How can I get the probability estimate of a text classification prediction with LibShortText using the logistic regression classifier?

Question

LibShortText is an open source library for short-text classification that relies on liblinear.

I read on https://github.com/cjlin1/liblinear:

-b probability_estimates: whether to output probability estimates, 0 or 1 (default 0); currently for logistic regression only

How can I get the probability estimate of a prediction with LibShortText using the logistic regression classifier?