mirror of https://github.com/ecmwf/eccodes.git
92 lines
2.5 KiB
C
92 lines
2.5 KiB
C
/*
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* (C) Copyright 2005- ECMWF.
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*
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* This software is licensed under the terms of the Apache Licence Version 2.0
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* which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
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*
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* In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
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* virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
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*/
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/*
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* C Implementation: grib_multi_write
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*
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* Description: How to encode GRIB2 messages containing multiple fields
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "eccodes.h"
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static void usage(const char* prog)
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{
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printf("usage: %s in.grib out.grib\n", prog);
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exit(1);
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}
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int main(int argc, char** argv)
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{
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int err = 0;
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FILE* in = NULL;
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FILE* of = NULL;
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long edition, step;
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char* filename = NULL;
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char* ofilename = NULL;
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codes_handle* h = NULL;
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codes_multi_handle* mh = NULL;
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const int start_section = 4; /* Grib2 Product Definition Section */
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if (argc < 3) usage(argv[0]);
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filename = argv[1];
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ofilename = argv[2];
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/* open input file */
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in = fopen(filename, "rb");
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if (!in) {
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fprintf(stderr, "ERROR: unable to open input file %s\n", filename);
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return 1;
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}
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/* new grib handle from input file */
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h = codes_handle_new_from_file(0, in, PRODUCT_GRIB, &err);
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CODES_CHECK(err, 0);
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CODES_CHECK(codes_get_long(h, "edition", &edition), 0);
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if (edition != 2) {
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fprintf(stderr, "ERROR: Input grib must be edition 2 for multi-fields\n");
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exit(1);
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}
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/* create a new empty multi-field handle */
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mh = codes_grib_multi_handle_new(NULL);
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if (!mh) {
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fprintf(stderr, "ERROR: Unable to create multi-field handle\n");
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exit(1);
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}
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for (step = 12; step <= 120; step += 12) {
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/* set step */
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codes_set_long(h, "step", step);
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/* append h to mh repeating from section 4 */
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/* i.e. starting from section 4 all the sections to the end of the message will be copied */
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codes_grib_multi_handle_append(h, start_section, mh);
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}
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/* open output file */
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of = fopen(ofilename, "w");
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if (!of) {
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fprintf(stderr, "ERROR: unable to open output file %s\n", ofilename);
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exit(1);
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}
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/* write multi-field handle to output file */
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codes_grib_multi_handle_write(mh, of);
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fclose(of);
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/* release memory */
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codes_handle_delete(h);
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codes_grib_multi_handle_delete(mh);
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fclose(in);
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return 0;
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}
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