test_led.c

来自「LINUX+9200基础实验 :点亮板子上的LED 驱动程序部分led_mod」· C语言 代码 · 共 47 行

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

main()
{
	int testdev;
	int err;
    int led_data;        

	testdev = open("/dev/led",O_RDWR);

	if ( testdev < 0  )
	{
		printf("Cann't open file testdev=0x%08X\n",testdev);
		exit(0);
	}


	while(num)
	{
		led_data = 0xffffffff;

		err = write(testdev, &led_data, 4);
		if(4 != err )
                {
			printf("write error: %d\n",err);
                }
		sleep(1);

		led_data = 0x0;
		err = write(testdev, &led_data, 4);
		if(4 != err )
		{
			printf("write error: %d\n",err);
		}
		sleep(1);
        //num--;
	}

	close(testdev);
}