Open the nth object in a group


H5O_OPEN_BY_IDX(loc_id, group_name, index_type, order, n, lapl_id)


<pre><code class="language-c">hid_t H5Oopen_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t n, hid_t lapl_id )</code></pre>

<pre><code class="language-fortran">SUBROUTINE h5oopen_by_idx_f(loc_id, group_name, index_type, order, n, &
       obj_id, hdferr, lapl_id)
    INTEGER(HID_T)  , INTENT(IN)            :: loc_id
    CHARACTER(LEN=*), INTENT(IN)            :: group_name
    INTEGER         , INTENT(IN)            :: index_type
    INTEGER         , INTENT(IN)            :: order
    INTEGER(HSIZE_T), INTENT(IN)            :: n
    INTEGER(HID_T)  , INTENT(OUT)           :: obj_id
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id</code></pre>

hid_t loc_idIN: Location identifier; may be a file, group, dataset, named datatype or attribute identifier
const char *group_name    IN: Name of group, relative to loc_id, in which object is located
H5_index_t index_typeIN: Type of index by which objects are ordered
H5_iter_order_t orderIN: Order of iteration within index
hsize_t nIN: Object to open
hid_t lapl_idIN: Link access property list


H5O_OPEN_BY_IDX opens the nth object in the group specified by loc_id and group_name.

loc_id specifies a location identifier. group_name specifies the group relative to loc_id in which the object can be found. If loc_id fully specifies the group in which the object resides, group_name can be a dot (.).

The specific object to be opened within the group is specified by index_type, order, and n as follows:

  • index_type specifies the type of index by which objects are ordered. Valid index types include H5_INDEX_NAME, indexed by name, and H5_INDEX_CRT_ORDER, indexed by creation order.
  • order specifies the order in which the links are to be referenced for the purposes of this function. Valid orders include H5_ITER_INC for increasing order, H5_ITER_DEC for decreasing order, and H5_ITER_NATIVE. Rather than implying a particular order, H5_ITER_NATIVE instructs the HDF5 library to iterate through the objects in the fastest available order, i.e., in a natural order.
  • n specifies the position of the object within the index. Note that this count is zero-based; 0 (zero) indicates that the function will return the value of the first object; if n is 5, the function will return the value of the sixth object; etc.

If lapl_id specifies the link access property list to be used in accessing the object.

An object opened with this function should be closed when it is no longer needed so that resource leaks will not develop. H5O_CLOSE can be used to close groups, datasets, or committed datatypes.


Returns an object identifier for the opened object if successful; otherwise returns a negative value.


Coming Soon!

Release    Change
1.8.11Fortran subroutine introduced in this release.
1.8.0Function introduced in this release.