close(pty_utmp_helper_pipe);
if (pty_utmp_helper_pipe >= 0) { close(pty_utmp_helper_pipe);    pty_utmp_helper_pipe = -1; }
static void pty_close(void){    if (pty_master_fd >= 0) {	close(pty_master_fd);	pty_master_fd = -1;    }    close(pty_utmp_helper_pipe);       /* this causes utmp to be cleaned up */}