Taking Your Pi Off-road - Raspberry Pi for Secret Agents - page 150

pi@raspberrypi ~ $ cd giskismet
pi@raspberrypi ~/giskismet $ perl Makefile.PL
pi@raspberrypi ~/giskismet $ make
pi@raspberrypi ~/giskismet $ sudo make install

3. Once installed, you may exit the source directory and delete it:

pi@raspberrypi ~/giskismet $ cd .. && rm -r giskismet

4. Getting a KML file out of GISKismet is a two-step process; first we import
the Kismet network data into a SQLite database, and then we select the
information that we want to export to KML with a SQL query. This line
will perform both steps with one command, but adjust [date] to the
correct filename:
pi@raspberrypi ~ $ giskismet -x kismetlogs/Kismet-[date].netxml -q
"select * from wireless" -o /tmp/mywifi.kml

The -x argument tells GISKismet to import the data from the specified
netxml file to a SQLite database in the current directory called wireless.
dbl by default. The -q argument specifies the SQL query that will be used to
obtain data from the database, which will be written in KML format to the
file we specify after the -o argument.
You can restrict which access points go into the database using Input Filters
(type giskismet without arguments to see them) or filter the KML output
through the SQL query, for example, select * from wireless where
Channel=1 would put only access points on channel one in the KML file.

5. Next, start the simple Python HTTP server:

pi@raspberrypi ~ $ cd /tmp && python -m SimpleHTTPServer

6. Now in Google Earth, add a new Network Link as in the previous section

but adjust the address to http://[IP address]:8000/mywifi.kml . You
should now see a list of all the access points in the sidebar to the left.

Using GPS as a time source
As we've mentioned in previous chapters, the Raspberry Pi lacks a Real-time Clock
and depends on other computers to relay the correct time through the network.
While the Pi may not have network connectivity out in the field, a GPS can actually
be used as an alternative time source. All we need to do is to tell ntpd , the Network
Time Protocol daemon, to use the time information supplied by gpsd as a potential
time source.