led_test.c

来自「LED测试应用程序文件 (基于AT91SAM9260开发板linux2.6.22」· C语言 代码 · 共 28 行

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
int main(int argc, char **argv)
{
   int on;
   int led_no;
   int fd;
   if(argc!=3 || sscanf(argv[1],"%d",&led_no)!=1 || sscanf(argv[2],"%d",&on)!=1 || on<0 || on>1 || led_no<0 || led_no>3)
   {
       printf("Usage: leds led_no 1|0\n");
       goto end1;
   }
   fd=open("/dev/leds",0);
   if(fd<0)
   {
      printf("Can't open /dev/leds\n");
      goto end1;
   }
   ioctl(fd,on,led_no);
   close(fd);
end1:
   return 0;

}