The HDF_VG_ATTACH function attaches (opens) a VGroup in an HDF file for reading or writing.

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

Examples


See HDF_SD_IDTOREF for an example using this function.

Syntax


Result = HDF_VG_ATTACH( FileHandle, VGroup_id [, /READ] [, /WRITE] )

Return Value


If successful, a handle for the specified group is returned. If it fails, 0 is returned.

Arguments


FileHandle

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

VGroup_id

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.

Version History


4.0

Introduced

See Also


HDF_VG_DETACH