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From: heiby@cuae2.UUCP (Ron Heiby)
Newsgroups: net.micro.att
Subject: Re: ATT 3b2 (SVR2) questions
Message-ID: <373@cuae2.UUCP>
Date: Fri, 19-Jul-85 10:04:53 EDT
Article-I.D.: cuae2.373
Posted: Fri Jul 19 10:04:53 1985
Date-Received: Sat, 20-Jul-85 11:54:39 EDT
References: <746@wlcrjs.UUCP>
Reply-To: heiby@cuae2.UUCP (Ron Heiby)
Distribution: na
Organization: AT&T-IS, /app/eng, Lisle, IL
Lines: 23

In article <746@wlcrjs.UUCP> djs@wlcrjs.UUCP (David Schmidt) writes:
>
>Many of the programs I'm trying to port require CBREAK and no
>ECHO modes.  How is this done under SVR2?

In Unix System V, the terminal modes have quite a lot of flexibility in
determining when a read() can complete.  They are documented in excruciating
detail in termio(7) (in the "AT&T 3B2 Computer UNIX System V Release 2.0
System Administration Utilities Guide", Select Code 305-422, Comcode
403778384, which is bundled with the 3B2 and which you should have received).

What you basically want to do is turn off ICANON and set VMIN and VTIME as
your application requires.  CBREAK is, I believe, MIN=1, TIME=0.  "The MIN
and TIME values are stored in the position for the EOF and EOL characters,
respectively.  The time value represents tenths of seconds."
To turn off echo modes, turn off that bit, as well.  (It may be that this
is automatic, but I don't think so.)  The parameters are changed via ioctl()
operations.  I strongly recommend using TCSETAW instead of TCSETA, because
some computer systems actually implement a no-wait mode stomper, which can
garble some characters being output at the time.
-- 
Ron Heiby	heiby@cuae2.UUCP	(via ihnp4)
AT&T-IS, /app/eng, Lisle, IL	(312) 810-6109