Last modified: 9 October 2014
Name: H5Aopen
Signature:
  hid_t `H5Aopen`( hid_t `obj_id`, const char *`attr_name`, hid_t `aapl_id` )

Purpose:
  Opens an attribute for an object specified by object identifier and attribute name.

Description:
  `H5Aopen` opens an existing attribute, `attr_name`, that is attached to an object specified an object identifier, `object_id`.

  The attribute access property list, `aapl_id`, is currently unused and should currently be `H5P_DEFAULT`.

  This function, `H5Aopen_by_idx`, or `H5Aopen_by_name` must be called before an attribute can be accessed for any further purpose, including reading, writing, or any modification.

  The attribute identifier returned by this function must be released with `H5Aclose` or resource leaks will develop.

Parameters:

  hid_t `obj_id` | IN: Identifer for object to which attribute is attached
  const char *`attr_name` | IN: Name of attribute to open
  hid_t `aapl_id` | IN: Attribute access property list

Returns:
  Returns an attribute identifier if successful; otherwise returns a negative value.

Fortran90 Interface: h5aopen_f

      SUBROUTINE h5aopen_f(obj_id, attr_name, attr_id, hdferr, aapl_id)
        IMPLICIT NONE
        INTEGER(HID_T), INTENT(IN) :: obj_id      ! Object identifier
        CHARACTER(LEN=*), INTENT(IN) :: attr_name ! Attribute name
        INTEGER(HID_T), INTENT(OUT) :: attr_id    ! Attribute identifier
        INTEGER, INTENT(OUT) :: hdferr            ! Error code:
                                                  ! 0 on success and -1 on failure
        INTEGER(HID_T), OPTIONAL, INTENT(IN) :: aapl_id
                                                  ! Attribute access property list
      END SUBROUTINE h5aopen_f

See Also:
  “Using Identifiers”

History:

  Release | C
  1.8.0 | Function introduced in this release.