New S-shaped falling bullet pattern.

[python-bulletml.git] / bulletml-to-bulletyaml

diff --git a/bulletml-to-bulletyaml b/bulletml-to-bulletyaml
index 749ccde..89f861b 100755 (executable)
--- a/bulletml-to-bulletyaml
+++ b/bulletml-to-bulletyaml
@@ -6,6 +6,9 @@ import yaml
 from bulletml import BulletML, bulletyaml
 
 def main(argv):
+    if not argv:
+        raise SystemExit("Usage: %s filename ..." % sys.argv[0])
+
     for filename in argv:
         print "# Loading", filename
         print yaml.dump(BulletML.FromDocument(open(filename, "rU")))