SIGIO
#define RECV SIGIO
(void) kill(__pid, SIGIO);
if (sig == SIGIO && rv == 0 && tactp != NULL) {
sigaddset( &ints_off, SIGIO );
gsignal(pty->pt_pgrp, SIGIO);
gsignal(pty->pt_pgrp, SIGIO);
(func = PTOU(p)->u_signal[SIGIO - 1]) != SIG_DFL &&
psignal(p, SIGIO);
(func = PTOU(curproc)->u_signal[SIGIO - 1]) != SIG_DFL &&
psignal(curproc, SIGIO);