Mixing netCDF & HDF in same program

• To: "'netcdfgroup@xxxxxxxxxxxxxxxx'" <netcdfgroup@xxxxxxxxxxxxxxxx>
• Subject: Mixing netCDF & HDF in same program
• From: "Davies, Harvey" <harvey.davies@xxxxxxxxxxxx>
• Date: Thu, 5 Oct 2000 19:22:10 +1100

This is a report on the modifications I had to make so the netCDF library
had
no names the same as those in the HDF library. (Initially there were lots of
conflicts because
HDF includes all the netcdf-2 names.)  I only wanted to use netcdf-3 names
so it
seemed reasonable to try to suppress the netcdf-2 names in the netcdf
library. (I
could have modified HDF rather than netCDF, but it turned out to be just a
couple of hours
work to do it this way.)

I ran configure with
CPPFLAGS="-DNDEBUG -DNO_NETCDF_2" ./configure

I had hoped that this would suppress the generation of the version 2 stuff
in v2i.c, but I had
to insert several #ifndef commands to make this happen.  I found the only
code in v2i.c which 
needed to be retained was that for function nctypelen (which was supposed to
disappear from
version 3 if I remember correctly :-(  )

This left just ten conflicting names. So I changed these by inserting the
following into nc.h:

/*
 *    Redefine following names to avoid conflict with HDF names
 */

#define nctypelen nc_nctypelen
int nctypelen(nc_type type);

#define NC_begins nc_NC_begins
#define NC_check_id nc_NC_check_id
#define NC_computeshapes nc_NC_computeshapes
#define NC_endef nc_NC_endef
#define NC_findattr nc_NC_findattr
#define NC_lookupattr nc_NC_lookupattr
#define NC_lookupvar nc_NC_lookupvar
#define NC_var_shape nc_NC_var_shape
#define NC_varoffset nc_NC_varoffset

Finally, I found it useful to define a NULL data-type like the HDF type
DFNT_NONE.
So I added the following line defining dummy type NC_NAT to netcdf.h as
follows:

/*
 *  The netcdf external data types
 */
typedef enum {
        NC_NAT =         0,      /* NAT = 'Not A Type' (c.f. NaN) */
        NC_BYTE =       1,      /* signed 1 byte integer */
        NC_CHAR =       2,      /* ISO/ASCII character */
        NC_SHORT =     3,      /* signed 2 byte integer */
        NC_INT =           4,      /* signed 4 byte integer */
        NC_FLOAT =      5,      /* single precision floating point number */
        NC_DOUBLE =   6       /* double precision floating point number */
} nc_type;

I will send a copy of my modified code to Unidata.

Harvey Davies, CSIRO Atmospheric Research,
Private Bag No. 1, Aspendale 3195
E-mail: harvey.davies@xxxxxxxxxxxx
Phone: +61 3 9239 4556
  Fax: +61 3 9239 4444

• Follow-Ups:
  • Re: Mixing netCDF & HDF in same program
    • From: Arlindo da Silva