...to get raw data from GPS I type:
$ cat /dev/rfcomm0
If your GPS is NMEA compliant (most of them are) you should see these sort of lines filling up your terminal:
$GPRMC,212215.000,A,4553.7413,...
$GPGGA,212216.000,4553.7425,N,006...
$GPGSA,A,3,31,11,23,32,,,,,,,,,5.7,3.7,4.2*30...