/usr/bin/gpsd

usage: gpsd [OPTIONS] device...

  Options include:
  -?, -h, --help            = help message
  -b, --readonly            = bluetooth-safe: open data sources read-only
  -D, --debug integer       = set debug level, default 0
  -F, --sockfile sockfile   = specify control socket location, default none
  -f, --framing FRAMING     = fix device framing to FRAMING (8N1, 8O1, etc.)
  -G, --listenany           = make gpsd listen on INADDR_ANY
  -l, --drivers             = list compiled in drivers, and exit.
  -n, --nowait              = don't wait for client connects to poll GPS
  -N, --foreground          = don't go into background
  -P, --pidfile pidfile     = set file to record process ID
  -p, --passive             = do not reconfigure the receiver automatically
  -r, --badtime             = use GPS time even if no fix
  -S, --port PORT           = set port for daemon, default 2947
  -s, --speed SPEED         = fix device speed to SPEED, default none
  -V, --version             = emit version and exit.

A device may be a local serial device for GNSS input, plus an optional
PPS device, or a URL in one of the following forms:
     tcp://host[:port]
     udp://host[:port]
     {dgpsip|ntrip}://[user:passwd@]host[:port][/stream]
     gpsd://host[:port][:/device]
in which case it specifies an input source for device, DGPS or ntrip data.

The following driver types are compiled into this gpsd instance:
				NMEA0183
	b		*	ALLYSTAR
				InertialSense
				Ashtech
			*	CASIC
				Delorme TripMate
				Pre-2003 Delorme EarthMate
				Furuno Electric GH-79L4
n				Garmin NMEA
	b	c		MTK-3301
				San Jose Navigation FV18
	b			True North
		c		Jackson Labs Fury
			*	AIVDM
n	b	c	*	EverMore
n			*	Garmin Serial binary
			*	Garmin USB binary
n	b		*	GeoStar
	b		*	GREIS
			*	iTalk
			*	Motorola Oncore
	b		*	Navcom NCT
n	b		*	SiRF
n			*	Skytraq
			*	SPARTN
n	b		*	SuperStarII
n	b		*	Trimble TSIP
				iSync
n	b	c	*	u-blox
	b		*	Zodiac
			*	NMEA2000
			*	RTCM104V2
			*	RTCM104V3
			*	Garmin Simple Text
			*	JSON slave driver
				PPS
# n: mode switch, b: speed switch, c: rate switch, *: non-NMEA packet type.
# Control socket for hotplug notifications enabled.
# KPPS DIS-abled.
# Netfeed enabled.
# NTRIP enabled.
# Shared memory export enabled.