eccodes/tests/index_orderby.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.
 */

#include "grib_api.h"

void usage(char* prog)
{
    printf("usage: %s infile\n", prog);
    exit(1);
}

int main(int argc, char* argv[])
{
    grib_index* index = NULL;
    grib_handle* h    = NULL;
    char* infile      = NULL;
    int i, j, k, l;
    long ostep, olevel, onumber;
    char oshortName[200];
    size_t lenshortName = 200;
    int ret = 0, count = 0;

    if (argc != 2) usage(argv[0]);
    infile  = argv[1];
    outfile = argv[2];

    printf("indexing...\n");
    /* Create an index from a grib file with a given set of keys*/
    index = grib_index_new_from_file(0, infile, "shortName,level,number,step", &ret);
    if (ret) {
        printf("error: %s\n", grib_get_error_message(ret));
        exit(ret);
    }
    printf("end indexing...\n");

    /* ask the index to order the fields thorough some keys*/
    ret = grib_index_orderby(index, "level,shortName,number:desc,step:asc");
    if (ret != GRIB_SUCCESS) exit(1);

    count = 0;
    /* loop through all the fields in the asked order*/
    while ((h = grib_handle_new_from_index(index, &ret)) != NULL) {
        count++;
        if (ret) {
            printf("error: %d\n", ret);
            exit(ret);
        }
        lenshortName = 200;
        grib_get_string(h, "shortName", oshortName, &lenshortName);
        grib_get_long(h, "level", &olevel);
        grib_get_long(h, "number", &onumber);
        grib_get_long(h, "step", &ostep);
        printf("shortName=%s ", oshortName);
        printf("level=%ld ", olevel);
        printf("number=%ld ", onumber);
        printf("step=%ld \n", ostep);
        grib_handle_delete(h);
    }
    if (ret != GRIB_END_OF_INDEX) {
        printf("error: %s\n", grib_get_error_message(ret));
        exit(ret);
    }
    printf("  %d messages selected\n", count);

    return 0;
}