POSIX compliant replacement for usleep(2)

sleepu.c

int
sleepu(double usec) {
        struct timespec req, rem;
        int r;

        req.tv_sec = 0;
        req.tv_nsec = usec * 1000;
        while((r = nanosleep(&req, &rem)) == -1 && errno == EINTR)
                req = rem;
        return r;
}