getttyent
while (NULL != (ty = getttyent())) {
struct ttyent *getttyent(void);
while ( (t = getttyent()) )
while ((typ = getttyent()) != NULL)
while ((typ = getttyent()) != NULL) {
while ((tty = getttyent()) != NULL) {
for (slot = 1; (ttyp = getttyent()); ++slot)