clist_getc
dcons_os_putc(dc, clist_getc(&tp->t_outq));
while ((c = clist_getc(&tq)) >= 0)
c = clist_getc(qp);
if (ureadc(clist_getc(&tp->t_canq), ap->a_uio) < 0) {
clist_getc(&tp->t_canq);
while ((c = clist_getc(cls)) != -1)
int clist_getc (struct clist *q);