Hi Ed
for a correct use of the creation of portable compound types you might take a
look at the code of the high level Table API.
see the files /hl/src/H5TB.c and /hl/test/test_table.c
and the function H5TBmake_table
the test_table.c test reads files saved in little and big endian machines
Pedro
At 10:39 AM 4/28/2005, you 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
</Pedro Vicente Nunes>
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