eccodes/examples/C/grib_set_pv.c

89 lines
2.1 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: grib_set_pv
*
* Description: how to set pv (vertical coordinate parameters)
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "eccodes.h"
static void usage(const char* prog) {
fprintf(stderr, "usage: %s in out\n",prog);
exit(1);
}
int main(int argc, char** argv)
{
int err = 0;
long NV = 0;
size_t size=0;
double pv[4]={1,2,3,4};
size_t pvsize=4;
FILE* in = NULL;
char* infile = NULL;
FILE* out = NULL;
char* outfile = NULL;
codes_handle *h = NULL;
const void* buffer = NULL;
if (argc != 3) usage(argv[0]);
infile = argv[1];
outfile= argv[2];
in = fopen(infile, "r");
if(!in) {
fprintf(stderr, "ERROR: unable to open input file %s\n",infile);
return 1;
}
out = fopen(outfile, "w");
if(!out) {
fprintf(stderr, "ERROR: unable to open output file %s\n",outfile);
fclose(in);
return 1;
}
/* create a new handle from a message in a file */
h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err);
if (h == NULL) {
fprintf(stderr, "Error: unable to create handle from file %s\n",infile);
}
CODES_CHECK(codes_set_long(h,"PVPresent", 1),0);
CODES_CHECK(codes_set_double_array(h, "pv", pv, pvsize),0);
/* Once we set the pv array, the NV key should be also set */
CODES_CHECK(codes_get_long(h, "NV", &NV),0);
assert( NV == pvsize );
/* get the coded message in a buffer */
CODES_CHECK(codes_get_message(h, &buffer, &size),0);
/* write the buffer in a file*/
if(fwrite(buffer, 1, size, out) != size)
{
perror(argv[1]);
exit(1);
}
codes_handle_delete(h);
fclose(in);
fclose(out);
return 0;
}