How to print the output of the demodulator

Hi all!

Now that I have triumphantly created an FM fadio using the very fine
USRP, and a highly sophisticated dipole antenna (wire), I am interested
in knowing what stream of floats the Demodulator is producing. Is there
a skin for this? How do I write my own Sink? Sorry if I am asking the
obvious.

Thanks in advance for your help.

Ranga