Re: [gpsd-users] Shared Memory Client Example?

[Ed Simmons]

Hi Kevin,

Did you compile GPSD using the option that enables shared memory export? 
I fell foul of this once, you need to do something like

scons shm_export=yes

but I forget the exact naming. Scons -h (i think) gives you the whole 
list of possible options to pass to scons.

Best,
Ed

On 21/12/2013 23:10, Kevin Russell wrote:
> I'm having trouble getting a basic client using shared memory 
> working.  Does anyone have a working example?  Any attempt to open 
> results in an error return "can't get host entry."
>
> Here's an example of what I'm running into...
>
> address@hidden ~/client $ cat client.c
> #include <gps.h>
> #include <stdlib.h>
> #include <errno.h>
>
> int main(void) {
>     int result;
>     struct gps_data_t data;
>     printf("Hello\n");
>     result = gps_open(GPSD_SHARED_MEMORY,0,&data);
>     printf("open returned %d %s\n",result,gps_errstr(errno));
>     if (result != 0) {
>         return 1;
>     }
>     result = gps_read(&data);
>     printf("read returned %d\n",result);
>     if (result != 0) {
>         return 1;
>     }
>     result = gps_close(&data);
>     printf("read returned %d\n",result);
>     if (result != 0) {
>         return 1;
>     }
> }
>
> address@hidden ~/client $ ./client
> Hello
> open returned -1 can't get host entry
> address@hidden ~/client $ gpsd -V
> gpsd: 3.6 (revision 3.6)
> address@hidden ~/client $ uname -a
> Linux raspberrypi 3.10.24+ #614 PREEMPT Thu Dec 19 20:38:42 GMT 2013 
> armv6l GNU/Linux
> address@hidden ~/client $ /etc/init.d/gpsd status
> [ ok ] gpsd is running.
> address@hidden ~/client $ gpxlogger
> <?xml version="1.0" encoding="utf-8"?>
> <gpx version="1.1" creator="GPSD 3.6 - http://catb.org/gpsd";
>         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance";
>         xmlns="http://www.topografix.com/GPX/1/1";
>         xsi:schemaLocation="http://www.topografix.com/GPX/1/1
> http://www.topografix.com/GPX/1/1/gpx.xsd";>
>  <metadata>
>   <time>2013-12-21T23:01:34.000Z</time>
>  </metadata>
>  <trk>
>   <src>GPSD 3.6</src>
>   <trkseg>
>    <trkpt lat="45.452308" lon="-122.763872">
>     <ele>-4.268000</ele>
>     <time>2013-12-21T23:01:35.000Z</time>
>     <src>GPSD tag="75"</src>
>     <fix>3d</fix>
>    </trkpt>
> ^C  </trkseg>
>  </trk>
> </gpx>
>
> Any suggestions appreciated.
>
>
> Kevin