cpu.lua widget args[]

[Daniel Martí]

I am trying to write an automated cpu vicious widget, just like I already did 
with dio.lua. In there, I could use:

vicious.register(iowidget, vicious.wodgets.dio,
    function (widget, args)
    ...
    end)

So that I could use args["{sdx read_mb}"] to get that value directly. I fail to 
find how to use such feature with cpu.lua. For example, args["{$2}"] in order 
to get the first cpu's percentage usage is not working.

Any ideas? Thanks for your time.