gpsd is a service daemon that mediates access to a GPS sensor connected
to the host computer by serial or USB interface, making its data on the
location/course/velocity of the sensor available to be queried on TCP
port 2947 of the host computer. With gpsd, multiple GPS client
applications (such as navigational and wardriving software) can share
access to a GPS without contention or loss of data. Also, gpsd
responds to queries with a format that is substantially easier to parse
than NMEA 0183. A client library is provided for applications.
After installing the software, gpsd will automatically connect to USB GPSes
when they are plugged in and requires no configuration. For serial
GPSes, you will need to start gpsd by hand. Once connected, the daemon
automatically discovers the correct baudrate, stop bits, and protocol.
The daemon will be quiescent when there are no clients asking for
location information, and copes gracefully when the GPS is unplugged