gpsfake
1
12 Feb 2005
gpsfake
test harness for gpsd, simulating a GPS
gpsfake
-1
-h
-b
-c interval
-i
-D debuglevel
-l
-m monitor
-n
-o options
-p
-r initcmd
-s speed
-v
logfile
DESCRIPTION
gpsfake is a test harness for
gpsd and its clients. It opens a pty
(pseudo-TTY), launches a gpsd instance that
thinks the slave side of the pty is its GPS device, and repeatedly
feeds the contents of a test logfile through the master side to the
GPS.
gpsfake does not require root
privileges, and can be run concurrently with a production
gpsd instance without causing problems.
The logfile may be of NMEA, SiRF packets, TSIP packets, or
Zodiac packets. Leading lines beginning with # will be treated as
comments and ignored.
The gpsd instance is run in
foreground. The thread sending fake GPS data to the daemon
is run in background.
OPTIONS
With the -1 option, the logfile is interpreted once only rather
than repeatedly. This option is intended to facilitate regression
testing.
The -b option enables a twirling-baton progress indicator
on standard error. At termination, it reports elapsed time.
The -c option sets the delay between sentences in
seconds. Fractional values of seconds are legal. The default is zero
(no delay).
The -l option makes the program dump a line or packet number
just before each sentence is fed to the daemon. If the sentence is
textual (e.g. NMEA), the text is dumped as well. If not, the packet
will be dumped in hexadecimal (except for RTCM packets, which aren't
dumped at all). This option is useful for checking that gpsfake is
getting packet boundaries right.
The -i option is for single-stepping through logfiles. It dumps
the line or packet number (and the sentence if the protocol is
textual) followed by "? ". Only when the user keys Enter is the line
actually fed to gpsd.
The -m option specifies a monitor program inside which the
daemon should be run. This option is intended to be used with
valgrind1,
gdb1
and similar programs.
The -g option uses the monitor facility to run the
gpsd instance within gpsfake under control
of gdb.
The -o option specifies options to pass to the daemon. The -n
option passes -n to start the daemon reading the GPS without waiting
for a client (equivalent to -o "-n"). The -D option passes a -D
option to the daemon: thus -D 4 is shorthand for -o "-D 4".
The -p option dumps the NMEA and GPSD notifications generated
by the log to standard output.
The -r option specifies an initialization comand to use.
The default is "w+r+"; "r=2" might be another interesting value.
The -s option sets the baud rate for the slave tty. The
default is 4800.
The -v option enables verbose progress reports to stderr. It
is mainly useful for debugging gpsfake itself.
The -x option dumps packets as
gpsfake gathers them. It is mainly useful
for debugging gpsfake itself.
The -h option makes gpsfake print
a usage message and exit.
The argument must be the name of a file containing the
data to be cycled at the device. gpsfake
will print a notification each time it cycles.
CUSTOM TESTS
gpsfake is a trivial wrapper around a
Python module, also named gpsfake, that can be used to fully script
sessions involving a gpsd instance, any
number of client sessions, and any number of fake GPSes feeding the
daemon instance with data from specified sentence logs.
Source and embedded documentation for this module is shipped with the
gpsd development tools. You can use it to
torture-test either gpsd itself or any
gpsd-aware client application.
Logfiles for the use with gpsfake can
be retrieved using gpspipe,
gpscat, or
gpsmon from the gpsd distribution, or any
other application which is able to create a compatible output.
SEE ALSO
gpsd8,
gps1,
libgps3,
libgpsd3,
gpsctl1,
gpspipe1,
gpsprof1
gpsmon1.
AUTHOR
Eric S. Raymond esr@thyrsus.com. There is a
project page for gpsd here.