eccodes/examples/C/grib_set_missing.c

92 lines
2.8 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: set_missing
*
* Description: how to set a key as missing.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "eccodes.h"
int main(int argc, char** argv)
{
int err = 0, is_missing = 0;
FILE* in = NULL;
const char* infile = "../../data/reduced_gaussian_pressure_level.grib2";
FILE* out = NULL;
const char* outfile = "out_surface_level.grib2";
codes_handle* h = NULL;
const void* buffer = NULL;
size_t size = 0;
char str[] = "sfc";
size_t str_len = 3;
long Ni = 0;
in = fopen(infile, "rb");
if (!in) {
fprintf(stderr, "Error: unable to open input file %s\n", infile);
return 1;
}
out = fopen(outfile, "wb");
if (!out) {
fprintf(stderr, "Error: unable to open output file %s\n", outfile);
fclose(in);
return 1;
}
/* create a new GRIB 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);
fclose(out);
return 1;
}
CODES_CHECK(codes_set_string(h, "typeOfFirstFixedSurface", str, &str_len), 0);
CODES_CHECK(codes_set_missing(h, "scaleFactorOfFirstFixedSurface"), 0);
CODES_CHECK(codes_set_missing(h, "scaledValueOfFirstFixedSurface"), 0);
/* Can also set to MISSING via codes_set_string */
CODES_CHECK(codes_set_string(h, "scaleFactorOfFirstFixedSurface", "missing", &str_len), 0);
CODES_CHECK(codes_set_string(h, "scaledValueOfFirstFixedSurface", "missing", &str_len), 0);
/* Set a Code Table key to missing via codes_set_string */
CODES_CHECK(codes_set_string(h, "typeOfFirstFixedSurface", "missing", &str_len), 0);
/* see GRIB-490 */
CODES_CHECK(codes_get_long(h, "Ni", &Ni), 0);
is_missing = codes_is_missing(h, "Ni", &err);
assert(!err);
if (is_missing != 1) assert(!"Ni should be missing");
CODES_CHECK(codes_set_long(h, "Ni", Ni), 0);
/* 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(outfile);
exit(1);
}
/* delete handle */
codes_handle_delete(h);
fclose(in);
fclose(out);
return 0;
}