global-key-binding
global-key-binding is a built-in function in `C source code
'.
(global-key-binding KEYS &optional ACCEPT-DEFAULT)
Return the binding for command KEYS in current global keymap only.
KEYS is a string or vector, a sequence of keystrokes.
The binding is probably a symbol with a function definition.
This function's return values are the same as those of `lookup-key'
(which see).
If optional argument ACCEPT-DEFAULT is non-nil, recognize default
bindings; see the description of `lookup-key' for more details about this.