read_tty
int read_tty = 0;
read_tty = 1;
if (read_tty)
read_tty(buf,sizeof(buf));
#ifndef read_tty
if (read_tty(wbuf,1) < 0 && !errno)
#ifdef read_tty
read_tty(&scrchar,1);
#ifndef read_tty
int read_tty(char *, ssize_t);