How to check out all the environment variables in visual studio

If I start the visual studio by devenv /useenv, visual studio will take in all the environment variables already set in the cmd shell. And there are tons of other ways to set environment variables in visual studio. What if after that, I want to check the value of a specific environment variable or all of them just I would do in a cmd shell by typing "set" or "set *". For example, if I do set FrameworkSDKDir in a visual studio command prompt, it will show the directory value.  How may I do the similar thing in visual studio since some environment variables are only valid inside visual studio but not the cmd shell from which it is opened.

Thanks
Patrick