Here is an example how to use H5Tget_native instead of constructing memory type
http://hdf.ncsa.uiuc.edu/training/other-ex5/h5nestc.c
At 10:39 AM 4/28/2005, Ed Hartnett wrote:
Howdy HDF5 People!
I have a program called tst_h_wrt_cmp, which write a little array of a
compound type.
Then I have another program called tst_h_rd_cmp.c, which reads them
back in and checks the value. This works on any one machine, but when
I run tst_h_wrt_cmp on a Sun, and try to read the resulting file on a
Linux machine, I get garbled data because the two machines use
different padding for the struct.
Is this expected behavior?
tst_h_wrt_cmp.c:
#include "tests.h"
#define FILE_NAME "tst_h_wrt_cmp.h5"
#define DIM1_LEN 3
#define COMPOUND_NAME "cmp"
#define VAR_NAME "var"
int
main()
{
hid_t fileid, access_plist, spaceid, typeid;
hid_t datasetid, datasetid1, typeid1;
int bool_out[DIM1_LEN] = {0, 1, 0}, bool_in[DIM1_LEN];
hsize_t dims[1];
struct s1 {
unsigned char c1;
double d;
} data[DIM1_LEN];
int i;
for (i=0; i<DIM1_LEN; i++)
{
data[i].c1 = 126;
data[i].d = -9999999;
}
printf("*** Checking packing of HDF5 compound types...");
/* Open file and create group. */
if ((access_plist = H5Pcreate(H5P_FILE_ACCESS)) < 0) ERR;
if (H5Pset_fclose_degree(access_plist, H5F_CLOSE_STRONG)) ERR;
if ((fileid = H5Fcreate(FILE_NAME, H5F_ACC_TRUNC, H5P_DEFAULT,
access_plist)) < 0) ERR;
/* Create a simple compound type. */
if ((typeid = H5Tcreate(H5T_COMPOUND, sizeof(struct s1))) < 0) ERR;
if (H5Tinsert(typeid, "c1", HOFFSET(struct s1, c1), H5T_NATIVE_UCHAR)
< 0) ERR;
if (H5Tinsert(typeid, "d", HOFFSET(struct s1, d), H5T_NATIVE_DOUBLE) <
0) ERR;
if (H5Tcommit(fileid, COMPOUND_NAME, typeid) < 0) ERR;
/* Create a space. */
dims[0] = DIM1_LEN;
if ((spaceid = H5Screate_simple(1, dims, dims)) < 0) ERR;
/* Create a dataset of this compound type. */
if ((datasetid = H5Dcreate(fileid, VAR_NAME, typeid, spaceid,
H5P_DEFAULT)) < 0) ERR;
/* Write some data. */
if (H5Dwrite(datasetid, typeid, H5S_ALL, H5S_ALL,
H5P_DEFAULT, data) < 0) ERR;
/* Release all resources. */
if (H5Fclose(fileid) < 0) ERR;
SUMMARIZE_ERR;
/* Print out our number of errors, if any, and exit badly. */
if (total_err)
{
printf("%d errors detected! Sorry!\n", total_err);
return 2;
}
printf("*** Tests successful!\n");
return 0;
}
tst_h_rd_cmp.c:
#include "tests.h"
#define FILE_NAME "tst_h_wrt_cmp.h5"
#define DIM1_LEN 3
#define COMPOUND_NAME "cmp"
#define VAR_NAME "var"
int
main()
{
hid_t fileid, access_plist, spaceid, typeid;
hid_t datasetid, datasetid1, typeid1;
int bool_out[DIM1_LEN] = {0, 1, 0}, bool_in[DIM1_LEN];
hsize_t dims[1];
struct s1 {
unsigned char c1;
double d;
} data[DIM1_LEN];
int i;
printf("*** Checking packing of HDF5 compound types...");
/* Open file. */
if ((access_plist = H5Pcreate(H5P_FILE_ACCESS)) < 0) ERR;
if (H5Pset_fclose_degree(access_plist, H5F_CLOSE_STRONG)) ERR;
if ((fileid = H5Fopen(FILE_NAME, H5F_ACC_RDONLY, access_plist)) < 0) ERR;
/* Open dataset. */
if ((datasetid = H5Dopen(fileid, VAR_NAME)) < 0) ERR;
/* Check space. */
if ((spaceid = H5Dget_space(datasetid)) < 0) ERR;
if (H5Sget_simple_extent_ndims(spaceid) != 1) ERR;
if (H5Sget_simple_extent_npoints(spaceid) != DIM1_LEN) ERR;
/* Get type. */
if ((typeid = H5Dget_type(datasetid)) < 0) ERR;
/* Read the data. */
if (H5Dread(datasetid, typeid, H5S_ALL, H5S_ALL,
H5P_DEFAULT, data) < 0) ERR;
/* Check the data. */
for (i=0; i<DIM1_LEN; i++)
if (data[i].c1 != 126 || data[i].d != -9999999) ERR;
/* Release all resources. */
if (H5Fclose(fileid) < 0) ERR;
SUMMARIZE_ERR;
/* Print out our number of errors, if any, and exit badly. */
if (total_err)
{
printf("%d errors detected! Sorry!\n", total_err);
return 2;
}
printf("*** Tests successful!\n");
return 0;
}
--
Ed Hartnett -- ed@xxxxxxxxxxxxxxxx
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Elena Pourmal, HDF QA, Maintenance and Support Team Leader
NCSA University of Illinois at Urbana-Champaign
605 E. Springfield Ave.
Champaign, IL 61820
epourmal@xxxxxxxxxxxxx
(217)333-0238 (office)
(217)244-1987 (fax)
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