$ go build s5.go

$ ./s5 -h
Usage of ./s5:
  -addr string
    	proxy listen address (default ":8080")
  -v	should every proxy request be logged to stdout

$ ./s5 -addr 127.0.0.1:2080 -v
2016/10/23 17:18:40 Listening 127.0.0.1:2080