eccodes/examples/C/bufr_keys_iterator.c

117 lines
3.2 KiB
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.
*/
/*
* C Implementation: bufr_keys_iterator
*
* Description: how to use keys_iterator functions and the
* codes_bufr_keys_iterator structure to get all the available
* keys in a BUFR message.
*
*/
#include "eccodes.h"
#define MAX_VAL_LEN 1024
static void usage(const char* prog)
{
printf("usage: %s infile\n", prog);
exit(1);
}
int main(int argc, char* argv[])
{
char* filename = NULL;
FILE* in = NULL;
/* message handle. Required in all the eccodes calls acting on a message.*/
codes_handle* h = NULL;
int err = 0, cnt = 0;
int keyType = 0;
int subsetNumber = 0;
char value[MAX_VAL_LEN];
size_t vlen = MAX_VAL_LEN;
size_t klen = 0;
if (argc != 2) usage(argv[0]);
filename = argv[1];
in = fopen(filename, "rb");
if (!in) {
fprintf(stderr, "Error: unable to open file %s\n", filename);
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) {
codes_bufr_keys_iterator* kiter = NULL;
if (h == NULL) {
fprintf(stderr, "Error: unable to create handle for message %d\n", cnt);
cnt++;
continue;
}
printf("message: %d\n", cnt);
/* we need to instruct ecCodes to unpack the data values */
CODES_CHECK(codes_set_long(h, "unpack", 1), 0);
/* get BUFR key iterator */
kiter = codes_bufr_keys_iterator_new(h, 0);
if (!kiter) {
fprintf(stderr, "Error: Unable to create BUFR keys iterator\n");
exit(1);
}
/* loop over the keys */
while (codes_bufr_keys_iterator_next(kiter)) {
/* get key name */
char* name = codes_bufr_keys_iterator_get_name(kiter);
if (strcmp(name, "subsetNumber") == 0) {
subsetNumber++;
printf("\n Subset %d:\n", subsetNumber);
continue;
}
printf(" %s=", name);
CODES_CHECK(codes_get_native_type(h, name, &keyType), 0);
/* get key size to see if it is an array */
CODES_CHECK(codes_get_size(h, name, &klen), 0);
if (klen == 1) {
/* not array */
vlen = MAX_VAL_LEN;
memset(value, 0, vlen);
codes_get_string(h, name, value, &vlen);
printf("%s\n", value);
}
else {
/* for arrays */
printf("(array of %zu)\n", klen);
}
}
/* delete key iterator */
codes_bufr_keys_iterator_delete(kiter);
/* delete handle */
codes_handle_delete(h);
cnt++;
}
fclose(in);
return 0;
}