hdf5/examples/h5_interm_group.c

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright by The HDF Group.                                               *
 * All rights reserved.                                                      *
 *                                                                           *
 * This file is part of HDF5.  The full HDF5 copyright notice, including     *
 * terms governing use, modification, and redistribution, is contained in    *
 * the COPYING file, which can be found at the root of the source code       *
 * distribution tree, or in https://www.hdfgroup.org/licenses.               *
 * If you do not have access to either file, you may request a copy from     *
 * help@hdfgroup.org.                                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/*
 * This program checks if group exists in a file and creates it including
 * all intermediate groups.
 */

#include "hdf5.h"

#define H5FILE_NAME "interm_group.h5"

int
main(void)
{

    hid_t      file;
    hid_t      g1_id, g2_id, g3_id;
    hid_t      grp_crt_plist;
    H5G_info_t g2_info;
    char       name[3];

    herr_t status;
    int    i;

    /*
     * Create a file using the default properties.
     */
    file = H5Fcreate(H5FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /*
     * Create a group in the file.
     */
    g1_id = H5Gcreate2(file, "/G1", H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);

    H5Gclose(g1_id);
    H5Fclose(file);

    /*
     * Now reopen the file and group in the file.
     */
    file = H5Fopen(H5FILE_NAME, H5F_ACC_RDWR, H5P_DEFAULT);

    /*
     * Check if group /G1 exists in the file.
     */
    if (H5Lexists(file, "/G1", H5P_DEFAULT) != FALSE)
        printf("Group /G1 exists in the file\n");

    /*
     * Check that group G2/G3 exists in /G1 and if not create it using
     * intermediate group creation property.
     */
    g1_id = H5Gopen2(file, "/G1", H5P_DEFAULT);
    /* Next commented call causes error stack to be printed out; the next one
     * works fine; is it a bug or a feature? EIP 04-25-07
     */
    /*  if (H5Lexists(g1_id, "G2/G3", H5P_DEFAULT) !=TRUE) { */
    if (H5Lexists(g1_id, "G2", H5P_DEFAULT) != TRUE) {

        grp_crt_plist = H5Pcreate(H5P_LINK_CREATE);

        /* Set flag for intermediate group creation */
        status = H5Pset_create_intermediate_group(grp_crt_plist, TRUE);
        g3_id  = H5Gcreate2(g1_id, "G2/G3", grp_crt_plist, H5P_DEFAULT, H5P_DEFAULT);
        H5Gclose(g3_id);
    }
    H5Gclose(g1_id);

    /* Now check if group /G1/G2 exists in the file, then open it and print
     * its members names
     */
    if (H5Lexists(file, "/G1/G2", H5P_DEFAULT)) {

        g2_id  = H5Gopen2(file, "/G1/G2", H5P_DEFAULT);
        status = H5Gget_info(g2_id, &g2_info);
        printf("Group /G1/G2 has %d member(s)\n", (int)g2_info.nlinks);

        for (i = 0; i < (int)g2_info.nlinks; i++) {
            H5Lget_name_by_idx(g2_id, ".", H5_INDEX_NAME, H5_ITER_NATIVE, (hsize_t)i, name, 3, H5P_DEFAULT);
            printf("Object's name is %s\n", name);
        }
        H5Gclose(g2_id);
    }
    H5Fclose(file);
    return 0;
}