eccodes/examples/python/grib_keys_iterator.c

/*
 * (C) Copyright 2005- 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.
 */

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

#include "eccodes.h"

#define MAX_VAL_LEN  1024

static void usage(char* progname);

int main(int argc, char *argv[])
{
  /* To skip read only and not coded keys
     unsigned long key_iterator_filter_flags=CODES_KEYS_ITERATOR_SKIP_READ_ONLY ||
     CODES_KEYS_ITERATOR_SKIP_COMPUTED;
  */
    unsigned long key_iterator_filter_flags=CODES_KEYS_ITERATOR_ALL_KEYS;

  /* Choose a namespace. E.g. "ls", "time", "parameter", "geography", "statistics" */
  const char* name_space="ls";

  /* name_space=NULL to get all the keys */
  /* char* name_space=0; */

  FILE* f = NULL;
  codes_handle* h=NULL;
  
  int err=0;
  int msg_count=0;

  char value[MAX_VAL_LEN];
  size_t vlen=MAX_VAL_LEN;

  if (argc != 2) usage(argv[0]);

    f = fopen(argv[1],"rb");
  if(!f) {
    perror(argv[1]);
    exit(1);
  }

    while((h = codes_handle_new_from_file(0,f,PRODUCT_GRIB,&err)) != NULL)
  {
    codes_keys_iterator* kiter=NULL;
    msg_count++;
    /*printf("-- GRIB N. %d --\n",msg_count);*/
    if(!h) {
      printf("ERROR: Unable to create grib handle\n");
      exit(1);
    }

        kiter=codes_keys_iterator_new(h,key_iterator_filter_flags,name_space);
    if (!kiter) {
      printf("ERROR: Unable to create keys iterator\n");
      exit(1);
    }

    while(codes_keys_iterator_next(kiter))
    {
      const char* name = codes_keys_iterator_get_name(kiter);
      vlen=MAX_VAL_LEN;
      memset(value, 0, vlen);
      CODES_CHECK(codes_get_string(h,name,value,&vlen),name);
      printf("%s = %s\n",name,value);
    }

    codes_keys_iterator_delete(kiter);
    codes_handle_delete(h);
  }
  fclose(f);
  return 0;
}

static void usage(char* progname)
{
  printf("\nUsage: %s grib_file\n",progname);
  exit(1);
}