freebsd stable - Jan 2017 - reset not working like 70% of the time

On Wed, Jan 25, 2017 at 4:52 AM, Eugene M. Zheganin <emz at norma.perm.ru>
wrote:
> does anyone suffer from this too ? Right now (and for several last
> years) a 100% decent way to reset a terminal session (for instance,
> after a connection reset, after acidentally displaying a binary file
> with symbols that are treated as terminal control sequence, after
> breaking a cu session, etc) is to launch midnight commander and then
> quit from it. And the reset is working like in 30% of cases only. Unlike
> in Linux, where it's 100% functional.
>
Using an application like that to reset the terminal is dubious at best.
You are at the mercy of how exactly it does terminal conditioning, and
nobody makes any promises about its actual behavior. In fact it could be
argued that, if it does not put the terminal back exactly the way it found
it, the application is broken. But this is actually impossible to do
correctly as the application can't know the terminal's full ANSI X3.64
state. Additionally there's a bit of a "religious issue" around
whether
full screen applications use xterm's alternate screen (and whether xterm
even has that enabled) which will save and restore more of the X3.64 state
around the application.

"tput reset; stty sane" (or just "reset") should usually put
the terminal
into a sensible state. If it doesn't, figure out whether the part that
isn't happening is a termios or a terminfo setting and focus on that part.
Check if xterm has "Enable alternate screen switching" checked on the
control-middle button menu.

-- 
brandon s allbery kf8nh                               sine nomine associates
allbery.b at gmail.com                                  ballbery at
sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net

On 2017-01-25 12:59:27, Brandon Allbery wrote:
> On Wed, Jan 25, 2017 at 4:52 AM, Eugene M. Zheganin <emz at
norma.perm.ru>
> wrote:
> 
> > does anyone suffer from this too ? Right now (and for several last
> > years) a 100% decent way to reset a terminal session (for instance,
> > after a connection reset, after acidentally displaying a binary file
> > with symbols that are treated as terminal control sequence, after
> > breaking a cu session, etc) is to launch midnight commander and then
> > quit from it. And the reset is working like in 30% of cases only.
Unlike
> > in Linux, where it's 100% functional.
> >
> 
> Using an application like that to reset the terminal is dubious at best.
> You are at the mercy of how exactly it does terminal conditioning, and
> nobody makes any promises about its actual behavior. In fact it could be
> argued that, if it does not put the terminal back exactly the way it found
> it, the application is broken. But this is actually impossible to do
> correctly as the application can't know the terminal's full ANSI
X3.64
> state. Additionally there's a bit of a "religious issue"
around whether
> full screen applications use xterm's alternate screen (and whether
xterm
> even has that enabled) which will save and restore more of the X3.64 state
> around the application.
> 
> "tput reset; stty sane" (or just "reset") should
usually put the terminal
> into a sensible state. If it doesn't, figure out whether the part that
> isn't happening is a termios or a terminfo setting and focus on that
part.
> Check if xterm has "Enable alternate screen switching" checked on
the
> control-middle button menu.
OP stated he's using konsole (KDE wannabe xterm).

OP, try and create a minimal file with script that doesn't clean up your
terminal
on reset(1). Make sure it doesn't contain confidential information. Publish
your
environment (env | grep TERM) and this script file somewhere. Let others know
the
URL. Then we can actually begin to answer your original question, whether or not
we see this as well. You could also try to reproduce your problems with
different
terminal emulators (xterm, freebsd console)

Regards,
-Martin