1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
<sect1 id="gpsdclient.c"><title><filename>libgps_core.c</filename></title>
<informaltable frame='all' pgwide='1'>
<tgroup cols='2'>
<colspec colname='c1'></colspec>
<colspec colname='c2'></colspec>
<spanspec spanname='s1' namest='c1' nameend='c2'></spanspec>
<thead>
<row>
<entry>Functions:-</entry><entry>The client interface library for the <application>gpsd</application> daemon.</entry>
</row>
</thead>
<tfoot>
<row>
<entry spanname='s1' align='left'>Notes based on code of Mon Apr 5 21:38:06 2010 -0400</entry>
</row>
</tfoot>
<tbody>
<row>
<entry><function>struct gps_data_t *gps_open(const char *host, const char *port)</function></entry>
<entry><para>Open a connection to a gps daemon.</para><para>Try to
get a <function>gps_data_t</function> structure. If it fails, return
a NULL.</para><para>Test for a specified host and/or port number,
using defaults if nothing is specified in the command line
invocation.</para><para>Try to connect to the now defined socket; on
error, release the resources and return NULL. On success, initialise
an internal <structname>struct gps_data_t</structname> and return
the pointer to it.</para></entry>
</row>
<row>
<entry><function>struct gps_data_t *gps_open_r(const char *host, const char *port, struct gps_data_t *gpsdata)</function></entry>
<entry><para>Variant of <function>gps_open()</function> for when
re-entrancy is required. Initializes storage passed by the
caller.</para></entry>
</row>
<row>
<entry><function>int gps_close(struct gps_data_t *gpsdata)</function></entry>
<entry><para>Close the fd associated with the
<function>gps_data_t</function> structure and stash the
result.</para><para>If there is a device id stored, NULL it and the
associated path.</para><para>If the device list has any data in it,
free this and mark the number of available devices as
invalid.</para><para>Free the <function>gps_data_t</function>
structure itself and return the stashed <function>close()</function>
result.</para></entry>
</row>
<row>
<entry><function>static void gps_unpack(char *buf, struct gps_data_t *gpsdata)</function></entry>
<entry><para>Keep looping through the data in
<function>buf</function> for JSON objects. Each time one is found,
analyze it and unpack it into the struct pointed at by gpsdata,
setting the gpsdata->set mask appropriately to indicate which data
is valid</para><para>This function is intended for GPSD internal use
only and should not be considered a stable part oof the
API.</para></entry>
</row>
<row>
<entry><function>int gps_poll(struct gps_data_t *gpsdata)</function></entry>
<entry><para>Poll the daemon and if there is no data or an error,
return -1.</para><para>If there is something to read, clear the
buffer, note the time as the received data time and the online time,
then unpack the data.</para><para>If profiling is active, use the
received data time, the fix time and the present time to calculate
the decode time and the client receipt time.</para></entry>
</row>
<row>
<entry><function>int gps_send(struct gps_data_t *gpsdata, const char *fmt, ... )</function></entry>
<entry><para>Gather up the instructions to a
<application>gpsd</application> instance for information to return
and write them to the device.</para><para>If the write fails, return
-1. This entry point is deprecated in favor of
<function>gps_stream()</function></para></entry>
</row>
<row>
<entry><function>bool gps_waiting(struct gps_data_t *gpsdata)</function></entry>
<entry><para>Return a boolean indicating whether input data is waiting on
the daemon socket. Does not block.</para></entry>
</row>
<row>
<entry><function>int gps_stream(struct gps_data_t *gpsdata, unsigned int, void *d)</function></entry>
<entry><para>Set watch and policy flags. This evaluates the flag mask passed
as the second argument, composes a corresponding command in the GPSD
write protocol, and ships it to the daemon. </para></entry>
</row>
<row>
<entry></entry>
<entry><para>The following three functions are guarded by an <function>#ifdef</function> so they only compile if it is required to be able to test the library and set up a command line exerciser interface.</para></entry>
</row>
<row>
<entry><function>static void data_dump(struct gps_data_t *collect, time_t now)</function></entry>
<entry><para>A data dumper used when debugging. It outputs data according to the command line input data.</para></entry>
</row>
<row>
<entry><function>static void dumpline(struct gps_data_t *ud UNUSED, char *buf, size_t ulen UNUSED, int level UNUSED)</function></entry>
<entry><para>A simple call to UNIX <function>puts()</function>.</para></entry>
</row>
<row>
<entry><function>int main(int argc, char *argv[])</function></entry>
<entry><para>A simple command line parser and endless loop to exercise the daemon when debugging.</para></entry>
</row>
</tbody>
</tgroup>
</informaltable>
</sect1>
|
