67     int fd;  in serialopen()  local
72     if ((fd = open(device, O_RDWR)) < 0)  in serialopen()
75     if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {  in serialopen()
76 	(void)close(fd);  in serialopen()
80     return fd;  in serialopen()
84 serialreadchar(int fd, int timeout)  in serialreadchar()  argument
95     FD_SET(fd, &fds);  in serialreadchar()
99     if ((n = select(fd + 1, &fds, 0, 0, &tv)) < 0)  in serialreadchar()
105     if ((n = read(fd, &ch, 1)) < 0)  in serialreadchar()
115 serialwrite(int fd, char *buf, int len)  in serialwrite()  argument
120 	n = write(fd, buf, len);  in serialwrite()
130 serialclose(int fd)  in serialclose()  argument
132     return close(fd);  in serialclose()