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

int main(int argc, char *argv[])
{
    int flag = 0;
    int freq = 0;
    int duration = 0;
    unsigned char buf[4];
    int fd = 0;
    int ret = 0;
    if(argc != 4)
    {
        printf("Usage: %s on 2 2400\n", argv[0]);
        return 1;
    }

    if(strcmp(argv[1], "on") == 0)
    {
        flag = 1;
    }
    else if(strcmp(argv[1], "off") == 0)
    {
        flag = 0;
    }
    else
    {
        printf("Usage: %s on 2 2400\n", argv[0]);
        return 1;
    }

    freq = atoi(argv[3]);
    duration = atoi(argv[2]);

    memset(buf, 0, sizeof(buf));
    buf[0] = flag;
    buf[1] = freq&0xff;
    buf[2] = (freq>>8)&0xff;
    buf[3] = duration&0xff;

    fd = open("/dev/buzzer", O_RDWR);
    if(fd < 0)
    {
        printf("open /dev/buzzer failed\n");
        return 1;
    }

    ret = write(fd, buf, sizeof(buf));
    if(ret < 0)
    {
        printf("write /dev/buzzer failed\n");
        return 1;
    }
    close(fd);
}