eccodes/examples/C/bufr_set_keys.c

102 lines
2.7 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_set_keys
*
* Description: how to set different type of keys in BUFR messages.
*
*/
#include "eccodes.h"
static void usage(const char* prog)
{
printf("usage: %s infile\n", prog);
exit(1);
}
int main(int argc, char* argv[])
{
FILE* in = NULL;
FILE* out = NULL;
/* message handle. Required in all the eccodes calls acting on a message.*/
codes_handle* h = NULL;
long longVal;
/*double doubleVal;*/
int err = 0;
int cnt = 0;
size_t size = 0;
const char* infile = "../../data/bufr/syno_multi.bufr";
const void* buffer = NULL;
if (argc != 2) {
usage(argv[0]);
return 1;
}
in = fopen(infile, "rb");
out = fopen(argv[1], "wb");
if (!in || !out) {
perror("Error: unable to open files");
if (out) fclose(out);
if (in) fclose(in);
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) {
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 expand the descriptors
i.e. unpack the data values */
/*CODES_CHECK(codes_set_long(h,"unpack",1),0);*/
/* this is the place where you may wish to modify the message */
/* e.g. we change the centre */
/* set bufrHeaderCentre */
longVal = 222;
CODES_CHECK(codes_set_long(h, "bufrHeaderCentre", longVal), 0);
printf(" set bufrHeaderCentre to: %ld\n", longVal);
/* check bufrHeaderCentre */
CODES_CHECK(codes_get_long(h, "bufrHeaderCentre", &longVal), 0);
printf(" bufrHeaderCentre's new value is: %ld\n", longVal);
/* get the modified message in a buffer */
CODES_CHECK(codes_get_message(h, &buffer, &size), 0);
/* write the buffer to a file */
if (fwrite(buffer, 1, size, out) != size) {
perror(argv[0]);
return 1;
}
/* delete handle */
codes_handle_delete(h);
cnt++;
}
fclose(in);
return 0;
}