w_or_r
close(w_or_r(pf[1], pf[0]));
close(w_or_r(0, 1));
dup(w_or_r(pf[0], pf[1]));
close(w_or_r(pf[0], pf[1]));
close(w_or_r(pf[0], pf[1]));
return (w_or_r(pf[1], pf[0]));