Sending Errors to A Specific Console?

[Tim Chase]

On 10/30/11 19:18, Hart Larry wrote:
> So my idea would be if first I could select a console such as
> tty22  where all error messages would go.

If you su/sudo to root, you can use "cat" to read the contents of 
/proc/kmsg so for your example, I'd switch to console #22, and type

   sudo cat /proc/kmsg

and all system/kernel messages should appear in this console as 
they would if you were monitoring the output of "dmesg -r"

Note that the "cat" command (or the following "sed" command) both 
hang awaiting additional output, so you have to use control+C to 
terminate them if you're experimenting rather than just leaving 
them running in the background.

> Then for those who figure its important to know of and examine
> them, maybe the PC speaker could ring 2 rapid bells.

Using the above command, you could do something like

   sudo sed '/^<[6]>/&\x07\x07/' /proc/kmsg

which would send two BELL characters to this console if the 
logging level (the first field in angled-brackets is the logging 
level, which you can see if you use "dmesg -r") was one of the 
defined set.  In this case, I just log-level 6 since that gives 
me most of what I would find important, but you can change it to 
something like "[367]" to log levels 3, 6, and 7, or even just

   sudo sed 's/^/\x07\x07/' /proc/kmsg

though this has the unfortunate side effect of ringing twice for 
EVERY line printed, which I think would annoy the SNOT out of me. 
<grins>


I don't know of these are the best solutions--especially the part 
where it involves leaving a console open with root access if you 
use "su" instead of configuring "sudo"; perhaps for this you 
could chown/chmod the file like

   chown :plugdev /proc/kmsg
   chmod g+r /proc/kmsg

and then run it as your regular user.  I don't know if this will 
work for you, but hopefully it's at least a start.

-tim