Debian – Reassign Ctrl and Alt keys – xmodmap ‘BadValue’ error

debiankeyboardx11xmodmapxorg

I am attempting to remap my keyboard in order to make emacs usable. My ergonomic keyboard puts its single Control key in an isolated 4-key island way off to the left.

The OS is Debian squeeze.

Here are the lines I am attempting to feed to xmodmap, I place them into a file ~/.Xmodmap:

clear Control
clear Mod1
! The Alt keys are labled 'Option' on my keyboard, 
! using xev shows them to send Alt_L and Alt_R keysym's respectively 
keysym Alt_L = Control_L
keysym Alt_R = Control_R
! The Super_L and Super_R keys are the Windows keys
keysym Super_L = Alt_L
keysym Super_R = Alt_R
add Control = Control_L Control_R
add Mod1 = Alt_L Alt_R

My goal is to make my Option (a.k.a. Alt) keys behave like Control keys, and to get my Windows (a.k.a. Super) keys to behave like Alt.

Here are the keycodes and keysms output by xev for the keys in question. Note, my keyboard (a Goldtouch ergonomic keyboard) has only one control key.

keycode 37 (keysym 0xffe3, Control_L)
keycode 64 (keysym 0xffe9, Alt_L)
keycode 133 (keysym 0xffeb, Super_L)
keycode 134 (keysym 0xffec, Super_R)
keycode 108 (keysym 0xffea, Alt_R)

Here is what xev displays while running xmodmap .Xmodmap

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 204, count 1

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 64, count 1

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 108, count 1

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 206, count 1

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 133, count 1

MappingNotify event, serial 34, synthetic NO, window 0x0,
    request MappingKeyboard, first_keycode 134, count 1

And here is the error returned by xmodmap:

X Error of failed request:  BadValue (integer parameter out of range for operation)
Major opcode of failed request:  118 (X_SetModifierMapping)
Value in failed request:  0x17
Serial number of failed request:  17
Current serial number in output stream:  17

any suggestions about how I can resolve this?

Best Answer

This has already been reported as Debian bug #564327, Debian bug #565279, Ubuntu bug #524774, and FreeDesktop bug 20145. There is a source patch attached to the FreeDesktop bug discussion. There are several workaround proposals in the Ubuntu bug discussion, in particular a .Xmodmap workaround.

Related Solutions

keyboard x11 xmodmap xkb – Assign Another Modifier to Alt Key for X11

(This answer is about xmodmap only. I'm sure it's possible to do this with XKB, I just don't know how.)

Modifiers and keysyms are assigned independently. But you get strange effects if you don't set them consistently. I think all you're missing is the add command to assign a modifier to Meta_L, though you may also need to clear and reassign the modifier keys. You may replace Mod1 and Mod2 by Mod3, Mod4 and Mod5: they are interchangeable, just make sure you don't use one for two different purposes.

clear Mod1
clear Mod2
remove Lock = Caps_Lock
keysym Caps_Lock = Alt_L
keysym Alt_L = Meta_L
add Mod1 = Alt_L Alt_R
add Mod2 = Meta_L Meta_R

AltGr keys don’t work with Ubuntu in VirtualBox

Run the command xev. In the xev window, press the AltGr key. You'll see something like

KeyPress event, serial 29, synthetic NO, window 0x6400001,
    root 0x105, subw 0x0, time 966635535, (243,-207), root:(1891,26),
    state 0x0, keycode 66 (keysym 0xff7e, Mode_switch), same_screen YES,
    XLookupString gives 0 bytes: 
    XmbLookupString gives 0 bytes: 
    XFilterEvent returns: False

Note the keycode; since the key isn't doing what you want, you'll see something else (possibly Alt_R) instead of Mode_switch. You want to assign this keycode to Mode_switch, which is X11's name for AltGr. Put the following command in a file called .Xmodmap (note capital X) in your home directory:

keycode 66 = Mode_switch

Additionally, you may need to assign a modifier to Mode_switch, but if all that's happening is a keycode discrepancy there'll already be one. See Set the key for spanish eñe letter for more information.

Run xmodmap ~/.Xmodmap to test your file. On many systems, including Ubuntu 10.04, this file is loaded automatically in the default Gnome environment. On other distributions or environments, you may need to indicate explicitly that you want to run xmodmap ~/.Xmodmap when you log in.

Best Answer

Related Solutions

keyboard x11 xmodmap xkb – Assign Another Modifier to Alt Key for X11

AltGr keys don’t work with Ubuntu in VirtualBox

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