ENGINE_INPUT
if ((rv = auimpl_engine_open(sp, flags | ENGINE_INPUT)) != 0)
if (e->e_flags & ENGINE_INPUT) {
if (e->e_flags & (ENGINE_INPUT | ENGINE_OUTPUT)) {
if (e->e_flags & ENGINE_INPUT) {
flags |= ENGINE_INPUT;
if (((flags & ENGINE_INPUT) && (t->e_flags & ENGINE_OUTPUT)) ||
((flags & ENGINE_OUTPUT) && (t->e_flags & ENGINE_INPUT))) {
if (flags & ENGINE_INPUT) {