1GPSFAKE(1)                    GPSD Documentation                    GPSFAKE(1)
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NAME

6       gpsfake - test harness for gpsd, simulating a GPS
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SYNOPSIS

9       gpsfake [-1] [-h] [-b] [-c interval] [-i] [-D debuglevel] [-l]
10               [-m monitor] [-n] [-o options] [-p] [-r initcmd] [-s speed]
11               [-u] [-v] [logfile...]
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DESCRIPTION

14       gpsfake is a test harness for gpsd and its clients. It opens a pty
15       (pseudo-TTY), launches a gpsd instance that thinks the slave side of
16       the pty is its GPS device, and repeatedly feeds the contents of one or
17       more test logfiles through the master side to the GPS. If there are
18       multiple logfiles, sentences from them are interleaved in the order the
19       fuiles are specified.
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21       gpsfake does not require root privileges, and can be run concurrently
22       with a production gpsd instance without causing problems.
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24       The logfiles may be of NMEA, SiRF packets, TSIP packets, or Zodiac
25       packets. Leading lines beginning with # will be treated as comments and
26       ignored.
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28       The gpsd instance is run in foreground. The thread sending fake GPS
29       data to the daemon is run in background.
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OPTIONS

32       With the -1 option, the logfile is interpreted once only rather than
33       repeatedly. This option is intended to facilitate regression testing.
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35       The -b option enables a twirling-baton progress indicator on standard
36       error. At termination, it reports elapsed time.
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38       The -c option sets the delay between sentences in seconds. Fractional
39       values of seconds are legal. The default is zero (no delay).
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41       The -l option makes the program dump a line or packet number just
42       before each sentence is fed to the daemon. If the sentence is textual
43       (e.g. NMEA), the text is dumped as well. If not, the packet will be
44       dumped in hexadecimal (except for RTCM packets, which aren't dumped at
45       all). This option is useful for checking that gpsfake is getting packet
46       boundaries right.
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48       The -i option is for single-stepping through logfiles. It dumps the
49       line or packet number (and the sentence if the protocol is textual)
50       followed by "? ". Only when the user keys Enter is the line actually
51       fed to gpsd.
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53       The -m option specifies a monitor program inside which the daemon
54       should be run. This option is intended to be used with valgrind(1),
55       gdb(1) and similar programs.
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57       The -g option uses the monitor facility to run the gpsd instance within
58       gpsfake under control of gdb.
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60       The -o option specifies options to pass to the daemon. The -n option
61       passes -n to start the daemon reading the GPS without waiting for a
62       client (equivalent to -o "-n"). The -D option passes a -D option to the
63       daemon: thus -D 4 is shorthand for -o "-D 4".
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65       The -p ("pipe") option sets watcher mode and dumps the NMEA and GPSD
66       notifications generated by the log to standard output. This is useful
67       for regression-testing.
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69       The -r option specifies an initialization command to use in pipe mode.
70       The default is ?WATCH={"enable":true,"json":true}.
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72       The -s option sets the baud rate for the slave tty. The default is
73       4800.
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75       The -u option forces the test framework to use UDP rather than pty
76       devices. This may be useful for testing from within chroot jails where
77       access to pty devices is locked out.
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79       The -v option enables verbose progress reports to stderr. It is mainly
80       useful for debugging gpsfake itself.
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82       The -x option dumps packets as gpsfake gathers them. It is mainly
83       useful for debugging gpsfake itself.
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85       The -h option makes gpsfake print a usage message and exit.
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87       The argument must be the name of a file containing the data to be
88       cycled at the device.  gpsfake will print a notification each time it
89       cycles.
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91       Normally, gpsfake creates a pty for each logfile and passes the slave
92       side of the debice to the daemon. If the header comment in the logfile
93       contains the string "UDP", packets are instead shipped via UDP port
94       5000 to the addess 192.168.0.1.255. You can monitoer them with this:
95       tcpdump -s0 -n -A -i lo udp and port 5000.
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CUSTOM TESTS

98       gpsfake is a trivial wrapper around a Python module, also named
99       gpsfake, that can be used to fully script sessions involving a gpsd
100       instance, any number of client sessions, and any number of fake GPSes
101       feeding the daemon instance with data from specified sentence logs.
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103       Source and embedded documentation for this module is shipped with the
104       gpsd development tools. You can use it to torture-test either gpsd
105       itself or any gpsd-aware client application.
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107       Logfiles for the use with gpsfake can be retrieved using gpspipe,
108       gpscat, or gpsmon from the gpsd distribution, or any other application
109       which is able to create a compatible output.
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111       If gpsfake exits with "Cannot execute gpsd: executable not found." the
112       environment variable GPSD_HOME can be set to the path where gpsd can be
113       found. (instead of adding that folder to the PATH envirnment variable
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SEE ALSO

116       gpsd(8), gps(1), libgps(3), libgpsd(3), gpsctl(1), gpspipe(1),
117       gpsprof(1) gpsmon(1).
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AUTHOR

120       Eric S. Raymond esr@thyrsus.com. There is a project page for gpsd
121       here[1].
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NOTES

124        1. here
125           http://gpsd.berlios.de/
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129The GPSD Project                  12 Feb 2005                       GPSFAKE(1)