add function to easily get the extension used for indexes

diff --git a/deltatar/deltatar.py b/deltatar/deltatar.py
index d909077..9344434 100644 (file)
--- a/deltatar/deltatar.py
+++ b/deltatar/deltatar.py
@@ -238,6 +238,12 @@ class DeltaTar(object):
 
         return "%s-%s.index%s" % (prefix, date_str, extension)
 
+    def get_index_extension(self):
+        '''
+        returns the extension used for index files
+        '''
+        return self.__index_extensions_dict[self.index_mode]
+
     def volume_name_func(self, backup_path, is_full, volume_number, guess_name=False):
         '''
         function that defines the name of tar volumes. It receives the