#include    <machine/apm_bios.h>

#include    <fcntl.h>
#include    <unistd.h>
#include    <stdio.h>
#include    <err.h>
#include    <sysexits.h>

#define PATH_APM    "/dev/apm"
#define TIME_FMT    "%d:%02d:%02d"
#define TIME_LEN    10

static void
_time2str(u_int t, char *s)
{
    snprintf(s, TIME_LEN, TIME_FMT,
	    t / (60 * 60),
	    (t % (60 * 60)) / 60,
	    t % 60);
}

int
main(int ac, char *av[])
{
    int		    afd;
    struct apm_info ai;
    char	    ts[TIME_LEN];

    if ((afd = open(PATH_APM, O_RDONLY)) == -1)
	err(EX_NOINPUT, "Cannot open apm device %s", PATH_APM);
    if (ioctl(afd, APMIO_GETINFO, &ai) == -1)
	err(1, "Cannot retrieve APM Information");
    close(afd);
    if (!ai.ai_acline)
    {
	_time2str(ai.ai_batt_time, ts);
	printf("%d%% (%s) Battery Life\n", ai.ai_batt_life, ts);
    }
    else
	printf("Machine is on AC Line power\n");

    return 0;
}