GetSystemUptime()

gistfile1.c

int32_t GetSystemUptime()
{
    int mib[2] = {CTL_KERN, KERN_BOOTTIME};
    size_t mib_size = sizeof(mib) /  sizeof(int);
    struct timeval boottime;
    size_t boottime_size = sizeof(boottime);
    
    if (!sysctl(mib, mib_size, &boottime, &boottime_size, NULL, 0)) {
        time_t now;
        time(&now);
        return now - boottime.tv_sec;
    }
    
    return -1;
}