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Re: 950207: tbl2cdf

>Organization: Dept. of Oceanography, Dalhousie University
>Keywords: 199502071539.AA01793

Hi Steven,

> I've downloaded tbl2cdf this morning and tried to compile it.
> 
> Am I doing something wrong?
> 
> Skye$ gcc -o tbl2cdf -I/opt/netcdf/include -L/opt/netcdf/lib -lnetcdf 
> tbl2cdf.c
> 
> tbl2cdf.c: In function `main':
> tbl2cdf.c:606: warning: passing arg 3 of `ncvarput' from incompatible pointer 
> t
> > ype
> tbl2cdf.c:606: warning: passing arg 4 of `ncvarput' from incompatible pointer 
> t
> > ype
> tbl2cdf.c:639: warning: passing arg 3 of `ncvarput' from incompatible pointer 
> t
> > ype
> tbl2cdf.c:639: warning: passing arg 4 of `ncvarput' from incompatible pointer 
> t
> > ype

No, these warnings are because tbl2cdf.c has never been updated to use use
longs instead of ints for coordinate indices (the `start' and `count'
parameters to ncvarget() and ncvarput()).  That change to netCDF was made in
October 1991 with the release of version 2.0 of netCDF, to permit porting
the code to 16-bit systems such as MSDOS.  Here's a brief description of the
change that was made to the netCDF interface at that time:

    ------ Wed Oct  9 1991      Changes in netCDF (1.11 to 2.0)

    The netCDF C interfaces were changed to use long values rather than ints for
    netCDF dimensions on all machines.  This changed the following interfaces 
that
    formerly use "int" or "int*" for dimensions and dimension pointers:

      int ncdimdef(int cdfid, const char* name, int length);
      int ncdiminq(int cdfid, int dimid, char* name, int* length);
      int ncvarput1(int cdfid, int varid, int *coords, void* value);
      int ncvarget1(int cdfid, int varid, int *coords, void* value);
      int ncvarput(int cdfid, int varid, int *start, int *count, void* value);
      int ncvarget(int cdfid, int varid, int *start, int *count, void* value);

    to use "long" or "long*" instead:

      int ncdimdef(int cdfid, const char* name, long length);
      int ncdiminq(int cdfid, int dimid, char* name, long* length);
      int ncvarput1(int cdfid, int varid, long *coords, void* value);
      int ncvarget1(int cdfid, int varid, long *coords, void* value);
      int ncvarput(int cdfid, int varid, long *start, long *count, void* value);
      int ncvarget(int cdfid, int varid, long *start, long *count, void* value);

    No change to data representation or file formats was required, since the XDR
    form of integers is 32 bits.  The main advantage of this change is that on
    platforms such as MSDOS machines on which integers are only 16 bits, it is
    now possible to access data from variables that have a dimension greater
    than 32767.  This is of some practical importance, since CD-ROM disks are
    being written with large datasets in netCDF form, and it is desirable to be
    able to access this data from inexpensive 16-bit machines.

    Since ints and longs are the same on most current platforms (Suns,
    DECstations, VAXen, IBM RS6000s, SGIs, HPs, CRAYs, ...), this change does
    not break old code.  Applications compiled with the old interface on such
    machines will work the same way as they did before without recompiling.
    Standard C compilers that support prototypes permit using int values for
    dimension size and automatically convert them to longs before the call.  C
    code that uses pointers to ints instead of pointers to longs (where required
    by the new interfaces) will elicit warning messages from lint and from

The tbl2cdf.c program is part of the collection of user-contributed netCDF
software, and as such is maintained by the contributors rather than Unidata.
I've CC:ed Chuck Denham, the author of this program, on this reply, in case
he has a newer version we can upload into the pub/netcdf/contrib/ directory
of our FTP server.  If the email address I have for him isn't obsolete, he
may see this (Hi, Chuck!).

> ld: Undefined symbol
>    _ncclose
>    _ncdimdef
>    _nccreate
>    _ncattput
>    _ncvardef
>    _ncvarput
>    _ncendef
> ld: l.outa05711: Permission denied
> ld: l.outa05711: output write error: Bad file number
> collect2: ld returned 2 exit status

These messages indicate some sort of problem with the way you have
specified to gcc where to find the netCDF library, or problems with the
installation of that library (was it also built with gcc?).  If the `make
test' worked OK before you installed the netCDF library, you might check how
gcc was invoked to successfully link nctest.c to the netCDF library and
imitate that.

______________________________________________________________________________

Russ Rew                                                UCAR Unidata Program
address@hidden                                          P.O. Box 3000
http://www.unidata.ucar.edu/                          Boulder, CO 80307-3000
______________________________________________________________________________