Date: Tue, 2 Apr 2013 23:15:22 +0200 From: Polytropon <freebsd@edvax.de> To: "Ronald F. Guilmette" <rfg@tristatelogic.com> Cc: freebsd-questions@freebsd.org Subject: Re: Recipie for CPU souffle' Message-ID: <20130402231522.71cb7352.freebsd@edvax.de> In-Reply-To: <15043.1364932520@server1.tristatelogic.com> References: <515AAE16.9030707@qeng-ho.org> <15043.1364932520@server1.tristatelogic.com>
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On Tue, 02 Apr 2013 12:55:20 -0700, Ronald F. Guilmette wrote:
> Is there any specific advantage to using that, relative to using mbmon?
As far as I understand, it's utilizing a different infrastructure
to obtain data. You can see "man amdtemp" in comparison to the
reporting mechanisms mbmon uses.
> >..."man speaker"...
>
> Humm... I'm looking at that now and it raises more questions that it answers.
It's just an interface to the PC speaker, what question? :-)
> First order question: Why is it that in FreeBSD there are so many man
> pages like this one, _purporting_ to describe some low level interface
> to some sort of hardware, and the man page _doesn't_ include a clear
> and explicit description of the relevant ioctls ?
Discovering those usually involved using the driver sources.
The driver description provided in the manpage doesn't cover
everything, but it says: "definitions for the ioctl(2)
interface are in <dev/speaker/speaker.h>".
> Second order question: Why can't I just pipe a .wav file to the
> /dev/speaker device file and have it play? Wouldn't that make quite
> a lot of sense?
No, that does not work. Read the manpage to recognize clearly
_what_ kind of input the /dev/speaker device accepts. It does
not understand WAV files.
However, try this example (cw.sh):
#!/bin/sh
read -p "CW ===> " TEXT
echo ${TEXT} | morse | awk '{
if(length($0) == 0)
printf("P4\n");
else {
gsub(" dit", "P32L32E", $0);
gsub(" di", "P32L32E", $0);
gsub(" dah", "P32L8E", $0);
printf("%sP16\n", $0);
}
}' | dd bs=256 of=/dev/speaker > /dev/null 2>&1
This script doesn't require any non-OS components. You can use
it as a basis to build a program that will send you system messages
in an audible way in morse code... :-)
> >/usr/sbin/spkrtest might be useful
>
> Humm... well... it is at least mildly entertaining.
But probably not required, because the simplest test you could
construct is something like
% echo "c" > /dev/speaker
Can you hear a sound? Yes? Good. Speaker works. Don't hear
anything? Either your system doesn't have a speaker, or the
driver isn't loaded. :-)
Hint: Make sure permissions are set properly.
own speaker root:operator
perm speaker 0660
You can add those to /etc/devfs.conf if you're a member of
the "operator" group.
> I wonder if whoever write and distributed this realized that he/she could
> be sued for copyright infringement for about 5 of the simple tunes that are
> embedded in that thing. Sad but true.
> :-(
Is it really that bad already? "Patent of swinging on a swing
or exercising a cat" time? ;-)
--
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...
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