환경변수 등록

http://onecellboy.tistory.com/220

http://ngee.tistory.com/488

https://m.blog.naver.com/PostView.nhn?blogId=dudwo567890&logNo=130160156727&proxyReferer=https%3A%2F%2Fwww.google.co.kr%2F

http://tip.daum.net/question/117611