Last modified: 17 August 2009
Name: H5Pget_elink_cb
Signature:
  herr_t `H5Pget_elink_cb`( hid_t `lapl_id`, H5L_elink_traverse_t *`func`, void **`op_data` )

Purpose:
  Retrieves the external link traversal callback function from the specified link access property list.

Description:
  `H5Pget_elink_cb` retrieves the user-defined external link traversal callback function defined in the specified link access property list.

  The callback function may adjust the file access property list and file access flag to use when opening a file through an external link. The callback will be executed by the HDF5 Library immediately before opening the target file.

Parameters:

  hid_t `lapl_id` |  | IN: Link access property list identifier.
  H5L_elink_traverse_t *`func` |  | OUT: User-defined external link traversal callback function.
  void **`op_data` |  | OUT: User-defined input data for the callback function.

Returns:
  Returns a non-negative value if successful; otherwise returns a negative value.

Failure Modes:
  `H5Pget_elink_cb` will fail if the link access property list identifier, `lapl_id`, is invalid.

  An invalid function pointer or data pointer, `func` or `op_data` respectively, may cause a segmentation fault or an invalid memory access.

Example Usage:
  The following code retrieves the external link callback settings on the link access property list `lapl_id` into local variables:

      H5L_elink_traverse_t elink_callback_func;
      void *elink_callback_udata;
      status = H5Pget_elink_cb(lapl_id, &elink_callback_func, &elink_callback_udata);

See Also:
  `H5Pset_elink_cb`

  `H5Pset_elink_fapl`, `H5Pset_elink_acc_flags`, `H5Lcreate_external`

  `H5Fopen` for discussion of `H5F_ACC_RDWR` and `H5F_ACC_RDONLY` file access flags

  `H5L_elink_traverse_t`

History:

  Release | Change
  1.8.3 | C function introduced in this release.