Re: lib/57867: Why does cbreak or raw affect terminal output differently?

[Anthony Howe <achowe%snert.com@localhost>]

The following reply was made to PR lib/57867; it has been noted by GNATS.

From: Anthony Howe <achowe%snert.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: lib/57867: Why does cbreak or raw affect terminal output
 differently?
Date: Wed, 24 Jan 2024 09:53:10 -0500

 On 2024-01-23 16:32, Brett Lymn wrote:
 > On Mon, Jan 22, 2024 at 07:50:02AM +0000, RVP wrote:
 
 > It should, see:
 > 
 > https://pubs.opengroup.org/onlinepubs/7908799/xcurses/intov.html#tag_001_005_002
 > 
 > the termios settings are different between raw and cbreak, see the function
 > _cursesi_gettmode in tty.c which defines the mode.
 
 The SUS Curses Issue 7 talks about cbreak(), raw(), nl() as functions affecting 
 input only (no mention about output).  Yet tty.c, raw(), disables `OPOST` that 
 influences output and cbreak() leaves what ever the termios oflag has set by stty.
 
 https://pubs.opengroup.org/onlinepubs/7908799/xcurses/cbreak.html
 https://pubs.opengroup.org/onlinepubs/7908799/xcurses/nonl.html
 
 When I was with MKS maintaining their Curses and balloting Xopen at the time, I 
 found historical Curses behaviour (which touches input/output terminal 
 behaviour) to conflict with XOpen drafts at the time which overlook how those 
 functions also affect terminal output.
 
 > Also, a couple of things:
 > 
 > 1) This isn't really a bug per se, it probably would have been better to ask on one of the
 > mailing lists.
 
 Well I filed this not as a bug, but as a `support` question, which I assume this 
 fell under in case it elevated to a bug.
 
 -- 
 Anthony C Howe
 achowe%snert.com@localhost                                   BarricadeMX & Milters
 http://nanozen.snert.com/                          http://software.snert.com/