Provided by: libgps-dev_2.36-2_i386 bug

NAME

       libgpsd - service library for GPS applications

SYNOPSIS

       C:

       #include <gpsd.h>

       int gpsd_open_dgps(char * dgpsserver);

       void gpsd_init(struct gps_device_t *session, struct * gps_context_t *,
                      char * device);

       int gpsd_activate(struct gps_device_t *session, bool reconfigurable);

       void gpsd_deactivate(struct gps_device_t * session);

       gps_mask_t gpsd_poll(struct gps_device_t * session);

       void gpsd_wrap(struct gps_device_t * session);

       void gpsd_report(int d, const char * fmt, ...);

DESCRIPTION

       libgps is a service library which supports querying GPS devices; link
       it with the linker option -lgps. There are two interfaces supported in
       it; one high-level interface that goes through gpsd(1) and is intended
       for concurrent use by several applications, and one low-level interface
       that speaks directly with the serial or USB device to which the GPS is
       attached. This page describes the low-level interface, which gpsd(1)
       itself uses. See gpsd(3) for a description of the high-level interface,
       which is almost certainly what you want.

       Calling gpsd_init() initializes a session structure to hold the data
       collected by the GPS.

       You may optionally specify a DGPS server, either as a string containing
       a server name or a string containining server name followed by a colon
       and a port name or number. To specify no DGPS, pass the null pointer.

       The second argument must be a context structure. The library will use
       it for information that need to be shared between sessions; presently
       this includes the leap-second correction and possibly a pointer to a
       shared-memory segment used to communicate with the Network Time
       Protocol daemon.

       After the session structure has been set up, you may modify some of its
       members.

       gpsd_device
           This member should hold the path name of the device.

       baudrate
           Communication speed in bits per second. For NMEA or SiRF devices,
           the library automatically hunts through all plausible baud rates,
           stopping on the one where it sees valid packets. By setting this
           field you can designate a speed to be tried at the front of the
           hunt queue

       raw_hook
           A hook function to be executed on each NMEA sentence or as it is
           read from the GPS. The data from non-NMEA GPSes like the EarthMate
           will be translated to an NMEA sentence before being passed to the
           hook. Parameters are a pointer to a gps_data structure full of
           parsed data, the sentence, the length of the sentence, and a
           rawness level.

       gpsd_activate() initializes the connection to the GPS.
       gpsd_deactivate() closes the connection. These functions are provided
       so that long-running programs can release a connection when there is no
       activity requiring the GPS, and re-acquire it later.

       gpsd_poll() queries the GPS and updates the part of the session
       structure that holds position, speed, GPS signal quality, and other
       data returned by the GPS. It returns a mask describing which fields
       have changed.

       gpsd_wrap() ends the session, implicitly performing a
       gpsd_deactivate().

       The calling application must define one additional function:
       gpsd_report(). The library will use this to issue ordinary status
       messages. Use first argument of 0 for errors, 1 for ordinary status
       messages, and 2 or higher for debugging messages.

       The low-level functions do not allocate or free any dynamic storage.
       They can thus be used in a long-running application (such as gpsd(8)
       itself) with a guarantee that they won´t cause memory leaks.

BUGS

       Writes to the context structure members are not guarded by a mutex.

SEE ALSO

       gpsd(8), cgps(1), libgpsd(3).

AUTHOR

       Eric S. Raymond <esr@thyrsus.com> based partly on earlier work by Remco
       Treffkorn, Derrick Brashear, and Russ Nelson.