get wireless signal

I'm trying to use this widget for awesome to display wireless signal strength, problem is its a year old and where it gets the data (/sys/class/net/*/wireless/link) is deprecated. This is what I got:

local f = io.open("/sys/class/net/eth1/wireless/link")
local signalStrength = f:read()

I tried looking for alternatives, like /proc/net/wireless, but I don't know how to only get the results of Quality - Link.

Thanks for the help, I figured it out, I knew there was a reason I came to /prog/.