eccodes/examples/C/bufr_read_temp.c

/*
 * Copyright 2005-2015 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.
 */

/*
 * C Implementation: bufr_read_temp
 *
 * Description: how to read a TEMP BUFR message.
 *
 */

#include "eccodes.h"


int main(int argc,char* argv[])
{
  FILE* in = NULL;

  /* message handle. Required in all the eccodes calls acting on a message.*/
  codes_handle* h=NULL;

  char* units= NULL;
  char* unitsPercent= NULL;
  double *sigt_pres=NULL, *sigt_geo=NULL, *sigt_t=NULL;
  double *sigt_rhu=NULL, *sigt_wsp=NULL, *sigt_wdir=NULL;
  long longVal;
  double doubleVal;
  size_t sigt_len=0, desc_len=0, len=0;
  int i, err=0;
  int cnt=0;
  char* infile = "../../data/bufr/temp_101.bufr";
  char key_name[128];

  in=fopen(infile,"r");
  if (!in) {
    printf("ERROR: unable to open file %s\n", infile);
    return 1;
  }

  /* loop over the messages in the bufr file */
  while ((h = codes_handle_new_from_file(NULL,in,PRODUCT_BUFR,&err)) != NULL || err != CODES_SUCCESS)
  {
    if (h == NULL) {
      printf("Error: unable to create handle for message %d\n",cnt);
      cnt++;
      continue;
    }

    printf("message: %d\n",cnt);

    /* we need to instruct ecCodes to expand the descriptors 
       i.e. unpack the data values */
    CODES_CHECK(codes_set_long(h,"unpack",1),0);

    sprintf(key_name,"/verticalSoundingSignificance=4/geopotential");

    /* get the size and allocate memory*/
    CODES_CHECK(codes_get_size(h,key_name,&sigt_len),0);

    printf("Number of T significant levels: %ld\n",sigt_len);

    /* Allocate memory */
    sigt_pres = malloc(sigt_len*sizeof(double));
    sigt_geo = malloc(sigt_len*sizeof(double));
    sigt_t = malloc(sigt_len*sizeof(double));
    sigt_rhu = malloc(sigt_len*sizeof(double));
    sigt_wsp = malloc(sigt_len*sizeof(double));
    sigt_wdir = malloc(sigt_len*sizeof(double));

    /* --------------------------
       Get pressure 
       ----------------------------*/

    /* get the values */
    len=sigt_len;
    CODES_CHECK(codes_get_double_array(h,key_name,sigt_pres,&len),0);

    /* --------------------------
       Get gepotential
       ----------------------------*/

    /* Check the size*/
    CODES_CHECK(codes_get_size(h,key_name,&len),0);
    if(len != sigt_len)
    {
      printf("incosistent number of geopotential values found!\n");
      return 1;
    }    

    /* get the values */
    CODES_CHECK(codes_get_double_array(h,key_name,sigt_geo,&len),0);

    /* --------------------------
       Get temperature
       ----------------------------*/

    /* Check the size*/
    if(len != sigt_len)
    {
      printf("incosistent number of temperature values found!\n");
      return 1;
    }    

    /* get the values */
    CODES_CHECK(codes_get_double_array(h,key_name,sigt_t,&len),0);


    /* delete handle */
    codes_handle_delete(h);

    /*Release memory*/
    free(sigt_pres);
    free(sigt_geo);
    free(sigt_t);
    free(sigt_rhu);
    free(sigt_wsp);
    free(sigt_wdir);

    cnt++;
  }

  fclose(in);
  return 0;
}