input ready under UNIX ??!!??

[John A. Ebersold]

Several years ago, on a PDP-11 under Ultrix-11 I did basically the following:
(Forgive the pigdin C :-)  ).

	long l;

	fp = fopen(the tty);
	fd = fileno(fp);

	if (ioctl(fd, FIONREAD, &l) != -1)
		if (l > 0)
			printf("There are characters\n");

I believe this is a Berkeleyism - the flavor I am not sure of.

There is also fcntl:

	fcntl(fd, FNDELAY, arg);
To quote the manual:

"nonblocking I/O; if no data is available to a read call, or if a write
operation would block, the call returns -1 with the error EWOULDBLOCK."

Also a Berkeleyism.