eccodes/examples/C/grib_clone.c

77 lines
2.1 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: grib_clone
*
* Description: How to create a new GRIB message by cloning
* an existing message.
*
*/
#include <stdio.h>
#include "eccodes.h"
int main(int argc, char* argv[])
{
FILE* in = NULL;
FILE* out = NULL;
codes_handle* source_handle = NULL;
const void* buffer = NULL;
size_t size = 0;
int err = 0;
if (argc != 3) {
return 1;
}
in = fopen(argv[1], "rb");
if (!in) {
perror("ERROR: unable to open input file");
return 1;
}
out = fopen(argv[2], "wb");
if (!out) {
perror("ERROR: unable to open output file");
fclose(in);
return 1;
}
/* loop over the messages in the source grib and clone them */
while ((source_handle = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err)) != NULL) {
codes_handle* clone_handle = codes_handle_clone(source_handle);
if (clone_handle == NULL) {
perror("ERROR: could not clone field");
return 1;
}
/* this is the place where you may wish to modify the clone */
/* e.g.
CODES_CHECK(codes_set_long(clone_handle, "centre", 250),0);
etc...
*/
/* get the coded message in a buffer */
CODES_CHECK(codes_get_message(clone_handle, &buffer, &size), 0);
/* write the buffer to a file */
if (fwrite(buffer, 1, size, out) != size) {
perror(argv[2]);
return 1;
}
codes_handle_delete(clone_handle);
codes_handle_delete(source_handle);
}
fclose(out);
fclose(in);
return 0;
}