linux-kernel - Re: [PATCH v7 0/3] console: Add persistent scrollback buffers for all VGA consoles

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Message-ID: <20161129104420.GA14384@angband.pl>
Date:   Tue, 29 Nov 2016 11:44:20 +0100
From:   Adam Borowski <kilobyte@...band.pl>
To:     Andrey Utkin <andrey_utkin@...tmail.com>
Cc:     Manuel Schölling <manuel.schoelling@....de>,
        plagnioj@...osoft.com, tomi.valkeinen@...com, jslaby@...e.cz,
        gregkh@...uxfoundation.org, linux-fbdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 0/3] console: Add persistent scrollback buffers for
 all VGA consoles

On Tue, Nov 29, 2016 at 10:01:15AM +0000, Andrey Utkin wrote:
> Regarding logout scrollback clearing not working for me. ncurses-6.0-rc1
> which I tested it with is the latest available in Gentoo portage, please
> confirm whether I need any newer version, or should I tune something
> else. I'd appreciate if you also tested your patch with gentoo setup.

Could you please check whether its terminfo carries the required
definitions?  In ncurses sources, that's misc/terminfo.src

The relevant parts are:
.--====
# The 3.0 kernel adds support for clearing scrollback buffer (capability E3).
# It is the same as xterm's erase-saved-lines feature.
linux3.0|linux 3.0 kernels,
        E3=\E[3J, use=linux2.6,

# This is Linux console for ncurses.
linux|linux console,
        use=linux3.0,
`----

I believe the first part was added first; if that's true it's possible this
will work for you:
    TERM=linux3.0 clear


I'm not sure what Gentoo does to clear the console during logout: it might
just invoke "clear" (or its underlying ncurses implementation), it might
carry a copy of Debian's "clear_console"[1], it might do something else
entirely.


Meow!

[1]. It originally came from Ubuntu, forked there from "clear".
-- 
The bill declaring Jesus as the King of Poland fails to specify whether
the addition is at the top or end of the list of kings.  What should the
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