Recipie for CPU souffle'

[Polytropon]

On Tue, 02 Apr 2013 19:10:59 -0700, Ronald F. Guilmette wrote:
> See how the entire ioctl() interface for these device types is completely
> documented IN THE MAN PAGE?  That's the way it should be... None of this
> rooting around in the sources for something that should have been documented
> properly, external to the kernel sources.

I agree that especially to developers, that sounds logical
and very helpful. Seems that manpages do not aim for that
goal anymore...



> It doesn't have to cover "everything".  But it _should_ completely describe
> the programatic interface.

At least is leaves questions, like stating "use the syscalls
in order to...", and the reader is left with the most obvious
question: _which_ syscalls?



> But like I said, somewher along the line, a lot of man page writers
> apparently got lazy... VERY lazy.

But keep in mind they're still alive! Judging from the manpages
of... *cough* can I say this? YOu know, more prominent open
source operating systems for desktops... they're usually much
worse _if_ there is a manpage. In most cases, there's none.



> >> 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.
> 
> Apparently not.
> 
> Why it doesn't work (or couldn't work) is less clear.

The speaker interface to the _PC speaker_ is not a DSP. It's
programming is much simpler. The "note language" that it
uses on FreeBSD is much more than other interfaces offer.
Better ones have stuff like pitch, duration, turn off.
Worse ones only can emit ^G (BEL character) and have
some terminal driver make a "beep" and nothing more.



> >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
> 
> Ummm....
> 
> % /tmp/beeps.sh
> CW ===> xxxxx
> /tmp/beeps.sh: morse: not found

Seems your OS is installed incompletely?

	% which morse
	/usr/games/morse

This is on my home 8.2 system. The "morse" program is part of
the "games" distribution. Maybe you've decided to leave it out
when installing your system?

Just in case, you can easily install it from the source tree,
cd /usr/src/games/morse/ and make install.




> >But probably not required, because the simplest test you could
> >construct is something like
> >
> >	% echo "c" > /dev/speaker
> 
> Humm... now _that_ is both interesting and enlightening.

I actually remember having used something comparable on
BASIC, when my brain wasn't fully developed yet. :-)

	echo "cdefgab>c" > /dev/speaker

It's still a nice interface to "generate attention sounds"
in case you want to make an audible alarm or signal for
some specific action, like a program which has aborted,
an unverified backup or the successful completition of
a task.



> >Can you hear a sound?
> 
> Yes.

This means two things: Your speaker is present and works, and
the /dev/speaker mechanism also works.



> >> 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?
> 
> Haven't you noticed?

I _try_ not to notice it, because in some cases, it's totally
insane what's happenning on that front...



> In the future, there will be no more engineers... only lawyers.

Two lawyers, three opinions. ;-)





-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...