eccodes/examples/set.c

87 lines
1.9 KiB
C

/*
* Copyright 2005-2015 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
*
* Description: how to set key values.
*
*
*
*
*/
#include <stdio.h>
#include <stdlib.h>
#include "grib_api.h"
int main(int argc, char** argv) {
int err = 0;
long centre=80;
long long_value=0;
char string_value[100];
size_t len = sizeof(string_value)/sizeof(char);
size_t size=0;
FILE* in = NULL;
char* infile = "../data/regular_latlon_surface.grib1";
FILE* out = NULL;
char* outfile = "out.grib1";
grib_handle *h = NULL;
const void* buffer = NULL;
in = fopen(infile,"r");
if(!in) {
printf("ERROR: unable to open file %s\n",infile);
return 1;
}
out = fopen(outfile,"w");
if(!out) {
printf("ERROR: unable to open file %s\n",outfile);
return 1;
}
/* create a new handle from a message in a file */
h = grib_handle_new_from_file(0,in,&err);
if (h == NULL) {
printf("Error: unable to create handle from file %s\n",infile);
}
/* set centre as a long */
GRIB_CHECK(grib_set_long(h,"centre",centre),0);
/* get centre as a long */
GRIB_CHECK(grib_get_long(h,"centre",&long_value),0);
printf("centre long value=%ld\n",long_value);
/* get centre as a string */
GRIB_CHECK(grib_get_string(h,"centre",string_value,&len),0);
printf("centre string value=%s\n",string_value);
/* get the coded message in a buffer */
GRIB_CHECK(grib_get_message(h,&buffer,&size),0);
/* write the buffer in a file*/
if(fwrite(buffer,1,size,out) != size)
{
perror(argv[1]);
exit(1);
}
/* delete handle */
grib_handle_delete(h);
fclose(in);
fclose(out);
return 0;
}