From: utzoo!decvax!wivax!linus!genradbo!mitccc!barmar
Newsgroups: net.unix-wizards
Title: Re: UNIX wish-list
Article-I.D.: mitccc.228
Posted: Fri Dec 17 00:10:13 1982
Received: Thu Dec 23 22:42:39 1982
References: ihnet.106

1) Device-independent I/O:

There is no such thing that is also useful.  Every device is going to
have certain operations that make no sense for it and certain operations
that are unique to it.  What would it mean to try to find the inter-record
gap on a disk file?  What does it mean to home the cursor on a tape?
Or rewind a tty.  Very few of these things make sense for a pipe, which is
just a pure stream of characters.  It would consider it a bug that
there is no way to send EOF through a pipe, although I can understand
why it works that way: EOF means that nothing more is coming - it is
tty's, not pipes, that break the rule.

2) I/O ready signal:
Well, if Unix had decent inter-process communications then the
way you would do this is simple.  On Multics we have things called
"event channels", which are objects that your process can go blocked on.
Another process can signal on an event channel, which causes the
blocked process to wake up.  You can block on multiple event channels,
and detect which channel it was that the signal came in on.

3) video editors picky about their output:
Well, if a video display managing program isn't connected to a tty,
then what terminal type should it use?  Don't say that it should use
the user's login terminal, because I might want to be able to say:
	emacs >/dev/tty5
(actually, I don't know if this really works right, but it should!)
					barmar