I need a way to find out the current MCS index of the WiFi connection in Linux. I am using Ubuntu, but it doesn't necessarily have to be Ubuntu specific. I have tried several tools; iwconfig, iw, lspci, wavemon, and wicd. None seem to show that value. Those are pretty much the extent of tools I have found, and searches for finding the MCS index never seem to actually answer the question. For instance, on Mac you can hold the Option key down and click on the WiFi connection, or use "airport -I" and get this value.
Is there any tool for Linux that will get the value, or is there some other way I can determine it?