HDF_VG_ATTACH

The HDF_VG_ATTACH procedure attaches (opens) a VGroup in a Hierarchical Data Format file for reading or writing. If successful, a handle for that group is returned. If it fails, 0 is returned.

If VGroupId is set to -1, a new VGroup is created. If neither the READ nor WRITE keywords are set, the VGroup is opened for reading.

Calling Sequence

Result = HDF_VG_ATTACH( FileHandle, VGroupId )

Arguments

FileHandle

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

VGroupId

The VGroup reference number, generally obtained by HDF_VG_GETID or HDF_VG_LONE.

Keywords

READ

Set this keyword to open the VGroup for reading.

WRITE

Set this keyword to open the VGroup for writing.

Example

See HDF_SD_IDTOREF for an example using this function.