Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!snorkelwacker!apple!bbn.com!gateway!ANDREW.CMU.EDU!vd09+
From: vd09+@ANDREW.CMU.EDU ("Vincent M. Del Vecchio")
Newsgroups: comp.emacs
Subject: Re: unbufferd input; hypercard emulator
Message-ID: <1362@archive.ARCHIVE.BBN.COM>
Date: 6 Sep 90 19:47:52 GMT
References: <12553@sdcc6.ucsd.edu>
Sender: news@bbn.com
Organization: BBN news/mail gateway
Lines: 23

I'm not sure what this has to do with Emacs, but I'll respond anyway.

What you have to do is turn off the buffering on the tty.  Generally,
check the tty man pages to find out more (and possibly check ioctl as
well).  In BSD4.3 (can't verify for anything else, but it will be fairly
similar), this should work:

#include <sgtty.h>

struct sgttyb buf;
ioctl(0,TIOCGETP, &buf);
buf.sg_flags |= CBREAK;
ioctl(0,TIOCSETP, &buf);

Then, when you read() or getchar(), it will return immediately.

+----------------------------------------------------------------------------+
| Vincent Del Vecchio     \ Disclaimer: Views expressed are not necessarily  |
| Box 4872                 \ those of any person/group I am associated with. |
| 5125 Margaret Morrison St.\   UUCP: {uunet,harvard}!andrew.cmu.edu!vd09    |
| Pittsburgh, PA  15213      \   BITNET: vd09+%andrew@cmuccvma.bitnet        |
| (412) 268-4441              \   Internet: vd09+@andrew.cmu.edu             |
+----------------------------------------------------------------------------+