NAME

       gpscat - dump the output from a GPS

SYNOPSIS

       gpscat [-?] [--debug LVL] [--help] [--packetizer] [--speed SPEED] [--typeflag] [--version]
              [-D LVL] [-h] [-p] [-s SPEED] [-t] [-V] 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 packet; 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 gpsd(8)'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:

       -?, -h, --help
           Display program usage and exit.

       -D LVL, --debug LVL
           In packetizer mode, enable progress messages from the packet getter. Probably only of
           interest to developers testing packet getter changes. Higher arguments to -D produce
           more output.

       -p, --packetizer
           Invoke packetizer mode.

       -s SPEED, --speed SPEED
           Set the port's baud rate (and optionally its parity and stop bits) to SPEED 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, Odd, Even) and stop bits (1 or 2).

           Specifying -s 4800N1 is frequently helpful with unknown devices.

       -t, --typeflag
           Invoke packetizer mode, with the packet type and length (in parentheses) reported
           before a colon and space on each line.

       -V, --version
           Display program version and exit.

SEE ALSO

       gpsd(8), gps(1), libgps(3), libgpsmm(3), gpsfake(1).  gpsprof(1), gpsctl(1), gpsdctl(8),
       gpsmon(1).

AUTHOR

       Eric S. Raymond <esr@thyrsus.com>.