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[patch] termios.3: Clarify the description of ONLRET

From: Simon Branch <hidden>
Date: 2021-11-29 18:45:38
Subsystem: the rest · Maintainer: Linus Torvalds

Hello!  While perusing various termios(3) and termios(4) manpages (as one does)
I noticed the following inconsistency for ONLRET.  FreeBSD and NetBSD say
this:

   If ONLRET is set, the NL character is assumed to do the carriage-return
   function; the column pointer will be set to 0.

OpenBSD says this:

   If ONLRET is set, NL also performs CR on output, and reset current column
   to 0.

POSIX says this:

   NL performs CR function.

The current Linux manpage says this (!):

   Don't output CR.

Perhaps I'm misunderstanding the purpose of this flag, but (if nothing else) the
constrast here is a little confusing.  It looks like Linux follows the same
behavior as all the other platforms:

   $ stty -icanon -onlcr -icrnl -echo onlret onocr; cat
   this is some text			(^J pressed)
                    and some more	(^M pressed before additional text)

Comments?  OK?

---
 man3/termios.3 | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/man3/termios.3 b/man3/termios.3
index c11937458..20641f14d 100644
--- a/man3/termios.3
+++ b/man3/termios.3
@@ -203,7 +203,9 @@ Map CR to NL on output.
 Don't output CR at column 0.
 .TP
 .B ONLRET
-Don't output CR.
+The NL character is assumed to do the carriage-return function;
+the kernel's idea of the current column is set to 0
+after both NL and CR.
 .TP
 .B OFILL
 Send fill characters for a delay, rather than using a timed delay.
-- 
2.34.0
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