main.c

来自「QQ2440 在linux嵌入式操作系统 的按键 测试源码」· C语言 代码 · 共 42 行

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


int main(void)
{
	int fd;
	fd = open("/dev/input/event0", 0, 0);
	if (fd < 0) {
		perror("open /dev/input/event0:");	
		exit(1);
	}
	for (;;) {
		fd_set FdsRead;
		int Result;
		FD_ZERO(&FdsRead);
		FD_SET(fd, &FdsRead);

		if ( (Result = select(fd + 1, &FdsRead, NULL, NULL, NULL)) > 0) {
			struct input_event {
			        struct timeval time;
				unsigned short type;
				unsigned short code;
				long value;
			} Point;
			int ret = read(fd, &Point, sizeof Point);
			if (ret != sizeof Point) {
				printf("sizeof Point is %d, ret is %d\n", sizeof Point, ret);
				perror("read /dev/input/event0:");
				exit(1);
			}
			printf("Type: %d Code: %d \n", Point.type, Point.code);
		
		}
	}
	return 0;
}