doselect
doselect(-1, fd, fd, timeout);
doselect(-1, fd, -1, timeout);
doselect(-1, -1, fd, timeout);
doselect(-1, -1, -1, timeout);
doselect(-1, fd, fd, timeout);
doselect(-1, fd, -1, timeout);
doselect(-1, -1, fd, timeout);
doselect(-1, -1, -1, timeout);
doselect(writer, fd, fd, timeout);
doselect(writer, fd, -1, timeout);
doselect(writer, -1, fd, timeout);
doselect(writer, -1, -1, timeout);
void doselect(pid_t, int, int, int);
nitems = scandir(SD, &queue, doselect, sortq);
static int doselect(const struct dirent *);