A wrapper that calls C5.0 to learn a decision tree, times its execution, and extracts the important bits from its output. C5.0 must be in your path for this learner to work. It is a commercial product and you can get information about purchasing it from Professor Quinlan's homepage at http://www.cse.unsw.edu.au/~quinlan/.
This wrapper runs C5.0, tests the lerned tree on the test data (if appropriate) and outputs:
test set error rate <whitespace> size of tree <whitespace> seconds.