+ redef fun close
+ do
+ if _file == null then return
+ if _file.address_is_null then
+ if last_error != null then return
+ last_error = new IOError("Cannot close unopened file")
+ return
+ end
+ var i = _file.io_close
+ if i != 0 then
+ last_error = new IOError("Close failed due to error {sys.errno.strerror}")
+ end
+ _file = null
+ end
+
+ # Sets the buffering mode for the current FileStream