tst_addvar.c

/* This program adds two new variables to an existing netCDF file.
 * It is used to test if netCDF can correctly calculate the file offsets
 * for the two new variables, in particular for files that align the
 * fix-size variables to a boundary larger than 4 bytes, for instance
 * a file created by PnetCDF with defaut alignment of 512 bytes.
 *
 * This program should run after tst_pnetcdf.c and takes the output file
 * from tst_pnetcdf.c as input on the command-line.
 *
 * To check the file offsets for all variables, adding a printf statement is
 * necessary in netcdf-4.3.3.1/libsrc/nc3internal.c around line 222,
 * for example,
 * printf("var %s: begin=%ld len=%ld end=%ld\n",(*vpp)->name->cp, (*vpp)->begin, (*vpp)->len, (*vpp)->begin+(*vpp)->len);
 *
 * Check the first new variable's begin to see whether it is less than
 * the last variable's offset in the existing file.
 */
#include <stdio.h>
#include <stdlib.h>
#include <netcdf.h>

#define ERR {if(err!=NC_NOERR){printf("Error at line=%d: %s\n", __LINE__, nc_strerror(err));}}

int main(int argc, char** argv) {
    int i, j, err, nerrs, ncid, varid[5], dimid[2];
    int old_buf[3][5], get_buf[3][5], new_buf[1024];

    if (argc != 2) {
        printf("Usage: %s [filename]\n",argv[0]);
        exit(0);
    }

    err = nc_open(argv[1], NC_WRITE, &ncid); ERR

    /* read all fixed-size variables */
    err = nc_inq_varid(ncid, "fixed_var_1", &varid[0]);
    err = nc_inq_varid(ncid, "fixed_var_3", &varid[1]);
    err = nc_inq_varid(ncid, "fixed_var_5", &varid[2]);
    err = nc_get_var_int(ncid, varid[0], old_buf[0]); ERR
    err = nc_get_var_int(ncid, varid[1], old_buf[1]); ERR
    err = nc_get_var_int(ncid, varid[2], old_buf[2]); ERR

    err = nc_redef(ncid); ERR

    /* add 2 new dimensions */
    err = nc_def_dim(ncid, "new_dim_1", 32, &dimid[0]); ERR
    err = nc_def_dim(ncid, "new_dim_2", 32, &dimid[1]); ERR

    /* add 2 new dimensions */
    err = nc_def_var(ncid, "new_var1", NC_INT,   2, dimid, &varid[3]); ERR
    err = nc_def_var(ncid, "new_var2", NC_FLOAT, 2, dimid, &varid[4]); ERR
    err = nc_enddef(ncid); ERR

    /* write more than 512 bytes (the default alignment used in PnetCDF) */
    for (i=0; i<1024; i++) new_buf[i] = -1;
    err = nc_put_var_int(ncid, varid[3], new_buf); ERR

    /* read and check all variables from the original file */
    err = nc_get_var_int(ncid, varid[0], get_buf[0]); ERR
    err = nc_get_var_int(ncid, varid[1], get_buf[1]); ERR
    err = nc_get_var_int(ncid, varid[2], get_buf[2]); ERR

    nerrs = 0;
    for (i=0; i<3; i++) {
        char varname[32];
        sprintf(varname, "fixed_var_%d",2*i+1);
        for (j=0; j<5; j++) {
            if (get_buf[i][j] != old_buf[i][j]) {
                printf("Error in %s line %d: expecting %s[%d]=%d but got %d\n",
                       __FILE__,__LINE__,varname,j,old_buf[i][j],get_buf[i][j]);
                nerrs++;
            }
        }
    }

    err = nc_close(ncid); ERR

    if (nerrs > 0) exit(-1);
/*
    SUMMARIZE_ERR;
    FINAL_RESULTS;
*/
    return 0;
}