Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 (Tek) 9/26/83; site tekcad.UUCP
Path: utzoo!linus!decvax!microsoft!fluke!ssc-vax!uw-beaver!tektronix!tekcad!franka
From: franka@tekcad.UUCP
Newsgroups: net.lang.c
Subject: Re: 1-char input in C - (nf)
Message-ID: <172@tekcad.UUCP>
Date: Sun, 25-Dec-83 13:10:47 EST
Article-I.D.: tekcad.172
Posted: Sun Dec 25 13:10:47 1983
Date-Received: Sun, 1-Jan-84 02:12:01 EST
Sender: franka@tekcad.UUCP
Organization: Tektronix, Beaverton OR
Lines: 31

#R:ihuxn:-46300:tekcad:2600002:000:1170
tekcad!franka    Dec 25 10:10:00 1983

>Your problem is a common one.  The problem is that UNIX is buffering up
>the data, as opposed to the C library routines.  The most portable solution
>(and easiest to understand) is to use the system() call to change the
>tty mode as follows:
>
>#include <stdio.h>
>main() {
>    system("stty raw");		/* dont buffer data */
>    getchar();
>    system("stty -raw");	/* restore normal buffering */
>}
>
>The other option is to use ioctl() (or gtty & stty on systems that have it)
>to set the tty modes properly.  The problem with this is that BELL, BSD and
>V7 systems are all different in the exact format of these ioctl()'s

	The other problem with this is that if somebody hits a ^C (or ^\)
during the getchar, the terminal gets put in "raw" mode. This is very, very
confusing to a novice user (I assume that is who you are writing for, with
such a limited command set) who suddenly cannot backspace, use the return
key on a command, etc.

               				From the truly menacing,
   /- -\       				but usually underestimated
    <->                                 and soon to be gone,
               				Frank Adrian
               				(tektronix!tekcad!franka)