eccodes/examples/C/bufr_keys_iterator.c

113 lines
2.9 KiB
C

/*
* Copyright 2005-2018 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;
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,"r");
if (!in) {
printf("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) {
printf("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) {
printf("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);
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 %lu)\n",klen);
}
}
/* delete key iterator */
codes_bufr_keys_iterator_delete(kiter);
/* delete handle */
codes_handle_delete(h);
cnt++;
}
fclose(in);
return 0;
}