【C语言】之获取屏幕显示器信息

比眉伴天荒 2022-05-30 05:52 702阅读 0赞

### 1、操作的设备为：`/dev/fb` （显存设备） ###

### 2、7完整源代码如下： ###

--------------------

#include <stdio.h>
    #include <unistd.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <linux/fb.h>
    
    int main(int argc, char **argv)
    { 
    	int fd;
    	
    	/* 打开fb设备文件 */
    	fd = open("/dev/fb0", O_RDWR);
    	if (-1 == fd)
    	{ 
    		perror("open fb");
    		return -1;
    	}
    
    	/* 获取fix屏幕信息:获取命令为FBIOGET_FSCREENINFO */
    	struct fb_fix_screeninfo fixInfo;
    
    	if (ioctl(fd, FBIOGET_FSCREENINFO, &fixInfo) == -1)
    	{ 
    		perror("get fscreeninfo");
    		close(fd);
    		return -2;
    	}
    	/* 打印fix信息 */
    	printf("id = %s\n", fixInfo.id); /* 厂商id信息 */
    	printf("line length = %d\n", fixInfo.line_length); 
    									/* 这里获取的是一行像素所需空间 * 该空间大小是出厂时就固定的了 * 厂商会对一行像素字节进行对齐*/
    
    	/* 获取var屏幕的信息:获取命令为FBIOGET_VSCREENINFO */
    	struct fb_var_screeninfo varInfo;
    
    	if (ioctl(fd, FBIOGET_VSCREENINFO, &varInfo) == -1)
    	{ 
    		perror("get var screen failed\n");
    		close(fd);
    		return -3;
    	}
    	/* 打印var信息 */
    	printf("xres = %d, yres = %d\n", varInfo.xres, varInfo.yres);
    	printf("bits_per_pixel = %d\n", varInfo.bits_per_pixel);
    	printf("red: offset = %d, length = %d\n", \
    					varInfo.red.offset, varInfo.red.length);
    	printf("green: offset = %d, length = %d\n", \
    					varInfo.green.offset, varInfo.green.length);
    	printf("blue: offset = %d, length = %d\n", \
    					varInfo.blue.offset, varInfo.blue.length);
    	printf("transp: offset = %d, length = %d\n", \
    					varInfo.transp.offset, varInfo.transp.length);
    
    	close(fd);
    	return 0;
    }