Linux Halt Beep |
Linux C Programming |
Quozl had an old 486/100 that was shutdown daily, but it normally had
no monitor attached. He needed a way to tell that it was ready to be
powered down. This patch against 2.2.12
adds a small fragment of code to generate a descending tone sequence
just after the "Power down" message.
(The function kd_mksound() from drivers/char/vt.c was used. This
function starts the tone generation and normally schedules a timer to
turn it off. Since the timers do not run at this point, the duration
of the tones had to be set using msleep() macro calls.)
Since writing this, Quozl has been told that it could have been done
in a process executed after the disks are unmounted. Oh well. Not
half as much fun! Here's how, on Debian ...
- create a file /etc/init.d/beep containing the sound effect, for example:
#!/bin/sh
echo -n "\007" > /dev/console
sleep 1
echo -n "\007" > /dev/console
sleep 1
echo -n "\007" > /dev/console
- link it to the run level 0 so that it executes on shutdown
# cd /etc/rc0.d
# ln -s ../init.d/beep S85beep
Got too many machines shutting down? Consider the Debian package
morse, which will let you emit a morse code signal identifying the
machine.
(14 November 2000)
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