11

There has been a similar question - but IMHO there has to be a simpler solution. If num-lock is on in the BIOS - why is it turned off during linux boot and/or KDE/Gnome/whatever startup?

9

Linux initializes most peripherals so that they'll be in a known state. This includes the keyboard: Linux's internal data about the keyboard had better match the LEDs, so what Linux does is to turn off the LEDs (as far as I recall, the CPU can't read the state of the LEDs on a PC keyboard) and declare all *Lock to be off.

I like to have NumLock on by default. For Linux text consoles, what I used to do¹ is to run

for t in /dev/tty[0-9]*; do setleds -D +num <$t; done

from a boot script (/etc/rc.local or /etc/init.d/50_local_setleds or wherever the distribution likes to put those).

Nowadays, at least on some distributions such as Debian, you can add LEDS=+num to /etc/console-tools/config (or /etc/kbd/config depending on which one you have).

The X window system has its own keyboard handling, so you need to deal with it separately. What I do is to switch caps lock permanently off (I don't have a Caps Lock key in my layout) and switch num lock permanently on (I don't have a Num Lock key in my layout, and the keypad keys send KP_1 and so on). If you want to retain the modifiers but make Num Lock default on, you can write a small program to call XKbLockModifiers to set the modifier inside X and XChangeKeyboardControl to set the physical LED.

¹ Used to, because I haven't bothered with text consoles in a while.

  • You mention consoles - was there not a kernel-option for numlock in old linux-kernels? 0.x or 1.y? Anyway - is there no Xconfig-option for numlock? – Nils Oct 26 '11 at 21:08
  • @Nils Mmmm maybe, I don't remember. I don't think there's anything for X, but I learned about keyboards in X before XKB existed, so I might be missing some of that newfangled stuff from the very late 20th century. – Gilles Oct 26 '11 at 21:13
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    I'll add a note that on Debian, the setting numlock after boot is done by the kbd package which creates an kbd init script. – carandraug Apr 24 '14 at 22:11
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    @Rodrigo The operating system can know the state of a key. What it can't know, as far as I know, is the state of the LED — it can only remember whether it last turned the LED on or off, but that doesn't work across an operating system change (e.g. BIOS → bootloader → Linux). – Gilles Nov 30 '16 at 18:05
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    @Rodrigo That question deals with applications obtaining information from the operating system. The part you are arguing about is how the operating system would obtain the information. – Gilles Nov 30 '16 at 18:52

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