text: /*
   * Copyright 2005-2017 ECMWF.
   *
   * This software is licensed under the terms of the Apache Licence Version 2.0
   * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
   *
   * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
   * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
   */
  
  /*
   * Description: compare values retrieved with grib_get_double_array and
   *               grib_get_double_element
   *
   * Author: Cristian D. Codorean
   *
   */
  #include "grib_api.h"
  
  void usage(char* prog) {
      printf("usage: %s filename\n",prog);
      exit(1);
  }
  
  int main(int argc, char** argv)
  {
      int err = 0,i = 0;
      double *values = NULL;
      size_t values_len= 0;
      double element_value=0;
  
      FILE* in = NULL;
      char* filename = NULL;
      grib_handle *h = NULL;
  
      if (argc<2) usage(argv[0]);
      filename=argv[1];
  
      in = fopen(filename,"r");
      if(!in) {
          printf("ERROR: unable to open file %s\n",filename);
          return 1;
      }
  
      /* create new handle from a message in a file*/
      h = grib_handle_new_from_file(0,in,&err);
      if (h == NULL) {
          printf("Error: unable to create handle from file %s\n",filename);
          return 1;
      }
  
      /* get the size of the values array */
      GRIB_CHECK(grib_get_size(h,"values",&values_len),0);
      values = (double*)malloc(values_len*sizeof(double));
  
      /* get data values*/
      GRIB_CHECK(grib_get_double_array(h,"values",values,&values_len),0);
  
      if (values_len < 100) exit(1);
  
      for (i = 0; i < 100; i++) {
          /* get a particular data value */
          GRIB_CHECK(grib_get_double_element(h, "values", i, &element_value),0);
  
          if (element_value != values[i]) {
              exit(1);
          }
      }
  
      free(values);
      grib_handle_delete(h);
  
      fclose(in);
      return 0;
  }
  