gpspipe - tool to connect to gpsd and retrieve sentences


gpspipe [OPTIONS] [server[:port[:device]]]

gpspipe -h

gpspipe -V


gpspipe is a tool to connect to gpsd and output the received sentences to stdout. This makes the program useful as a pipe from gpsd to another program or file.

gpspipe does not require root privileges, and can be run concurrently with other tools connecting to the local gpsd without causing problems.

The output will consist of one or both of the raw NMEA or native gpsd sentences. Each line can be optionally time stamped. There is also an option to exit gracefully after a given count of packets.

gpspipe may be run as a daemon, but requires the -o, --output flag for writing the output to a file.


-?, -h, --help

Print a usage message and exit.

-2, --split24

-2 sets the split24 flag on AIS reports.

-B, --nobuffer

Do not buffer the output.

-d, --daemonize

Run as a daemon.

-D LVL, --debug LVL

Set debug level to LVL.

-l, --sleep

Sleep for ten seconds before attempting to connect to gpsd. This is very useful when running as a daemon, giving gpsd time to start before attempting a connection.

-n COUNT, --count COUNT

Exit after COUNT messages are output.

-o FILE, --output FILE

Cause the collected data to be written to the specified file. Use of this option is mandatory if gpspipe is run as a daemon.

-p, --profile

Dump profiling information in JSON.

-P, --pps

Enables dumping of PPS drift JSON in NMEA and raw modes.

-r, --nmea

Cause NMEA sentences to be output. This may be NMEA, pseudo NMEA built from binary data, or some combination of both.

-R, --raw

Causes super-raw (gps binary) data to be output. This will forward exactly what the device sent.

-s DEV, --serial DEV

Cause the collected data to be written to the specified serial device (DEV) with settings 4800 8N1. Thus gpspipe can be used with -s, --serial and -r, --nmea options to emulate a serial port hardwired to a GPS that gpsd is managing.

-S, --scaled

Set the scaled flag. This is for AIS and SUBFRAME data only. Scaled data will be output in the JSON, instead of raw data in the JSON.

-t, --timestamp

Add a UTC timestamp to each sentence output.

-T FMT, --timefmt FMT

Set the format of the timestamp. See strftime(3) for the available placeholders. Setting this option implies -t (--timestamp). Default setting is "%F %T"

-u, --usec

Use usec resolution time stamp, implies -t (--timestamp). Use twice (-uu) to output sec.usec.

-v, --spinner

Show a spinning activity indicator on stderr. This is useful if stdout is redirected into a file or a pipe. By default the spinner is advanced with every messages written; specifying -v, or --spinner, more than once will double the number of messages required to rotate the spinner.

-V, --version

Print the program version and exit.

-w, --json

Cause native gpsd JSON sentences to be output.

-x SEC, --seconds SEC

Exit after delay of SEC seconds.

-Z, --zulu

Set the timestamp format iso8601: implies -t.

At least one of -R, -r or -w must be specified.

You must use -o if you use -d.


By default, clients collect data from the local gpsd daemon running on localhost, using the default GPSD port 2947. The optional argument to any client may override this behavior: [server[:port[:device]]]

For further explanation, and examples, see the ARGUMENTS section in the gps(1) man page


When gpsd is running, this example will send one hundred raw NMEA sentences to standard output, then exit:

$ gpspipe -r -n 100

When gpsd is running, this example will wait at most 5 seconds for a TPV message, print it to stdout, then exit:

$ gpspipe -x 5 -w|sed -n '/TPV/{p;q}'

Use gpspipe and socat to serve NMEA from the local gpsd on tcp port 2948:

$ socat EXEC:'gpspipe -r' TCP-LISTEN:2948,reuseaddr,fork

The paranoid may wish to have socat run as user 'nobody' and only accept connections from the local network. Using the -B option to gpspipe will reduce latency and jitter The "su=nobody" means this must be run as root:

# socat EXEC:'gpspipe -rB' \



on success.


on failure


gpsd(8), gps(1), gpsfake(1), socat(1).


Project web site:


This file is Copyright 2013 by the GPSD project
SPDX-License-Identifier: BSD-2-clause