_tx_snd
return (_tx_snd(fd, buf, nbytes, flags, TX_TLI_API));
extern int _tx_snd(int, char *, unsigned, int, int);
return (_tx_snd(fd, buf, nbytes, flags, TX_XTI_API));
return (_tx_snd(fd, buf, nbytes, flags, TX_XTI_XNS5_API));