Last modified: 24 August 2012
Name: H5Literate_by_name
Signature:
herr_t H5Literate_by_name( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t *idx, H5L_iterate_t op, void *op_data, hid_t *lapl_id )

Purpose:
Iterates through links in a group.

Description:
H5Literate_by_name iterates through the links in a group, specified by loc_id and group_name, in the order of the specified index, index_type, using a user-defined callback routine op. H5Literate_by_name does not recursively follow links into subgroups of the specified group.

index_type specifies the index to be used. If the links have not been indexed by the index type, they will first be sorted by that index then the iteration will begin; if the links have been so indexed, the sorting step will be unnecesary, so the iteration may begin more quickly. Valid values include the following:
     H5_INDEX_NAME Alpha-numeric index on name
     H5_INDEX_CRT_ORDER     Index on creation order

order specifies the order in which objects are to be inspected along the index specified in index_type. Valid values include the following:
     H5_ITER_INC Increasing order
     H5_ITER_DEC Decreasing order
     H5_ITER_NATIVE     Fastest available order

idx allows an interrupted iteration to be resumed; it is passed in by the application with a starting point and returned by the library with the point at which the iteration stopped.

H5Literate_by_name is not recursive. In particular, if a member of group_name is found to be a group, call it subgroup_a, H5Literate_by_name does not examine the members of subgroup_a. When recursive iteration is required, the application must handle the recursion, explicitly calling H5Literate_by_name on discovered subgroups.

H5Literate_by_name assumes that the membership of the group being iterated over remains unchanged through the iteration; if any of the links in the group change during the iteration, the function’s behavior is undefined. Note, however, that objects pointed to by the links can be modified.

H5Literate_by_name is the same as H5Giterate, except that H5Giterate always proceeds in alphanumeric order.

Programming Note for C++ Developers Using C Functions:

If a C routine that takes a function pointer as an argument is called from within C++ code, the C routine should be returned from normally.

Examples of this kind of routine include callbacks such as H5Pset_elink_cb and H5Pset_type_conv_cb and functions such as H5Tconvert and H5Ewalk2.

Exiting the routine in its normal fashion allows the HDF5 C Library to clean up its work properly. In other words, if the C++ application jumps out of the routine back to the C++ “catch” statement, the library is not given the opportunity to close any temporary data structures that were set up when the routine was called. The C++ application should save some state as the routine is started so that any problem that occurs might be diagnosed.

Parameters:
hid_t loc_id IN: File or group identifier specifying location of subject group
const char *group_name     IN: Name of subject group
H5_index_t index_type IN: Type of index which determines the order
H5_iter_order_t order IN: Order within index
hsize_t *idx IN: Iteration position at which to start
OUT: Position at which an interrupted iteration may be restarted
H5L_iterate_t op IN: Callback function passing data regarding the link to the calling application
void *op_data IN: User-defined pointer to data required by the application for its processing of the link
hid_t lapl_id IN: Link access property list

Returns:
On success, returns the return value of the first operator that returns a positive value, or zero if all members were processed with no operator returning non-zero.

On failure, returns a negative value if something goes wrong within the library, or the first negative value returned by an operator.

Fortran2003 Interface: h5literate_f

History:
Release     Change
1.8.8 Fortran subroutine added.
1.8.0 C function introduced.