H5A_OPEN_BY_IDX opens an existing attribute that is attached to an object specified by location and name,
obj_name , respectively. If
loc_id fully specifies the object to which the attribute is attached,
obj_name should be
'.' (a dot).
The attribute is identified by an index type, an index traversal order, and a position in the index,
n, respectively. These parameters and their valid values are discussed in the description of H5A_ITERATE2.
The attribute access property list,
aapl_id, is currently unused and should currently be
The link access property list,
lapl_id, may provide information regarding the properties of links required to access the object,
obj_name. See “Link Access Properties” in the H5P APIs.
This function, H5A_OPEN , or H5A_OPEN_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 H5A_CLOSE or resource leaks will develop.