Add i18n

cmd/cbconvert-gui/i18n/detect_unix.go

@@ -0,0 +1,26 @@
+//go:build !windows
+
+package i18n
+
+import (
+	"os"
+	"strings"
+)
+
+// systemLangCode returns the two-letter language code from the POSIX locale environment, or "".
+func systemLangCode() string {
+	for _, env := range []string{"LC_ALL", "LC_MESSAGES", "LANG"} {
+		v := os.Getenv(env)
+		if v == "" || v == "C" || v == "POSIX" {
+			continue
+		}
+
+		if i := strings.IndexAny(v, "_.@"); i >= 0 {
+			v = v[:i]
+		}
+
+		return strings.ToLower(v)
+	}
+
+	return ""
+}