manipulating the lights on a keyboard

[J0hny_Lightning]

I came across the following link: www.mghansen.de/dosstuff/keyctlhowto.html that shows how to control the LEDs on the keyboard. I'm pretty new to perl and was wondering if anyone could point me in the right direction on implementing this in a perl script. This is similar to a plugin I saw once for xmms that blinks the LEDs to the music, but I couldnt find the link for your guys. Thanks in advance. --J0hny_Lightning

[derby]

Here's how you can do it with Inline under linux (the only OS I tested). You need the appropriate perms to the console so YMMV (also, most error checking removed for brevity sake).

(original Inline code)

Read more... (1026 Bytes)

-derby

Update: Whoa! I forgot that ioctl is normally available under pure perl. I hade to steal the KD_* and LED_* constants from the include file but it works fine.

(buggy pure perl code)

Read more... (695 Bytes)

Update (again): Noticed a small bug in the above perl code when resetting the lights back to original. Here it is again:

#!/usr/bin/perl

require "sys/ioctl.ph";

open( FH, "/dev/console" ) ||
                die "cannot open console";

$KDSETLED = 0x4B32;
$KDGETLED = 0x4B31;
$LED_NUM  = 0x02;
$LED_CAP  = 0x04;
$LED_SCR  = 0x01;

ioctl(FH, $KDGETLED, $orig);
@ary = unpack("ccccs",$orig);

foreach $state ( $LED_NUM, $LED_CAP, $LED_SCR, $ary[0] ) {
        $i = 0;
        $i |= $state;
        ioctl(FH, $KDSETLED, $i);
        sleep( 2 );
}

[Tommy]

++derby!

--
Tommy Butler, a.k.a. TOMMY

[skyknight]

I am not aware of any libraries in CPAN that give you this functionality, but this might be good excuse to learn XS. If you can figure out how to twiddle the LEDs in C/C++, then just wrap it up with XS so you can call into it with Perl. From a short term practicality standpoint this would probably be a largely futile effort, but from a scholarly point of view, just learning XS would make it worth your troubles.

[The Mad Hatter]

Looking at the BASIC code on that website, I noticed they used peek and poke. MJD's PeekPoke module for Perl provides peek and poke functions. I don't know if it would work, but you might be able to adapt that BASIC code to Perl code using PeekPoke. Just a thought...

[Abigail-II]

You can't decend low enough into the OS to do this directly from Perl. But you should be able to do this with the help of XS, and perhaps some C.

And whatever you need to do on your system to get it working is very likely not going to work on a different OS.

Abigail

[hardburn]

There are some platform-specific libraries for manipulating keyboard LEDs (like xleds), but the link above is working with hardcoded memory locations. It'll work on any i386 platform, regardless of OS. Now, getting to work on a different architecture is a different matter . . .

----
I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident.
-- Schemer

Note: All code is untested, unless otherwise stated

[PodMaster]

keyboard light yields Keyboard Lights.
numlock yields Get Numlock Status, (Win32) Turn on NumLock if needed (Mr. Muskrat also wrote Show Status of Caps, Num, and ScrollLock on Win32).

I also recall seing an obfu that did this (linux), you can Super Search for it if you like.

MJD says "you can't just make shit up and expect the computer to know what you mean, retardo!"

I run a Win32 PPM repository for perl 5.6.x and 5.8.x -- I take requests (README).

** The third rule of perl club is a statement of fact: pod is sexy.

[JaWi]

From a `real' console which understands EMCA-48 CSI sequences (like Linux for example), you can use the following snippet to control the leds on your keyboard:

#!/usr/bin/perl -w
while ( 1 )
{
  print "\e[".$_."q" and sleep 1 for ( 0..3 );
}

This will turn on each individual led on turn.
For more information on see the man-page of console_codes(4).

HTH,

JaWi

-- JaWi

"A chicken is an egg's way of producing more eggs."

[J0hny_Lightning]

Awesome stuff, thanks a lot for your help.


--J0hny_Lightning