ISPIPE
io->flags |= ISPIPE;
if (!(in.flags & (ISPIPE|ISTAPE)) &&
#define ISPIPE 0x02 /* pipe (not truncatable) */
if (!(in.flags & (ISPIPE|ISTAPE)) && !isatty(in.fd)) {
if (in.flags & ISPIPE) {
&& (artyp != ISPIPE)) {
artyp = ISPIPE;
case ISPIPE:
if ((artyp != ISPIPE) || (lstrval <= 0))
if (artyp == ISPIPE) {
case ISPIPE:
case ISPIPE:
case ISPIPE:
case ISPIPE: