Routines (alphabetical) > Routines: H > HDF Routines > HDF_DUPDD

# HDF_DUPDD

The HDF_DUPDD procedure generates new references to existing data in an HDF file.

## Syntax

HDF_DUPDD, FileHandle, NewTag, NewRef, OldTag, OldRef

## Arguments

### FileHandle

The HDF file handle returned from a previous call to HDF_OPEN.

### NewTag

An integer tag for new data descriptor.

### NewRef

An integer reference number for the new data descriptor.

### OldTag

The integer tag of data descriptor to duplicate.

### OldRef

The reference number of data descriptor to duplicate.

## Keywords

None

## Version History

4.0 | Introduced