LPF_INPUT
if (pp->filters[LPF_INPUT]) {
filtcmd = pp->filters[LPF_INPUT];
if (pp->filters[LPF_OUTPUT] && !pp->filters[LPF_INPUT] && !of_pid) {
if (pp->filters[LPF_INPUT] == NULL
if (pp->filters[LPF_INPUT] == NULL) { /* use output filter */
prog = pp->filters[LPF_INPUT];
prog = pp->filters[LPF_INPUT];