+For splitfile appender, the format is
+\verbatim --log=root.app:splitfile:size:mylogfile_%.format\endverbatim
+
+The size is in bytes, and the % wildcard will be replaced by the number of the
+file. If no % is present, it will be appended at the end.
+
+rollfile appender is also available, it can be used as
+\verbatim --log=root.app:rollfile:size:mylogfile\endverbatim
+When the file grows to be larger than the size, it will be emptied and new log
+events will be sent at its beginning
+