How do I know what to put in DefaultKeyBinding.dict? I am trying to create a few system level key bindings. I know about ~/Library/KeyBindings/DefaultKeyBinding.dict but I am not sure what to put in there/or how to go about finding the commands and codes.

I would like keybindings to  


Opt &lt;-   //Move cursor back a word  
Opt ->   //Move cursor forward a word  
Opt Cmd &lt;- //Home  
Opt Cmd -> //End  
(the same commands, but adding Shift to select instead of just move


Is there a good resource to help me figure this out?
There is a wonderful resource on DefaultKeyBinding.dict including an example file as well as all the shortcut strings and methods you need, available at:


https://github.com/ttscoff/KeyBindings


There are also numerous other resources listed at the bottom of the page, including the official Apple Developer documentation:


https://developer.apple.com/library/mac/documentation/cocoa/conceptual/eventoverview/TextDefaultsBindings/TextDefaultsBindings.html