Linux – How to map the Caps Lock key to Escape key in Arch Linux

Non XFCE-related stuff

It won't be exactly an answer to your problem, sorry for that, but still should be useful for someone at least. In Gnome it was fixed in recent Ubuntus. By it I mean treating Win not as a modifier key. In the old days, e.g. in Ubuntu 9.04, you had to do following change:

Go to System -> Preferences -> Keyboard, under Layouts tab click Layout options... button and in Alt/Win key behavior list choose Meta is mapped to Win keys (or Meta is mapped to Left Win) instead of Default.

What it really does? Changes altwin option in $HOME/.gconf/desktop/gnome/peripherals/keyboard/kbd/%gconf.xml file (or creates it if it does not exist):

<?xml version="1.0"?>
<gconf>
        <entry name="options" mtime="1298496603" type="list" ltype="string">
                <li type="string">
                        <stringvalue>altwin     altwin:meta_win</stringvalue>
                </li>
        </entry>
</gconf>

If you've chosen Left Win, then there will be following string value:

altwin     altwin:left_meta_win

In Ubuntu 10.10 it's not needed as Default apparently has changed.

But you have XFCE, not Gnome, so this rather won't help you.

XFCE-related stuff

I've downloaded Xubuntu (9.10), played with it a bit and finally found a solution.

Firstly, though, I must say that keyboard settings are really screwed in XFCE. In Settings -> Keyboard under Layout tab you don't have too many options. You cannot change XkbOptions there and even if you do it manually in ~/.config/xfce4/xfconf/xfce-perchannel-xml/keyboard-layout.xml, it will be overwritten. So I've changed /etc/default/console-setup by adding altwin:meta_win to XKBOPTIONS (use comma as separator if there are some other option(s) already). Still, no luck.

tl;dr

What's the solution?

Do not care about XFCE way of handling keyboard, because it's apparently broken. Use setxkbmap directly:

setxkbmap -option altwin:meta_win

(or left_meta_win, whatever you prefer)

Now you have to check that it really solved your problem. :)

How to apply it permanently?

echo -option altwin:meta_win >>~/.Xkbmap

It can be also done for all users by writing to /etc/X11/Xkbmap instead.

How can I quickly check if altwin:meta_win or altwin:left_meta_win has been applied?

setxkbmap -print

Line with xkb_symbols should have something like altwin(meta_win).

Well to change the led indicator on VT console you can use setleds. So if you're in a VT you can just type

setleds

and you'll get your current led status. If you don't want to enable numlock, just light it up you can type:

setleds -L +num 

It comes trickier in X and this is the "simplest" way to try it. Please note that X is usually ran as root so you'll either have to check permissions on X-windows tty or run it with root privileges. Usually X is tty7. /dev/console should work being the system console and by that all VTs should be affected.

sudo su -c 'setleds -L +num < /dev/tty7'

I think this will also work:

sudo su -c 'setleds -L +num < /dev/console'

here's list of light options

 [{+|-}num] [{+|-}caps] [{+|-}scroll]

If you don't have setleds in you system, my guess is that you can get it from this emerge package sys-apps/kbd.

If you are more of person who likes to code stuff here's a link to en example code to change leds in X. I did not test this, but just by looking the code looked ok.

And here's a shell script to do what you originally wanted. To have caps or other leds as HDD indicators.

#!/bin/bash

# Check interval seconds
CHECKINTERVAL=0.1

# console
CONSOLE=/dev/console

#indicator to use [caps, num, scroll]
INDICATOR=caps

getVmstat() {
  cat /proc/vmstat|egrep "pgpgin|pgpgout"  
}
#turn led on
function led_on()
{
    setleds -L +${INDICATOR} < ${CONSOLE}
}
#turn led off
function led_off()
{
    setleds -L -${INDICATOR} < ${CONSOLE}
}
# initialise variables
NEW=$(getVmstat)
OLD=$(getVmstat)
## 
while [ 1 ] ; do
  sleep $CHECKINTERVAL # slowdown a bit
  # get status 
  NEW=$(getVmstat)
  #compare state
  if [ "$NEW" = "$OLD" ]; then  
    led_off ## no change, led off
  else
    led_on  ## change, led on
  fi
  OLD=$NEW  
done