- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <sys/ioctl.h>
- #include <fcntl.h>
- #include <linux/fb.h>
- int main(int argc,char **argv)
- {
- int turn;
- int fd;
- if(argc==1)
- {
- fprintf(stderr,"\nUsage:bcklight on/off !\n\n");
- exit(1);
- }
- fd=open("/dev/fb0",O_RDWR);
- if(fd<0)
- {
- perror("open LCD device!");
- exit(1);
- }
- if(strcmp(argv[1],"on")==0)
- turn=1;
- else if(strcmp(argv[1],"off")==0)
- turn=0;
- else
- {
- fprintf(stderr,"\nUsage:backligt on/off!\n\n");
- exit(1);
- }
- ioctl(fb,FBIOBLANK,turn);
- close(fb);
- return 0;
- }
复制代码 编译时出现如下错误:
backlight.c:35: error: 'fb' undeclared (first use in this function)
backlight.c:35: error: (Each undeclared identifier is reported only once
backlight.c:35: error: for each function it appears in.)
make: *** [backlight] 错误 on/ofd
请问是怎么回事啊?
就是按照教程上弄的,为什么不对啊,请教一下各位高人了。谢谢 |