init

source/gettext_syslocale.d

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+module gettext_syslocale;
+
+import gettext;
+import std.file : exists, isFile;
+import std.path : buildPath, baseName;
+import std.process : environment;
+import std.string : split, empty;
+
+/**
+ * Extends the gettext library with support for system locale and standard GNU/Linux paths.
+ * 
+ * This module automatically selects the language from system environment variables
+ * (LC_ALL, LC_MESSAGES, LANG) and searches for .mo files in the standard path
+ * /usr/share/locale/<language>/LC_MESSAGES/<programName>.mo.
+ * It first checks the full language code (e.g., "ru_RU"), then the short code (e.g., "ru").
+ *
+ * Params:
+ *   programName = The name of the program (required parameter).
+ */
+bool initializeSystemLocale(string programName) @safe
+{
+	if (programName.empty)
+	{
+		throw new Exception("Program name must not be empty");
+	}
+
+	// Get the language from the system locale
+	string fullLang = getSystemLanguage();
+	if (fullLang.empty)
+	{
+		selectLanguage(""); // Empty MoFile if no locale is defined
+		return false;
+	}
+
+	// Check full and short language codes
+	string shortLang = fullLang.split("_")[0];
+	foreach (lang; [fullLang, shortLang])
+	{
+		if (tryLoadMoFile(programName, lang))
+		{
+			return true; // Successfully loaded .mo file
+		}
+	}
+
+	// If no file is found, use an empty MoFile
+	selectLanguage("");
+	return false;
+}
+
+/**
+ * Attempts to load an .mo file for the specified program name and language code.
+ *
+ * Params:
+ *   programName = The name of the program.
+ *   lang = The language code (e.g., "ru_RU" or "ru").
+ *
+ * Returns:
+ *   true if the .mo file is found and loaded, false otherwise.
+ */
+private bool tryLoadMoFile(string programName, string lang) @safe
+{
+	string moPath = buildPath("/usr/share/locale", lang, "LC_MESSAGES", programName ~ ".mo");
+	if (moPath.exists && moPath.isFile)
+	{
+		selectLanguage(moPath);
+		return true;
+	}
+	return false;
+}
+
+/**
+ * Retrieves the language from the system locale.
+ *
+ * Checks environment variables LC_ALL, LC_MESSAGES, LANG in that order.
+ * Returns the full language code (e.g., "ru_RU" from "ru_RU.UTF-8").
+ * If the locale contains only a short code (e.g., "ru"), returns it as is.
+ *
+ * Returns:
+ *   The full language code (e.g., "ru_RU", "zh_CN") or an empty string if no locale is defined.
+ */
+private string getSystemLanguage() @safe
+{
+	foreach (var; ["LC_ALL", "LC_MESSAGES", "LANG"])
+	{
+		string value = environment.get(var);
+		if (!value.empty)
+		{
+			// Split on dot to ignore encoding (e.g., .UTF-8)
+			auto parts = value.split(".");
+			return parts[0]; // Return the full language code (e.g., ru_RU or ru)
+		}
+	}
+	return "";
+}