add C unit tests

Makefile.am

@@ -75,9 +75,19 @@ src_libtrexio_la_SOURCES = $(SOURCES)
 # section related to tests
 
 TESTS_C = \
-  tests/io_all \
   tests/io_num_hdf5 \
-  tests/io_num_text 
+  tests/io_num_text \
+  tests/io_dset_float_hdf5 \
+  tests/io_dset_float_text \
+  tests/io_dset_int_hdf5 \
+  tests/io_dset_int_text \
+  tests/io_str_hdf5 \
+  tests/io_str_text \
+  tests/io_dset_str_hdf5 \
+  tests/io_dset_str_text \
+  tests/overwrite_all_hdf5 \
+  tests/overwrite_all_text \
+  tests/io_all
 
 TESTS_F = \
   tests/test_f
@@ -89,19 +99,29 @@ check_PROGRAMS = $(TESTS)
 
 # specify common options for all tests
 LDADD = src/libtrexio.la
-
+# in principal, specifying -no-install (see example below) is not mandatory
-# in principal, specifying -no-install (see example below) for each test provides better 
+# for the tests to compile and pass, but the compilations itself differs
-# and faster (?) `make check` but becomes tedious as the number of tests increases
+tests_io_num_hdf5_LDFLAGS = -no-install
-
+tests_io_num_text_LDFLAGS = -no-install
-#tests_io_all_LDFLAGS = -no-install
+tests_io_dset_float_hdf5_LDFLAGS = -no-install
+tests_io_dset_float_text_LDFLAGS = -no-install
+tests_io_dset_int_hdf5_LDFLAGS = -no-install
+tests_io_dset_int_text_LDFLAGS = -no-install
+tests_io_str_hdf5_LDFLAGS = -no-install
+tests_io_str_text_LDFLAGS = -no-install
+tests_io_dset_str_hdf5_LDFLAGS = -no-install
+tests_io_dset_str_text_LDFLAGS = -no-install
+tests_overwrite_all_hdf5_LDFLAGS = -no-install
+tests_overwrite_all_text_LDFLAGS = -no-install
+tests_io_all_LDFLAGS = -no-install
 
 test_trexio_f = $(srcdir)/tests/trexio_f.f90
 
 $(test_trexio_f): $(trexio_f)
 	cp $(trexio_f) $(test_trexio_f)
 
-
 tests_test_f_SOURCES = $(test_trexio_f) tests/test_f.f90
+tests_test_f_LDFLAGS = -no-install
 
 
 if TREXIO_DEVEL

tests/io_dset_float_hdf5.c

@@ -0,0 +1,148 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (floating point) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical dataset in a file
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_nucleus_coord(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numerical (floating point) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  double* coord;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical (floating point) dataset from the file
+  coord = (double*) calloc(3*num, sizeof(double));
+  rc = trexio_read_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  double x = coord[30] - 2.14171677;
+  assert( x*x < 1.e-14 );
+  free(coord);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_float_text.c

@@ -0,0 +1,148 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (floating point) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical dataset in a file
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_nucleus_coord(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numerical (floating point) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  double* coord;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical (floating point) dataset from the file
+  coord = (double*) calloc(3*num, sizeof(double));
+  rc = trexio_read_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+
+  double x = coord[30] - 2.14171677;
+  assert( x*x < 1.e-14 );
+  free(coord);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_int_hdf5.c

@@ -0,0 +1,134 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (int) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  int nucl_index[12] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical (integer) dataset in a file
+  rc = trexio_write_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file 
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_basis_nucleus_index(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numericali (int) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  int* nucl_index;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical dataset from the file
+  nucl_index = (int*) calloc(num, sizeof(int));
+  rc = trexio_read_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+  assert ( nucl_index[num-1] == num );
+
+  free(nucl_index);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  //rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_int_text.c

@@ -0,0 +1,134 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to write a dataset with numerical (int) values into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  int nucl_index[12] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12};
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write numerical (integer) dataset in a file
+  rc = trexio_write_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file 
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset exists
+  rc = trexio_has_basis_nucleus_index(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another dataset does not exist
+  rc = trexio_has_mo_coefficient(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with numericali (int) values from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  int* nucl_index;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read numerical dataset from the file
+  nucl_index = (int*) calloc(num, sizeof(int));
+  rc = trexio_read_basis_nucleus_index(file, nucl_index);
+  assert (rc == TREXIO_SUCCESS);
+  assert ( nucl_index[num-1] == num );
+
+  free(nucl_index);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset  (TREXIO_FILE, TEST_BACKEND);
+
+  //rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_str_hdf5.c

@@ -0,0 +1,157 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write an array of strings into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  const char* labels[] = {"C"       ,
+                          "Na FAKE" ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H FAKE"  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write dataset of string in the file (including FAKE statements)
+  int max_str_len = 16;
+  rc = trexio_write_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset of strings in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset of strings exists
+  rc = trexio_has_nucleus_label(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the dataset of strings does not exist
+  rc = trexio_has_mo_symmetry(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with strings from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  char** labels;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read the arrays of strings truncated to max_str_len=2 symbols
+  int max_str_len = 2;
+
+  labels = (char**) malloc(num*sizeof(char*));
+  for (int i=0; i<num; i++){
+    labels[i] = (char*) malloc((max_str_len+1)*sizeof(char));
+  }
+
+  rc = trexio_read_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(labels[0], "C")  == 0);
+  assert (strcmp(labels[1], "Na") == 0);
+
+  for (int i=0; i<num; i++){
+    free(labels[i]);
+  }
+  free(labels);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_dset_str_text.c

@@ -0,0 +1,157 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write an array of strings into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  const char* labels[] = {"C"       ,
+                          "Na FAKE" ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "C"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H"       ,
+                          "H FAKE"  };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write numerical attribute in an empty file
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // write dataset of string in the file (including FAKE statements)
+  int max_str_len = 16;
+  rc = trexio_write_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a dataset of strings in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written dataset of strings exists
+  rc = trexio_has_nucleus_label(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that the dataset of strings does not exist
+  rc = trexio_has_mo_symmetry(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_dset_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a dataset with strings from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  int num;
+  char **labels;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read numerical attribute from the file
+  rc = trexio_read_nucleus_num(file, &num);
+  assert (rc == TREXIO_SUCCESS);
+  assert (num == 12);
+
+  // read the arrays of strings truncated to max_str_len=2 symbols
+  int max_str_len = 2;
+
+  labels = (char**) malloc(num*sizeof(char*));
+  for (int i=0; i<num; i++){
+    labels[i] = (char*) malloc((max_str_len+1)*sizeof(char));
+  }
+
+  rc = trexio_read_nucleus_label(file, labels, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(labels[0], "C")  == 0);
+  assert (strcmp(labels[1], "Na") == 0);
+
+  for (int i=0; i<num; i++){
+    free(labels[i]);
+  }
+  free(labels);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_dset_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_dset_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_dset_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_str_hdf5.c

@@ -0,0 +1,133 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write a string attribute (single variable-length string) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  const char* sym = "B3U with some comments";
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write string attribute in an empty file
+  int max_str_len = 32;
+  rc = trexio_write_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a string attribute in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written string attribute exists
+  rc = trexio_has_nucleus_point_group(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another string attribute does not exist
+  rc = trexio_has_mo_type(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a string attribute from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  char* sym;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read string attribute from the file
+  int max_str_len = 32;
+  sym = (char*) malloc(max_str_len*sizeof(char));
+
+  rc = trexio_read_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  char * pch;
+  pch = strtok(sym, " ");
+  assert (strcmp(pch, "B3U") == 0);
+  /* alternative test when 3 symbols are read from the file to sym */
+  /*rc = trexio_read_nucleus_point_group(file, sym, 3);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(sym, "B3U") == 0 );*/
+  free(sym);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/io_str_text.c

@@ -0,0 +1,133 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write_str (const char* file_name, const back_end_t backend) {
+
+/* Try to write a string attribute (single variable-length string) into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  const char* sym = "B3U with some comments";
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write string attribute in an empty file
+  int max_str_len = 32;
+  rc = trexio_write_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_has_str (const char* file_name, const back_end_t backend) {
+
+/* Try to check the existence of a string attribute in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+/*================= START OF TEST ==================*/
+
+  // open file
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // check that the previously written string attribute exists
+  rc = trexio_has_nucleus_point_group(file);
+  assert (rc == TREXIO_SUCCESS);
+
+  // check that another string attribute does not exist
+  rc = trexio_has_mo_type(file);
+  assert (rc == TREXIO_HAS_NOT);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_read_str (const char* file_name, const back_end_t backend) {
+
+/* Try to read a string attribute from the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be read
+  char* sym;
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'read' mode
+  file = trexio_open(file_name, 'r', backend);
+  assert (file != NULL);
+
+  // read string attribute from the file
+  int max_str_len = 32;
+  sym = (char*) malloc(max_str_len*sizeof(char));
+
+  rc = trexio_read_nucleus_point_group(file, sym, max_str_len);
+  assert (rc == TREXIO_SUCCESS);
+
+  char * pch;
+  pch = strtok(sym, " ");
+  assert (strcmp(pch, "B3U") == 0);
+  /* alternative test when 3 symbols are read from the file to sym */
+  /*rc = trexio_read_nucleus_point_group(file, sym, 3);
+  assert (rc == TREXIO_SUCCESS);
+  assert (strcmp(sym, "B3U") == 0 );*/
+  free(sym);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write_str (TREXIO_FILE, TEST_BACKEND);
+  test_has_str   (TREXIO_FILE, TEST_BACKEND);
+  test_read_str  (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/overwrite_all_hdf5.c

@@ -0,0 +1,141 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_HDF5
+#define TREXIO_FILE 	"test.h5"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write (const char* file_name, const back_end_t backend) {
+
+/* Try to write a full set of data (num+dset_num+str+dset_str) related to benzene molecule into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+  const char* sym = "D6h";
+  const char* labels[] = {"C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write the data
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 4);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 2);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_overwrite (const char* file_name, const back_end_t backend) {
+
+/* Try to overwrite the data that already exists in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 24;
+  double coord[3] = {
+  0.00000000 ,  666.666,  0.00000000 ,
+  };
+  const char* sym = "Unknown";
+  const char* labels[] = {"Ru" ,
+                          "U"  ,
+                          "Cl" ,
+                          "Na" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // check that the previously written data cannot be overwritten
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 16);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 4);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write     (TREXIO_FILE, TEST_BACKEND);
+  test_overwrite (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+

tests/overwrite_all_text.c

@@ -0,0 +1,141 @@
+#include "trexio.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define TEST_BACKEND 	TREXIO_TEXT
+#define TREXIO_FILE 	"test.dir"
+#define RM_COMMAND 	"rm -rf " TREXIO_FILE
+
+static int test_write (const char* file_name, const back_end_t backend) {
+
+/* Try to write a full set of data (num+dset_num+str+dset_str) related to benzene molecule into the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 12;
+  double coord[36] = {
+  0.00000000 ,  1.39250319 ,  0.00000000 ,
+ -1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -1.20594314 , -0.69625160 ,  0.00000000 ,
+  0.00000000 , -1.39250319 ,  0.00000000 ,
+  1.20594314 , -0.69625160 ,  0.00000000 ,
+  1.20594314 ,  0.69625160 ,  0.00000000 ,
+ -2.14171677 ,  1.23652075 ,  0.00000000 ,
+ -2.14171677 , -1.23652075 ,  0.00000000 ,
+  0.00000000 , -2.47304151 ,  0.00000000 ,
+  2.14171677 , -1.23652075 ,  0.00000000 ,
+  2.14171677 ,  1.23652075 ,  0.00000000 ,
+  0.00000000 ,  2.47304151 ,  0.00000000 ,
+  };
+  const char* sym = "D6h";
+  const char* labels[] = {"C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "C" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // write the data
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_SUCCESS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 4);
+  assert (rc == TREXIO_SUCCESS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 2);
+  assert (rc == TREXIO_SUCCESS);
+  
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+static int test_overwrite (const char* file_name, const back_end_t backend) {
+
+/* Try to overwrite the data that already exists in the TREXIO file */
+
+  trexio_t* file = NULL;
+  trexio_exit_code rc;
+
+  // parameters to be written
+  int num = 24;
+  double coord[3] = {
+  0.00000000 ,  666.666,  0.00000000 ,
+  };
+  const char* sym = "Unknown";
+  const char* labels[] = {"Ru" ,
+                          "U"  ,
+                          "Cl" ,
+                          "Na" ,
+                          "H" };
+
+/*================= START OF TEST ==================*/
+
+  // open file in 'write' mode
+  file = trexio_open(file_name, 'w', backend);
+  assert (file != NULL);
+
+  // check that the previously written data cannot be overwritten
+  rc = trexio_write_nucleus_num(file, num);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+
+  rc = trexio_write_nucleus_coord(file, coord);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_point_group(file, sym, 16);
+  assert (rc == TREXIO_ATTR_ALREADY_EXISTS);
+  
+  rc = trexio_write_nucleus_label(file, labels, 4);
+  assert (rc == TREXIO_DSET_ALREADY_EXISTS);
+
+  // close current session
+  rc = trexio_close(file);
+  assert (rc == TREXIO_SUCCESS);
+
+/*================= END OF TEST ==================*/
+
+  return 0;
+}
+
+
+int main(void) {
+
+/*============== Test launcher ================*/
+
+  int rc;
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  test_write     (TREXIO_FILE, TEST_BACKEND);
+  test_overwrite (TREXIO_FILE, TEST_BACKEND);
+
+  rc = system(RM_COMMAND);
+  assert (rc == 0);
+
+  return 0;
+}
+
+