From: Karel Zak <kzak@redhat.com>
To: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: kerolasa@gmail.com, util-linux <util-linux@vger.kernel.org>
Subject: Re: [PATCH] dmesg: add --follow-new
Date: Mon, 1 Jun 2020 09:53:25 +0200 [thread overview]
Message-ID: <20200601075325.ufmficzg5u57ocek@ws.net.home> (raw)
In-Reply-To: <1d1e123b-d107-78c2-e76c-c5be3dcdf89e@yandex-team.ru>
On Sun, May 31, 2020 at 03:18:47PM +0300, Konstantin Khlebnikov wrote:
> On 31/05/2020 14.49, Sami Kerola wrote:
> > On Sat, 30 May 2020 at 15:08, Konstantin Khlebnikov
> > <khlebnikov@yandex-team.ru> wrote:
> > > Option --follow-new (-W) works the same as --follow (-w) but initially
> > > seeks to the end of kernel ring buffer, so it prints only new messages.
> > > Useful for capturing kernel messages during actions without past log.
IMHO good idea.
> > I wonder if it would be more useful to add '-n, --lines=[+]NUM' that
> > would be similar
> > to tail(1) option and argument. The --follow-new with an option that
> > lists NUM last
> > messages would be --lines=0
It does not seem use-friendly ;-) I guess type "-W" is pretty
straightforward.
> > That said should --since and --until options similar to journalctl(1)
> > be considered
> > as well?
--since '1 hour ago' would be nice, but I have doubts it's will so
easy to implement due to crazy timestamps in the log.
> Implementation is also non-trivial - currently dmesg reads and prints
> messages from /dev/kmsg in a loop. It doesn't know how many lines left.
> /dev/kmsg doesn't support lseek with non-zero offset, only SET/DATA/END.
Yes.
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
next prev parent reply other threads:[~2020-06-01 7:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-30 14:07 [PATCH] dmesg: add --follow-new Konstantin Khlebnikov
2020-05-31 11:49 ` Sami Kerola
2020-05-31 12:18 ` Konstantin Khlebnikov
2020-06-01 7:53 ` Karel Zak [this message]
2020-06-01 7:56 ` Karel Zak
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