Function: x-get-resource

Return the value of ATTRIBUTE, of class CLASS, from the X defaults database.
This uses `INSTANCE.ATTRIBUTE' as the key and `Emacs.CLASS' as the
class, where INSTANCE is the name under which Emacs was invoked, or
the name specified by the `-name' or `-rn' command-line arguments.

The optional arguments COMPONENT and SUBCLASS add to the key and the
class, respectively. You must specify both of them or neither.
If you specify them, the key is `INSTANCE.COMPONENT.ATTRIBUTE'
and the class is `Emacs.CLASS.SUBCLASS'.

(fn ATTRIBUTE CLASS &optional COMPONENT SUBCLASS)