// Package env contains functions for dealing with environment variablespackage env import (	"os"	"os/user" 	homedir "github.com/mitchellh/go-homedir") // ShellExpandHelp describes what ShellExpand does for inclusion into helpconst ShellExpandHelp = "\n\nLeading `~` will be expanded in the file name as will environment variables such as `${RCLONE_CONFIG_DIR}`.\n" // ShellExpand replaces a leading "~" with the home directory" and// expands all environment variables afterwards.func ShellExpand(s string) string {	if s != "" {		if s[0] == '~' {			newS, err := homedir.Expand(s)			if err == nil {				s = newS			}		}		s = os.ExpandEnv(s)	}	return s} // CurrentUser finds the current user name or "" if not foundfunc CurrentUser() (userName string) {	userName = os.Getenv("USER")	// If we are making docs just use $USER	if userName == "$USER" {		return userName	}	// Try reading using the OS	usr, err := user.Current()	if err == nil {		return usr.Username	}	// Fall back to reading $USER then $LOGNAME	if userName != "" {		return userName	}	return os.Getenv("LOGNAME")}