处，因为在arm lilnux中没有截屏命令。
(Function: arm Series development board, linux system under the screen capture programs, read and write directly to FBdev equipment, save as bmp format images. Embedded arm development board for the user useful, because there is no cut in the arm lilnux screen commands.)