python/scripts/aubiocut: make -i optional

diff --git a/python/scripts/aubiocut b/python/scripts/aubiocut
index 9121594..a469310 100755 (executable)
--- a/python/scripts/aubiocut
+++ b/python/scripts/aubiocut
@@ -114,8 +114,12 @@ def parse_args():
             help="be quiet")
     (options, args) = parser.parse_args()
     if not options.source_file:
-        print "no file name given\n", usage
-        sys.exit(1)
+        import os.path
+        if len(args) == 1:
+            options.source_file = args[0]
+        else:
+            print "no file name given\n", usage
+            sys.exit(1)
     return options, args
 
 if __name__ == '__main__':