envflag.go
func flagAsEnv(name string) string {
	name = strings.ToUpper(EnvPrefix + name)
	name = strings.Replace(name, ".", "_", -1)
	name = strings.Replace(name, "-", "_", -1)
	return name
}
func flagAsEnv(name string) string {
	name = strings.ToUpper(EnvPrefix + name)
	name = strings.Replace(name, ".", "_", -1)
	name = strings.Replace(name, "-", "_", -1)
	return name
}
// To be unix'y, we translate flagnames to their uppercase equivalents.