Re: Change from 3.23 to 3.24 - program doesn't work?

[Mike Tubby]

On 21/06/2022 19:11, Gary E. Miller wrote:

> Yo Mike!
>
> Care to share with everyone?
>     
    
    
    Hi Gary,
    
    Its a work project, so I would have to remove some code to protect
    the innocent.
    
    I am tidying up and the code and productionising it and have just
    re-introduced the API version check which fails, thus:
    
        22-06-2022 13:48:22 GMT [Info] GPSD
        version: 3.22 API version: 3.14  App built against API version:
        11.0
        22-06-2022 13:48:22 GMT [Notice] GPSD API mis-match ... exiting!
    
    the code that generates this error is in my reader:
    
          /* check the GPSD version and API info here */
          if (gpsd_data.set & VERSION_SET) {
      
              xlog(XLOG_INFO, "GPSD version: %s API version: %d.%d  App
      built against API version: %d.%d\n",
                  gpsd_data.version.release,
      gpsd_data.version.proto_major, gpsd_data.version.proto_minor,
      GPSD_API_MAJOR_VERSION, GPSD_API_MINOR_VERSION);
      
              if (gpsd_data.version.proto_major !=
      GPSD_API_MAJOR_VERSION || gpsd_data.version.proto_minor !=
      GPSD_API_MINOR_VERSION)
                  terminate(3, "GPSD API mis-match ... exiting!\n");
      
          } else {
              /* process the rest of the data */
              process_gpsd_data(&gpsd_data);
          }
    
    
    I am slightly confused ... is there:
    
        a) just an API version to check; or
        b) an API version *and* a protocol version to ckeck?
    
    the header file /usr/include/gps.h contains this definition for the
    version information:
    
    struct version_t {
          char release[64];                   /* external version */
          char rev[64];                       /* internal revision ID */
          int proto_major, proto_minor;       /* API major and minor
      versions */
          char remote[GPS_PATH_MAX];          /* could be from a remote
      device */
      };
      
      
    which appears to use "API version" interchangeably with
    "proto version" ?
    
    I am testing on a Debian system with GPSD version 3.22, variables:
    
        version.release    contains "3.22" which is okay
        version.proto_major    contains int(3)
        version.proto_minor    contains int(14)
    
    yet the comments say the API major/minor numbers int(11) and int(0)
    should be there - if they are the API versions?
    
    
    If we have both a "protocol version" and an "API version" to deal
    with then version_t appears to need extending:
    
    struct version_t {
          char release[64];                   /* external version */
          char rev[64];                       /* internal revision ID */
        int proto_major, proto_minor;       /*
            Protocol major and minor versions */
             
              int api_major, api_minor;           /* API major and minor
              versions */
            char remote[GPS_PATH_MAX];          /* could
      be from a remote device */
      };
    
    and the origin of the 3.14 needs exporting in /usr/include/gps.h
    
    
    
    Can you advise further?
    
    
    Mike
    
    
> On Tue, 21 Jun 2022 18:28:37 +0100
> Mike Tubby <mike@tubby.org> wrote:
>
> > David,
> >
> > I have emailed you off list with an example from one of my projects 
> > which works with GPSD 3.15 through 3.24 which you may find helpful.
> >
> > Mike
> >
> > On 20/06/2022 19:25, David Taylor wrote:
> > > On 20/06/2022 18:39, Gary E. Miller wrote:  
> > > > Yo David!
> > > >
> > > > On Mon, 20 Jun 2022 11:22:39 +0100
> > > > David Taylor <gm8arv@yahoo.co.uk> wrote:
> > > >  
> > > > > On 20/06/2022 07:41, Gary E. Miller wrote:  
> > > > > > Yo David!
> > > > > >
> > > > > > I can't see how that ever worked.  Your program does not check
> > > > > > if the receiver JSON has the data you are trying to read.
> > > > > >
> > > > > > Take a look at example.c for ideas on what is missing.  
> > > > > >               
> > > > > Gary,
> > > > >
> > > > > I could not find "example.c" for gpsd.  
> > > > >             
> > > > It is in the git repo, in the tar ball, in the libgps man page, ion
> > > > the web page,  etc.
> > > >
> > > > Since you don't know how to grep or search:
> > > >
> > > > https://gpsd.io/gpsd-client-example-code.html
> > > >
> > > >
> > > >  
> > > > > I did find gpssnmp.c and a compiled version, which appears to be a
> > > > > tidied up version of the software I submitted some time back, for
> > > > > which, thanks!  
> > > > >             
> > > > Yeah, bot used by many.
> > > >  
> > > > > On running the compiled version, though, I get a "connection
> > > > > failed" error.
> > > > >
> > > > >      pi@RasPi-22:~/gpsd/gpsd-3.24.1~dev/clients $ gpssnmp -g
> > > > > .1.3.6.1.2.1.25.1.33 gpssnmp: ERROR: connection failed  
> > > > >             
> > > > Hmm, I see that.  I'll look at it.
> > > >
> > > > WHile we are talking SNMP, I have been asked where those OIDs came
> > > > from?
> > > >
> > > > RGDS
> > > > GARY  
> > > >           
> > > Gary,
> > >
> > > I didn't find example.c in the GIT download.  I've used "find..." 
> > > before, but when I saw lib... I thought "that can't be the right 
> > > file"...  Thanks for the example URL.
> > >
> > > Thanks for checking out gpssnmp.c.  The only peculiar thing about
> > > this RPi is that ipV6 is disabled, but it was disabled on the
> > > previous 3.23 install.
> > >
> > > The OIDs are invented by me.  If you can find better - more
> > > official - ones let's swap.
> > >
> > > Cheers,
> > > David  
> > >         
> >
> >       
>
>
>
> RGDS
> GARY
> ---------------------------------------------------------------------------
> Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
> 	gem@rellim.com  Tel:+1 541 382 8588
>
> 	    Veritas liberabit vos. -- Quid est veritas?
>     "If you can't measure it, you can't improve it." - Lord Kelvin
>