Sending Errors to A Specific Console?

[Janina Sajka]

Henry's way is the correct way. However, there's an easy workaround.

Use a terminal application rather than the console. There are advantages
to this approach beyond shielding you from error messages print outs.

Best terminal choice, imho, is screen. It's extremely powerful, yet easy
to pick up incrementally. At first, you won't even know the
difference--it's that good.

Janina

Henry Yen writes:
> Two concepts are needed for the best solution for this.  First, the concept
> of the naming of the Linux virtual consoles.  You already know that
> consoles are "/dev/ttyN" (so console "tty22" is device "/dev/tty22").
> "/dev/tty" and "/dev/tty0" are usually synonyms for "whatever console
> is currently selected at the primary display".  Some time ago, Linux
> also added a "/dev/console", which typically has the same effect as the
> above two, but is now treated as a separate device.  Yes, that's confusing,
> but the documentation file (/usr/src/linux/Documentation/devices.txt) wants
> to make this clear distinction.
> 
> The second concept is that of syslog (the syslog daemon).  Depending on which
> syslog you are using (usually "syslog-ng", but sometimes just "syslog"),
> you can configure exactly how various log messages are handled.  A regular
> program or daemon can emit a message to the "syslog", and the Linux kernel
> itself, of course, also emits messages.  Note that the verbosity of kernel
> messages can be separately specified as the "kernel log level".  Anyhow,
> the syslog/syslog-ng configuration file specifies what you want to do with
> each message that the "syslog" service receives, with options such as writing
> the message to a file (e.g. "/var/log/messages"), piping the message to a
> new program invocation, and/or writing the message to a "/dev/ttyN" console
> (or perhaps "/dev/tty0" or "/dev/console").
> 
> If you are already getting messages on the "console", figure out which
> syslog daemon you're running and look for "console" or "tty" in its
> corresponding config file (e.g. "/etc/syslog-ng/syslog-ng.conf" or
> "/etc/syslog.conf").  This scheme allows a tremendous amount of flexibility
> and will allow you to process these messages in just about any way you
> might want.  There are "man" pages available for klog and syslog.
> 
> Oh, an additional wrinkle.  The "klogconsole" command is used to control
> (I believe) an additional copy of kernel messages that are directed to
> a specified console/tty.
> 
> On Sun, Oct 30, 2011 at 17:18:09PM -0700, Hart Larry wrote:
> > Hi All:  This is first of 2 complicated questions?  The other evening I had 
> > a hard-drive failure--and 9 lines of errors were blasting out, but even 
> > worse each time I would change consoles, the same errors showed up again.  
> > So my idea would be if first I could select a console such as tty22  where 
> > all error messages would go.  Then for those who figure its important to 
> > know of and examine them, maybe the PC speaker could ring 2 rapid bells.  
> > At least that wouldn't messup my screen while I am reading in Pine.  When 
> > looking up this concept, it seemed like a program "klogd" might do this, 
> > but in asking at our LUG last evening, maybe not.
> > Even when I plugin or disconnect a USB device, the message comes on my 
> > current console.
> 
> -- 
> Henry Yen                                       Aegis Information Systems, Inc.
> Senior Systems Programmer                       Hicksville, New York
> 
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-- 

Janina Sajka,	Phone:	+1.443.300.2200
		sip:janina at asterisk.rednote.net

Chair, Open Accessibility	janina at a11y.org	
Linux Foundation		http://a11y.org

Chair, Protocols & Formats
Web Accessibility Initiative	http://www.w3.org/wai/pf
World Wide Web Consortium (W3C)