eccodes/tests/largefile.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_internal.h"

#ifndef ECCODES_ON_WINDOWS
#include <unistd.h>
#endif

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

int main(int argc, char* argv[])
{
    off_t offsetin = 0, offsetout = 0;
    off_t size     = 100000000;
    size_t rsizein = 10, rsizeout = 0;
    double doff = 0;
    FILE* f     = 0;
    char str[10];
    int i;

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

    printf("sizeof(off_t)=%d sizeof(long)=%d\n", sizeof(off_t), sizeof(long));

    f = fopen(argv[1], "r");
    if (!f) {
        printf("%s\n", strerror(errno));
        exit(errno);
    }

    offsetin = size;
    for (i = 0; i < 100000; i++) {
        printf("i=%d  ", i);
        if (fseeko(f, offsetin, SEEK_SET)) {
            printf("fseeko error\n");
            printf("- %d - %s\n", errno, strerror(errno));
            exit(1);
        }
        rsizeout = fread(str, 1, rsizein, f);
        if (rsizeout != rsizein) {
            printf("rsizein=%d rsizeout=%d\n", rsizein, rsizeout);
            printf("end of file\n");
            exit(1);
        }
        offsetout = ftello(f);
        doff      = (double)offsetout;
        printf("%20.0f \n", doff);
        if (offsetout != offsetin + rsizeout) {
            printf("offset error: offsetout=%jd offsetin=%jd\n", offsetout, offsetin + rsizeout);
            exit(1);
        }
        offsetin = offsetout + size;
    }

    fclose(f);
    return 0;
}