unix: Detect via locale.conf instead of locale command (#14)

* unix: Detect via locale.conf instead of locale command

Signed-off-by: Xuanwo <github@xuanwo.io>

* tests: Hack /etc/locale.conf

Signed-off-by: Xuanwo <github@xuanwo.io>

locale_darwin.go

@@ -12,7 +12,7 @@ import (
 var detectors = []detector{
  detectViaEnvLanguage,
  detectViaEnvLc,
- detectViaLocale,
+ detectViaLocaleConf,
  detectViaUserDefaultsSystem,
 }
 

locale_freebsd.go

@@ -5,5 +5,5 @@ package locale
 var detectors = []detector{
  detectViaEnvLanguage,
  detectViaEnvLc,
- detectViaLocale,
+ detectViaLocaleConf,
 }

locale_linux.go

@@ -5,5 +5,5 @@ package locale
 var detectors = []detector{
  detectViaEnvLanguage,
  detectViaEnvLc,
- detectViaLocale,
+ detectViaLocaleConf,
 }

locale_openbsd.go

@@ -5,5 +5,5 @@ package locale
 var detectors = []detector{
  detectViaEnvLanguage,
  detectViaEnvLc,
- detectViaLocale,
+ detectViaLocaleConf,
 }

locale_solaris.go

@@ -5,5 +5,5 @@ package locale
 var detectors = []detector{
  detectViaEnvLanguage,
  detectViaEnvLc,
- detectViaLocale,
+ detectViaLocaleConf,
 }

locale_unix.go

@@ -5,12 +5,22 @@ package locale
 
 import (
  "bufio"
- "bytes"
  "os"
- "os/exec"
+ "path"
  "strings"
 )
 
+// Unless we call LookupEnv more than 9 times, we should not use Environ.
+//
+// goos: linux
+// goarch: amd64
+// pkg: github.com/Xuanwo/go-locale
+// BenchmarkLookupEnv
+// BenchmarkLookupEnv-8 37024654 32.4 ns/op
+// BenchmarkEnviron
+// BenchmarkEnviron-8 4275735 281 ns/op
+// PASS
+
 // envs is the env to be checked.
 //
 // LC_ALL will overwrite all LC_* options.
@@ -50,11 +60,22 @@ func detectViaEnvLc() ([]string, error) {
  return nil, &Error{"detect via env lc", ErrNotDetected}
 }
 
-func detectViaLocale() ([]string, error) {
- cmd := exec.Command("locale")
+func detectViaLocaleConf() (_ []string, err error) {
+ defer func() {
+ if err != nil {
+ err = &Error{"detect via locale conf", err}
+ }
+ }()
+
+ fp := getLocaleConfPath()
+ if fp == "" {
+ return nil, ErrNotDetected
+ }
 
- var out bytes.Buffer
- cmd.Stdout = &out
+ f, err := os.Open(fp)
+ if err != nil {
+ return nil, err
+ }
 
  // Output should be like:
  //
@@ -72,13 +93,8 @@ func detectViaLocale() ([]string, error) {
  // LC_MEASUREMENT="en_US.UTF-8"
  // LC_IDENTIFICATION="en_US.UTF-8"
  // LC_ALL=
- err := cmd.Run()
- if err != nil {
- return nil, &Error{"detect via locale", err}
- }
-
  m := make(map[string]string)
- s := bufio.NewScanner(&out)
+ s := bufio.NewScanner(f)
  for s.Scan() {
  value := strings.Split(s.Text(), "=")
  // Ignore not set locale value.
@@ -94,7 +110,49 @@ func detectViaLocale() ([]string, error) {
  return []string{parseEnvLc(x)}, nil
  }
  }
- return nil, &Error{"detect via locale", ErrNotDetected}
+ return nil, ErrNotDetected
+}
+
+// getLocaleConfPath will try to get correct locale conf path.
+//
+// Following path could be returned:
+// - "$XDG_CONFIG_HOME/locale.conf" (follow XDG Base Directory specification)
+// - "$HOME/.config/locale.conf" (user level locale config)
+// - "/etc/locale.conf" (system level locale config)
+// - "" (empty means no valid path found, caller need to handle this.)
+//
+// ref:
+// - POSIX Locale: https://pubs.opengroup.org/onlinepubs/9699919799/
+// - XDG Base Directory: https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html
+func getLocaleConfPath() string {
+ // Try to loading from $XDG_CONFIG_HOME/locale.conf
+ xdg, ok := os.LookupEnv("XDG_CONFIG_HOME")
+ if ok {
+ fp := path.Join(xdg, "locale.conf")
+ _, err := os.Stat(fp)
+ if err == nil {
+ return fp
+ }
+ }
+
+ // Try to loading from $HOME/.config/locale.conf
+ home, ok := os.LookupEnv("HOME")
+ if ok {
+ fp := path.Join(home, ".config", "locale.conf")
+ _, err := os.Stat(fp)
+ if err == nil {
+ return fp
+ }
+ }
+
+ // Try to loading from /etc/locale.conf
+ fp := "/etc/locale.conf"
+ _, err := os.Stat(fp)
+ if err == nil {
+ return fp
+ }
+
+ return ""
 }
 
 // parseEnvLanguage will parse LANGUAGE env.

locale_unix_test.go

@@ -5,10 +5,13 @@ package locale
 
 import (
  "errors"
+ "io/ioutil"
  "os"
+ "path"
  "strings"
  "sync"
  "testing"
+ "time"
 
  . "github.com/smartystreets/goconvey/convey"
 )
@@ -112,11 +115,87 @@ func TestDetectViaEnvLc(t *testing.T) {
  })
 }
 
-func TestDetectViaLocale(t *testing.T) {
- Convey("detect via locale", t, func() {
- lang, err := detectViaLocale()
+func TestGetLocaleConfPath(t *testing.T) {
+ Convey("get locale conf path", t, func() {
+ // Make sure env has clear before current test.
+ setupEnv()
+
+ Reset(func() {
+ // Reset all env after every Convey.
+ setupEnv()
+ })
+
+ Convey("When user set XDG_CONFIG_HOME", func() {
+ tmpDir := setupLocaleConf("locale.conf")
+ Reset(func() {
+ _ = os.RemoveAll(tmpDir)
+ })
+
+ err := os.Setenv("XDG_CONFIG_HOME", tmpDir)
+ if err != nil {
+ t.Error(err)
+ }
+
+ fp := getLocaleConfPath()
+
+ Convey("The path should be equal", func() {
+ So(fp, ShouldEqual, path.Join(tmpDir, "locale.conf"))
+ })
+ })
+
+ Convey("When user set HOME", func() {
+ tmpDir := setupLocaleConf(".config/locale.conf")
+ Reset(func() {
+ _ = os.RemoveAll(tmpDir)
+ })
+
+ err := os.Setenv("HOME", tmpDir)
+ if err != nil {
+ t.Error(err)
+ }
+
+ fp := getLocaleConfPath()
+
+ Convey("The path should be equal", func() {
+ So(fp, ShouldEqual, path.Join(tmpDir, ".config/locale.conf"))
+ })
+ })
+
+ Convey("When fallback to system level locale.conf", func() {
+ var localeExist bool
+ _, err := os.Stat("/etc/locale.conf")
+ if err == nil {
+ localeExist = true
+ }
+
+ fp := getLocaleConfPath()
 
- Convey("The error should not be nil", func() {
+ Convey("The path should be equal", func() {
+ So(fp == "/etc/locale.conf", ShouldEqual, localeExist)
+ })
+ })
+ })
+}
+
+func TestDetectViaLocaleConf(t *testing.T) {
+ Convey("detect via locale conf", t, func() {
+ setupEnv()
+ Reset(func() {
+ setupEnv()
+ })
+
+ tmpDir := setupLocaleConf("locale.conf")
+ Reset(func() {
+ _ = os.RemoveAll(tmpDir)
+ })
+ err := os.Setenv("XDG_CONFIG_HOME", tmpDir)
+ if err != nil {
+ t.Error(err)
+ }
+
+ lang, err := detectViaLocaleConf()
+
+ Convey("The error should be nil", func() {
  So(err, ShouldBeNil)
  })
  Convey("The lang should not be empty", func() {
@@ -125,12 +204,42 @@ func TestDetectViaLocale(t *testing.T) {
  })
 }
 
+func BenchmarkLookupEnv(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ _, _ = os.LookupEnv("LANGUAGE")
+ }
+}
+
+func BenchmarkEnviron(b *testing.B) {
+ for i := 0; i < b.N; i++ {
+ _ = os.Environ()
+ }
+}
+
 var env struct {
  Env map[string]string
  sync.Mutex
  sync.Once
 }
 
+func setupLocaleConf(filePath string) (dir string) {
+ confContent := `LANG=en_US.UTF-8`
+ tmpDir := "/tmp/" + time.Now().String()
+ baseDir := path.Dir(path.Join(tmpDir, filePath))
+
+ err := os.MkdirAll(baseDir, 0755)
+ if err != nil {
+ panic(err)
+ }
+
+ err = ioutil.WriteFile(path.Join(tmpDir, filePath), []byte(confContent), 0644)
+ if err != nil {
+ panic(err)
+ }
+
+ return tmpDir
+}
+
 func setupEnv() {
  env.Lock()
  defer env.Unlock()