/************************************************************

This example writes a variable length string, reads it back,
and then appends to it.

 ************************************************************/

#include "hdf5.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define FILE            "vs2x.h5"
#define DATASET         "DS1"
#define DIM0            4

int
main (void)
{
    hid_t       file, memtype, space, dset;
                                            /* Handles */
    herr_t      status;
    char        *wdata = "Parting";
    char        *rdata;                    /* Read buffer */
    char        *data;
    size_t  rsize;

    /*
     * Create a new file using the default properties.
     */
    file = H5Fcreate (FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);
    memtype = H5Tcopy (H5T_C_S1);
    status = H5Tset_size (memtype, H5T_VARIABLE);
   

    space = H5Screate (H5S_SCALAR);

    /*
     * Create the dataset and write the variable-length string data to
     * it.
     */
    dset = H5Dcreate (file, DATASET, memtype, space, H5P_DEFAULT, H5P_DEFAULT,
                H5P_DEFAULT);
    /* Write string to dataset */
    status = H5Dwrite (dset, memtype, H5S_ALL, H5S_ALL, H5P_DEFAULT, &wdata);
    
    /* Read string back */
    status = H5Dread (dset, memtype, H5S_ALL, H5S_ALL, H5P_DEFAULT, &rdata);
    
    rsize = strlen (rdata)+1;
    printf ("Size of String Read From Dataset=%i\n", rsize);
    printf ("String Read From Dataset=%s\n", rdata);
    
    /* Append data to string and write it back*/
    data = (char *)calloc ((rsize+22), sizeof (char));
    strcpy (data, (const char *)rdata);
     
    strcat (data, " is such sweet sorrow");
    printf( "New String to Write to Dataset = %s\n", data);
     
    status = H5Dwrite (dset, memtype, H5S_ALL, H5S_ALL, H5P_DEFAULT, &data);

    
    /*
     * Close and release resources.
     */
    status = H5Dclose (dset);
    status = H5Sclose (space);
    status = H5Tclose (memtype);
    status = H5Fclose (file);

}