@@ -1900,7 +1900,10 @@ def main():

     win = DotWindow()

     win.connect('destroy', gtk.main_quit)

     win.set_filter(options.filter)

-    if len(args) >= 1:

+    if len(args) == 0:

+        if not sys.stdin.isatty():

+            win.set_dotcode(sys.stdin.read())

+    else:

         if args[0] == '-':

             win.set_dotcode(sys.stdin.read())

         else: