os/user
一般情况下我们可以使用 os/user 包提供的 Current() 函数来获取用户信息：
user, err := user.Current()
if nil == err {
return user.HomeDir, nil
}
但这个方式交叉编译后不能完全跨平台，在 darwin 下需要 cgo 才能正常工作。
改进
为了解决这个问题，我们需要进行一点增强，在通过 os/user 获取失败时再通过环境变量、命令来获取：
// Home returns the home directory for the executing user.
//
// This uses an OS-specific method for discovering the home directory.
// An error is returned if a home directory cannot be detected.
func Home() (string, error) {
user, err := user.Current()
if nil == err {
return user.HomeDir, nil
}
// cross compile support
if "windows" == runtime.GOOS {
return homeWindows()
}
// Unix-like system, so just assume Unix
return homeUnix()
}
func homeUnix() (string, error) {
// First prefer the HOME environmental variable
if home := os.Getenv("HOME"); home != "" {
return home, nil
}
// If that fails, try the shell
var stdout bytes.Buffer
cmd := exec.Command("sh", "-c", "eval echo ~$USER")
cmd.Stdout = &stdout
if err := cmd.Run(); err != nil {
return "", err
}
result := strings.TrimSpace(stdout.String())
if result == "" {
return "", errors.New("blank output when reading home directory")
}
return result, nil
}
func homeWindows() (string, error) {
drive := os.Getenv("HOMEDRIVE")
path := os.Getenv("HOMEPATH")
home := drive + path
if drive == "" || path == "" {
home = os.Getenv("USERPROFILE")
}
if home == "" {
return "", errors.New("HOMEDRIVE, HOMEPATH, and USERPROFILE are blank")
}
return home, nil
}