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Diffstat (limited to 'HDF5Examples/C/H5T/h5ex_t_stringatt.c')
-rw-r--r-- | HDF5Examples/C/H5T/h5ex_t_stringatt.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/HDF5Examples/C/H5T/h5ex_t_stringatt.c b/HDF5Examples/C/H5T/h5ex_t_stringatt.c new file mode 100644 index 0000000..26e86d2 --- /dev/null +++ b/HDF5Examples/C/H5T/h5ex_t_stringatt.c @@ -0,0 +1,155 @@ +/************************************************************ + + This example shows how to read and write string datatypes + to an attribute. The program first writes strings to an + attribute with a dataspace of DIM0, then closes the file. + Next, it reopens the file, reads back the data, and + outputs it to the screen. + + This file is intended for use with HDF5 Library version 1.8 + + ************************************************************/ + +#include "hdf5.h" +#include <stdio.h> +#include <stdlib.h> + +#define FILE "h5ex_t_stringatt.h5" +#define DATASET "DS1" +#define ATTRIBUTE "A1" +#define DIM0 4 +#define SDIM 8 + +int +main(void) +{ + hid_t file, filetype, memtype, space, dset, attr; + /* Handles */ + herr_t status; + hsize_t dims[1] = {DIM0}; + size_t sdim; + char wdata[DIM0][SDIM] = {"Parting", "is such", "sweet", "sorrow."}, + /* Write buffer */ + **rdata; /* Read buffer */ + int ndims, i; + + /* + * Create a new file using the default properties. + */ + file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT); + + /* + * Create file and memory datatypes. For this example we will save + * the strings as FORTRAN strings, therefore they do not need space + * for the null terminator in the file. + */ + filetype = H5Tcopy(H5T_FORTRAN_S1); + status = H5Tset_size(filetype, SDIM - 1); + memtype = H5Tcopy(H5T_C_S1); + status = H5Tset_size(memtype, SDIM); + + /* + * Create dataset with a null dataspace. + */ + space = H5Screate(H5S_NULL); + dset = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT); + status = H5Sclose(space); + + /* + * Create dataspace. Setting maximum size to NULL sets the maximum + * size to be the current size. + */ + space = H5Screate_simple(1, dims, NULL); + + /* + * Create the attribute and write the string data to it. + */ + attr = H5Acreate(dset, ATTRIBUTE, filetype, space, H5P_DEFAULT, H5P_DEFAULT); + status = H5Awrite(attr, memtype, wdata[0]); + + /* + * Close and release resources. + */ + status = H5Aclose(attr); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Tclose(filetype); + status = H5Tclose(memtype); + status = H5Fclose(file); + + /* + * Now we begin the read section of this example. Here we assume + * the attribute and string have the same name and rank, but can + * have any size. Therefore we must allocate a new array to read + * in data using malloc(). + */ + + /* + * Open file, dataset, and attribute. + */ + file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT); + dset = H5Dopen(file, DATASET, H5P_DEFAULT); + attr = H5Aopen(dset, ATTRIBUTE, H5P_DEFAULT); + + /* + * Get the datatype and its size. + */ + filetype = H5Aget_type(attr); + sdim = H5Tget_size(filetype); + sdim++; /* Make room for null terminator */ + + /* + * Get dataspace and allocate memory for read buffer. This is a + * two dimensional attribute so the dynamic allocation must be done + * in steps. + */ + space = H5Aget_space(attr); + ndims = H5Sget_simple_extent_dims(space, dims, NULL); + + /* + * Allocate array of pointers to rows. + */ + rdata = (char **)malloc(dims[0] * sizeof(char *)); + + /* + * Allocate space for integer data. + */ + rdata[0] = (char *)malloc(dims[0] * sdim * sizeof(char)); + + /* + * Set the rest of the pointers to rows to the correct addresses. + */ + for (i = 1; i < dims[0]; i++) + rdata[i] = rdata[0] + i * sdim; + + /* + * Create the memory datatype. + */ + memtype = H5Tcopy(H5T_C_S1); + status = H5Tset_size(memtype, sdim); + + /* + * Read the data. + */ + status = H5Aread(attr, memtype, rdata[0]); + + /* + * Output the data to the screen. + */ + for (i = 0; i < dims[0]; i++) + printf("%s[%d]: %s\n", ATTRIBUTE, i, rdata[i]); + + /* + * Close and release resources. + */ + free(rdata[0]); + free(rdata); + status = H5Aclose(attr); + status = H5Dclose(dset); + status = H5Sclose(space); + status = H5Tclose(filetype); + status = H5Tclose(memtype); + status = H5Fclose(file); + + return 0; +} |