16 Nov 2006
gpscat
1
The GPSD Project
GPSD Documentation
gpscat
dump the output from a GPS
gpscat
-s speed
-p
-t
-D debuglevel
file-or-serial-port
DESCRIPTION
gpscat is a simple program for
logging and packetizing GPS data streams. It takes input from a
specified file or serial device (presumed to have a GPS attached) and
reports to standard output. The program runs until end of input or it is
interrupted by ^C or other means. It does not terminate on a bad
backet; this is intentional.
In raw mode (the default) gpscat
simply dumps its input to standard output. Nonprintable characters
other than ASCII whitespace are rendered as hexadecimal string escapes.
In packetizing mode, gpscat uses the
same code as
gpsd8's
packet sniffer to break the input into packets. Packets are reported
one per line; line breaks in the packets themselves are
escaped.
This program is useful as a sanity checker when examining a new
device. It can be used as a primitive NMEA logger, but beware that
(a) interrupting it likely to cut off output in mid-sentence, and (b)
to avoid displaying incomplete NMEA sentences right up next to shell
prompts that often contain a $, raw mode always emits an extra final
linefeed.
Also, be aware that packetizing mode will produce useless
results — probably consuming the entirety of input and appearing
to hang — if it is fed data that is not a sequence of packets
of one of the known types.
The program accepts the following options:
-p
Invoke packetizer mode.
-s
Set the port's baud rate (and optionally its parity and stop
bits) before reading. Argument should begin with one of the normal integer
baud rates (300, 1200, 4800, 9600, 19200, 38400, etc.). It may be
followed by an optional suffix [NOE][12] to set parity (None, Even,
Odd) and stop bits (1 or 2).
-t
Invoke packetizer mode, with the packet type and length (in
parentheses) reported before a colon and space on each line.
-D
In packetizer mode, enable progress messages from the packet
getter. Probably only of interest to developers testing packet
getter changes.
-h
Display program usage and exit.
Specifying -s 4800N1 is frequently helpful with unknown
devices.
SEE ALSO
gpsd8,
gps1,
libgps3,
libgpsmm3,
gpsfake1.
gpsprof1,
gpsctl1,
gpsdctl8,
gpsmon1.
AUTHOR
Eric S. Raymond esr@thyrsus.com.