#include <stdio.h>
#include <string.h>
#include <netcdf.h>

#define FILENAME "test.nc"

int main()
{
    int ncid;
    int dim1_id, dim2_id, var1_id, var2_id, status;
    int var1ndims = 1; // vector
    int var1size = 3; // length 3
    int var2ndims = 1; // vector
    int var2size = 2; // length 2

    // create netcdf-4 classic file and overwrite if already exists; note MATLAB nccreate defaults to netcdf4-classic
    status = nc_create(FILENAME, NC_CLOBBER|NC_NETCDF4|NC_CLASSIC_MODEL, &ncid);
    if(status != NC_NOERR) {
        printf("Could not create file.\n");
    }

    // define the dimension for var1
    status = nc_def_dim(ncid, "dim1", var1size, &dim1_id);
    if(status != NC_NOERR) {
        printf("Could not create dim1.\n");
    }  

    // create var1 with dim1
    status = nc_def_var(ncid, "var1", NC_DOUBLE, var1ndims, &dim1_id, &var1_id);
    if(status != NC_NOERR) {
         printf("Could not create var1.\n");
    }

    // close the file 
    status = nc_close(ncid);
    printf("status after close = %d\n", status);
	
    // close the file 
    status = nc_close(ncid);
    printf("error code after close = %d\n", status);	

    // now reopen the file and add a second variable with dimension name as previously-defined var1
    printf("reopening file to write a second variable...\n");
    status = nc_open("test.nc", NC_WRITE, &ncid);
  
    // put back into define mode
    status = nc_redef(ncid);
    if(status != NC_NOERR) {
        printf("Could not put back into define mode.\n");
    }
    printf("status = %d\n", status);

    // define the dimension for var2 -- give it same name as existing var1
    status = nc_def_dim(ncid, "var1", var2size, &dim2_id);
    if(status != NC_NOERR) {
        printf("Could not create dim2.\n");
    }
  
    // create var2 with same dimension name as previously-defined var1, this should go awry
    status = nc_def_var(ncid, "var2", NC_DOUBLE, var2ndims, &dim2_id, &var2_id);
    if(status != NC_NOERR) {
         printf("Could not create var2.\n");
    }
    printf("error code = %d\n", status);

    // close the file 
    status = nc_close(ncid);
    printf("error code after close = %d\n", status);

    // close the file 
    status = nc_close(ncid);
    printf("error code after close = %d\n", status);
	
    printf("End of test.\n\n");

    return 0;
}