How can I rebind keyboard keys in OS X?

Question

I need a custom keyboard shortcut for back slash \.

I have created ~/Library/KeyBindings/DefaultKeyBinding.dict and put this in it:

{
    "@ö" = ("insertText:", "\\");
}

It is supposed to trigger back slash when pressing ⌘ + ö (Yes, I have an "ö" character on my keyboard).

When trying to source the file, I get this error:

-bash: DefaultKeyBinding.dict: line 2: syntax error near unexpected token `('
-bash: DefaultKeyBinding.dict: line 2: `    "@ö" = ("insertText:", "\\");'

What's wrong with the syntax? Is there a better way?

Answer 1

To enable CmdÖ -> \ just remap the key combo with Karabiner. The shortcut you need isn't pre-defined so you have to write your own:

1. Download, install and open Karabiner
2. Open in the menulet Karabiner -> Preferences
3. Open the tab Misc & Uninstall
4. Hit the button Open private.xml
5. Open the file private.xml with an appropriate editor

6. Enter the customized keycode

   Example 1 (cmdÖ -> \):

   <?xml version="1.0"?>
   <root>
       <item>
         <name>Command-Ö to Backslash</name>
         <appendix>(Change Command-Ö to \)</appendix>
         <identifier>remap.command_ö_to_backslash</identifier>
         <autogen>__KeyToKey__ KeyCode::GERMAN_O_UMLAUT, MODIFIERFLAG_EITHER_LEFT_OR_RIGHT_COMMAND, KeyCode::KEY_7, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L</autogen>
       </item>
   </root>
   

   Example 2 (cmd_RÖ -> \ cmd_R is the right command key only, cmd_LÖ doesn't have an output!):

   <?xml version="1.0"?>
   <root>
       <item>
         <name>Command_R-Ö to Backslash</name>
         <appendix>(Change Command_R-Ö to \)</appendix>
         <identifier>remap.command_r_ö_to_backslash</identifier>
         <autogen>__KeyToKey__ KeyCode::GERMAN_O_UMLAUT, ModifierFlag::COMMAND_R, KeyCode::KEY_7, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L</autogen>
       </item>
   </root>
   

   Example 3 (cmd_R -> \ you can't use the right command key for any other purpose then):

   <?xml version="1.0"?>
   <root>
       <item>
         <name>Command_R to Backslash</name>
         <appendix>(Change Command_R to \)</appendix>
         <identifier>remap.command_r_to_backslash</identifier>
         <autogen>__KeyToKey__ KeyCode::COMMAND_R, KeyCode::KEY_7, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L</autogen>
       </item>
   </root>
   

   Example 4 (cmd_R -> \ similar to example 3 but you can use the right command key as normal command key-> hitting cmd_R yields \ but cmd_RS saves files):

   <?xml version="1.0"?>
   <root>
       <item>
         <name>When you type Command_R only, send Backslash</name>
         <appendix>(Change Command_R lazy to \)</appendix>
         <identifier>remap.command_r_lazy_to_backslash</identifier>
         <autogen>__KeyOverlaidModifier__ KeyCode::COMMAND_R, KeyCode::VK_LAZY_COMMAND_R, KeyCode::KEY_7, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L</autogen>
       </item>
   </root>
   

7. Save the file

8. Open in the menulet Karabiner -> Preferences the tab Change Key
9. Hit the ReloadXML button
10. Enable the remapping. It should be listed at the beginning.

Answer 2

Why don't you use Karabiner ?

A powerful and stable keyboard customizer for OS X.

• You can easily customize from prepared settings.

• You can also add your own settings by XML.

https://pqrs.org/osx/karabiner/

Answer 3

From a brief web search for DefaultKeyBinding.dict, according to this page:

Only application that [use] Cocoa text system will support this.

This is not a shell file, and will not work when 'source'ed via bash.

^{Source: @mtklr comment.}