System.Environment.Environment.ReadXdgUserDir C# (CSharp) Méthode

		private static string ReadXdgUserDir (string config_dir, string home_dir, 
			string key, string fallback)
		{
			string env_path = internalGetEnvironmentVariable (key);
			if (env_path != null && env_path != String.Empty) {
				return env_path;
			}

			string user_dirs_path = Path.Combine (config_dir, "user-dirs.dirs");

			if (!File.Exists (user_dirs_path)) {
				return Path.Combine (home_dir, fallback);
			}

			try {
				using(StreamReader reader = new StreamReader (user_dirs_path)) {
					string line;
					while ((line = reader.ReadLine ()) != null) {
						line = line.Trim ();
						int delim_index = line.IndexOf ('=');
                        if(delim_index > 8 && line.Substring (0, delim_index) == key) {
                            string path = line.Substring (delim_index + 1).Trim ('"');
                            bool relative = false;

                            if (path.StartsWith ("$HOME/")) {
                                relative = true;
                                path = path.Substring (6);
                            } else if (!path.StartsWith ("/")) {
                                relative = true;
                            }

                            return relative ? Path.Combine (home_dir, path) : path;
                        }
					}
				}
			} catch (FileNotFoundException) {
			}

			return Path.Combine (home_dir, fallback);
		}